gpio: pca953x.c: add interrupt handling capability
Most of the GPIO expanders controlled by the pca953x driver are able to report changes on the input pins through an *INT pin. This patch implements the irq_chip functionality (edge detection only). The driver has been tested on an Arcom Zeus. [akpm@linux-foundation.org: the compiler does inlining for us nowadays] Signed-off-by: Marc Zyngier <maz@misterjones.org> Cc: Eric Miao <eric.y.miao@gmail.com> Cc: Haojian Zhuang <haojian.zhuang@gmail.com> Cc: David Brownell <david-b@pacbell.net> Cc: Nate Case <ncase@xes-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Marc Zyngier
Linus Torvalds
parent
8c35c89aa3
commit
89ea8bbe9c
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@ -134,6 +134,13 @@ config GPIO_PCA953X
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This driver can also be built as a module. If so, the module
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will be called pca953x.
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config GPIO_PCA953X_IRQ
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bool "Interrupt controller support for PCA953x"
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depends on GPIO_PCA953X=y
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help
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Say yes here to enable the pca953x to be used as an interrupt
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controller. It requires the driver to be built in the kernel.
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config GPIO_PCF857X
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tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders"
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depends on I2C
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@ -14,6 +14,8 @@
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/gpio.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/i2c.h>
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#include <linux/i2c/pca953x.h>
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#ifdef CONFIG_OF_GPIO
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@ -26,23 +28,28 @@
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#define PCA953X_INVERT 2
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#define PCA953X_DIRECTION 3
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#define PCA953X_GPIOS 0x00FF
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#define PCA953X_INT 0x0100
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static const struct i2c_device_id pca953x_id[] = {
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{ "pca9534", 8, },
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{ "pca9535", 16, },
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{ "pca9534", 8 | PCA953X_INT, },
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{ "pca9535", 16 | PCA953X_INT, },
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{ "pca9536", 4, },
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{ "pca9537", 4, },
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{ "pca9538", 8, },
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{ "pca9539", 16, },
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{ "pca9554", 8, },
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{ "pca9555", 16, },
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{ "pca9537", 4 | PCA953X_INT, },
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{ "pca9538", 8 | PCA953X_INT, },
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{ "pca9539", 16 | PCA953X_INT, },
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{ "pca9554", 8 | PCA953X_INT, },
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{ "pca9555", 16 | PCA953X_INT, },
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{ "pca9556", 8, },
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{ "pca9557", 8, },
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{ "max7310", 8, },
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{ "max7315", 8, },
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{ "pca6107", 8, },
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{ "tca6408", 8, },
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{ "tca6416", 16, },
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{ "max7312", 16 | PCA953X_INT, },
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{ "max7313", 16 | PCA953X_INT, },
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{ "max7315", 8 | PCA953X_INT, },
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{ "pca6107", 8 | PCA953X_INT, },
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{ "tca6408", 8 | PCA953X_INT, },
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{ "tca6416", 16 | PCA953X_INT, },
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/* NYET: { "tca6424", 24, }, */
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{ }
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};
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@ -53,6 +60,15 @@ struct pca953x_chip {
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uint16_t reg_output;
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uint16_t reg_direction;
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#ifdef CONFIG_GPIO_PCA953X_IRQ
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struct mutex irq_lock;
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uint16_t irq_mask;
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uint16_t irq_stat;
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uint16_t irq_trig_raise;
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uint16_t irq_trig_fall;
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int irq_base;
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#endif
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struct i2c_client *client;
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struct pca953x_platform_data *dyn_pdata;
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struct gpio_chip gpio_chip;
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@ -202,6 +218,210 @@ static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
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gc->names = chip->names;
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}
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#ifdef CONFIG_GPIO_PCA953X_IRQ
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static int pca953x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
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{
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struct pca953x_chip *chip;
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chip = container_of(gc, struct pca953x_chip, gpio_chip);
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return chip->irq_base + off;
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}
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static void pca953x_irq_mask(unsigned int irq)
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{
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struct pca953x_chip *chip = get_irq_chip_data(irq);
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chip->irq_mask &= ~(1 << (irq - chip->irq_base));
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}
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static void pca953x_irq_unmask(unsigned int irq)
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{
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struct pca953x_chip *chip = get_irq_chip_data(irq);
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chip->irq_mask |= 1 << (irq - chip->irq_base);
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}
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static void pca953x_irq_bus_lock(unsigned int irq)
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{
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struct pca953x_chip *chip = get_irq_chip_data(irq);
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mutex_lock(&chip->irq_lock);
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}
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static void pca953x_irq_bus_sync_unlock(unsigned int irq)
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{
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struct pca953x_chip *chip = get_irq_chip_data(irq);
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mutex_unlock(&chip->irq_lock);
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}
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static int pca953x_irq_set_type(unsigned int irq, unsigned int type)
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{
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struct pca953x_chip *chip = get_irq_chip_data(irq);
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uint16_t level = irq - chip->irq_base;
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uint16_t mask = 1 << level;
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if (!(type & IRQ_TYPE_EDGE_BOTH)) {
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dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
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irq, type);
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return -EINVAL;
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}
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if (type & IRQ_TYPE_EDGE_FALLING)
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chip->irq_trig_fall |= mask;
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else
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chip->irq_trig_fall &= ~mask;
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if (type & IRQ_TYPE_EDGE_RISING)
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chip->irq_trig_raise |= mask;
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else
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chip->irq_trig_raise &= ~mask;
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return pca953x_gpio_direction_input(&chip->gpio_chip, level);
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}
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static struct irq_chip pca953x_irq_chip = {
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.name = "pca953x",
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.mask = pca953x_irq_mask,
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.unmask = pca953x_irq_unmask,
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.bus_lock = pca953x_irq_bus_lock,
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.bus_sync_unlock = pca953x_irq_bus_sync_unlock,
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.set_type = pca953x_irq_set_type,
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};
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static uint16_t pca953x_irq_pending(struct pca953x_chip *chip)
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{
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uint16_t cur_stat;
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uint16_t old_stat;
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uint16_t pending;
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uint16_t trigger;
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int ret;
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ret = pca953x_read_reg(chip, PCA953X_INPUT, &cur_stat);
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if (ret)
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return 0;
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/* Remove output pins from the equation */
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cur_stat &= chip->reg_direction;
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old_stat = chip->irq_stat;
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trigger = (cur_stat ^ old_stat) & chip->irq_mask;
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if (!trigger)
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return 0;
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chip->irq_stat = cur_stat;
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pending = (old_stat & chip->irq_trig_fall) |
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(cur_stat & chip->irq_trig_raise);
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pending &= trigger;
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return pending;
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}
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static irqreturn_t pca953x_irq_handler(int irq, void *devid)
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{
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struct pca953x_chip *chip = devid;
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uint16_t pending;
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uint16_t level;
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pending = pca953x_irq_pending(chip);
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if (!pending)
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return IRQ_HANDLED;
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do {
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level = __ffs(pending);
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handle_nested_irq(level + chip->irq_base);
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pending &= ~(1 << level);
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} while (pending);
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return IRQ_HANDLED;
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}
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static int pca953x_irq_setup(struct pca953x_chip *chip,
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const struct i2c_device_id *id)
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{
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struct i2c_client *client = chip->client;
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struct pca953x_platform_data *pdata = client->dev.platform_data;
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int ret;
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if (pdata->irq_base && (id->driver_data & PCA953X_INT)) {
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int lvl;
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ret = pca953x_read_reg(chip, PCA953X_INPUT,
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&chip->irq_stat);
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if (ret)
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goto out_failed;
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/*
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* There is no way to know which GPIO line generated the
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* interrupt. We have to rely on the previous read for
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* this purpose.
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*/
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chip->irq_stat &= chip->reg_direction;
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chip->irq_base = pdata->irq_base;
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mutex_init(&chip->irq_lock);
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for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
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int irq = lvl + chip->irq_base;
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set_irq_chip_data(irq, chip);
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set_irq_chip_and_handler(irq, &pca953x_irq_chip,
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handle_edge_irq);
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set_irq_nested_thread(irq, 1);
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#ifdef CONFIG_ARM
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set_irq_flags(irq, IRQF_VALID);
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#else
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set_irq_noprobe(irq);
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#endif
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}
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ret = request_threaded_irq(client->irq,
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NULL,
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pca953x_irq_handler,
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IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
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dev_name(&client->dev), chip);
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if (ret) {
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dev_err(&client->dev, "failed to request irq %d\n",
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client->irq);
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goto out_failed;
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}
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chip->gpio_chip.to_irq = pca953x_gpio_to_irq;
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}
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return 0;
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out_failed:
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chip->irq_base = 0;
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return ret;
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}
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static void pca953x_irq_teardown(struct pca953x_chip *chip)
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{
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if (chip->irq_base)
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free_irq(chip->client->irq, chip);
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}
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#else /* CONFIG_GPIO_PCA953X_IRQ */
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static int pca953x_irq_setup(struct pca953x_chip *chip,
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const struct i2c_device_id *id)
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{
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struct i2c_client *client = chip->client;
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struct pca953x_platform_data *pdata = client->dev.platform_data;
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if (pdata->irq_base && (id->driver_data & PCA953X_INT))
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dev_warn(&client->dev, "interrupt support not compiled in\n");
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return 0;
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}
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static void pca953x_irq_teardown(struct pca953x_chip *chip)
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{
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}
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#endif
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/*
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* Handlers for alternative sources of platform_data
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*/
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@ -286,7 +506,7 @@ static int __devinit pca953x_probe(struct i2c_client *client,
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/* initialize cached registers from their original values.
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* we can't share this chip with another i2c master.
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*/
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pca953x_setup_gpio(chip, id->driver_data);
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pca953x_setup_gpio(chip, id->driver_data & PCA953X_GPIOS);
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ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
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if (ret)
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@ -301,6 +521,9 @@ static int __devinit pca953x_probe(struct i2c_client *client,
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if (ret)
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goto out_failed;
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ret = pca953x_irq_setup(chip, id);
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if (ret)
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goto out_failed;
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ret = gpiochip_add(&chip->gpio_chip);
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if (ret)
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@ -317,6 +540,7 @@ static int __devinit pca953x_probe(struct i2c_client *client,
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return 0;
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out_failed:
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pca953x_irq_teardown(chip);
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kfree(chip->dyn_pdata);
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kfree(chip);
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return ret;
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@ -345,6 +569,7 @@ static int pca953x_remove(struct i2c_client *client)
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return ret;
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}
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pca953x_irq_teardown(chip);
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kfree(chip->dyn_pdata);
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kfree(chip);
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return 0;
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@ -13,6 +13,9 @@ struct pca953x_platform_data {
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/* initial polarity inversion setting */
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uint16_t invert;
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/* interrupt base */
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int irq_base;
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void *context; /* param to setup/teardown */
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int (*setup)(struct i2c_client *client,
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