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path: root/drivers/gpio/tc35892-gpio.c
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Diffstat (limited to 'drivers/gpio/tc35892-gpio.c')
-rw-r--r--drivers/gpio/tc35892-gpio.c381
1 files changed, 381 insertions, 0 deletions
diff --git a/drivers/gpio/tc35892-gpio.c b/drivers/gpio/tc35892-gpio.c
new file mode 100644
index 000000000000..1be6288780de
--- /dev/null
+++ b/drivers/gpio/tc35892-gpio.c
@@ -0,0 +1,381 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License, version 2
+ * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
+ * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/tc35892.h>
+
+/*
+ * These registers are modified under the irq bus lock and cached to avoid
+ * unnecessary writes in bus_sync_unlock.
+ */
+enum { REG_IBE, REG_IEV, REG_IS, REG_IE };
+
+#define CACHE_NR_REGS 4
+#define CACHE_NR_BANKS 3
+
+struct tc35892_gpio {
+ struct gpio_chip chip;
+ struct tc35892 *tc35892;
+ struct device *dev;
+ struct mutex irq_lock;
+
+ int irq_base;
+
+ /* Caches of interrupt control registers for bus_lock */
+ u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
+ u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
+};
+
+static inline struct tc35892_gpio *to_tc35892_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct tc35892_gpio, chip);
+}
+
+static int tc35892_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
+ struct tc35892 *tc35892 = tc35892_gpio->tc35892;
+ u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
+ u8 mask = 1 << (offset % 8);
+ int ret;
+
+ ret = tc35892_reg_read(tc35892, reg);
+ if (ret < 0)
+ return ret;
+
+ return ret & mask;
+}
+
+static void tc35892_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+ struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
+ struct tc35892 *tc35892 = tc35892_gpio->tc35892;
+ u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
+ unsigned pos = offset % 8;
+ u8 data[] = {!!val << pos, 1 << pos};
+
+ tc35892_block_write(tc35892, reg, ARRAY_SIZE(data), data);
+}
+
+static int tc35892_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int val)
+{
+ struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
+ struct tc35892 *tc35892 = tc35892_gpio->tc35892;
+ u8 reg = TC35892_GPIODIR0 + offset / 8;
+ unsigned pos = offset % 8;
+
+ tc35892_gpio_set(chip, offset, val);
+
+ return tc35892_set_bits(tc35892, reg, 1 << pos, 1 << pos);
+}
+
+static int tc35892_gpio_direction_input(struct gpio_chip *chip,
+ unsigned offset)
+{
+ struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
+ struct tc35892 *tc35892 = tc35892_gpio->tc35892;
+ u8 reg = TC35892_GPIODIR0 + offset / 8;
+ unsigned pos = offset % 8;
+
+ return tc35892_set_bits(tc35892, reg, 1 << pos, 0);
+}
+
+static int tc35892_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+ struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
+
+ return tc35892_gpio->irq_base + offset;
+}
+
+static struct gpio_chip template_chip = {
+ .label = "tc35892",
+ .owner = THIS_MODULE,
+ .direction_input = tc35892_gpio_direction_input,
+ .get = tc35892_gpio_get,
+ .direction_output = tc35892_gpio_direction_output,
+ .set = tc35892_gpio_set,
+ .to_irq = tc35892_gpio_to_irq,
+ .can_sleep = 1,
+};
+
+static int tc35892_gpio_irq_set_type(unsigned int irq, unsigned int type)
+{
+ struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
+ int offset = irq - tc35892_gpio->irq_base;
+ int regoffset = offset / 8;
+ int mask = 1 << (offset % 8);
+
+ if (type == IRQ_TYPE_EDGE_BOTH) {
+ tc35892_gpio->regs[REG_IBE][regoffset] |= mask;
+ return 0;
+ }
+
+ tc35892_gpio->regs[REG_IBE][regoffset] &= ~mask;
+
+ if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
+ tc35892_gpio->regs[REG_IS][regoffset] |= mask;
+ else
+ tc35892_gpio->regs[REG_IS][regoffset] &= ~mask;
+
+ if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
+ tc35892_gpio->regs[REG_IEV][regoffset] |= mask;
+ else
+ tc35892_gpio->regs[REG_IEV][regoffset] &= ~mask;
+
+ return 0;
+}
+
+static void tc35892_gpio_irq_lock(unsigned int irq)
+{
+ struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
+
+ mutex_lock(&tc35892_gpio->irq_lock);
+}
+
+static void tc35892_gpio_irq_sync_unlock(unsigned int irq)
+{
+ struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
+ struct tc35892 *tc35892 = tc35892_gpio->tc35892;
+ static const u8 regmap[] = {
+ [REG_IBE] = TC35892_GPIOIBE0,
+ [REG_IEV] = TC35892_GPIOIEV0,
+ [REG_IS] = TC35892_GPIOIS0,
+ [REG_IE] = TC35892_GPIOIE0,
+ };
+ int i, j;
+
+ for (i = 0; i < CACHE_NR_REGS; i++) {
+ for (j = 0; j < CACHE_NR_BANKS; j++) {
+ u8 old = tc35892_gpio->oldregs[i][j];
+ u8 new = tc35892_gpio->regs[i][j];
+
+ if (new == old)
+ continue;
+
+ tc35892_gpio->oldregs[i][j] = new;
+ tc35892_reg_write(tc35892, regmap[i] + j * 8, new);
+ }
+ }
+
+ mutex_unlock(&tc35892_gpio->irq_lock);
+}
+
+static void tc35892_gpio_irq_mask(unsigned int irq)
+{
+ struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
+ int offset = irq - tc35892_gpio->irq_base;
+ int regoffset = offset / 8;
+ int mask = 1 << (offset % 8);
+
+ tc35892_gpio->regs[REG_IE][regoffset] &= ~mask;
+}
+
+static void tc35892_gpio_irq_unmask(unsigned int irq)
+{
+ struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
+ int offset = irq - tc35892_gpio->irq_base;
+ int regoffset = offset / 8;
+ int mask = 1 << (offset % 8);
+
+ tc35892_gpio->regs[REG_IE][regoffset] |= mask;
+}
+
+static struct irq_chip tc35892_gpio_irq_chip = {
+ .name = "tc35892-gpio",
+ .bus_lock = tc35892_gpio_irq_lock,
+ .bus_sync_unlock = tc35892_gpio_irq_sync_unlock,
+ .mask = tc35892_gpio_irq_mask,
+ .unmask = tc35892_gpio_irq_unmask,
+ .set_type = tc35892_gpio_irq_set_type,
+};
+
+static irqreturn_t tc35892_gpio_irq(int irq, void *dev)
+{
+ struct tc35892_gpio *tc35892_gpio = dev;
+ struct tc35892 *tc35892 = tc35892_gpio->tc35892;
+ u8 status[CACHE_NR_BANKS];
+ int ret;
+ int i;
+
+ ret = tc35892_block_read(tc35892, TC35892_GPIOMIS0,
+ ARRAY_SIZE(status), status);
+ if (ret < 0)
+ return IRQ_NONE;
+
+ for (i = 0; i < ARRAY_SIZE(status); i++) {
+ unsigned int stat = status[i];
+ if (!stat)
+ continue;
+
+ while (stat) {
+ int bit = __ffs(stat);
+ int line = i * 8 + bit;
+
+ handle_nested_irq(tc35892_gpio->irq_base + line);
+ stat &= ~(1 << bit);
+ }
+
+ tc35892_reg_write(tc35892, TC35892_GPIOIC0 + i, status[i]);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int tc35892_gpio_irq_init(struct tc35892_gpio *tc35892_gpio)
+{
+ int base = tc35892_gpio->irq_base;
+ int irq;
+
+ for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
+ set_irq_chip_data(irq, tc35892_gpio);
+ set_irq_chip_and_handler(irq, &tc35892_gpio_irq_chip,
+ handle_simple_irq);
+ set_irq_nested_thread(irq, 1);
+#ifdef CONFIG_ARM
+ set_irq_flags(irq, IRQF_VALID);
+#else
+ set_irq_noprobe(irq);
+#endif
+ }
+
+ return 0;
+}
+
+static void tc35892_gpio_irq_remove(struct tc35892_gpio *tc35892_gpio)
+{
+ int base = tc35892_gpio->irq_base;
+ int irq;
+
+ for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
+#ifdef CONFIG_ARM
+ set_irq_flags(irq, 0);
+#endif
+ set_irq_chip_and_handler(irq, NULL, NULL);
+ set_irq_chip_data(irq, NULL);
+ }
+}
+
+static int __devinit tc35892_gpio_probe(struct platform_device *pdev)
+{
+ struct tc35892 *tc35892 = dev_get_drvdata(pdev->dev.parent);
+ struct tc35892_gpio_platform_data *pdata;
+ struct tc35892_gpio *tc35892_gpio;
+ int ret;
+ int irq;
+
+ pdata = tc35892->pdata->gpio;
+ if (!pdata)
+ return -ENODEV;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ tc35892_gpio = kzalloc(sizeof(struct tc35892_gpio), GFP_KERNEL);
+ if (!tc35892_gpio)
+ return -ENOMEM;
+
+ mutex_init(&tc35892_gpio->irq_lock);
+
+ tc35892_gpio->dev = &pdev->dev;
+ tc35892_gpio->tc35892 = tc35892;
+
+ tc35892_gpio->chip = template_chip;
+ tc35892_gpio->chip.ngpio = tc35892->num_gpio;
+ tc35892_gpio->chip.dev = &pdev->dev;
+ tc35892_gpio->chip.base = pdata->gpio_base;
+
+ tc35892_gpio->irq_base = tc35892->irq_base + TC35892_INT_GPIO(0);
+
+ /* Bring the GPIO module out of reset */
+ ret = tc35892_set_bits(tc35892, TC35892_RSTCTRL,
+ TC35892_RSTCTRL_GPIRST, 0);
+ if (ret < 0)
+ goto out_free;
+
+ ret = tc35892_gpio_irq_init(tc35892_gpio);
+ if (ret)
+ goto out_free;
+
+ ret = request_threaded_irq(irq, NULL, tc35892_gpio_irq, IRQF_ONESHOT,
+ "tc35892-gpio", tc35892_gpio);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
+ goto out_removeirq;
+ }
+
+ ret = gpiochip_add(&tc35892_gpio->chip);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
+ goto out_freeirq;
+ }
+
+ platform_set_drvdata(pdev, tc35892_gpio);
+
+ return 0;
+
+out_freeirq:
+ free_irq(irq, tc35892_gpio);
+out_removeirq:
+ tc35892_gpio_irq_remove(tc35892_gpio);
+out_free:
+ kfree(tc35892_gpio);
+ return ret;
+}
+
+static int __devexit tc35892_gpio_remove(struct platform_device *pdev)
+{
+ struct tc35892_gpio *tc35892_gpio = platform_get_drvdata(pdev);
+ int irq = platform_get_irq(pdev, 0);
+ int ret;
+
+ ret = gpiochip_remove(&tc35892_gpio->chip);
+ if (ret < 0) {
+ dev_err(tc35892_gpio->dev,
+ "unable to remove gpiochip: %d\n", ret);
+ return ret;
+ }
+
+ free_irq(irq, tc35892_gpio);
+ tc35892_gpio_irq_remove(tc35892_gpio);
+
+ platform_set_drvdata(pdev, NULL);
+ kfree(tc35892_gpio);
+
+ return 0;
+}
+
+static struct platform_driver tc35892_gpio_driver = {
+ .driver.name = "tc35892-gpio",
+ .driver.owner = THIS_MODULE,
+ .probe = tc35892_gpio_probe,
+ .remove = __devexit_p(tc35892_gpio_remove),
+};
+
+static int __init tc35892_gpio_init(void)
+{
+ return platform_driver_register(&tc35892_gpio_driver);
+}
+subsys_initcall(tc35892_gpio_init);
+
+static void __exit tc35892_gpio_exit(void)
+{
+ platform_driver_unregister(&tc35892_gpio_driver);
+}
+module_exit(tc35892_gpio_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("TC35892 GPIO driver");
+MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");