diff options
Diffstat (limited to 'drivers/staging/dream/generic_gpio.c')
-rw-r--r-- | drivers/staging/dream/generic_gpio.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/staging/dream/generic_gpio.c b/drivers/staging/dream/generic_gpio.c new file mode 100644 index 000000000000..fe24d38345d0 --- /dev/null +++ b/drivers/staging/dream/generic_gpio.c @@ -0,0 +1,274 @@ +/* arch/arm/mach-msm/generic_gpio.c + * + * Copyright (C) 2007 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <asm/gpio.h> +#include "gpio_chip.h" + +#define GPIO_NUM_TO_CHIP_INDEX(gpio) ((gpio)>>5) + +struct gpio_state { + unsigned long flags; + int refcount; +}; + +static DEFINE_SPINLOCK(gpio_chips_lock); +static LIST_HEAD(gpio_chip_list); +static struct gpio_chip **gpio_chip_array; +static unsigned long gpio_chip_array_size; + +int register_gpio_chip(struct gpio_chip *new_gpio_chip) +{ + int err = 0; + struct gpio_chip *gpio_chip; + int i; + unsigned long irq_flags; + unsigned int chip_array_start_index, chip_array_end_index; + + new_gpio_chip->state = kzalloc((new_gpio_chip->end + 1 - new_gpio_chip->start) * sizeof(new_gpio_chip->state[0]), GFP_KERNEL); + if (new_gpio_chip->state == NULL) { + printk(KERN_ERR "register_gpio_chip: failed to allocate state\n"); + return -ENOMEM; + } + + spin_lock_irqsave(&gpio_chips_lock, irq_flags); + chip_array_start_index = GPIO_NUM_TO_CHIP_INDEX(new_gpio_chip->start); + chip_array_end_index = GPIO_NUM_TO_CHIP_INDEX(new_gpio_chip->end); + if (chip_array_end_index >= gpio_chip_array_size) { + struct gpio_chip **new_gpio_chip_array; + unsigned long new_gpio_chip_array_size = chip_array_end_index + 1; + + new_gpio_chip_array = kmalloc(new_gpio_chip_array_size * sizeof(new_gpio_chip_array[0]), GFP_ATOMIC); + if (new_gpio_chip_array == NULL) { + printk(KERN_ERR "register_gpio_chip: failed to allocate array\n"); + err = -ENOMEM; + goto failed; + } + for (i = 0; i < gpio_chip_array_size; i++) + new_gpio_chip_array[i] = gpio_chip_array[i]; + for (i = gpio_chip_array_size; i < new_gpio_chip_array_size; i++) + new_gpio_chip_array[i] = NULL; + gpio_chip_array = new_gpio_chip_array; + gpio_chip_array_size = new_gpio_chip_array_size; + } + list_for_each_entry(gpio_chip, &gpio_chip_list, list) { + if (gpio_chip->start > new_gpio_chip->end) { + list_add_tail(&new_gpio_chip->list, &gpio_chip->list); + goto added; + } + if (gpio_chip->end >= new_gpio_chip->start) { + printk(KERN_ERR "register_gpio_source %u-%u overlaps with %u-%u\n", + new_gpio_chip->start, new_gpio_chip->end, + gpio_chip->start, gpio_chip->end); + err = -EBUSY; + goto failed; + } + } + list_add_tail(&new_gpio_chip->list, &gpio_chip_list); +added: + for (i = chip_array_start_index; i <= chip_array_end_index; i++) { + if (gpio_chip_array[i] == NULL || gpio_chip_array[i]->start > new_gpio_chip->start) + gpio_chip_array[i] = new_gpio_chip; + } +failed: + spin_unlock_irqrestore(&gpio_chips_lock, irq_flags); + if (err) + kfree(new_gpio_chip->state); + return err; +} + +static struct gpio_chip *get_gpio_chip_locked(unsigned int gpio) +{ + unsigned long i; + struct gpio_chip *chip; + + i = GPIO_NUM_TO_CHIP_INDEX(gpio); + if (i >= gpio_chip_array_size) + return NULL; + chip = gpio_chip_array[i]; + if (chip == NULL) + return NULL; + list_for_each_entry_from(chip, &gpio_chip_list, list) { + if (gpio < chip->start) + return NULL; + if (gpio <= chip->end) + return chip; + } + return NULL; +} + +static int request_gpio(unsigned int gpio, unsigned long flags) +{ + int err = 0; + struct gpio_chip *chip; + unsigned long irq_flags; + unsigned long chip_index; + + spin_lock_irqsave(&gpio_chips_lock, irq_flags); + chip = get_gpio_chip_locked(gpio); + if (chip == NULL) { + err = -EINVAL; + goto err; + } + chip_index = gpio - chip->start; + if (chip->state[chip_index].refcount == 0) { + chip->configure(chip, gpio, flags); + chip->state[chip_index].flags = flags; + chip->state[chip_index].refcount++; + } else if ((flags & IRQF_SHARED) && (chip->state[chip_index].flags & IRQF_SHARED)) + chip->state[chip_index].refcount++; + else + err = -EBUSY; +err: + spin_unlock_irqrestore(&gpio_chips_lock, irq_flags); + return err; +} + +int gpio_request(unsigned gpio, const char *label) +{ + return request_gpio(gpio, 0); +} +EXPORT_SYMBOL(gpio_request); + +void gpio_free(unsigned gpio) +{ + struct gpio_chip *chip; + unsigned long irq_flags; + unsigned long chip_index; + + spin_lock_irqsave(&gpio_chips_lock, irq_flags); + chip = get_gpio_chip_locked(gpio); + if (chip) { + chip_index = gpio - chip->start; + chip->state[chip_index].refcount--; + } + spin_unlock_irqrestore(&gpio_chips_lock, irq_flags); +} +EXPORT_SYMBOL(gpio_free); + +static int gpio_get_irq_num(unsigned int gpio, unsigned int *irqp, unsigned long *irqnumflagsp) +{ + int ret = -ENOTSUPP; + struct gpio_chip *chip; + unsigned long irq_flags; + + spin_lock_irqsave(&gpio_chips_lock, irq_flags); + chip = get_gpio_chip_locked(gpio); + if (chip && chip->get_irq_num) + ret = chip->get_irq_num(chip, gpio, irqp, irqnumflagsp); + spin_unlock_irqrestore(&gpio_chips_lock, irq_flags); + return ret; +} + +int gpio_to_irq(unsigned gpio) +{ + int ret, irq; + ret = gpio_get_irq_num(gpio, &irq, NULL); + if (ret) + return ret; + return irq; +} +EXPORT_SYMBOL(gpio_to_irq); + +int gpio_configure(unsigned int gpio, unsigned long flags) +{ + int ret = -ENOTSUPP; + struct gpio_chip *chip; + unsigned long irq_flags; + + spin_lock_irqsave(&gpio_chips_lock, irq_flags); + chip = get_gpio_chip_locked(gpio); + if (chip) + ret = chip->configure(chip, gpio, flags); + spin_unlock_irqrestore(&gpio_chips_lock, irq_flags); + return ret; +} +EXPORT_SYMBOL(gpio_configure); + +int gpio_direction_input(unsigned gpio) +{ + return gpio_configure(gpio, GPIOF_INPUT); +} +EXPORT_SYMBOL(gpio_direction_input); + +int gpio_direction_output(unsigned gpio, int value) +{ + gpio_set_value(gpio, value); + return gpio_configure(gpio, GPIOF_DRIVE_OUTPUT); +} +EXPORT_SYMBOL(gpio_direction_output); + +int gpio_get_value(unsigned gpio) +{ + int ret = -ENOTSUPP; + struct gpio_chip *chip; + unsigned long irq_flags; + + spin_lock_irqsave(&gpio_chips_lock, irq_flags); + chip = get_gpio_chip_locked(gpio); + if (chip && chip->read) + ret = chip->read(chip, gpio); + spin_unlock_irqrestore(&gpio_chips_lock, irq_flags); + return ret; +} +EXPORT_SYMBOL(gpio_get_value); + +void gpio_set_value(unsigned gpio, int on) +{ + int ret = -ENOTSUPP; + struct gpio_chip *chip; + unsigned long irq_flags; + + spin_lock_irqsave(&gpio_chips_lock, irq_flags); + chip = get_gpio_chip_locked(gpio); + if (chip && chip->write) + ret = chip->write(chip, gpio, on); + spin_unlock_irqrestore(&gpio_chips_lock, irq_flags); +} +EXPORT_SYMBOL(gpio_set_value); + +int gpio_read_detect_status(unsigned int gpio) +{ + int ret = -ENOTSUPP; + struct gpio_chip *chip; + unsigned long irq_flags; + + spin_lock_irqsave(&gpio_chips_lock, irq_flags); + chip = get_gpio_chip_locked(gpio); + if (chip && chip->read_detect_status) + ret = chip->read_detect_status(chip, gpio); + spin_unlock_irqrestore(&gpio_chips_lock, irq_flags); + return ret; +} +EXPORT_SYMBOL(gpio_read_detect_status); + +int gpio_clear_detect_status(unsigned int gpio) +{ + int ret = -ENOTSUPP; + struct gpio_chip *chip; + unsigned long irq_flags; + + spin_lock_irqsave(&gpio_chips_lock, irq_flags); + chip = get_gpio_chip_locked(gpio); + if (chip && chip->clear_detect_status) + ret = chip->clear_detect_status(chip, gpio); + spin_unlock_irqrestore(&gpio_chips_lock, irq_flags); + return ret; +} +EXPORT_SYMBOL(gpio_clear_detect_status); |