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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.c173
1 files changed, 123 insertions, 50 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 996a73390..be74bd370 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -20,6 +20,7 @@
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
+#include <linux/compat.h>
#include <uapi/linux/gpio.h>
#include "gpiolib.h"
@@ -316,7 +317,7 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct gpio_device *gdev = filp->private_data;
struct gpio_chip *chip = gdev->chip;
- int __user *ip = (int __user *)arg;
+ void __user *ip = (void __user *)arg;
/* We fail any subsequent ioctl():s when the chip is gone */
if (!chip)
@@ -388,6 +389,14 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return -EINVAL;
}
+#ifdef CONFIG_COMPAT
+static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
/**
* gpio_chrdev_open() - open the chardev for ioctl operations
* @inode: inode for this chardev
@@ -431,7 +440,9 @@ static const struct file_operations gpio_fileops = {
.owner = THIS_MODULE,
.llseek = noop_llseek,
.unlocked_ioctl = gpio_ioctl,
- .compat_ioctl = gpio_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = gpio_ioctl_compat,
+#endif
};
static void gpiodevice_release(struct device *dev)
@@ -616,21 +627,38 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
goto err_free_label;
}
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
for (i = 0; i < chip->ngpio; i++) {
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.
+ /*
+ * 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;
- }
- spin_unlock_irqrestore(&gpio_lock, flags);
+ 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);
+ }
+ }
#ifdef CONFIG_PINCTRL
INIT_LIST_HEAD(&gdev->pin_ranges);
@@ -1552,8 +1580,8 @@ EXPORT_SYMBOL_GPL(gpiod_direction_input);
static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
- struct gpio_chip *chip;
- int status = -EINVAL;
+ struct gpio_chip *gc = desc->gdev->chip;
+ int ret;
/* GPIOs used for IRQs shall not be set as output */
if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
@@ -1563,28 +1591,50 @@ static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
return -EIO;
}
- /* Open drain pin should not be driven to 1 */
- if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
- return gpiod_direction_input(desc);
-
- /* Open source pin should not be driven to 0 */
- if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
- return gpiod_direction_input(desc);
+ if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
+ /* First see if we can enable open drain in hardware */
+ if (gc->set_single_ended) {
+ ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
+ LINE_MODE_OPEN_DRAIN);
+ if (!ret)
+ goto set_output_value;
+ }
+ /* Emulate open drain by not actively driving the line high */
+ if (value)
+ return gpiod_direction_input(desc);
+ }
+ else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
+ if (gc->set_single_ended) {
+ ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
+ LINE_MODE_OPEN_SOURCE);
+ if (!ret)
+ goto set_output_value;
+ }
+ /* Emulate open source by not actively driving the line low */
+ if (!value)
+ return gpiod_direction_input(desc);
+ } else {
+ /* Make sure to disable open drain/source hardware, if any */
+ if (gc->set_single_ended)
+ gc->set_single_ended(gc,
+ gpio_chip_hwgpio(desc),
+ LINE_MODE_PUSH_PULL);
+ }
- chip = desc->gdev->chip;
- if (!chip->set || !chip->direction_output) {
+set_output_value:
+ if (!gc->set || !gc->direction_output) {
gpiod_warn(desc,
"%s: missing set() or direction_output() operations\n",
__func__);
return -EIO;
}
- status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
- if (status == 0)
+ ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
+ if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
trace_gpio_value(desc_to_gpio(desc), 0, value);
- trace_gpio_direction(desc_to_gpio(desc), 0, status);
- return status;
+ trace_gpio_direction(desc_to_gpio(desc), 0, ret);
+ return ret;
}
/**
@@ -1846,10 +1896,10 @@ static void gpio_chip_set_multiple(struct gpio_chip *chip,
}
}
-static void gpiod_set_array_value_priv(bool raw, bool can_sleep,
- unsigned int array_size,
- struct gpio_desc **desc_array,
- int *value_array)
+void gpiod_set_array_value_complex(bool raw, bool can_sleep,
+ unsigned int array_size,
+ struct gpio_desc **desc_array,
+ int *value_array)
{
int i = 0;
@@ -1955,8 +2005,8 @@ void gpiod_set_raw_array_value(unsigned int array_size,
{
if (!desc_array)
return;
- gpiod_set_array_value_priv(true, false, array_size, desc_array,
- value_array);
+ gpiod_set_array_value_complex(true, false, array_size, desc_array,
+ value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
@@ -1977,8 +2027,8 @@ void gpiod_set_array_value(unsigned int array_size,
{
if (!desc_array)
return;
- gpiod_set_array_value_priv(false, false, array_size, desc_array,
- value_array);
+ gpiod_set_array_value_complex(false, false, array_size, desc_array,
+ value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_array_value);
@@ -2003,8 +2053,8 @@ EXPORT_SYMBOL_GPL(gpiod_cansleep);
*/
int gpiod_to_irq(const struct gpio_desc *desc)
{
- struct gpio_chip *chip;
- int offset;
+ struct gpio_chip *chip;
+ int offset;
/*
* Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
@@ -2016,7 +2066,16 @@ int gpiod_to_irq(const struct gpio_desc *desc)
chip = desc->gdev->chip;
offset = gpio_chip_hwgpio(desc);
- return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
+ if (chip->to_irq) {
+ int retirq = chip->to_irq(chip, offset);
+
+ /* Zero means NO_IRQ */
+ if (!retirq)
+ return -ENXIO;
+
+ return retirq;
+ }
+ return -ENXIO;
}
EXPORT_SYMBOL_GPL(gpiod_to_irq);
@@ -2030,17 +2089,30 @@ EXPORT_SYMBOL_GPL(gpiod_to_irq);
*/
int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
{
- if (offset >= chip->ngpio)
- return -EINVAL;
+ struct gpio_desc *desc;
+
+ desc = gpiochip_get_desc(chip, offset);
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
+ /* Flush direction if something changed behind our back */
+ if (chip->get_direction) {
+ int dir = chip->get_direction(chip, offset);
- if (test_bit(FLAG_IS_OUT, &chip->gpiodev->descs[offset].flags)) {
+ if (dir)
+ clear_bit(FLAG_IS_OUT, &desc->flags);
+ else
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ }
+
+ if (test_bit(FLAG_IS_OUT, &desc->flags)) {
chip_err(chip,
"%s: tried to flag a GPIO set as output for IRQ\n",
__func__);
return -EIO;
}
- set_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
+ set_bit(FLAG_USED_AS_IRQ, &desc->flags);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
@@ -2188,8 +2260,8 @@ void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
might_sleep_if(extra_checks);
if (!desc_array)
return;
- gpiod_set_array_value_priv(true, true, array_size, desc_array,
- value_array);
+ gpiod_set_array_value_complex(true, true, array_size, desc_array,
+ value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
@@ -2211,8 +2283,8 @@ void gpiod_set_array_value_cansleep(unsigned int array_size,
might_sleep_if(extra_checks);
if (!desc_array)
return;
- gpiod_set_array_value_priv(false, true, array_size, desc_array,
- value_array);
+ gpiod_set_array_value_complex(false, true, array_size, desc_array,
+ value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
@@ -2726,15 +2798,16 @@ int gpiod_hog(struct gpio_desc *desc, const char *name,
local_desc = gpiochip_request_own_desc(chip, hwnum, name);
if (IS_ERR(local_desc)) {
- pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n",
- name, chip->label, hwnum);
- return PTR_ERR(local_desc);
+ status = PTR_ERR(local_desc);
+ pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
+ name, chip->label, hwnum, status);
+ return status;
}
status = gpiod_configure_flags(desc, name, lflags, dflags);
if (status < 0) {
- pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n",
- name, chip->label, hwnum);
+ pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
+ name, chip->label, hwnum, status);
gpiochip_free_own_desc(desc);
return status;
}