forked from Minki/linux
0e9a5edf5d
Commit 14e85c0e69 ("gpio: remove gpio_descs global array") changed
gpio_to_desc()'s behavior to return NULL not only for GPIOs numbers
not in the valid range, but also for all GPIOs whose controller has not
been probed yet. Although this behavior is more correct (nothing hints
that these GPIO numbers will be populated later), this affects
gpio_request() and gpio_request_one() which call gpiod_request() with a
NULL descriptor, causing it to return -EINVAL instead of the expected
-EPROBE_DEFER for a non-probed GPIO.
gpiod_request() is only called with a descriptor obtained from
gpio_to_desc() from these two functions, so address the issue there.
Other ways to obtain GPIOs rely on well-defined mappings and can thus
return -EPROBE_DEFER only for relevant GPIOs, and are thus not affected
by this issue.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
113 lines
2.4 KiB
C
113 lines
2.4 KiB
C
#include <linux/gpio/consumer.h>
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#include <linux/gpio/driver.h>
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#include <linux/gpio.h>
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#include "gpiolib.h"
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void gpio_free(unsigned gpio)
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{
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gpiod_free(gpio_to_desc(gpio));
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}
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EXPORT_SYMBOL_GPL(gpio_free);
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/**
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* gpio_request_one - request a single GPIO with initial configuration
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* @gpio: the GPIO number
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* @flags: GPIO configuration as specified by GPIOF_*
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* @label: a literal description string of this GPIO
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*/
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int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
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{
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struct gpio_desc *desc;
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int err;
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desc = gpio_to_desc(gpio);
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/* Compatibility: assume unavailable "valid" GPIOs will appear later */
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if (!desc && gpio_is_valid(gpio))
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return -EPROBE_DEFER;
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err = gpiod_request(desc, label);
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if (err)
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return err;
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if (flags & GPIOF_OPEN_DRAIN)
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set_bit(FLAG_OPEN_DRAIN, &desc->flags);
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if (flags & GPIOF_OPEN_SOURCE)
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set_bit(FLAG_OPEN_SOURCE, &desc->flags);
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if (flags & GPIOF_ACTIVE_LOW)
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set_bit(FLAG_ACTIVE_LOW, &desc->flags);
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if (flags & GPIOF_DIR_IN)
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err = gpiod_direction_input(desc);
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else
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err = gpiod_direction_output_raw(desc,
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(flags & GPIOF_INIT_HIGH) ? 1 : 0);
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if (err)
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goto free_gpio;
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if (flags & GPIOF_EXPORT) {
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err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE);
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if (err)
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goto free_gpio;
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}
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return 0;
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free_gpio:
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gpiod_free(desc);
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return err;
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}
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EXPORT_SYMBOL_GPL(gpio_request_one);
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int gpio_request(unsigned gpio, const char *label)
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{
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struct gpio_desc *desc = gpio_to_desc(gpio);
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/* Compatibility: assume unavailable "valid" GPIOs will appear later */
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if (!desc && gpio_is_valid(gpio))
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return -EPROBE_DEFER;
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return gpiod_request(desc, label);
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}
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EXPORT_SYMBOL_GPL(gpio_request);
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/**
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* gpio_request_array - request multiple GPIOs in a single call
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* @array: array of the 'struct gpio'
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* @num: how many GPIOs in the array
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*/
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int gpio_request_array(const struct gpio *array, size_t num)
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{
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int i, err;
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for (i = 0; i < num; i++, array++) {
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err = gpio_request_one(array->gpio, array->flags, array->label);
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if (err)
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goto err_free;
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}
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return 0;
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err_free:
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while (i--)
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gpio_free((--array)->gpio);
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return err;
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}
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EXPORT_SYMBOL_GPL(gpio_request_array);
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/**
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* gpio_free_array - release multiple GPIOs in a single call
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* @array: array of the 'struct gpio'
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* @num: how many GPIOs in the array
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*/
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void gpio_free_array(const struct gpio *array, size_t num)
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{
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while (num--)
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gpio_free((array++)->gpio);
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}
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EXPORT_SYMBOL_GPL(gpio_free_array);
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