#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "gpiolib.h" #define CREATE_TRACE_POINTS #include /* Implementation infrastructure for GPIO interfaces. * * The GPIO programming interface allows for inlining speed-critical * get/set operations for common cases, so that access to SOC-integrated * GPIOs can sometimes cost only an instruction or two per bit. */ /* When debugging, extend minimal trust to callers and platform code. * Also emit diagnostic messages that may help initial bringup, when * board setup or driver bugs are most common. * * Otherwise, minimize overhead in what may be bitbanging codepaths. */ #ifdef DEBUG #define extra_checks 1 #else #define extra_checks 0 #endif /* Device and char device-related information */ static DEFINE_IDA(gpio_ida); static dev_t gpio_devt; #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */ static struct bus_type gpio_bus_type = { .name = "gpio", }; /* gpio_lock prevents conflicts during gpio_desc[] table updates. * While any GPIO is requested, its gpio_chip is not removable; * each GPIO's "requested" flag serves as a lock and refcount. */ DEFINE_SPINLOCK(gpio_lock); static DEFINE_MUTEX(gpio_lookup_lock); static LIST_HEAD(gpio_lookup_list); LIST_HEAD(gpio_devices); static void gpiochip_free_hogs(struct gpio_chip *chip); static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip); static bool gpiolib_initialized; static inline void desc_set_label(struct gpio_desc *d, const char *label) { d->label = label; } /** * Convert a GPIO number to its descriptor */ struct gpio_desc *gpio_to_desc(unsigned gpio) { struct gpio_device *gdev; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) { if (gdev->base <= gpio && gdev->base + gdev->ngpio > gpio) { spin_unlock_irqrestore(&gpio_lock, flags); return &gdev->descs[gpio - gdev->base]; } } spin_unlock_irqrestore(&gpio_lock, flags); if (!gpio_is_valid(gpio)) WARN(1, "invalid GPIO %d\n", gpio); return NULL; } EXPORT_SYMBOL_GPL(gpio_to_desc); /** * Get the GPIO descriptor corresponding to the given hw number for this chip. */ struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum) { struct gpio_device *gdev = chip->gpiodev; if (hwnum >= gdev->ngpio) return ERR_PTR(-EINVAL); return &gdev->descs[hwnum]; } /** * Convert a GPIO descriptor to the integer namespace. * This should disappear in the future but is needed since we still * use GPIO numbers for error messages and sysfs nodes */ int desc_to_gpio(const struct gpio_desc *desc) { return desc->gdev->base + (desc - &desc->gdev->descs[0]); } EXPORT_SYMBOL_GPL(desc_to_gpio); /** * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs * @desc: descriptor to return the chip of */ struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) { if (!desc || !desc->gdev || !desc->gdev->chip) return NULL; return desc->gdev->chip; } EXPORT_SYMBOL_GPL(gpiod_to_chip); /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ static int gpiochip_find_base(int ngpio) { struct gpio_device *gdev; int base = ARCH_NR_GPIOS - ngpio; list_for_each_entry_reverse(gdev, &gpio_devices, list) { /* found a free space? */ if (gdev->base + gdev->ngpio <= base) break; else /* nope, check the space right before the chip */ base = gdev->base - ngpio; } if (gpio_is_valid(base)) { pr_debug("%s: found new base at %d\n", __func__, base); return base; } else { pr_err("%s: cannot find free range\n", __func__); return -ENOSPC; } } /** * gpiod_get_direction - return the current direction of a GPIO * @desc: GPIO to get the direction of * * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error. * * This function may sleep if gpiod_cansleep() is true. */ int gpiod_get_direction(struct gpio_desc *desc) { struct gpio_chip *chip; unsigned offset; int status = -EINVAL; chip = gpiod_to_chip(desc); offset = gpio_chip_hwgpio(desc); if (!chip->get_direction) return status; status = chip->get_direction(chip, offset); if (status > 0) { /* GPIOF_DIR_IN, or other positive */ status = 1; clear_bit(FLAG_IS_OUT, &desc->flags); } if (status == 0) { /* GPIOF_DIR_OUT */ set_bit(FLAG_IS_OUT, &desc->flags); } return status; } EXPORT_SYMBOL_GPL(gpiod_get_direction); /* * Add a new chip to the global chips list, keeping the list of chips sorted * by range(means [base, base + ngpio - 1]) order. * * Return -EBUSY if the new chip overlaps with some other chip's integer * space. */ static int gpiodev_add_to_list(struct gpio_device *gdev) { struct gpio_device *prev, *next; if (list_empty(&gpio_devices)) { /* initial entry in list */ list_add_tail(&gdev->list, &gpio_devices); return 0; } next = list_entry(gpio_devices.next, struct gpio_device, list); if (gdev->base + gdev->ngpio <= next->base) { /* add before first entry */ list_add(&gdev->list, &gpio_devices); return 0; } prev = list_entry(gpio_devices.prev, struct gpio_device, list); if (prev->base + prev->ngpio <= gdev->base) { /* add behind last entry */ list_add_tail(&gdev->list, &gpio_devices); return 0; } list_for_each_entry_safe(prev, next, &gpio_devices, list) { /* at the end of the list */ if (&next->list == &gpio_devices) break; /* add between prev and next */ if (prev->base + prev->ngpio <= gdev->base && gdev->base + gdev->ngpio <= next->base) { list_add(&gdev->list, &prev->list); return 0; } } dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n"); return -EBUSY; } /** * Convert a GPIO name to its descriptor */ static struct gpio_desc *gpio_name_to_desc(const char * const name) { struct gpio_device *gdev; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) { int i; for (i = 0; i != gdev->ngpio; ++i) { struct gpio_desc *desc = &gdev->descs[i]; if (!desc->name || !name) continue; if (!strcmp(desc->name, name)) { spin_unlock_irqrestore(&gpio_lock, flags); return desc; } } } spin_unlock_irqrestore(&gpio_lock, flags); return NULL; } /* * Takes the names from gc->names and checks if they are all unique. If they * are, they are assigned to their gpio descriptors. * * Warning if one of the names is already used for a different GPIO. */ static int gpiochip_set_desc_names(struct gpio_chip *gc) { struct gpio_device *gdev = gc->gpiodev; int i; if (!gc->names) return 0; /* First check all names if they are unique */ for (i = 0; i != gc->ngpio; ++i) { struct gpio_desc *gpio; gpio = gpio_name_to_desc(gc->names[i]); if (gpio) dev_warn(&gdev->dev, "Detected name collision for GPIO name '%s'\n", gc->names[i]); } /* Then add all names to the GPIO descriptors */ for (i = 0; i != gc->ngpio; ++i) gdev->descs[i].name = gc->names[i]; return 0; } /** * gpio_ioctl() - ioctl handler for the GPIO chardev */ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct gpio_device *gdev = filp->private_data; struct gpio_chip *chip = gdev->chip; void __user *ip = (void __user *)arg; /* We fail any subsequent ioctl():s when the chip is gone */ if (!chip) return -ENODEV; /* Fill in the struct and pass to userspace */ if (cmd == GPIO_GET_CHIPINFO_IOCTL) { struct gpiochip_info chipinfo; strncpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name)); chipinfo.name[sizeof(chipinfo.name)-1] = '\0'; strncpy(chipinfo.label, gdev->label, sizeof(chipinfo.label)); chipinfo.label[sizeof(chipinfo.label)-1] = '\0'; chipinfo.lines = gdev->ngpio; if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) return -EFAULT; return 0; } else if (cmd == GPIO_GET_LINEINFO_IOCTL) { struct gpioline_info lineinfo; struct gpio_desc *desc; if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) return -EFAULT; if (lineinfo.line_offset > gdev->ngpio) return -EINVAL; desc = &gdev->descs[lineinfo.line_offset]; if (desc->name) { strncpy(lineinfo.name, desc->name, sizeof(lineinfo.name)); lineinfo.name[sizeof(lineinfo.name)-1] = '\0'; } else { lineinfo.name[0] = '\0'; } if (desc->label) { strncpy(lineinfo.consumer, desc->label, sizeof(lineinfo.consumer)); lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0'; } else { lineinfo.consumer[0] = '\0'; } /* * Userspace only need to know that the kernel is using * this GPIO so it can't use it. */ lineinfo.flags = 0; if (test_bit(FLAG_REQUESTED, &desc->flags) || test_bit(FLAG_IS_HOGGED, &desc->flags) || test_bit(FLAG_USED_AS_IRQ, &desc->flags) || test_bit(FLAG_EXPORT, &desc->flags) || test_bit(FLAG_SYSFS, &desc->flags)) lineinfo.flags |= GPIOLINE_FLAG_KERNEL; if (test_bit(FLAG_IS_OUT, &desc->flags)) lineinfo.flags |= GPIOLINE_FLAG_IS_OUT; if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW; if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN; if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE; if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) return -EFAULT; return 0; } return -EINVAL; } #ifdef CONFIG_COMPAT static long gpio_ioctl_compat(struct file *filp, unsigned int cmd, unsigned long arg) { return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); } #endif /** * gpio_chrdev_open() - open the chardev for ioctl operations * @inode: inode for this chardev * @filp: file struct for storing private data * Returns 0 on success */ static int gpio_chrdev_open(struct inode *inode, struct file *filp) { struct gpio_device *gdev = container_of(inode->i_cdev, struct gpio_device, chrdev); /* Fail on open if the backing gpiochip is gone */ if (!gdev || !gdev->chip) return -ENODEV; get_device(&gdev->dev); filp->private_data = gdev; return 0; } /** * gpio_chrdev_release() - close chardev after ioctl operations * @inode: inode for this chardev * @filp: file struct for storing private data * Returns 0 on success */ static int gpio_chrdev_release(struct inode *inode, struct file *filp) { struct gpio_device *gdev = container_of(inode->i_cdev, struct gpio_device, chrdev); if (!gdev) return -ENODEV; put_device(&gdev->dev); return 0; } static const struct file_operations gpio_fileops = { .release = gpio_chrdev_release, .open = gpio_chrdev_open, .owner = THIS_MODULE, .llseek = noop_llseek, .unlocked_ioctl = gpio_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = gpio_ioctl_compat, #endif }; static void gpiodevice_release(struct device *dev) { struct gpio_device *gdev = dev_get_drvdata(dev); list_del(&gdev->list); ida_simple_remove(&gpio_ida, gdev->id); kfree(gdev->label); kfree(gdev->descs); kfree(gdev); } static int gpiochip_setup_dev(struct gpio_device *gdev) { int status; cdev_init(&gdev->chrdev, &gpio_fileops); gdev->chrdev.owner = THIS_MODULE; gdev->chrdev.kobj.parent = &gdev->dev.kobj; gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id); status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1); if (status < 0) chip_warn(gdev->chip, "failed to add char device %d:%d\n", MAJOR(gpio_devt), gdev->id); else chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n", MAJOR(gpio_devt), gdev->id); status = device_add(&gdev->dev); if (status) goto err_remove_chardev; status = gpiochip_sysfs_register(gdev); if (status) goto err_remove_device; /* From this point, the .release() function cleans up gpio_device */ gdev->dev.release = gpiodevice_release; pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n", __func__, gdev->base, gdev->base + gdev->ngpio - 1, dev_name(&gdev->dev), gdev->chip->label ? : "generic"); return 0; err_remove_device: device_del(&gdev->dev); err_remove_chardev: cdev_del(&gdev->chrdev); return status; } static void gpiochip_setup_devs(void) { struct gpio_device *gdev; int err; list_for_each_entry(gdev, &gpio_devices, list) { err = gpiochip_setup_dev(gdev); if (err) pr_err("%s: Failed to initialize gpio device (%d)\n", dev_name(&gdev->dev), err); } } /** * gpiochip_add_data() - register a gpio_chip * @chip: the chip to register, with chip->base initialized * Context: potentially before irqs will work * * Returns a negative errno if the chip can't be registered, such as * because the chip->base is invalid or already associated with a * different chip. Otherwise it returns zero as a success code. * * When gpiochip_add_data() is called very early during boot, so that GPIOs * can be freely used, the chip->parent device must be registered before * the gpio framework's arch_initcall(). Otherwise sysfs initialization * for GPIOs will fail rudely. * * gpiochip_add_data() must only be called after gpiolib initialization, * ie after core_initcall(). * * If chip->base is negative, this requests dynamic assignment of * a range of valid GPIOs. */ int gpiochip_add_data(struct gpio_chip *chip, void *data) { unsigned long flags; int status = 0; unsigned i; int base = chip->base; struct gpio_device *gdev; /* * First: allocate and populate the internal stat container, and * set up the struct device. */ gdev = kzalloc(sizeof(*gdev), GFP_KERNEL); if (!gdev) return -ENOMEM; gdev->dev.bus = &gpio_bus_type; gdev->chip = chip; chip->gpiodev = gdev; if (chip->parent) { gdev->dev.parent = chip->parent; gdev->dev.of_node = chip->parent->of_node; } else { #ifdef CONFIG_OF_GPIO /* If the gpiochip has an assigned OF node this takes precedence */ if (chip->of_node) gdev->dev.of_node = chip->of_node; #endif } gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL); if (gdev->id < 0) { status = gdev->id; goto err_free_gdev; } dev_set_name(&gdev->dev, "gpiochip%d", gdev->id); device_initialize(&gdev->dev); dev_set_drvdata(&gdev->dev, gdev); if (chip->parent && chip->parent->driver) gdev->owner = chip->parent->driver->owner; else if (chip->owner) /* TODO: remove chip->owner */ gdev->owner = chip->owner; else gdev->owner = THIS_MODULE; gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL); if (!gdev->descs) { status = -ENOMEM; goto err_free_gdev; } if (chip->ngpio == 0) { chip_err(chip, "tried to insert a GPIO chip with zero lines\n"); status = -EINVAL; goto err_free_descs; } if (chip->label) gdev->label = kstrdup(chip->label, GFP_KERNEL); else gdev->label = kstrdup("unknown", GFP_KERNEL); if (!gdev->label) { status = -ENOMEM; goto err_free_descs; } gdev->ngpio = chip->ngpio; gdev->data = data; spin_lock_irqsave(&gpio_lock, flags); /* * TODO: this allocates a Linux GPIO number base in the global * GPIO numberspace for this chip. In the long run we want to * get *rid* of this numberspace and use only descriptors, but * it may be a pipe dream. It will not happen before we get rid * of the sysfs interface anyways. */ if (base < 0) { base = gpiochip_find_base(chip->ngpio); if (base < 0) { status = base; spin_unlock_irqrestore(&gpio_lock, flags); goto err_free_label; } /* * TODO: it should not be necessary to reflect the assigned * base outside of the GPIO subsystem. Go over drivers and * see if anyone makes use of this, else drop this and assign * a poison instead. */ chip->base = base; } gdev->base = base; status = gpiodev_add_to_list(gdev); if (status) { spin_unlock_irqrestore(&gpio_lock, flags); goto err_free_label; } spin_unlock_irqrestore(&gpio_lock, flags); for (i = 0; i < chip->ngpio; i++) { struct gpio_desc *desc = &gdev->descs[i]; desc->gdev = gdev; /* * REVISIT: most hardware initializes GPIOs as inputs * (often with pullups enabled) so power usage is * minimized. Linux code should set the gpio direction * first thing; but until it does, and in case * chip->get_direction is not set, we may expose the * wrong direction in sysfs. */ if (chip->get_direction) { /* * If we have .get_direction, set up the initial * direction flag from the hardware. */ int dir = chip->get_direction(chip, i); if (!dir) set_bit(FLAG_IS_OUT, &desc->flags); } else if (!chip->direction_input) { /* * If the chip lacks the .direction_input callback * we logically assume all lines are outputs. */ set_bit(FLAG_IS_OUT, &desc->flags); } } #ifdef CONFIG_PINCTRL INIT_LIST_HEAD(&gdev->pin_ranges); #endif status = gpiochip_set_desc_names(chip); if (status) goto err_remove_from_list; status = of_gpiochip_add(chip); if (status) goto err_remove_chip; acpi_gpiochip_add(chip); /* * By first adding the chardev, and then adding the device, * we get a device node entry in sysfs under * /sys/bus/gpio/devices/gpiochipN/dev that can be used for * coldplug of device nodes and other udev business. * We can do this only if gpiolib has been initialized. * Otherwise, defer until later. */ if (gpiolib_initialized) { status = gpiochip_setup_dev(gdev); if (status) goto err_remove_chip; } return 0; err_remove_chip: acpi_gpiochip_remove(chip); gpiochip_free_hogs(chip); of_gpiochip_remove(chip); err_remove_from_list: spin_lock_irqsave(&gpio_lock, flags); list_del(&gdev->list); spin_unlock_irqrestore(&gpio_lock, flags); err_free_label: kfree(gdev->label); err_free_descs: kfree(gdev->descs); err_free_gdev: ida_simple_remove(&gpio_ida, gdev->id); /* failures here can mean systems won't boot... */ pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__, gdev->base, gdev->base + gdev->ngpio - 1, chip->label ? : "generic"); kfree(gdev); return status; } EXPORT_SYMBOL_GPL(gpiochip_add_data); /** * gpiochip_get_data() - get per-subdriver data for the chip */ void *gpiochip_get_data(struct gpio_chip *chip) { return chip->gpiodev->data; } EXPORT_SYMBOL_GPL(gpiochip_get_data); /** * gpiochip_remove() - unregister a gpio_chip * @chip: the chip to unregister * * A gpio_chip with any GPIOs still requested may not be removed. */ void gpiochip_remove(struct gpio_chip *chip) { struct gpio_device *gdev = chip->gpiodev; struct gpio_desc *desc; unsigned long flags; unsigned i; bool requested = false; /* FIXME: should the legacy sysfs handling be moved to gpio_device? */ gpiochip_sysfs_unregister(gdev); /* Numb the device, cancelling all outstanding operations */ gdev->chip = NULL; gpiochip_irqchip_remove(chip); acpi_gpiochip_remove(chip); gpiochip_remove_pin_ranges(chip); gpiochip_free_hogs(chip); of_gpiochip_remove(chip); /* * We accept no more calls into the driver from this point, so * NULL the driver data pointer */ gdev->data = NULL; spin_lock_irqsave(&gpio_lock, flags); for (i = 0; i < gdev->ngpio; i++) { desc = &gdev->descs[i]; if (test_bit(FLAG_REQUESTED, &desc->flags)) requested = true; } spin_unlock_irqrestore(&gpio_lock, flags); if (requested) dev_crit(&gdev->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n"); /* * The gpiochip side puts its use of the device to rest here: * if there are no userspace clients, the chardev and device will * be removed, else it will be dangling until the last user is * gone. */ cdev_del(&gdev->chrdev); device_del(&gdev->dev); put_device(&gdev->dev); } EXPORT_SYMBOL_GPL(gpiochip_remove); static void devm_gpio_chip_release(struct device *dev, void *res) { struct gpio_chip *chip = *(struct gpio_chip **)res; gpiochip_remove(chip); } static int devm_gpio_chip_match(struct device *dev, void *res, void *data) { struct gpio_chip **r = res; if (!r || !*r) { WARN_ON(!r || !*r); return 0; } return *r == data; } /** * devm_gpiochip_add_data() - Resource manager piochip_add_data() * @dev: the device pointer on which irq_chip belongs to. * @chip: the chip to register, with chip->base initialized * Context: potentially before irqs will work * * Returns a negative errno if the chip can't be registered, such as * because the chip->base is invalid or already associated with a * different chip. Otherwise it returns zero as a success code. * * The gpio chip automatically be released when the device is unbound. */ int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip, void *data) { struct gpio_chip **ptr; int ret; ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr), GFP_KERNEL); if (!ptr) return -ENOMEM; ret = gpiochip_add_data(chip, data); if (ret < 0) { devres_free(ptr); return ret; } *ptr = chip; devres_add(dev, ptr); return 0; } EXPORT_SYMBOL_GPL(devm_gpiochip_add_data); /** * devm_gpiochip_remove() - Resource manager of gpiochip_remove() * @dev: device for which which resource was allocated * @chip: the chip to remove * * A gpio_chip with any GPIOs still requested may not be removed. */ void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip) { int ret; ret = devres_release(dev, devm_gpio_chip_release, devm_gpio_chip_match, chip); if (!ret) WARN_ON(ret); } EXPORT_SYMBOL_GPL(devm_gpiochip_remove); /** * gpiochip_find() - iterator for locating a specific gpio_chip * @data: data to pass to match function * @callback: Callback function to check gpio_chip * * Similar to bus_find_device. It returns a reference to a gpio_chip as * determined by a user supplied @match callback. The callback should return * 0 if the device doesn't match and non-zero if it does. If the callback is * non-zero, this function will return to the caller and not iterate over any * more gpio_chips. */ struct gpio_chip *gpiochip_find(void *data, int (*match)(struct gpio_chip *chip, void *data)) { struct gpio_device *gdev; struct gpio_chip *chip; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) if (gdev->chip && match(gdev->chip, data)) break; /* No match? */ if (&gdev->list == &gpio_devices) chip = NULL; else chip = gdev->chip; spin_unlock_irqrestore(&gpio_lock, flags); return chip; } EXPORT_SYMBOL_GPL(gpiochip_find); static int gpiochip_match_name(struct gpio_chip *chip, void *data) { const char *name = data; return !strcmp(chip->label, name); } static struct gpio_chip *find_chip_by_name(const char *name) { return gpiochip_find((void *)name, gpiochip_match_name); } #ifdef CONFIG_GPIOLIB_IRQCHIP /* * The following is irqchip helper code for gpiochips. */ /** * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip * @gpiochip: the gpiochip to set the irqchip chain to * @irqchip: the irqchip to chain to the gpiochip * @parent_irq: the irq number corresponding to the parent IRQ for this * chained irqchip * @parent_handler: the parent interrupt handler for the accumulated IRQ * coming out of the gpiochip. If the interrupt is nested rather than * cascaded, pass NULL in this handler argument */ void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip, struct irq_chip *irqchip, int parent_irq, irq_flow_handler_t parent_handler) { unsigned int offset; if (!gpiochip->irqdomain) { chip_err(gpiochip, "called %s before setting up irqchip\n", __func__); return; } if (parent_handler) { if (gpiochip->can_sleep) { chip_err(gpiochip, "you cannot have chained interrupts on a " "chip that may sleep\n"); return; } /* * The parent irqchip is already using the chip_data for this * irqchip, so our callbacks simply use the handler_data. */ irq_set_chained_handler_and_data(parent_irq, parent_handler, gpiochip); gpiochip->irq_parent = parent_irq; } /* Set the parent IRQ for all affected IRQs */ for (offset = 0; offset < gpiochip->ngpio; offset++) irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset), parent_irq); } EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip); /** * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip * @d: the irqdomain used by this irqchip * @irq: the global irq number used by this GPIO irqchip irq * @hwirq: the local IRQ/GPIO line offset on this gpiochip * * This function will set up the mapping for a certain IRQ line on a * gpiochip by assigning the gpiochip as chip data, and using the irqchip * stored inside the gpiochip. */ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hwirq) { struct gpio_chip *chip = d->host_data; irq_set_chip_data(irq, chip); /* * This lock class tells lockdep that GPIO irqs are in a different * category than their parents, so it won't report false recursion. */ irq_set_lockdep_class(irq, chip->lock_key); irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler); /* Chips that can sleep need nested thread handlers */ if (chip->can_sleep && !chip->irq_not_threaded) irq_set_nested_thread(irq, 1); irq_set_noprobe(irq); /* * No set-up of the hardware will happen if IRQ_TYPE_NONE * is passed as default type. */ if (chip->irq_default_type != IRQ_TYPE_NONE) irq_set_irq_type(irq, chip->irq_default_type); return 0; } static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq) { struct gpio_chip *chip = d->host_data; if (chip->can_sleep) irq_set_nested_thread(irq, 0); irq_set_chip_and_handler(irq, NULL, NULL); irq_set_chip_data(irq, NULL); } static const struct irq_domain_ops gpiochip_domain_ops = { .map = gpiochip_irq_map, .unmap = gpiochip_irq_unmap, /* Virtually all GPIO irqchips are twocell:ed */ .xlate = irq_domain_xlate_twocell, }; static int gpiochip_irq_reqres(struct irq_data *d) { struct gpio_chip *chip = irq_data_get_irq_chip_data(d); if (!try_module_get(chip->gpiodev->owner)) return -ENODEV; if (gpiochip_lock_as_irq(chip, d->hwirq)) { chip_err(chip, "unable to lock HW IRQ %lu for IRQ\n", d->hwirq); module_put(chip->gpiodev->owner); return -EINVAL; } return 0; } static void gpiochip_irq_relres(struct irq_data *d) { struct gpio_chip *chip = irq_data_get_irq_chip_data(d); gpiochip_unlock_as_irq(chip, d->hwirq); module_put(chip->gpiodev->owner); } static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) { return irq_find_mapping(chip->irqdomain, offset); } /** * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip * @gpiochip: the gpiochip to remove the irqchip from * * This is called only from gpiochip_remove() */ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) { unsigned int offset; acpi_gpiochip_free_interrupts(gpiochip); if (gpiochip->irq_parent) { irq_set_chained_handler(gpiochip->irq_parent, NULL); irq_set_handler_data(gpiochip->irq_parent, NULL); } /* Remove all IRQ mappings and delete the domain */ if (gpiochip->irqdomain) { for (offset = 0; offset < gpiochip->ngpio; offset++) irq_dispose_mapping( irq_find_mapping(gpiochip->irqdomain, offset)); irq_domain_remove(gpiochip->irqdomain); } if (gpiochip->irqchip) { gpiochip->irqchip->irq_request_resources = NULL; gpiochip->irqchip->irq_release_resources = NULL; gpiochip->irqchip = NULL; } } /** * gpiochip_irqchip_add() - adds an irqchip to a gpiochip * @gpiochip: the gpiochip to add the irqchip to * @irqchip: the irqchip to add to the gpiochip * @first_irq: if not dynamically assigned, the base (first) IRQ to * allocate gpiochip irqs from * @handler: the irq handler to use (often a predefined irq core function) * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE * to have the core avoid setting up any default type in the hardware. * @lock_key: lockdep class * * This function closely associates a certain irqchip with a certain * gpiochip, providing an irq domain to translate the local IRQs to * global irqs in the gpiolib core, and making sure that the gpiochip * is passed as chip data to all related functions. Driver callbacks * need to use gpiochip_get_data() to get their local state containers back * from the gpiochip passed as chip data. An irqdomain will be stored * in the gpiochip that shall be used by the driver to handle IRQ number * translation. The gpiochip will need to be initialized and registered * before calling this function. * * This function will handle two cell:ed simple IRQs and assumes all * the pins on the gpiochip can generate a unique IRQ. Everything else * need to be open coded. */ int _gpiochip_irqchip_add(struct gpio_chip *gpiochip, struct irq_chip *irqchip, unsigned int first_irq, irq_flow_handler_t handler, unsigned int type, struct lock_class_key *lock_key) { struct device_node *of_node; unsigned int offset; unsigned irq_base = 0; if (!gpiochip || !irqchip) return -EINVAL; if (!gpiochip->parent) { pr_err("missing gpiochip .dev parent pointer\n"); return -EINVAL; } of_node = gpiochip->parent->of_node; #ifdef CONFIG_OF_GPIO /* * If the gpiochip has an assigned OF node this takes precedence * FIXME: get rid of this and use gpiochip->parent->of_node * everywhere */ if (gpiochip->of_node) of_node = gpiochip->of_node; #endif gpiochip->irqchip = irqchip; gpiochip->irq_handler = handler; gpiochip->irq_default_type = type; gpiochip->to_irq = gpiochip_to_irq; gpiochip->lock_key = lock_key; gpiochip->irqdomain = irq_domain_add_simple(of_node, gpiochip->ngpio, first_irq, &gpiochip_domain_ops, gpiochip); if (!gpiochip->irqdomain) { gpiochip->irqchip = NULL; return -EINVAL; } /* * It is possible for a driver to override this, but only if the * alternative functions are both implemented. */ if (!irqchip->irq_request_resources && !irqchip->irq_release_resources) { irqchip->irq_request_resources = gpiochip_irq_reqres; irqchip->irq_release_resources = gpiochip_irq_relres; } /* * Prepare the mapping since the irqchip shall be orthogonal to * any gpiochip calls. If the first_irq was zero, this is * necessary to allocate descriptors for all IRQs. */ for (offset = 0; offset < gpiochip->ngpio; offset++) { irq_base = irq_create_mapping(gpiochip->irqdomain, offset); if (offset == 0) /* * Store the base into the gpiochip to be used when * unmapping the irqs. */ gpiochip->irq_base = irq_base; } acpi_gpiochip_request_interrupts(gpiochip); return 0; } EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add); #else /* CONFIG_GPIOLIB_IRQCHIP */ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {} #endif /* CONFIG_GPIOLIB_IRQCHIP */ /** * gpiochip_generic_request() - request the gpio function for a pin * @chip: the gpiochip owning the GPIO * @offset: the offset of the GPIO to request for GPIO function */ int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset) { return pinctrl_request_gpio(chip->gpiodev->base + offset); } EXPORT_SYMBOL_GPL(gpiochip_generic_request); /** * gpiochip_generic_free() - free the gpio function from a pin * @chip: the gpiochip to request the gpio function for * @offset: the offset of the GPIO to free from GPIO function */ void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset) { pinctrl_free_gpio(chip->gpiodev->base + offset); } EXPORT_SYMBOL_GPL(gpiochip_generic_free); #ifdef CONFIG_PINCTRL /** * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping * @chip: the gpiochip to add the range for * @pctldev: the pin controller to map to * @gpio_offset: the start offset in the current gpio_chip number space * @pin_group: name of the pin group inside the pin controller */ int gpiochip_add_pingroup_range(struct gpio_chip *chip, struct pinctrl_dev *pctldev, unsigned int gpio_offset, const char *pin_group) { struct gpio_pin_range *pin_range; struct gpio_device *gdev = chip->gpiodev; int ret; pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); if (!pin_range) { chip_err(chip, "failed to allocate pin ranges\n"); return -ENOMEM; } /* Use local offset as range ID */ pin_range->range.id = gpio_offset; pin_range->range.gc = chip; pin_range->range.name = chip->label; pin_range->range.base = gdev->base + gpio_offset; pin_range->pctldev = pctldev; ret = pinctrl_get_group_pins(pctldev, pin_group, &pin_range->range.pins, &pin_range->range.npins); if (ret < 0) { kfree(pin_range); return ret; } pinctrl_add_gpio_range(pctldev, &pin_range->range); chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n", gpio_offset, gpio_offset + pin_range->range.npins - 1, pinctrl_dev_get_devname(pctldev), pin_group); list_add_tail(&pin_range->node, &gdev->pin_ranges); return 0; } EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range); /** * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping * @chip: the gpiochip to add the range for * @pinctrl_name: the dev_name() of the pin controller to map to * @gpio_offset: the start offset in the current gpio_chip number space * @pin_offset: the start offset in the pin controller number space * @npins: the number of pins from the offset of each pin space (GPIO and * pin controller) to accumulate in this range */ int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, unsigned int gpio_offset, unsigned int pin_offset, unsigned int npins) { struct gpio_pin_range *pin_range; struct gpio_device *gdev = chip->gpiodev; int ret; pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); if (!pin_range) { chip_err(chip, "failed to allocate pin ranges\n"); return -ENOMEM; } /* Use local offset as range ID */ pin_range->range.id = gpio_offset; pin_range->range.gc = chip; pin_range->range.name = chip->label; pin_range->range.base = gdev->base + gpio_offset; pin_range->range.pin_base = pin_offset; pin_range->range.npins = npins; pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name, &pin_range->range); if (IS_ERR(pin_range->pctldev)) { ret = PTR_ERR(pin_range->pctldev); chip_err(chip, "could not create pin range\n"); kfree(pin_range); return ret; } chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n", gpio_offset, gpio_offset + npins - 1, pinctl_name, pin_offset, pin_offset + npins - 1); list_add_tail(&pin_range->node, &gdev->pin_ranges); return 0; } EXPORT_SYMBOL_GPL(gpiochip_add_pin_range); /** * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings * @chip: the chip to remove all the mappings for */ void gpiochip_remove_pin_ranges(struct gpio_chip *chip) { struct gpio_pin_range *pin_range, *tmp; struct gpio_device *gdev = chip->gpiodev; list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) { list_del(&pin_range->node); pinctrl_remove_gpio_range(pin_range->pctldev, &pin_range->range); kfree(pin_range); } } EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); #endif /* CONFIG_PINCTRL */ /* These "optional" allocation calls help prevent drivers from stomping * on each other, and help provide better diagnostics in debugfs. * They're called even less than the "set direction" calls. */ static int __gpiod_request(struct gpio_desc *desc, const char *label) { struct gpio_chip *chip = desc->gdev->chip; int status; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); /* NOTE: gpio_request() can be called in early boot, * before IRQs are enabled, for non-sleeping (SOC) GPIOs. */ if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { desc_set_label(desc, label ? : "?"); status = 0; } else { status = -EBUSY; goto done; } if (chip->request) { /* chip->request may sleep */ spin_unlock_irqrestore(&gpio_lock, flags); status = chip->request(chip, gpio_chip_hwgpio(desc)); spin_lock_irqsave(&gpio_lock, flags); if (status < 0) { desc_set_label(desc, NULL); clear_bit(FLAG_REQUESTED, &desc->flags); goto done; } } if (chip->get_direction) { /* chip->get_direction may sleep */ spin_unlock_irqrestore(&gpio_lock, flags); gpiod_get_direction(desc); spin_lock_irqsave(&gpio_lock, flags); } done: if (status < 0) { /* Clear flags that might have been set by the caller before * requesting the GPIO. */ clear_bit(FLAG_ACTIVE_LOW, &desc->flags); clear_bit(FLAG_OPEN_DRAIN, &desc->flags); clear_bit(FLAG_OPEN_SOURCE, &desc->flags); } spin_unlock_irqrestore(&gpio_lock, flags); return status; } /* * This descriptor validation needs to be inserted verbatim into each * function taking a descriptor, so we need to use a preprocessor * macro to avoid endless duplication. If the desc is NULL it is an * optional GPIO and calls should just bail out. */ #define VALIDATE_DESC(desc) do { \ if (!desc) \ return 0; \ if (!desc->gdev) { \ pr_warn("%s: invalid GPIO\n", __func__); \ return -EINVAL; \ } \ if ( !desc->gdev->chip ) { \ dev_warn(&desc->gdev->dev, \ "%s: backing chip is gone\n", __func__); \ return 0; \ } } while (0) #define VALIDATE_DESC_VOID(desc) do { \ if (!desc) \ return; \ if (!desc->gdev) { \ pr_warn("%s: invalid GPIO\n", __func__); \ return; \ } \ if (!desc->gdev->chip) { \ dev_warn(&desc->gdev->dev, \ "%s: backing chip is gone\n", __func__); \ return; \ } } while (0) int gpiod_request(struct gpio_desc *desc, const char *label) { int status = -EPROBE_DEFER; struct gpio_device *gdev; VALIDATE_DESC(desc); gdev = desc->gdev; if (try_module_get(gdev->owner)) { status = __gpiod_request(desc, label); if (status < 0) module_put(gdev->owner); else get_device(&gdev->dev); } if (status) gpiod_dbg(desc, "%s: status %d\n", __func__, status); return status; } static bool __gpiod_free(struct gpio_desc *desc) { bool ret = false; unsigned long flags; struct gpio_chip *chip; might_sleep(); gpiod_unexport(desc); spin_lock_irqsave(&gpio_lock, flags); chip = desc->gdev->chip; if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { if (chip->free) { spin_unlock_irqrestore(&gpio_lock, flags); might_sleep_if(chip->can_sleep); chip->free(chip, gpio_chip_hwgpio(desc)); spin_lock_irqsave(&gpio_lock, flags); } desc_set_label(desc, NULL); clear_bit(FLAG_ACTIVE_LOW, &desc->flags); clear_bit(FLAG_REQUESTED, &desc->flags); clear_bit(FLAG_OPEN_DRAIN, &desc->flags); clear_bit(FLAG_OPEN_SOURCE, &desc->flags); clear_bit(FLAG_IS_HOGGED, &desc->flags); ret = true; } spin_unlock_irqrestore(&gpio_lock, flags); return ret; } void gpiod_free(struct gpio_desc *desc) { if (desc && desc->gdev && __gpiod_free(desc)) { module_put(desc->gdev->owner); put_device(&desc->gdev->dev); } else { WARN_ON(extra_checks); } } /** * gpiochip_is_requested - return string iff signal was requested * @chip: controller managing the signal * @offset: of signal within controller's 0..(ngpio - 1) range * * Returns NULL if the GPIO is not currently requested, else a string. * The string returned is the label passed to gpio_request(); if none has been * passed it is a meaningless, non-NULL constant. * * This function is for use by GPIO controller drivers. The label can * help with diagnostics, and knowing that the signal is used as a GPIO * can help avoid accidentally multiplexing it to another controller. */ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) { struct gpio_desc *desc; if (offset >= chip->ngpio) return NULL; desc = &chip->gpiodev->descs[offset]; if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) return NULL; return desc->label; } EXPORT_SYMBOL_GPL(gpiochip_is_requested); /** * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor * @desc: GPIO descriptor to request * @label: label for the GPIO * * Function allows GPIO chip drivers to request and use their own GPIO * descriptors via gpiolib API. Difference to gpiod_request() is that this * function will not increase reference count of the GPIO chip module. This * allows the GPIO chip module to be unloaded as needed (we assume that the * GPIO chip driver handles freeing the GPIOs it has requested). */ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum, const char *label) { struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum); int err; if (IS_ERR(desc)) { chip_err(chip, "failed to get GPIO descriptor\n"); return desc; } err = __gpiod_request(desc, label); if (err < 0) return ERR_PTR(err); return desc; } EXPORT_SYMBOL_GPL(gpiochip_request_own_desc); /** * gpiochip_free_own_desc - Free GPIO requested by the chip driver * @desc: GPIO descriptor to free * * Function frees the given GPIO requested previously with * gpiochip_request_own_desc(). */ void gpiochip_free_own_desc(struct gpio_desc *desc) { if (desc) __gpiod_free(desc); } EXPORT_SYMBOL_GPL(gpiochip_free_own_desc); /* * Drivers MUST set GPIO direction before making get/set calls. In * some cases this is done in early boot, before IRQs are enabled. * * As a rule these aren't called more than once (except for drivers * using the open-drain emulation idiom) so these are natural places * to accumulate extra debugging checks. Note that we can't (yet) * rely on gpio_request() having been called beforehand. */ /** * gpiod_direction_input - set the GPIO direction to input * @desc: GPIO to set to input * * Set the direction of the passed GPIO to input, such as gpiod_get_value() can * be called safely on it. * * Return 0 in case of success, else an error code. */ int gpiod_direction_input(struct gpio_desc *desc) { struct gpio_chip *chip; int status = -EINVAL; VALIDATE_DESC(desc); chip = desc->gdev->chip; if (!chip->get || !chip->direction_input) { gpiod_warn(desc, "%s: missing get() or direction_input() operations\n", __func__); return -EIO; } status = chip->direction_input(chip, gpio_chip_hwgpio(desc)); if (status == 0) clear_bit(FLAG_IS_OUT, &desc->flags); trace_gpio_direction(desc_to_gpio(desc), 1, status); return status; } EXPORT_SYMBOL_GPL(gpiod_direction_input); static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value) { struct gpio_chip *gc = desc->gdev->chip; int ret; /* GPIOs used for IRQs shall not be set as output */ if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) { gpiod_err(desc, "%s: tried to set a GPIO tied to an IRQ as output\n", __func__); return -EIO; } if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { /* First see if we can enable open drain in hardware */ if (gc->set_single_ended) { ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc), LINE_MODE_OPEN_DRAIN); if (!ret) goto set_output_value; } /* Emulate open drain by not actively driving the line high */ if (value) return gpiod_direction_input(desc); } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) { if (gc->set_single_ended) { ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc), LINE_MODE_OPEN_SOURCE); if (!ret) goto set_output_value; } /* Emulate open source by not actively driving the line low */ if (!value) return gpiod_direction_input(desc); } else { /* Make sure to disable open drain/source hardware, if any */ if (gc->set_single_ended) gc->set_single_ended(gc, gpio_chip_hwgpio(desc), LINE_MODE_PUSH_PULL); } set_output_value: if (!gc->set || !gc->direction_output) { gpiod_warn(desc, "%s: missing set() or direction_output() operations\n", __func__); return -EIO; } ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value); if (!ret) set_bit(FLAG_IS_OUT, &desc->flags); trace_gpio_value(desc_to_gpio(desc), 0, value); trace_gpio_direction(desc_to_gpio(desc), 0, ret); return ret; } /** * gpiod_direction_output_raw - set the GPIO direction to output * @desc: GPIO to set to output * @value: initial output value of the GPIO * * Set the direction of the passed GPIO to output, such as gpiod_set_value() can * be called safely on it. The initial value of the output must be specified * as raw value on the physical line without regard for the ACTIVE_LOW status. * * Return 0 in case of success, else an error code. */ int gpiod_direction_output_raw(struct gpio_desc *desc, int value) { VALIDATE_DESC(desc); return _gpiod_direction_output_raw(desc, value); } EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); /** * gpiod_direction_output - set the GPIO direction to output * @desc: GPIO to set to output * @value: initial output value of the GPIO * * Set the direction of the passed GPIO to output, such as gpiod_set_value() can * be called safely on it. The initial value of the output must be specified * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into * account. * * Return 0 in case of success, else an error code. */ int gpiod_direction_output(struct gpio_desc *desc, int value) { VALIDATE_DESC(desc); if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; return _gpiod_direction_output_raw(desc, value); } EXPORT_SYMBOL_GPL(gpiod_direction_output); /** * gpiod_set_debounce - sets @debounce time for a @gpio * @gpio: the gpio to set debounce time * @debounce: debounce time is microseconds * * returns -ENOTSUPP if the controller does not support setting * debounce. */ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) { struct gpio_chip *chip; VALIDATE_DESC(desc); chip = desc->gdev->chip; if (!chip->set || !chip->set_debounce) { gpiod_dbg(desc, "%s: missing set() or set_debounce() operations\n", __func__); return -ENOTSUPP; } return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce); } EXPORT_SYMBOL_GPL(gpiod_set_debounce); /** * gpiod_is_active_low - test whether a GPIO is active-low or not * @desc: the gpio descriptor to test * * Returns 1 if the GPIO is active-low, 0 otherwise. */ int gpiod_is_active_low(const struct gpio_desc *desc) { VALIDATE_DESC(desc); return test_bit(FLAG_ACTIVE_LOW, &desc->flags); } EXPORT_SYMBOL_GPL(gpiod_is_active_low); /* I/O calls are only valid after configuration completed; the relevant * "is this a valid GPIO" error checks should already have been done. * * "Get" operations are often inlinable as reading a pin value register, * and masking the relevant bit in that register. * * When "set" operations are inlinable, they involve writing that mask to * one register to set a low value, or a different register to set it high. * Otherwise locking is needed, so there may be little value to inlining. * *------------------------------------------------------------------------ * * IMPORTANT!!! The hot paths -- get/set value -- assume that callers * have requested the GPIO. That can include implicit requesting by * a direction setting call. Marking a gpio as requested locks its chip * in memory, guaranteeing that these table lookups need no more locking * and that gpiochip_remove() will fail. * * REVISIT when debugging, consider adding some instrumentation to ensure * that the GPIO was actually requested. */ static int _gpiod_get_raw_value(const struct gpio_desc *desc) { struct gpio_chip *chip; int offset; int value; chip = desc->gdev->chip; offset = gpio_chip_hwgpio(desc); value = chip->get ? chip->get(chip, offset) : -EIO; value = value < 0 ? value : !!value; trace_gpio_value(desc_to_gpio(desc), 1, value); return value; } /** * gpiod_get_raw_value() - return a gpio's raw value * @desc: gpio whose value will be returned * * Return the GPIO's raw value, i.e. the value of the physical line disregarding * its ACTIVE_LOW status, or negative errno on failure. * * This function should be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_get_raw_value(const struct gpio_desc *desc) { VALIDATE_DESC(desc); /* Should be using gpio_get_value_cansleep() */ WARN_ON(desc->gdev->chip->can_sleep); return _gpiod_get_raw_value(desc); } EXPORT_SYMBOL_GPL(gpiod_get_raw_value); /** * gpiod_get_value() - return a gpio's value * @desc: gpio whose value will be returned * * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into * account, or negative errno on failure. * * This function should be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_get_value(const struct gpio_desc *desc) { int value; VALIDATE_DESC(desc); /* Should be using gpio_get_value_cansleep() */ WARN_ON(desc->gdev->chip->can_sleep); value = _gpiod_get_raw_value(desc); if (value < 0) return value; if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; return value; } EXPORT_SYMBOL_GPL(gpiod_get_value); /* * _gpio_set_open_drain_value() - Set the open drain gpio's value. * @desc: gpio descriptor whose state need to be set. * @value: Non-zero for setting it HIGH otherwise it will set to LOW. */ static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value) { int err = 0; struct gpio_chip *chip = desc->gdev->chip; int offset = gpio_chip_hwgpio(desc); if (value) { err = chip->direction_input(chip, offset); if (!err) clear_bit(FLAG_IS_OUT, &desc->flags); } else { err = chip->direction_output(chip, offset, 0); if (!err) set_bit(FLAG_IS_OUT, &desc->flags); } trace_gpio_direction(desc_to_gpio(desc), value, err); if (err < 0) gpiod_err(desc, "%s: Error in set_value for open drain err %d\n", __func__, err); } /* * _gpio_set_open_source_value() - Set the open source gpio's value. * @desc: gpio descriptor whose state need to be set. * @value: Non-zero for setting it HIGH otherwise it will set to LOW. */ static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value) { int err = 0; struct gpio_chip *chip = desc->gdev->chip; int offset = gpio_chip_hwgpio(desc); if (value) { err = chip->direction_output(chip, offset, 1); if (!err) set_bit(FLAG_IS_OUT, &desc->flags); } else { err = chip->direction_input(chip, offset); if (!err) clear_bit(FLAG_IS_OUT, &desc->flags); } trace_gpio_direction(desc_to_gpio(desc), !value, err); if (err < 0) gpiod_err(desc, "%s: Error in set_value for open source err %d\n", __func__, err); } static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value) { struct gpio_chip *chip; chip = desc->gdev->chip; trace_gpio_value(desc_to_gpio(desc), 0, value); if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) _gpio_set_open_drain_value(desc, value); else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) _gpio_set_open_source_value(desc, value); else chip->set(chip, gpio_chip_hwgpio(desc), value); } /* * set multiple outputs on the same chip; * use the chip's set_multiple function if available; * otherwise set the outputs sequentially; * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word * defines which outputs are to be changed * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word * defines the values the outputs specified by mask are to be set to */ static void gpio_chip_set_multiple(struct gpio_chip *chip, unsigned long *mask, unsigned long *bits) { if (chip->set_multiple) { chip->set_multiple(chip, mask, bits); } else { int i; for (i = 0; i < chip->ngpio; i++) { if (mask[BIT_WORD(i)] == 0) { /* no more set bits in this mask word; * skip ahead to the next word */ i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1; continue; } /* set outputs if the corresponding mask bit is set */ if (__test_and_clear_bit(i, mask)) chip->set(chip, i, test_bit(i, bits)); } } } void gpiod_set_array_value_complex(bool raw, bool can_sleep, unsigned int array_size, struct gpio_desc **desc_array, int *value_array) { int i = 0; while (i < array_size) { struct gpio_chip *chip = desc_array[i]->gdev->chip; unsigned long mask[BITS_TO_LONGS(chip->ngpio)]; unsigned long bits[BITS_TO_LONGS(chip->ngpio)]; int count = 0; if (!can_sleep) WARN_ON(chip->can_sleep); memset(mask, 0, sizeof(mask)); do { struct gpio_desc *desc = desc_array[i]; int hwgpio = gpio_chip_hwgpio(desc); int value = value_array[i]; if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; trace_gpio_value(desc_to_gpio(desc), 0, value); /* * collect all normal outputs belonging to the same chip * open drain and open source outputs are set individually */ if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { _gpio_set_open_drain_value(desc, value); } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) { _gpio_set_open_source_value(desc, value); } else { __set_bit(hwgpio, mask); if (value) __set_bit(hwgpio, bits); else __clear_bit(hwgpio, bits); count++; } i++; } while ((i < array_size) && (desc_array[i]->gdev->chip == chip)); /* push collected bits to outputs */ if (count != 0) gpio_chip_set_multiple(chip, mask, bits); } } /** * gpiod_set_raw_value() - assign a gpio's raw value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the raw value of the GPIO, i.e. the value of its physical line without * regard for its ACTIVE_LOW status. * * This function should be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ void gpiod_set_raw_value(struct gpio_desc *desc, int value) { VALIDATE_DESC_VOID(desc); /* Should be using gpiod_set_value_cansleep() */ WARN_ON(desc->gdev->chip->can_sleep); _gpiod_set_raw_value(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_raw_value); /** * gpiod_set_value() - assign a gpio's value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into * account * * This function should be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ void gpiod_set_value(struct gpio_desc *desc, int value) { VALIDATE_DESC_VOID(desc); /* Should be using gpiod_set_value_cansleep() */ WARN_ON(desc->gdev->chip->can_sleep); if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; _gpiod_set_raw_value(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_value); /** * gpiod_set_raw_array_value() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor / value arrays * @desc_array: array of GPIO descriptors whose values will be assigned * @value_array: array of values to assign * * Set the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. * * This function should be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ void gpiod_set_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, int *value_array) { if (!desc_array) return; gpiod_set_array_value_complex(true, false, array_size, desc_array, value_array); } EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value); /** * gpiod_set_array_value() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor / value arrays * @desc_array: array of GPIO descriptors whose values will be assigned * @value_array: array of values to assign * * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. * * This function should be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ void gpiod_set_array_value(unsigned int array_size, struct gpio_desc **desc_array, int *value_array) { if (!desc_array) return; gpiod_set_array_value_complex(false, false, array_size, desc_array, value_array); } EXPORT_SYMBOL_GPL(gpiod_set_array_value); /** * gpiod_cansleep() - report whether gpio value access may sleep * @desc: gpio to check * */ int gpiod_cansleep(const struct gpio_desc *desc) { VALIDATE_DESC(desc); return desc->gdev->chip->can_sleep; } EXPORT_SYMBOL_GPL(gpiod_cansleep); /** * gpiod_to_irq() - return the IRQ corresponding to a GPIO * @desc: gpio whose IRQ will be returned (already requested) * * Return the IRQ corresponding to the passed GPIO, or an error code in case of * error. */ int gpiod_to_irq(const struct gpio_desc *desc) { struct gpio_chip *chip; int offset; /* * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics * requires this function to not return zero on an invalid descriptor * but rather a negative error number. */ if (!desc || !desc->gdev || !desc->gdev->chip) return -EINVAL; chip = desc->gdev->chip; offset = gpio_chip_hwgpio(desc); if (chip->to_irq) { int retirq = chip->to_irq(chip, offset); /* Zero means NO_IRQ */ if (!retirq) return -ENXIO; return retirq; } return -ENXIO; } EXPORT_SYMBOL_GPL(gpiod_to_irq); /** * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ * @chip: the chip the GPIO to lock belongs to * @offset: the offset of the GPIO to lock as IRQ * * This is used directly by GPIO drivers that want to lock down * a certain GPIO line to be used for IRQs. */ int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset) { struct gpio_desc *desc; desc = gpiochip_get_desc(chip, offset); if (IS_ERR(desc)) return PTR_ERR(desc); /* Flush direction if something changed behind our back */ if (chip->get_direction) { int dir = chip->get_direction(chip, offset); if (dir) clear_bit(FLAG_IS_OUT, &desc->flags); else set_bit(FLAG_IS_OUT, &desc->flags); } if (test_bit(FLAG_IS_OUT, &desc->flags)) { chip_err(chip, "%s: tried to flag a GPIO set as output for IRQ\n", __func__); return -EIO; } set_bit(FLAG_USED_AS_IRQ, &desc->flags); return 0; } EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq); /** * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ * @chip: the chip the GPIO to lock belongs to * @offset: the offset of the GPIO to lock as IRQ * * This is used directly by GPIO drivers that want to indicate * that a certain GPIO is no longer used exclusively for IRQ. */ void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) { if (offset >= chip->ngpio) return; clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags); } EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq); bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset) { if (offset >= chip->ngpio) return false; return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags); } EXPORT_SYMBOL_GPL(gpiochip_line_is_irq); bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset) { if (offset >= chip->ngpio) return false; return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags); } EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain); bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset) { if (offset >= chip->ngpio) return false; return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags); } EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source); /** * gpiod_get_raw_value_cansleep() - return a gpio's raw value * @desc: gpio whose value will be returned * * Return the GPIO's raw value, i.e. the value of the physical line disregarding * its ACTIVE_LOW status, or negative errno on failure. * * This function is to be called from contexts that can sleep. */ int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) { might_sleep_if(extra_checks); VALIDATE_DESC(desc); return _gpiod_get_raw_value(desc); } EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep); /** * gpiod_get_value_cansleep() - return a gpio's value * @desc: gpio whose value will be returned * * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into * account, or negative errno on failure. * * This function is to be called from contexts that can sleep. */ int gpiod_get_value_cansleep(const struct gpio_desc *desc) { int value; might_sleep_if(extra_checks); VALIDATE_DESC(desc); value = _gpiod_get_raw_value(desc); if (value < 0) return value; if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; return value; } EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); /** * gpiod_set_raw_value_cansleep() - assign a gpio's raw value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the raw value of the GPIO, i.e. the value of its physical line without * regard for its ACTIVE_LOW status. * * This function is to be called from contexts that can sleep. */ void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) { might_sleep_if(extra_checks); VALIDATE_DESC_VOID(desc); _gpiod_set_raw_value(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); /** * gpiod_set_value_cansleep() - assign a gpio's value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into * account * * This function is to be called from contexts that can sleep. */ void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) { might_sleep_if(extra_checks); VALIDATE_DESC_VOID(desc); if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; _gpiod_set_raw_value(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); /** * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor / value arrays * @desc_array: array of GPIO descriptors whose values will be assigned * @value_array: array of values to assign * * Set the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. * * This function is to be called from contexts that can sleep. */ void gpiod_set_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, int *value_array) { might_sleep_if(extra_checks); if (!desc_array) return; gpiod_set_array_value_complex(true, true, array_size, desc_array, value_array); } EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep); /** * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor / value arrays * @desc_array: array of GPIO descriptors whose values will be assigned * @value_array: array of values to assign * * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. * * This function is to be called from contexts that can sleep. */ void gpiod_set_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, int *value_array) { might_sleep_if(extra_checks); if (!desc_array) return; gpiod_set_array_value_complex(false, true, array_size, desc_array, value_array); } EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep); /** * gpiod_add_lookup_table() - register GPIO device consumers * @table: table of consumers to register */ void gpiod_add_lookup_table(struct gpiod_lookup_table *table) { mutex_lock(&gpio_lookup_lock); list_add_tail(&table->list, &gpio_lookup_list); mutex_unlock(&gpio_lookup_lock); } /** * gpiod_remove_lookup_table() - unregister GPIO device consumers * @table: table of consumers to unregister */ void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) { mutex_lock(&gpio_lookup_lock); list_del(&table->list); mutex_unlock(&gpio_lookup_lock); } static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, unsigned int idx, enum gpio_lookup_flags *flags) { char prop_name[32]; /* 32 is max size of property name */ enum of_gpio_flags of_flags; struct gpio_desc *desc; unsigned int i; for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { if (con_id) snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id, gpio_suffixes[i]); else snprintf(prop_name, sizeof(prop_name), "%s", gpio_suffixes[i]); desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx, &of_flags); if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER)) break; } if (IS_ERR(desc)) return desc; if (of_flags & OF_GPIO_ACTIVE_LOW) *flags |= GPIO_ACTIVE_LOW; if (of_flags & OF_GPIO_SINGLE_ENDED) { if (of_flags & OF_GPIO_ACTIVE_LOW) *flags |= GPIO_OPEN_DRAIN; else *flags |= GPIO_OPEN_SOURCE; } return desc; } static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, unsigned int idx, enum gpiod_flags flags, enum gpio_lookup_flags *lookupflags) { struct acpi_device *adev = ACPI_COMPANION(dev); struct acpi_gpio_info info; struct gpio_desc *desc; char propname[32]; int i; /* Try first from _DSD */ for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { if (con_id && strcmp(con_id, "gpios")) { snprintf(propname, sizeof(propname), "%s-%s", con_id, gpio_suffixes[i]); } else { snprintf(propname, sizeof(propname), "%s", gpio_suffixes[i]); } desc = acpi_get_gpiod_by_index(adev, propname, idx, &info); if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER)) break; } /* Then from plain _CRS GPIOs */ if (IS_ERR(desc)) { if (!acpi_can_fallback_to_crs(adev, con_id)) return ERR_PTR(-ENOENT); desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info); if (IS_ERR(desc)) return desc; if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) && info.gpioint) { dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n"); return ERR_PTR(-ENOENT); } } if (info.polarity == GPIO_ACTIVE_LOW) *lookupflags |= GPIO_ACTIVE_LOW; return desc; } static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev) { const char *dev_id = dev ? dev_name(dev) : NULL; struct gpiod_lookup_table *table; mutex_lock(&gpio_lookup_lock); list_for_each_entry(table, &gpio_lookup_list, list) { if (table->dev_id && dev_id) { /* * Valid strings on both ends, must be identical to have * a match */ if (!strcmp(table->dev_id, dev_id)) goto found; } else { /* * One of the pointers is NULL, so both must be to have * a match */ if (dev_id == table->dev_id) goto found; } } table = NULL; found: mutex_unlock(&gpio_lookup_lock); return table; } static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, unsigned int idx, enum gpio_lookup_flags *flags) { struct gpio_desc *desc = ERR_PTR(-ENOENT); struct gpiod_lookup_table *table; struct gpiod_lookup *p; table = gpiod_find_lookup_table(dev); if (!table) return desc; for (p = &table->table[0]; p->chip_label; p++) { struct gpio_chip *chip; /* idx must always match exactly */ if (p->idx != idx) continue; /* If the lookup entry has a con_id, require exact match */ if (p->con_id && (!con_id || strcmp(p->con_id, con_id))) continue; chip = find_chip_by_name(p->chip_label); if (!chip) { dev_err(dev, "cannot find GPIO chip %s\n", p->chip_label); return ERR_PTR(-ENODEV); } if (chip->ngpio <= p->chip_hwnum) { dev_err(dev, "requested GPIO %d is out of range [0..%d] for chip %s\n", idx, chip->ngpio, chip->label); return ERR_PTR(-EINVAL); } desc = gpiochip_get_desc(chip, p->chip_hwnum); *flags = p->flags; return desc; } return desc; } static int dt_gpio_count(struct device *dev, const char *con_id) { int ret; char propname[32]; unsigned int i; for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { if (con_id) snprintf(propname, sizeof(propname), "%s-%s", con_id, gpio_suffixes[i]); else snprintf(propname, sizeof(propname), "%s", gpio_suffixes[i]); ret = of_gpio_named_count(dev->of_node, propname); if (ret >= 0) break; } return ret; } static int platform_gpio_count(struct device *dev, const char *con_id) { struct gpiod_lookup_table *table; struct gpiod_lookup *p; unsigned int count = 0; table = gpiod_find_lookup_table(dev); if (!table) return -ENOENT; for (p = &table->table[0]; p->chip_label; p++) { if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) || (!con_id && !p->con_id)) count++; } if (!count) return -ENOENT; return count; } /** * gpiod_count - return the number of GPIOs associated with a device / function * or -ENOENT if no GPIO has been assigned to the requested function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer */ int gpiod_count(struct device *dev, const char *con_id) { int count = -ENOENT; if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) count = dt_gpio_count(dev, con_id); else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) count = acpi_gpio_count(dev, con_id); if (count < 0) count = platform_gpio_count(dev, con_id); return count; } EXPORT_SYMBOL_GPL(gpiod_count); /** * gpiod_get - obtain a GPIO for a given GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @flags: optional GPIO initialization flags * * Return the GPIO descriptor corresponding to the function con_id of device * dev, -ENOENT if no GPIO has been assigned to the requested function, or * another IS_ERR() code if an error occurred while trying to acquire the GPIO. */ struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id, enum gpiod_flags flags) { return gpiod_get_index(dev, con_id, 0, flags); } EXPORT_SYMBOL_GPL(gpiod_get); /** * gpiod_get_optional - obtain an optional GPIO for a given GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @flags: optional GPIO initialization flags * * This is equivalent to gpiod_get(), except that when no GPIO was assigned to * the requested function it will return NULL. This is convenient for drivers * that need to handle optional GPIOs. */ struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, const char *con_id, enum gpiod_flags flags) { return gpiod_get_index_optional(dev, con_id, 0, flags); } EXPORT_SYMBOL_GPL(gpiod_get_optional); /** * gpiod_parse_flags - helper function to parse GPIO lookup flags * @desc: gpio to be setup * @lflags: gpio_lookup_flags - returned from of_find_gpio() or * of_get_gpio_hog() * * Set the GPIO descriptor flags based on the given GPIO lookup flags. */ static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags) { if (lflags & GPIO_ACTIVE_LOW) set_bit(FLAG_ACTIVE_LOW, &desc->flags); if (lflags & GPIO_OPEN_DRAIN) set_bit(FLAG_OPEN_DRAIN, &desc->flags); if (lflags & GPIO_OPEN_SOURCE) set_bit(FLAG_OPEN_SOURCE, &desc->flags); } /** * gpiod_configure_flags - helper function to configure a given GPIO * @desc: gpio whose value will be assigned * @con_id: function within the GPIO consumer * @dflags: gpiod_flags - optional GPIO initialization flags * * Return 0 on success, -ENOENT if no GPIO has been assigned to the * requested function and/or index, or another IS_ERR() code if an error * occurred while trying to acquire the GPIO. */ static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, enum gpiod_flags dflags) { int status; /* No particular flag request, return here... */ if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) { pr_debug("no flags found for %s\n", con_id); return 0; } /* Process flags */ if (dflags & GPIOD_FLAGS_BIT_DIR_OUT) status = gpiod_direction_output(desc, dflags & GPIOD_FLAGS_BIT_DIR_VAL); else status = gpiod_direction_input(desc); return status; } /** * gpiod_get_index - obtain a GPIO from a multi-index GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @idx: index of the GPIO to obtain in the consumer * @flags: optional GPIO initialization flags * * This variant of gpiod_get() allows to access GPIOs other than the first * defined one for functions that define several GPIOs. * * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the * requested function and/or index, or another IS_ERR() code if an error * occurred while trying to acquire the GPIO. */ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, const char *con_id, unsigned int idx, enum gpiod_flags flags) { struct gpio_desc *desc = NULL; int status; enum gpio_lookup_flags lookupflags = 0; dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id); if (dev) { /* Using device tree? */ if (IS_ENABLED(CONFIG_OF) && dev->of_node) { dev_dbg(dev, "using device tree for GPIO lookup\n"); desc = of_find_gpio(dev, con_id, idx, &lookupflags); } else if (ACPI_COMPANION(dev)) { dev_dbg(dev, "using ACPI for GPIO lookup\n"); desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags); } } /* * Either we are not using DT or ACPI, or their lookup did not return * a result. In that case, use platform lookup as a fallback. */ if (!desc || desc == ERR_PTR(-ENOENT)) { dev_dbg(dev, "using lookup tables for GPIO lookup\n"); desc = gpiod_find(dev, con_id, idx, &lookupflags); } if (IS_ERR(desc)) { dev_dbg(dev, "lookup for GPIO %s failed\n", con_id); return desc; } gpiod_parse_flags(desc, lookupflags); status = gpiod_request(desc, con_id); if (status < 0) return ERR_PTR(status); status = gpiod_configure_flags(desc, con_id, flags); if (status < 0) { dev_dbg(dev, "setup of GPIO %s failed\n", con_id); gpiod_put(desc); return ERR_PTR(status); } return desc; } EXPORT_SYMBOL_GPL(gpiod_get_index); /** * fwnode_get_named_gpiod - obtain a GPIO from firmware node * @fwnode: handle of the firmware node * @propname: name of the firmware property representing the GPIO * * This function can be used for drivers that get their configuration * from firmware. * * Function properly finds the corresponding GPIO using whatever is the * underlying firmware interface and then makes sure that the GPIO * descriptor is requested before it is returned to the caller. * * In case of error an ERR_PTR() is returned. */ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, const char *propname) { struct gpio_desc *desc = ERR_PTR(-ENODEV); bool active_low = false; bool single_ended = false; int ret; if (!fwnode) return ERR_PTR(-EINVAL); if (is_of_node(fwnode)) { enum of_gpio_flags flags; desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0, &flags); if (!IS_ERR(desc)) { active_low = flags & OF_GPIO_ACTIVE_LOW; single_ended = flags & OF_GPIO_SINGLE_ENDED; } } else if (is_acpi_node(fwnode)) { struct acpi_gpio_info info; desc = acpi_node_get_gpiod(fwnode, propname, 0, &info); if (!IS_ERR(desc)) active_low = info.polarity == GPIO_ACTIVE_LOW; } if (IS_ERR(desc)) return desc; if (active_low) set_bit(FLAG_ACTIVE_LOW, &desc->flags); if (single_ended) { if (active_low) set_bit(FLAG_OPEN_DRAIN, &desc->flags); else set_bit(FLAG_OPEN_SOURCE, &desc->flags); } ret = gpiod_request(desc, NULL); if (ret) return ERR_PTR(ret); return desc; } EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod); /** * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO * function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @index: index of the GPIO to obtain in the consumer * @flags: optional GPIO initialization flags * * This is equivalent to gpiod_get_index(), except that when no GPIO with the * specified index was assigned to the requested function it will return NULL. * This is convenient for drivers that need to handle optional GPIOs. */ struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, const char *con_id, unsigned int index, enum gpiod_flags flags) { struct gpio_desc *desc; desc = gpiod_get_index(dev, con_id, index, flags); if (IS_ERR(desc)) { if (PTR_ERR(desc) == -ENOENT) return NULL; } return desc; } EXPORT_SYMBOL_GPL(gpiod_get_index_optional); /** * gpiod_hog - Hog the specified GPIO desc given the provided flags * @desc: gpio whose value will be assigned * @name: gpio line name * @lflags: gpio_lookup_flags - returned from of_find_gpio() or * of_get_gpio_hog() * @dflags: gpiod_flags - optional GPIO initialization flags */ int gpiod_hog(struct gpio_desc *desc, const char *name, unsigned long lflags, enum gpiod_flags dflags) { struct gpio_chip *chip; struct gpio_desc *local_desc; int hwnum; int status; chip = gpiod_to_chip(desc); hwnum = gpio_chip_hwgpio(desc); gpiod_parse_flags(desc, lflags); local_desc = gpiochip_request_own_desc(chip, hwnum, name); if (IS_ERR(local_desc)) { status = PTR_ERR(local_desc); pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n", name, chip->label, hwnum, status); return status; } status = gpiod_configure_flags(desc, name, dflags); if (status < 0) { pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n", name, chip->label, hwnum, status); gpiochip_free_own_desc(desc); return status; } /* Mark GPIO as hogged so it can be identified and removed later */ set_bit(FLAG_IS_HOGGED, &desc->flags); pr_info("GPIO line %d (%s) hogged as %s%s\n", desc_to_gpio(desc), name, (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input", (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":""); return 0; } /** * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog * @chip: gpio chip to act on * * This is only used by of_gpiochip_remove to free hogged gpios */ static void gpiochip_free_hogs(struct gpio_chip *chip) { int id; for (id = 0; id < chip->ngpio; id++) { if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags)) gpiochip_free_own_desc(&chip->gpiodev->descs[id]); } } /** * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @flags: optional GPIO initialization flags * * This function acquires all the GPIOs defined under a given function. * * Return a struct gpio_descs containing an array of descriptors, -ENOENT if * no GPIO has been assigned to the requested function, or another IS_ERR() * code if an error occurred while trying to acquire the GPIOs. */ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, const char *con_id, enum gpiod_flags flags) { struct gpio_desc *desc; struct gpio_descs *descs; int count; count = gpiod_count(dev, con_id); if (count < 0) return ERR_PTR(count); descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count, GFP_KERNEL); if (!descs) return ERR_PTR(-ENOMEM); for (descs->ndescs = 0; descs->ndescs < count; ) { desc = gpiod_get_index(dev, con_id, descs->ndescs, flags); if (IS_ERR(desc)) { gpiod_put_array(descs); return ERR_CAST(desc); } descs->desc[descs->ndescs] = desc; descs->ndescs++; } return descs; } EXPORT_SYMBOL_GPL(gpiod_get_array); /** * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO * function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @flags: optional GPIO initialization flags * * This is equivalent to gpiod_get_array(), except that when no GPIO was * assigned to the requested function it will return NULL. */ struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev, const char *con_id, enum gpiod_flags flags) { struct gpio_descs *descs; descs = gpiod_get_array(dev, con_id, flags); if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT)) return NULL; return descs; } EXPORT_SYMBOL_GPL(gpiod_get_array_optional); /** * gpiod_put - dispose of a GPIO descriptor * @desc: GPIO descriptor to dispose of * * No descriptor can be used after gpiod_put() has been called on it. */ void gpiod_put(struct gpio_desc *desc) { gpiod_free(desc); } EXPORT_SYMBOL_GPL(gpiod_put); /** * gpiod_put_array - dispose of multiple GPIO descriptors * @descs: struct gpio_descs containing an array of descriptors */ void gpiod_put_array(struct gpio_descs *descs) { unsigned int i; for (i = 0; i < descs->ndescs; i++) gpiod_put(descs->desc[i]); kfree(descs); } EXPORT_SYMBOL_GPL(gpiod_put_array); static int __init gpiolib_dev_init(void) { int ret; /* Register GPIO sysfs bus */ ret = bus_register(&gpio_bus_type); if (ret < 0) { pr_err("gpiolib: could not register GPIO bus type\n"); return ret; } ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip"); if (ret < 0) { pr_err("gpiolib: failed to allocate char dev region\n"); bus_unregister(&gpio_bus_type); } else { gpiolib_initialized = true; gpiochip_setup_devs(); } return ret; } core_initcall(gpiolib_dev_init); #ifdef CONFIG_DEBUG_FS static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev) { unsigned i; struct gpio_chip *chip = gdev->chip; unsigned gpio = gdev->base; struct gpio_desc *gdesc = &gdev->descs[0]; int is_out; int is_irq; for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) { if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) { if (gdesc->name) { seq_printf(s, " gpio-%-3d (%-20.20s)\n", gpio, gdesc->name); } continue; } gpiod_get_direction(gdesc); is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags); seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s", gpio, gdesc->name ? gdesc->name : "", gdesc->label, is_out ? "out" : "in ", chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ", is_irq ? "IRQ" : " "); seq_printf(s, "\n"); } } static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) { unsigned long flags; struct gpio_device *gdev = NULL; loff_t index = *pos; s->private = ""; spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) if (index-- == 0) { spin_unlock_irqrestore(&gpio_lock, flags); return gdev; } spin_unlock_irqrestore(&gpio_lock, flags); return NULL; } static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { unsigned long flags; struct gpio_device *gdev = v; void *ret = NULL; spin_lock_irqsave(&gpio_lock, flags); if (list_is_last(&gdev->list, &gpio_devices)) ret = NULL; else ret = list_entry(gdev->list.next, struct gpio_device, list); spin_unlock_irqrestore(&gpio_lock, flags); s->private = "\n"; ++*pos; return ret; } static void gpiolib_seq_stop(struct seq_file *s, void *v) { } static int gpiolib_seq_show(struct seq_file *s, void *v) { struct gpio_device *gdev = v; struct gpio_chip *chip = gdev->chip; struct device *parent; if (!chip) { seq_printf(s, "%s%s: (dangling chip)", (char *)s->private, dev_name(&gdev->dev)); return 0; } seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private, dev_name(&gdev->dev), gdev->base, gdev->base + gdev->ngpio - 1); parent = chip->parent; if (parent) seq_printf(s, ", parent: %s/%s", parent->bus ? parent->bus->name : "no-bus", dev_name(parent)); if (chip->label) seq_printf(s, ", %s", chip->label); if (chip->can_sleep) seq_printf(s, ", can sleep"); seq_printf(s, ":\n"); if (chip->dbg_show) chip->dbg_show(s, chip); else gpiolib_dbg_show(s, gdev); return 0; } static const struct seq_operations gpiolib_seq_ops = { .start = gpiolib_seq_start, .next = gpiolib_seq_next, .stop = gpiolib_seq_stop, .show = gpiolib_seq_show, }; static int gpiolib_open(struct inode *inode, struct file *file) { return seq_open(file, &gpiolib_seq_ops); } static const struct file_operations gpiolib_operations = { .owner = THIS_MODULE, .open = gpiolib_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; static int __init gpiolib_debugfs_init(void) { /* /sys/kernel/debug/gpio */ (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, NULL, NULL, &gpiolib_operations); return 0; } subsys_initcall(gpiolib_debugfs_init); #endif /* DEBUG_FS */