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path: root/drivers/gpio/gpiolib.c
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Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c151
1 files changed, 84 insertions, 67 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 4e51fe3c1fc4..21da9c19a0cb 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -8,6 +8,7 @@
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/gpio.h>
+#include <linux/of_gpio.h>
#include <linux/idr.h>
#include <linux/slab.h>
@@ -56,9 +57,9 @@ struct gpio_desc {
#define FLAG_TRIG_RISE 6 /* trigger on rising edge */
#define FLAG_ACTIVE_LOW 7 /* sysfs value has active low */
-#define PDESC_ID_SHIFT 16 /* add new flags before this one */
+#define ID_SHIFT 16 /* add new flags before this one */
-#define GPIO_FLAGS_MASK ((1 << PDESC_ID_SHIFT) - 1)
+#define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1)
#define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
#ifdef CONFIG_DEBUG_FS
@@ -68,12 +69,7 @@ struct gpio_desc {
static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];
#ifdef CONFIG_GPIO_SYSFS
-struct poll_desc {
- struct work_struct work;
- struct sysfs_dirent *value_sd;
-};
-
-static struct idr pdesc_idr;
+static DEFINE_IDR(dirent_idr);
#endif
static inline void desc_set_label(struct gpio_desc *d, const char *label)
@@ -324,24 +320,16 @@ static const DEVICE_ATTR(value, 0644,
static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
{
- struct work_struct *work = priv;
+ struct sysfs_dirent *value_sd = priv;
- schedule_work(work);
+ sysfs_notify_dirent(value_sd);
return IRQ_HANDLED;
}
-static void gpio_notify_sysfs(struct work_struct *work)
-{
- struct poll_desc *pdesc;
-
- pdesc = container_of(work, struct poll_desc, work);
- sysfs_notify_dirent(pdesc->value_sd);
-}
-
static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
unsigned long gpio_flags)
{
- struct poll_desc *pdesc;
+ struct sysfs_dirent *value_sd;
unsigned long irq_flags;
int ret, irq, id;
@@ -352,18 +340,16 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
if (irq < 0)
return -EIO;
- id = desc->flags >> PDESC_ID_SHIFT;
- pdesc = idr_find(&pdesc_idr, id);
- if (pdesc) {
- free_irq(irq, &pdesc->work);
- cancel_work_sync(&pdesc->work);
- }
+ id = desc->flags >> ID_SHIFT;
+ value_sd = idr_find(&dirent_idr, id);
+ if (value_sd)
+ free_irq(irq, value_sd);
desc->flags &= ~GPIO_TRIGGER_MASK;
if (!gpio_flags) {
ret = 0;
- goto free_sd;
+ goto free_id;
}
irq_flags = IRQF_SHARED;
@@ -374,55 +360,46 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
- if (!pdesc) {
- pdesc = kmalloc(sizeof(*pdesc), GFP_KERNEL);
- if (!pdesc) {
- ret = -ENOMEM;
+ if (!value_sd) {
+ value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value");
+ if (!value_sd) {
+ ret = -ENODEV;
goto err_out;
}
do {
ret = -ENOMEM;
- if (idr_pre_get(&pdesc_idr, GFP_KERNEL))
- ret = idr_get_new_above(&pdesc_idr,
- pdesc, 1, &id);
+ if (idr_pre_get(&dirent_idr, GFP_KERNEL))
+ ret = idr_get_new_above(&dirent_idr, value_sd,
+ 1, &id);
} while (ret == -EAGAIN);
if (ret)
- goto free_mem;
+ goto free_sd;
desc->flags &= GPIO_FLAGS_MASK;
- desc->flags |= (unsigned long)id << PDESC_ID_SHIFT;
+ desc->flags |= (unsigned long)id << ID_SHIFT;
- if (desc->flags >> PDESC_ID_SHIFT != id) {
+ if (desc->flags >> ID_SHIFT != id) {
ret = -ERANGE;
goto free_id;
}
-
- pdesc->value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value");
- if (!pdesc->value_sd) {
- ret = -ENODEV;
- goto free_id;
- }
- INIT_WORK(&pdesc->work, gpio_notify_sysfs);
}
- ret = request_irq(irq, gpio_sysfs_irq, irq_flags,
- "gpiolib", &pdesc->work);
- if (ret)
- goto free_sd;
+ ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
+ "gpiolib", value_sd);
+ if (ret < 0)
+ goto free_id;
desc->flags |= gpio_flags;
return 0;
-free_sd:
- if (pdesc)
- sysfs_put(pdesc->value_sd);
free_id:
- idr_remove(&pdesc_idr, id);
+ idr_remove(&dirent_idr, id);
desc->flags &= GPIO_FLAGS_MASK;
-free_mem:
- kfree(pdesc);
+free_sd:
+ if (value_sd)
+ sysfs_put(value_sd);
err_out:
return ret;
}
@@ -993,8 +970,6 @@ static int __init gpiolib_sysfs_init(void)
unsigned long flags;
unsigned gpio;
- idr_init(&pdesc_idr);
-
status = class_register(&gpio_class);
if (status < 0)
return status;
@@ -1100,16 +1075,24 @@ int gpiochip_add(struct gpio_chip *chip)
}
}
+ of_gpiochip_add(chip);
+
unlock:
spin_unlock_irqrestore(&gpio_lock, flags);
- if (status == 0)
- status = gpiochip_export(chip);
+
+ if (status)
+ goto fail;
+
+ status = gpiochip_export(chip);
+ if (status)
+ goto fail;
+
+ return 0;
fail:
/* failures here can mean systems won't boot... */
- if (status)
- pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n",
- chip->base, chip->base + chip->ngpio - 1,
- chip->label ? : "generic");
+ pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n",
+ chip->base, chip->base + chip->ngpio - 1,
+ chip->label ? : "generic");
return status;
}
EXPORT_SYMBOL_GPL(gpiochip_add);
@@ -1128,6 +1111,8 @@ int gpiochip_remove(struct gpio_chip *chip)
spin_lock_irqsave(&gpio_lock, flags);
+ of_gpiochip_remove(chip);
+
for (id = chip->base; id < chip->base + chip->ngpio; id++) {
if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) {
status = -EBUSY;
@@ -1148,6 +1133,38 @@ int gpiochip_remove(struct gpio_chip *chip)
}
EXPORT_SYMBOL_GPL(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_chip *chip = NULL;
+ unsigned long flags;
+ int i;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+ for (i = 0; i < ARCH_NR_GPIOS; i++) {
+ if (!gpio_desc[i].chip)
+ continue;
+
+ if (match(gpio_desc[i].chip, data)) {
+ chip = gpio_desc[i].chip;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ return chip;
+}
/* These "optional" allocation calls help prevent drivers from stomping
* on each other, and help provide better diagnostics in debugfs.
@@ -1229,7 +1246,7 @@ void gpio_free(unsigned gpio)
if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
if (chip->free) {
spin_unlock_irqrestore(&gpio_lock, flags);
- might_sleep_if(extra_checks && chip->can_sleep);
+ might_sleep_if(chip->can_sleep);
chip->free(chip, gpio - chip->base);
spin_lock_irqsave(&gpio_lock, flags);
}
@@ -1367,7 +1384,7 @@ int gpio_direction_input(unsigned gpio)
spin_unlock_irqrestore(&gpio_lock, flags);
- might_sleep_if(extra_checks && chip->can_sleep);
+ might_sleep_if(chip->can_sleep);
if (status) {
status = chip->request(chip, gpio);
@@ -1420,7 +1437,7 @@ int gpio_direction_output(unsigned gpio, int value)
spin_unlock_irqrestore(&gpio_lock, flags);
- might_sleep_if(extra_checks && chip->can_sleep);
+ might_sleep_if(chip->can_sleep);
if (status) {
status = chip->request(chip, gpio);
@@ -1478,7 +1495,7 @@ int gpio_set_debounce(unsigned gpio, unsigned debounce)
spin_unlock_irqrestore(&gpio_lock, flags);
- might_sleep_if(extra_checks && chip->can_sleep);
+ might_sleep_if(chip->can_sleep);
return chip->set_debounce(chip, gpio, debounce);
@@ -1528,7 +1545,7 @@ int __gpio_get_value(unsigned gpio)
struct gpio_chip *chip;
chip = gpio_to_chip(gpio);
- WARN_ON(extra_checks && chip->can_sleep);
+ WARN_ON(chip->can_sleep);
return chip->get ? chip->get(chip, gpio - chip->base) : 0;
}
EXPORT_SYMBOL_GPL(__gpio_get_value);
@@ -1547,7 +1564,7 @@ void __gpio_set_value(unsigned gpio, int value)
struct gpio_chip *chip;
chip = gpio_to_chip(gpio);
- WARN_ON(extra_checks && chip->can_sleep);
+ WARN_ON(chip->can_sleep);
chip->set(chip, gpio - chip->base, value);
}
EXPORT_SYMBOL_GPL(__gpio_set_value);