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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 13:00:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 13:00:56 -0800
commitb0885d01f9ab1274109c02942c881d598f939623 (patch)
tree8c0e33fa141f2732a5c8e0e2db8b457d5cd865f9 /drivers/gpio/gpiolib.c
parentbad73c5aa069f1f14cc07ce7bbae8d463635560c (diff)
parentfc13d5a5b17c657b7682c145d367dcb859c507d9 (diff)
Merge tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6
Pull GPIO updates from Grant Likely: "GPIO follow up patch and type change for v3.5 merge window Primarily device driver additions, features and bug fixes. Not much touching gpio common subsystem support. Should not be scary." * tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6: (34 commits) gpio: Provide the STMPE GPIO driver with its own IRQ Domain gpio: add TS-5500 DIO blocks support gpio: pcf857x: use client->irq for gpio_to_irq() gpio: stmpe: Add DT support for stmpe gpio gpio: pl061 depends on ARM gpio/pl061: remove old comment gpio: SPEAr: add spi chipselect control driver gpio: gpio-max710x: Support device tree probing gpio: twl4030: Use only TWL4030_MODULE_LED for LED configuration gpio: tegra: read output value when gpio is set in direction_out gpio: pca953x: Add compatible strings to gpio-pca953x driver gpio: pca953x: Register an IRQ domain gpio: mvebu: Set free callback for gpio_chip gpio: tegra: Drop exporting static functions gpio: tegra: Staticize non-exported symbols gpio: tegra: fix suspend/resume apis gpio-pch: Set parent dev for gpio chip gpio: em: Fix build errors GPIO: clps711x: use platform_device_unregister in gpio_clps711x_init() gpio/tc3589x: convert to use the simple irqdomain ...
Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c124
1 files changed, 84 insertions, 40 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 58b9838801c..199fca15f27 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -191,6 +191,32 @@ err:
return ret;
}
+/* caller ensures gpio is valid and requested, chip->get_direction may sleep */
+static int gpio_get_direction(unsigned gpio)
+{
+ struct gpio_chip *chip;
+ struct gpio_desc *desc = &gpio_desc[gpio];
+ int status = -EINVAL;
+
+ chip = gpio_to_chip(gpio);
+ gpio -= chip->base;
+
+ if (!chip->get_direction)
+ return status;
+
+ status = chip->get_direction(chip, gpio);
+ if (status > 0) {
+ /* GPIOF_DIR_IN, or other positive */
+ status = 1;
+ clear_bit(FLAG_IS_OUT, &desc->flags);
+ }
+ if (status == 0) {
+ /* GPIOF_DIR_OUT */
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ }
+ return status;
+}
+
#ifdef CONFIG_GPIO_SYSFS
/* lock protects against unexport_gpio() being called while
@@ -223,6 +249,7 @@ static ssize_t gpio_direction_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
const struct gpio_desc *desc = dev_get_drvdata(dev);
+ unsigned gpio = desc - gpio_desc;
ssize_t status;
mutex_lock(&sysfs_lock);
@@ -230,6 +257,7 @@ static ssize_t gpio_direction_show(struct device *dev,
if (!test_bit(FLAG_EXPORT, &desc->flags))
status = -EIO;
else
+ gpio_get_direction(gpio);
status = sprintf(buf, "%s\n",
test_bit(FLAG_IS_OUT, &desc->flags)
? "out" : "in");
@@ -704,8 +732,9 @@ int gpio_export(unsigned gpio, bool direction_may_change)
{
unsigned long flags;
struct gpio_desc *desc;
- int status = -EINVAL;
+ int status;
const char *ioname = NULL;
+ struct device *dev;
/* can't export until sysfs is available ... */
if (!gpio_class.p) {
@@ -713,59 +742,66 @@ int gpio_export(unsigned gpio, bool direction_may_change)
return -ENOENT;
}
- if (!gpio_is_valid(gpio))
- goto done;
+ if (!gpio_is_valid(gpio)) {
+ pr_debug("%s: gpio %d is not valid\n", __func__, gpio);
+ return -EINVAL;
+ }
mutex_lock(&sysfs_lock);
spin_lock_irqsave(&gpio_lock, flags);
desc = &gpio_desc[gpio];
- if (test_bit(FLAG_REQUESTED, &desc->flags)
- && !test_bit(FLAG_EXPORT, &desc->flags)) {
- status = 0;
- if (!desc->chip->direction_input
- || !desc->chip->direction_output)
- direction_may_change = false;
+ if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
+ test_bit(FLAG_EXPORT, &desc->flags)) {
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ pr_debug("%s: gpio %d unavailable (requested=%d, exported=%d)\n",
+ __func__, gpio,
+ test_bit(FLAG_REQUESTED, &desc->flags),
+ test_bit(FLAG_EXPORT, &desc->flags));
+ status = -EPERM;
+ goto fail_unlock;
}
+
+ if (!desc->chip->direction_input || !desc->chip->direction_output)
+ direction_may_change = false;
spin_unlock_irqrestore(&gpio_lock, flags);
if (desc->chip->names && desc->chip->names[gpio - desc->chip->base])
ioname = desc->chip->names[gpio - desc->chip->base];
- if (status == 0) {
- struct device *dev;
-
- dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
- desc, ioname ? ioname : "gpio%u", gpio);
- if (!IS_ERR(dev)) {
- status = sysfs_create_group(&dev->kobj,
- &gpio_attr_group);
-
- if (!status && direction_may_change)
- status = device_create_file(dev,
- &dev_attr_direction);
-
- if (!status && gpio_to_irq(gpio) >= 0
- && (direction_may_change
- || !test_bit(FLAG_IS_OUT,
- &desc->flags)))
- status = device_create_file(dev,
- &dev_attr_edge);
-
- if (status != 0)
- device_unregister(dev);
- } else
- status = PTR_ERR(dev);
- if (status == 0)
- set_bit(FLAG_EXPORT, &desc->flags);
+ dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
+ desc, ioname ? ioname : "gpio%u", gpio);
+ if (IS_ERR(dev)) {
+ status = PTR_ERR(dev);
+ goto fail_unlock;
}
- mutex_unlock(&sysfs_lock);
-
-done:
+ status = sysfs_create_group(&dev->kobj, &gpio_attr_group);
if (status)
- pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
+ goto fail_unregister_device;
+ if (direction_may_change) {
+ status = device_create_file(dev, &dev_attr_direction);
+ if (status)
+ goto fail_unregister_device;
+ }
+
+ if (gpio_to_irq(gpio) >= 0 && (direction_may_change ||
+ !test_bit(FLAG_IS_OUT, &desc->flags))) {
+ status = device_create_file(dev, &dev_attr_edge);
+ if (status)
+ goto fail_unregister_device;
+ }
+
+ set_bit(FLAG_EXPORT, &desc->flags);
+ mutex_unlock(&sysfs_lock);
+ return 0;
+
+fail_unregister_device:
+ device_unregister(dev);
+fail_unlock:
+ mutex_unlock(&sysfs_lock);
+ pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
return status;
}
EXPORT_SYMBOL_GPL(gpio_export);
@@ -1075,6 +1111,7 @@ int gpiochip_add(struct gpio_chip *chip)
* 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.
*/
gpio_desc[id].flags = !chip->direction_input
@@ -1304,9 +1341,15 @@ int gpio_request(unsigned gpio, const char *label)
desc_set_label(desc, NULL);
module_put(chip->owner);
clear_bit(FLAG_REQUESTED, &desc->flags);
+ goto done;
}
}
-
+ if (chip->get_direction) {
+ /* chip->get_direction may sleep */
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ gpio_get_direction(gpio);
+ spin_lock_irqsave(&gpio_lock, flags);
+ }
done:
if (status)
pr_debug("gpio_request: gpio-%d (%s) status %d\n",
@@ -1842,6 +1885,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
continue;
+ gpio_get_direction(gpio);
is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
seq_printf(s, " gpio-%-3d (%-20.20s) %s %s",
gpio, gdesc->label,