*/
struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
{
- if (!desc || !desc->gdev || !desc->gdev->chip)
+ if (!desc || !desc->gdev)
return NULL;
return desc->gdev->chip;
}
* gpiod_get_direction - return the current direction of a GPIO
* @desc: GPIO to get the direction of
*
- * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
+ * Returns 0 for output, 1 for input, or an error code in case of error.
*
* This function may sleep if gpiod_cansleep() is true.
*/
if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
return -EINVAL;
+ /*
+ * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
+ * the hardware actually supports enabling both at the same time the
+ * electrical result would be disastrous.
+ */
+ if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
+ (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
+ return -EINVAL;
+
/* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+ ret = gpiod_set_transitory(desc, false);
+ if (ret < 0)
+ goto out_free_descs;
+
/*
* Lines have to be requested explicitly for input
* or output, else the line will be treated "as is".
* @events: KFIFO for the GPIO events
* @read_lock: mutex lock to protect reads from colliding with adding
* new events to the FIFO
+ * @timestamp: cache for the timestamp storing it between hardirq
+ * and IRQ thread, used to bring the timestamp close to the actual
+ * event
*/
struct lineevent_state {
struct gpio_device *gdev;
wait_queue_head_t wait;
DECLARE_KFIFO(events, struct gpioevent_data, 16);
struct mutex read_lock;
+ u64 timestamp;
};
#define GPIOEVENT_REQUEST_VALID_FLAGS \
struct gpioevent_data ge;
int ret, level;
- ge.timestamp = ktime_get_real_ns();
+ /* Do not leak kernel stack to userspace */
+ memset(&ge, 0, sizeof(ge));
+
+ ge.timestamp = le->timestamp;
level = gpiod_get_value_cansleep(le->desc);
if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
return IRQ_HANDLED;
}
+static irqreturn_t lineevent_irq_handler(int irq, void *p)
+{
+ struct lineevent_state *le = p;
+
+ /*
+ * Just store the timestamp in hardirq context so we get it as
+ * close in time as possible to the actual event.
+ */
+ le->timestamp = ktime_get_real_ns();
+
+ return IRQ_WAKE_THREAD;
+}
+
static int lineevent_create(struct gpio_device *gdev, void __user *ip)
{
struct gpioevent_request eventreq;
/* Request a thread to read the events */
ret = request_threaded_irq(le->irq,
- NULL,
+ lineevent_irq_handler,
lineevent_irq_thread,
irqflags,
le->label,
list_del(&gdev->list);
ida_simple_remove(&gpio_ida, gdev->id);
- kfree(gdev->label);
+ kfree_const(gdev->label);
kfree(gdev->descs);
kfree(gdev);
}
goto err_free_descs;
}
- if (chip->label)
- gdev->label = kstrdup(chip->label, GFP_KERNEL);
- else
- gdev->label = kstrdup("unknown", GFP_KERNEL);
+ gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
if (!gdev->label) {
status = -ENOMEM;
goto err_free_descs;
struct gpio_desc *desc = &gdev->descs[i];
desc->gdev = gdev;
- /*
- * REVISIT: most hardware initializes GPIOs as inputs
- * (often with pullups enabled) so power usage is
- * minimized. Linux code should set the gpio direction
- * first thing; but until it does, and in case
- * chip->get_direction is not set, we may expose the
- * wrong direction in sysfs.
- */
- if (chip->get_direction) {
- /*
- * If we have .get_direction, set up the initial
- * direction flag from the hardware.
- */
- int dir = chip->get_direction(chip, i);
-
- if (!dir)
- set_bit(FLAG_IS_OUT, &desc->flags);
- } else if (!chip->direction_input) {
- /*
- * If the chip lacks the .direction_input callback
- * we logically assume all lines are outputs.
- */
- set_bit(FLAG_IS_OUT, &desc->flags);
- }
+ /* REVISIT: most hardware initializes GPIOs as inputs (often
+ * with pullups enabled) so power usage is minimized. Linux
+ * code should set the gpio direction first thing; but until
+ * it does, and in case chip->get_direction is not set, we may
+ * expose the wrong direction in sysfs.
+ */
+ desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
}
#ifdef CONFIG_PINCTRL
list_del(&gdev->list);
spin_unlock_irqrestore(&gpio_lock, flags);
err_free_label:
- kfree(gdev->label);
+ kfree_const(gdev->label);
err_free_descs:
kfree(gdev->descs);
err_free_gdev:
}
/**
- * devm_gpiochip_add_data() - Resource manager piochip_add_data()
+ * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
* @dev: the device pointer on which irq_chip belongs to.
* @chip: the chip to register, with chip->base initialized
* @data: driver-private data associated with this chip
gpiochip->irq.valid_mask = NULL;
}
-static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
- unsigned int offset)
+bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
+ unsigned int offset)
{
/* No mask means all valid */
if (likely(!gpiochip->irq.valid_mask))
return true;
return test_bit(offset, gpiochip->irq.valid_mask);
}
+EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
/**
* gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
* macro to avoid endless duplication. If the desc is NULL it is an
* optional GPIO and calls should just bail out.
*/
+static int validate_desc(const struct gpio_desc *desc, const char *func)
+{
+ if (!desc)
+ return 0;
+ if (IS_ERR(desc)) {
+ pr_warn("%s: invalid GPIO (errorpointer)\n", func);
+ return PTR_ERR(desc);
+ }
+ if (!desc->gdev) {
+ pr_warn("%s: invalid GPIO (no device)\n", func);
+ return -EINVAL;
+ }
+ if (!desc->gdev->chip) {
+ dev_warn(&desc->gdev->dev,
+ "%s: backing chip is gone\n", func);
+ return 0;
+ }
+ return 1;
+}
+
#define VALIDATE_DESC(desc) do { \
- if (!desc) \
- return 0; \
- if (IS_ERR(desc)) { \
- pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
- return PTR_ERR(desc); \
- } \
- if (!desc->gdev) { \
- pr_warn("%s: invalid GPIO (no device)\n", __func__); \
- return -EINVAL; \
- } \
- if ( !desc->gdev->chip ) { \
- dev_warn(&desc->gdev->dev, \
- "%s: backing chip is gone\n", __func__); \
- return 0; \
- } } while (0)
+ int __valid = validate_desc(desc, __func__); \
+ if (__valid <= 0) \
+ return __valid; \
+ } while (0)
#define VALIDATE_DESC_VOID(desc) do { \
- if (!desc) \
- return; \
- if (IS_ERR(desc)) { \
- pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
- return; \
- } \
- if (!desc->gdev) { \
- pr_warn("%s: invalid GPIO (no device)\n", __func__); \
- return; \
- } \
- if (!desc->gdev->chip) { \
- dev_warn(&desc->gdev->dev, \
- "%s: backing chip is gone\n", __func__); \
+ int __valid = validate_desc(desc, __func__); \
+ if (__valid <= 0) \
return; \
- } } while (0)
-
+ } while (0)
int gpiod_request(struct gpio_desc *desc, const char *label)
{
*/
int gpiod_direction_output(struct gpio_desc *desc, int value)
{
- struct gpio_chip *gc = desc->gdev->chip;
+ struct gpio_chip *gc;
int ret;
VALIDATE_DESC(desc);
return -EIO;
}
+ gc = desc->gdev->chip;
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
/* First see if we can enable open drain in hardware */
ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
}
EXPORT_SYMBOL_GPL(gpiod_set_debounce);
+/**
+ * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
+ * @desc: descriptor of the GPIO for which to configure persistence
+ * @transitory: True to lose state on suspend or reset, false for persistence
+ *
+ * Returns:
+ * 0 on success, otherwise a negative error code.
+ */
+int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
+{
+ struct gpio_chip *chip;
+ unsigned long packed;
+ int gpio;
+ int rc;
+
+ VALIDATE_DESC(desc);
+ /*
+ * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
+ * persistence state.
+ */
+ if (transitory)
+ set_bit(FLAG_TRANSITORY, &desc->flags);
+ else
+ clear_bit(FLAG_TRANSITORY, &desc->flags);
+
+ /* If the driver supports it, set the persistence state now */
+ chip = desc->gdev->chip;
+ if (!chip->set_config)
+ return 0;
+
+ packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
+ !transitory);
+ gpio = gpio_chip_hwgpio(desc);
+ rc = chip->set_config(chip, gpio, packed);
+ if (rc == -ENOTSUPP) {
+ dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
+ gpio);
+ return 0;
+ }
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gpiod_set_transitory);
+
/**
* gpiod_is_active_low - test whether a GPIO is active-low or not
* @desc: the gpio descriptor to test
if (offset >= chip->ngpio)
return false;
- return !test_bit(FLAG_SLEEP_MAY_LOSE_VALUE,
- &chip->gpiodev->descs[offset].flags);
+ return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
if (lflags & GPIO_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
- if (lflags & GPIO_SLEEP_MAY_LOSE_VALUE)
- set_bit(FLAG_SLEEP_MAY_LOSE_VALUE, &desc->flags);
+
+ status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
+ if (status < 0)
+ return status;
/* No particular flag request, return here... */
if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
struct gpio_desc *desc = NULL;
int status;
enum gpio_lookup_flags lookupflags = 0;
+ /* Maybe we have a device name, maybe not */
+ const char *devname = dev ? dev_name(dev) : "?";
dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
return desc;
}
- status = gpiod_request(desc, con_id);
+ /*
+ * If a connection label was passed use that, else attempt to use
+ * the device name as label
+ */
+ status = gpiod_request(desc, con_id ? con_id : devname);
if (status < 0)
return ERR_PTR(status);
}
EXPORT_SYMBOL_GPL(gpiod_get_index);
+/**
+ * gpiod_get_from_of_node() - obtain a GPIO from an OF node
+ * @node: handle of the OF node
+ * @propname: name of the DT property representing the GPIO
+ * @index: index of the GPIO to obtain for the consumer
+ * @dflags: GPIO initialization flags
+ * @label: label to attach to the requested GPIO
+ *
+ * Returns:
+ * On successful request the GPIO pin is configured in accordance with
+ * provided @dflags. If the node does not have the requested GPIO
+ * property, NULL is returned.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
+ const char *propname, int index,
+ enum gpiod_flags dflags,
+ const char *label)
+{
+ struct gpio_desc *desc;
+ unsigned long lflags = 0;
+ enum of_gpio_flags flags;
+ bool active_low = false;
+ bool single_ended = false;
+ bool open_drain = false;
+ bool transitory = false;
+ int ret;
+
+ desc = of_get_named_gpiod_flags(node, propname,
+ index, &flags);
+
+ if (!desc || IS_ERR(desc)) {
+ /* If it is not there, just return NULL */
+ if (PTR_ERR(desc) == -ENOENT)
+ return NULL;
+ return desc;
+ }
+
+ active_low = flags & OF_GPIO_ACTIVE_LOW;
+ single_ended = flags & OF_GPIO_SINGLE_ENDED;
+ open_drain = flags & OF_GPIO_OPEN_DRAIN;
+ transitory = flags & OF_GPIO_TRANSITORY;
+
+ ret = gpiod_request(desc, label);
+ if (ret)
+ return ERR_PTR(ret);
+
+ if (active_low)
+ lflags |= GPIO_ACTIVE_LOW;
+
+ if (single_ended) {
+ if (open_drain)
+ lflags |= GPIO_OPEN_DRAIN;
+ else
+ lflags |= GPIO_OPEN_SOURCE;
+ }
+
+ if (transitory)
+ lflags |= GPIO_TRANSITORY;
+
+ ret = gpiod_configure_flags(desc, propname, lflags, dflags);
+ if (ret < 0) {
+ gpiod_put(desc);
+ return ERR_PTR(ret);
+ }
+
+ return desc;
+}
+EXPORT_SYMBOL(gpiod_get_from_of_node);
+
/**
* fwnode_get_named_gpiod - obtain a GPIO from firmware node
* @fwnode: handle of the firmware node
* @propname: name of the firmware property representing the GPIO
- * @index: index of the GPIO to obtain in the consumer
+ * @index: index of the GPIO to obtain for the consumer
* @dflags: GPIO initialization flags
* @label: label to attach to the requested GPIO
*
* This function can be used for drivers that get their configuration
- * from firmware.
+ * from opaque firmware.
*
- * Function properly finds the corresponding GPIO using whatever is the
+ * The function properly finds the corresponding GPIO using whatever is the
* underlying firmware interface and then makes sure that the GPIO
* descriptor is requested before it is returned to the caller.
*
{
struct gpio_desc *desc = ERR_PTR(-ENODEV);
unsigned long lflags = 0;
- bool active_low = false;
- bool single_ended = false;
- bool open_drain = false;
int ret;
if (!fwnode)
return ERR_PTR(-EINVAL);
if (is_of_node(fwnode)) {
- enum of_gpio_flags flags;
-
- desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname,
- index, &flags);
- if (!IS_ERR(desc)) {
- active_low = flags & OF_GPIO_ACTIVE_LOW;
- single_ended = flags & OF_GPIO_SINGLE_ENDED;
- open_drain = flags & OF_GPIO_OPEN_DRAIN;
- }
+ desc = gpiod_get_from_of_node(to_of_node(fwnode),
+ propname, index,
+ dflags,
+ label);
+ return desc;
} else if (is_acpi_node(fwnode)) {
struct acpi_gpio_info info;
desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
- if (!IS_ERR(desc)) {
- active_low = info.polarity == GPIO_ACTIVE_LOW;
- ret = acpi_gpio_update_gpiod_flags(&dflags, info.flags);
- if (ret)
- pr_debug("Override GPIO initialization flags\n");
- }
- }
+ if (IS_ERR(desc))
+ return desc;
- if (IS_ERR(desc))
- return desc;
+ acpi_gpio_update_gpiod_flags(&dflags, &info);
+ if (info.polarity == GPIO_ACTIVE_LOW)
+ lflags |= GPIO_ACTIVE_LOW;
+ }
+
+ /* Currently only ACPI takes this path */
ret = gpiod_request(desc, label);
if (ret)
return ERR_PTR(ret);
- if (active_low)
- lflags |= GPIO_ACTIVE_LOW;
-
- if (single_ended) {
- if (open_drain)
- lflags |= GPIO_OPEN_DRAIN;
- else
- lflags |= GPIO_OPEN_SOURCE;
- }
-
ret = gpiod_configure_flags(desc, propname, lflags, dflags);
if (ret < 0) {
gpiod_put(desc);
projects / linux-2.6-microblaze.git / blobdiff