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);