#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>
/* Optional implementation infrastructure for GPIO interfaces.
#define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control */
#define FLAG_TRIG_FALL 5 /* trigger on falling edge */
#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
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)
* * configures behavior of poll(2) on /value
* * available only if pin can generate IRQs on input
* * is read/write as "none", "falling", "rising", or "both"
+ * /active_low
+ * * configures polarity of /value
+ * * is read/write as zero/nonzero
+ * * also affects existing and subsequent "falling" and "rising"
+ * /edge configuration
*/
static ssize_t gpio_direction_show(struct device *dev,
return status ? : size;
}
-static const DEVICE_ATTR(direction, 0644,
+static /* const */ DEVICE_ATTR(direction, 0644,
gpio_direction_show, gpio_direction_store);
static ssize_t gpio_value_show(struct device *dev,
mutex_lock(&sysfs_lock);
- if (!test_bit(FLAG_EXPORT, &desc->flags))
+ if (!test_bit(FLAG_EXPORT, &desc->flags)) {
status = -EIO;
- else
- status = sprintf(buf, "%d\n", !!gpio_get_value_cansleep(gpio));
+ } else {
+ int value;
+
+ value = !!gpio_get_value_cansleep(gpio);
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+
+ status = sprintf(buf, "%d\n", value);
+ }
mutex_unlock(&sysfs_lock);
return status;
status = strict_strtol(buf, 0, &value);
if (status == 0) {
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
gpio_set_value_cansleep(gpio, value != 0);
status = size;
}
return status;
}
-static /*const*/ DEVICE_ATTR(value, 0644,
+static const DEVICE_ATTR(value, 0644,
gpio_value_show, gpio_value_store);
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;
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;
if (test_bit(FLAG_TRIG_FALL, &gpio_flags))
- irq_flags |= IRQF_TRIGGER_FALLING;
+ irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
+ IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
if (test_bit(FLAG_TRIG_RISE, &gpio_flags))
- irq_flags |= IRQF_TRIGGER_RISING;
+ 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, "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:
- 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;
}
static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
+static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
+ int value)
+{
+ int status = 0;
+
+ if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value)
+ return 0;
+
+ if (value)
+ set_bit(FLAG_ACTIVE_LOW, &desc->flags);
+ else
+ clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
+
+ /* reconfigure poll(2) support if enabled on one edge only */
+ if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^
+ !!test_bit(FLAG_TRIG_FALL, &desc->flags))) {
+ unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK;
+
+ gpio_setup_irq(desc, dev, 0);
+ status = gpio_setup_irq(desc, dev, trigger_flags);
+ }
+
+ return status;
+}
+
+static ssize_t gpio_active_low_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ const struct gpio_desc *desc = dev_get_drvdata(dev);
+ ssize_t status;
+
+ mutex_lock(&sysfs_lock);
+
+ if (!test_bit(FLAG_EXPORT, &desc->flags))
+ status = -EIO;
+ else
+ status = sprintf(buf, "%d\n",
+ !!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
+
+ mutex_unlock(&sysfs_lock);
+
+ return status;
+}
+
+static ssize_t gpio_active_low_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct gpio_desc *desc = dev_get_drvdata(dev);
+ ssize_t status;
+
+ mutex_lock(&sysfs_lock);
+
+ if (!test_bit(FLAG_EXPORT, &desc->flags)) {
+ status = -EIO;
+ } else {
+ long value;
+
+ status = strict_strtol(buf, 0, &value);
+ if (status == 0)
+ status = sysfs_set_active_low(desc, dev, value != 0);
+ }
+
+ mutex_unlock(&sysfs_lock);
+
+ return status ? : size;
+}
+
+static const DEVICE_ATTR(active_low, 0644,
+ gpio_active_low_show, gpio_active_low_store);
+
static const struct attribute *gpio_attrs[] = {
- &dev_attr_direction.attr,
&dev_attr_value.attr,
+ &dev_attr_active_low.attr,
NULL,
};
* /sys/class/gpio/unexport ... write-only
* integer N ... number of GPIO to unexport
*/
-static ssize_t export_store(struct class *class, const char *buf, size_t len)
+static ssize_t export_store(struct class *class,
+ struct class_attribute *attr,
+ const char *buf, size_t len)
{
long gpio;
int status;
return status ? : len;
}
-static ssize_t unexport_store(struct class *class, const char *buf, size_t len)
+static ssize_t unexport_store(struct class *class,
+ struct class_attribute *attr,
+ const char *buf, size_t len)
{
long gpio;
int status;
unsigned long flags;
struct gpio_desc *desc;
int status = -EINVAL;
- char *ioname = NULL;
+ const char *ioname = NULL;
/* can't export until sysfs is available ... */
if (!gpio_class.p) {
struct device *dev;
dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
- desc, ioname ? ioname : "gpio%d", gpio);
+ desc, ioname ? ioname : "gpio%u", gpio);
if (!IS_ERR(dev)) {
- if (direction_may_change)
- status = sysfs_create_group(&dev->kobj,
+ status = sysfs_create_group(&dev->kobj,
&gpio_attr_group);
- else
+
+ if (!status && direction_may_change)
status = device_create_file(dev,
- &dev_attr_value);
+ &dev_attr_direction);
if (!status && gpio_to_irq(gpio) >= 0
&& (direction_may_change
}
EXPORT_SYMBOL_GPL(gpio_export_link);
+
+/**
+ * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value
+ * @gpio: gpio to change
+ * @value: non-zero to use active low, i.e. inverted values
+ *
+ * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute.
+ * The GPIO does not have to be exported yet. If poll(2) support has
+ * been enabled for either rising or falling edge, it will be
+ * reconfigured to follow the new polarity.
+ *
+ * Returns zero on success, else an error.
+ */
+int gpio_sysfs_set_active_low(unsigned gpio, int value)
+{
+ struct gpio_desc *desc;
+ struct device *dev = NULL;
+ int status = -EINVAL;
+
+ if (!gpio_is_valid(gpio))
+ goto done;
+
+ mutex_lock(&sysfs_lock);
+
+ desc = &gpio_desc[gpio];
+
+ if (test_bit(FLAG_EXPORT, &desc->flags)) {
+ dev = class_find_device(&gpio_class, NULL, desc, match_export);
+ if (dev == NULL) {
+ status = -ENODEV;
+ goto unlock;
+ }
+ }
+
+ status = sysfs_set_active_low(desc, dev, value);
+
+unlock:
+ mutex_unlock(&sysfs_lock);
+
+done:
+ if (status)
+ pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low);
+
/**
* gpio_unexport - reverse effect of gpio_export()
* @gpio: gpio to make unavailable
void gpio_unexport(unsigned gpio)
{
struct gpio_desc *desc;
- int status = -EINVAL;
+ int status = 0;
- if (!gpio_is_valid(gpio))
+ if (!gpio_is_valid(gpio)) {
+ status = -EINVAL;
goto done;
+ }
mutex_lock(&sysfs_lock);
clear_bit(FLAG_EXPORT, &desc->flags);
put_device(dev);
device_unregister(dev);
- status = 0;
} else
status = -ENODEV;
}
unsigned long flags;
unsigned gpio;
- idr_init(&pdesc_idr);
-
status = class_register(&gpio_class);
if (status < 0)
return status;
}
}
+ 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) not registered\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);
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;
}
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.
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);
}
desc_set_label(desc, NULL);
module_put(desc->chip->owner);
+ clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
clear_bit(FLAG_REQUESTED, &desc->flags);
} else
WARN_ON(extra_checks);
}
EXPORT_SYMBOL_GPL(gpio_free);
+/**
+ * gpio_request_one - request a single GPIO with initial configuration
+ * @gpio: the GPIO number
+ * @flags: GPIO configuration as specified by GPIOF_*
+ * @label: a literal description string of this GPIO
+ */
+int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
+{
+ int err;
+
+ err = gpio_request(gpio, label);
+ if (err)
+ return err;
+
+ if (flags & GPIOF_DIR_IN)
+ err = gpio_direction_input(gpio);
+ else
+ err = gpio_direction_output(gpio,
+ (flags & GPIOF_INIT_HIGH) ? 1 : 0);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(gpio_request_one);
+
+/**
+ * gpio_request_array - request multiple GPIOs in a single call
+ * @array: array of the 'struct gpio'
+ * @num: how many GPIOs in the array
+ */
+int gpio_request_array(struct gpio *array, size_t num)
+{
+ int i, err;
+
+ for (i = 0; i < num; i++, array++) {
+ err = gpio_request_one(array->gpio, array->flags, array->label);
+ if (err)
+ goto err_free;
+ }
+ return 0;
+
+err_free:
+ while (i--)
+ gpio_free((--array)->gpio);
+ return err;
+}
+EXPORT_SYMBOL_GPL(gpio_request_array);
+
+/**
+ * gpio_free_array - release multiple GPIOs in a single call
+ * @array: array of the 'struct gpio'
+ * @num: how many GPIOs in the array
+ */
+void gpio_free_array(struct gpio *array, size_t num)
+{
+ while (num--)
+ gpio_free((array++)->gpio);
+}
+EXPORT_SYMBOL_GPL(gpio_free_array);
/**
* gpiochip_is_requested - return string iff signal was requested
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);
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);
goto lose;
}
}
- if(chip->pull_updown)
- {
- status = chip->pull_updown(chip, gpio,value);
- if (status == 0)
- clear_bit(FLAG_IS_OUT, &desc->flags);
- }
+ status = chip->pull_updown(chip, gpio,value);
+ if (status == 0)
+ clear_bit(FLAG_IS_OUT, &desc->flags);
lose:
return status;
}
EXPORT_SYMBOL_GPL(gpio_pull_updown);
+/**
+ * gpio_set_debounce - sets @debounce time for a @gpio
+ * @gpio: the gpio to set debounce time
+ * @debounce: debounce time is microseconds
+ */
+int gpio_set_debounce(unsigned gpio, unsigned debounce)
+{
+ unsigned long flags;
+ struct gpio_chip *chip;
+ struct gpio_desc *desc = &gpio_desc[gpio];
+ int status = -EINVAL;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ if (!gpio_is_valid(gpio))
+ goto fail;
+ chip = desc->chip;
+ if (!chip || !chip->set || !chip->set_debounce)
+ goto fail;
+ gpio -= chip->base;
+ if (gpio >= chip->ngpio)
+ goto fail;
+ status = gpio_ensure_requested(desc, gpio);
+ if (status < 0)
+ goto fail;
+
+ /* now we know the gpio is valid and chip won't vanish */
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ might_sleep_if(chip->can_sleep);
+
+ return chip->set_debounce(chip, gpio, debounce);
+
+fail:
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ if (status)
+ pr_debug("%s: gpio-%d status %d\n",
+ __func__, gpio, status);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(gpio_set_debounce);
/* I/O calls are only valid after configuration completed; the relevant
* "is this a valid GPIO" error checks should already have been done.
if (!gpio_is_valid(gpio))
return -1;
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);
if (!gpio_is_valid(gpio))
return;
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);
projects / firefly-linux-kernel-4.4.55.git / blobdiff