mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 21:54:06 +08:00
1bd6b601fe
As GPIO descriptors are not going to remain unique anymore, having this function public is not safe. Restrain its use to gpiolib since we have no user outside of it. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
1950 lines
51 KiB
C
1950 lines
51 KiB
C
#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/spinlock.h>
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#include <linux/list.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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#include <linux/gpio.h>
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#include <linux/of_gpio.h>
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#include <linux/idr.h>
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#include <linux/slab.h>
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#include <linux/acpi.h>
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#include <linux/gpio/driver.h>
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#include "gpiolib.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/gpio.h>
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/* Implementation infrastructure for GPIO interfaces.
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*
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* The GPIO programming interface allows for inlining speed-critical
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* get/set operations for common cases, so that access to SOC-integrated
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* GPIOs can sometimes cost only an instruction or two per bit.
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*/
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/* When debugging, extend minimal trust to callers and platform code.
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* Also emit diagnostic messages that may help initial bringup, when
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* board setup or driver bugs are most common.
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*
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* Otherwise, minimize overhead in what may be bitbanging codepaths.
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*/
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#ifdef DEBUG
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#define extra_checks 1
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#else
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#define extra_checks 0
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#endif
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/* gpio_lock prevents conflicts during gpio_desc[] table updates.
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* While any GPIO is requested, its gpio_chip is not removable;
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* each GPIO's "requested" flag serves as a lock and refcount.
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*/
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DEFINE_SPINLOCK(gpio_lock);
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static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];
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#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio)
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static DEFINE_MUTEX(gpio_lookup_lock);
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static LIST_HEAD(gpio_lookup_list);
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LIST_HEAD(gpio_chips);
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static inline void desc_set_label(struct gpio_desc *d, const char *label)
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{
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d->label = label;
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}
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/**
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* Convert a GPIO number to its descriptor
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*/
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struct gpio_desc *gpio_to_desc(unsigned gpio)
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{
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if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio))
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return NULL;
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else
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return &gpio_desc[gpio];
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}
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EXPORT_SYMBOL_GPL(gpio_to_desc);
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/**
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* Get the GPIO descriptor corresponding to the given hw number for this chip.
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*/
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struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
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u16 hwnum)
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{
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if (hwnum >= chip->ngpio)
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return ERR_PTR(-EINVAL);
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return &chip->desc[hwnum];
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}
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/**
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* Convert a GPIO descriptor to the integer namespace.
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* This should disappear in the future but is needed since we still
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* use GPIO numbers for error messages and sysfs nodes
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*/
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int desc_to_gpio(const struct gpio_desc *desc)
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{
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return desc - &gpio_desc[0];
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}
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EXPORT_SYMBOL_GPL(desc_to_gpio);
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/* Warn when drivers omit gpio_request() calls -- legal but ill-advised
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* when setting direction, and otherwise illegal. Until board setup code
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* and drivers use explicit requests everywhere (which won't happen when
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* those calls have no teeth) we can't avoid autorequesting. This nag
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* message should motivate switching to explicit requests... so should
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* the weaker cleanup after faults, compared to gpio_request().
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*
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* NOTE: the autorequest mechanism is going away; at this point it's
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* only "legal" in the sense that (old) code using it won't break yet,
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* but instead only triggers a WARN() stack dump.
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*/
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static int gpio_ensure_requested(struct gpio_desc *desc)
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{
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const struct gpio_chip *chip = desc->chip;
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const int gpio = desc_to_gpio(desc);
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if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0,
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"autorequest GPIO-%d\n", gpio)) {
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if (!try_module_get(chip->owner)) {
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gpiod_err(desc, "%s: module can't be gotten\n",
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__func__);
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clear_bit(FLAG_REQUESTED, &desc->flags);
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/* lose */
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return -EIO;
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}
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desc_set_label(desc, "[auto]");
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/* caller must chip->request() w/o spinlock */
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if (chip->request)
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return 1;
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}
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return 0;
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}
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/**
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* gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
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* @desc: descriptor to return the chip of
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*/
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struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
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{
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return desc ? desc->chip : NULL;
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}
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EXPORT_SYMBOL_GPL(gpiod_to_chip);
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/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
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static int gpiochip_find_base(int ngpio)
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{
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struct gpio_chip *chip;
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int base = ARCH_NR_GPIOS - ngpio;
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list_for_each_entry_reverse(chip, &gpio_chips, list) {
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/* found a free space? */
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if (chip->base + chip->ngpio <= base)
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break;
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else
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/* nope, check the space right before the chip */
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base = chip->base - ngpio;
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}
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if (gpio_is_valid(base)) {
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pr_debug("%s: found new base at %d\n", __func__, base);
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return base;
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} else {
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pr_err("%s: cannot find free range\n", __func__);
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return -ENOSPC;
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}
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}
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/**
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* gpiod_get_direction - return the current direction of a GPIO
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* @desc: GPIO to get the direction of
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*
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* Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
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*
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* This function may sleep if gpiod_cansleep() is true.
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*/
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int gpiod_get_direction(const struct gpio_desc *desc)
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{
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struct gpio_chip *chip;
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unsigned offset;
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int status = -EINVAL;
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chip = gpiod_to_chip(desc);
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offset = gpio_chip_hwgpio(desc);
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if (!chip->get_direction)
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return status;
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status = chip->get_direction(chip, offset);
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if (status > 0) {
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/* GPIOF_DIR_IN, or other positive */
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status = 1;
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/* FLAG_IS_OUT is just a cache of the result of get_direction(),
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* so it does not affect constness per se */
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clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
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}
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if (status == 0) {
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/* GPIOF_DIR_OUT */
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set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
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}
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return status;
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}
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EXPORT_SYMBOL_GPL(gpiod_get_direction);
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/*
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* Add a new chip to the global chips list, keeping the list of chips sorted
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* by base order.
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*
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* Return -EBUSY if the new chip overlaps with some other chip's integer
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* space.
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*/
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static int gpiochip_add_to_list(struct gpio_chip *chip)
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{
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struct list_head *pos = &gpio_chips;
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struct gpio_chip *_chip;
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int err = 0;
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/* find where to insert our chip */
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list_for_each(pos, &gpio_chips) {
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_chip = list_entry(pos, struct gpio_chip, list);
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/* shall we insert before _chip? */
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if (_chip->base >= chip->base + chip->ngpio)
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break;
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}
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/* are we stepping on the chip right before? */
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if (pos != &gpio_chips && pos->prev != &gpio_chips) {
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_chip = list_entry(pos->prev, struct gpio_chip, list);
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if (_chip->base + _chip->ngpio > chip->base) {
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dev_err(chip->dev,
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"GPIO integer space overlap, cannot add chip\n");
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err = -EBUSY;
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}
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}
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if (!err)
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list_add_tail(&chip->list, pos);
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return err;
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}
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/**
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* gpiochip_add() - register a gpio_chip
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* @chip: the chip to register, with chip->base initialized
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* Context: potentially before irqs or kmalloc will work
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*
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* Returns a negative errno if the chip can't be registered, such as
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* because the chip->base is invalid or already associated with a
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* different chip. Otherwise it returns zero as a success code.
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*
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* When gpiochip_add() is called very early during boot, so that GPIOs
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* can be freely used, the chip->dev device must be registered before
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* the gpio framework's arch_initcall(). Otherwise sysfs initialization
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* for GPIOs will fail rudely.
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*
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* If chip->base is negative, this requests dynamic assignment of
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* a range of valid GPIOs.
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*/
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int gpiochip_add(struct gpio_chip *chip)
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{
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unsigned long flags;
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int status = 0;
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unsigned id;
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int base = chip->base;
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if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1))
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&& base >= 0) {
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status = -EINVAL;
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goto fail;
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}
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spin_lock_irqsave(&gpio_lock, flags);
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if (base < 0) {
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base = gpiochip_find_base(chip->ngpio);
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if (base < 0) {
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status = base;
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goto unlock;
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}
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chip->base = base;
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}
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status = gpiochip_add_to_list(chip);
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if (status == 0) {
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chip->desc = &gpio_desc[chip->base];
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for (id = 0; id < chip->ngpio; id++) {
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struct gpio_desc *desc = &chip->desc[id];
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desc->chip = chip;
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/* REVISIT: most hardware initializes GPIOs as
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* inputs (often with pullups enabled) so power
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* usage is minimized. Linux code should set the
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* gpio direction first thing; but until it does,
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* and in case chip->get_direction is not set,
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* we may expose the wrong direction in sysfs.
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*/
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desc->flags = !chip->direction_input
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? (1 << FLAG_IS_OUT)
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: 0;
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}
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}
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spin_unlock_irqrestore(&gpio_lock, flags);
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#ifdef CONFIG_PINCTRL
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INIT_LIST_HEAD(&chip->pin_ranges);
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#endif
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of_gpiochip_add(chip);
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acpi_gpiochip_add(chip);
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if (status)
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goto fail;
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status = gpiochip_export(chip);
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if (status)
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goto fail;
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pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
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chip->base, chip->base + chip->ngpio - 1,
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chip->label ? : "generic");
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return 0;
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unlock:
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spin_unlock_irqrestore(&gpio_lock, flags);
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fail:
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/* failures here can mean systems won't boot... */
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pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
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chip->base, chip->base + chip->ngpio - 1,
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chip->label ? : "generic");
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return status;
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}
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EXPORT_SYMBOL_GPL(gpiochip_add);
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/* Forward-declaration */
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static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
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/**
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* gpiochip_remove() - unregister a gpio_chip
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* @chip: the chip to unregister
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*
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* A gpio_chip with any GPIOs still requested may not be removed.
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*/
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int gpiochip_remove(struct gpio_chip *chip)
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{
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unsigned long flags;
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int status = 0;
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unsigned id;
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acpi_gpiochip_remove(chip);
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spin_lock_irqsave(&gpio_lock, flags);
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gpiochip_irqchip_remove(chip);
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gpiochip_remove_pin_ranges(chip);
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of_gpiochip_remove(chip);
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for (id = 0; id < chip->ngpio; id++) {
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if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
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status = -EBUSY;
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break;
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}
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}
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if (status == 0) {
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for (id = 0; id < chip->ngpio; id++)
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chip->desc[id].chip = NULL;
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list_del(&chip->list);
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}
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spin_unlock_irqrestore(&gpio_lock, flags);
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if (status == 0)
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gpiochip_unexport(chip);
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return status;
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}
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EXPORT_SYMBOL_GPL(gpiochip_remove);
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/**
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* gpiochip_find() - iterator for locating a specific gpio_chip
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* @data: data to pass to match function
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* @callback: Callback function to check gpio_chip
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*
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* Similar to bus_find_device. It returns a reference to a gpio_chip as
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* determined by a user supplied @match callback. The callback should return
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* 0 if the device doesn't match and non-zero if it does. If the callback is
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* non-zero, this function will return to the caller and not iterate over any
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* more gpio_chips.
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*/
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struct gpio_chip *gpiochip_find(void *data,
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int (*match)(struct gpio_chip *chip,
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void *data))
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{
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struct gpio_chip *chip;
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unsigned long flags;
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spin_lock_irqsave(&gpio_lock, flags);
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list_for_each_entry(chip, &gpio_chips, list)
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if (match(chip, data))
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break;
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/* No match? */
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if (&chip->list == &gpio_chips)
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chip = NULL;
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spin_unlock_irqrestore(&gpio_lock, flags);
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return chip;
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}
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EXPORT_SYMBOL_GPL(gpiochip_find);
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static int gpiochip_match_name(struct gpio_chip *chip, void *data)
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{
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const char *name = data;
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return !strcmp(chip->label, name);
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}
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static struct gpio_chip *find_chip_by_name(const char *name)
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{
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return gpiochip_find((void *)name, gpiochip_match_name);
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}
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#ifdef CONFIG_GPIOLIB_IRQCHIP
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/*
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* The following is irqchip helper code for gpiochips.
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*/
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/**
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* gpiochip_add_chained_irqchip() - adds a chained irqchip to a gpiochip
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* @gpiochip: the gpiochip to add the irqchip to
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* @irqchip: the irqchip to add to the gpiochip
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* @parent_irq: the irq number corresponding to the parent IRQ for this
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* chained irqchip
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* @parent_handler: the parent interrupt handler for the accumulated IRQ
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* coming out of the gpiochip
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*/
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void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
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struct irq_chip *irqchip,
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int parent_irq,
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irq_flow_handler_t parent_handler)
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{
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if (gpiochip->can_sleep) {
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chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
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return;
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}
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irq_set_chained_handler(parent_irq, parent_handler);
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/*
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* The parent irqchip is already using the chip_data for this
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* irqchip, so our callbacks simply use the handler_data.
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*/
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irq_set_handler_data(parent_irq, gpiochip);
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}
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EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
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/*
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* This lock class tells lockdep that GPIO irqs are in a different
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* category than their parents, so it won't report false recursion.
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*/
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static struct lock_class_key gpiochip_irq_lock_class;
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/**
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* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
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* @d: the irqdomain used by this irqchip
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* @irq: the global irq number used by this GPIO irqchip irq
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* @hwirq: the local IRQ/GPIO line offset on this gpiochip
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*
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* This function will set up the mapping for a certain IRQ line on a
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* gpiochip by assigning the gpiochip as chip data, and using the irqchip
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* stored inside the gpiochip.
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*/
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static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
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irq_hw_number_t hwirq)
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{
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struct gpio_chip *chip = d->host_data;
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irq_set_chip_data(irq, chip);
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irq_set_lockdep_class(irq, &gpiochip_irq_lock_class);
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irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
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/* Chips that can sleep need nested thread handlers */
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if (chip->can_sleep)
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irq_set_nested_thread(irq, 1);
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#ifdef CONFIG_ARM
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set_irq_flags(irq, IRQF_VALID);
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#else
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irq_set_noprobe(irq);
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#endif
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/*
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* No set-up of the hardware will happen if IRQ_TYPE_NONE
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* is passed as default type.
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*/
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if (chip->irq_default_type != IRQ_TYPE_NONE)
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irq_set_irq_type(irq, chip->irq_default_type);
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return 0;
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}
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static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
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{
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struct gpio_chip *chip = d->host_data;
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#ifdef CONFIG_ARM
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set_irq_flags(irq, 0);
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#endif
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if (chip->can_sleep)
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irq_set_nested_thread(irq, 0);
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irq_set_chip_and_handler(irq, NULL, NULL);
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irq_set_chip_data(irq, NULL);
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}
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static const struct irq_domain_ops gpiochip_domain_ops = {
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.map = gpiochip_irq_map,
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.unmap = gpiochip_irq_unmap,
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/* Virtually all GPIO irqchips are twocell:ed */
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.xlate = irq_domain_xlate_twocell,
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};
|
|
|
|
static int gpiochip_irq_reqres(struct irq_data *d)
|
|
{
|
|
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
|
|
|
|
if (gpio_lock_as_irq(chip, d->hwirq)) {
|
|
chip_err(chip,
|
|
"unable to lock HW IRQ %lu for IRQ\n",
|
|
d->hwirq);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void gpiochip_irq_relres(struct irq_data *d)
|
|
{
|
|
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
|
|
|
|
gpio_unlock_as_irq(chip, d->hwirq);
|
|
}
|
|
|
|
static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
return irq_find_mapping(chip->irqdomain, offset);
|
|
}
|
|
|
|
/**
|
|
* gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
|
|
* @gpiochip: the gpiochip to remove the irqchip from
|
|
*
|
|
* This is called only from gpiochip_remove()
|
|
*/
|
|
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
|
|
{
|
|
unsigned int offset;
|
|
|
|
/* Remove all IRQ mappings and delete the domain */
|
|
if (gpiochip->irqdomain) {
|
|
for (offset = 0; offset < gpiochip->ngpio; offset++)
|
|
irq_dispose_mapping(gpiochip->irq_base + offset);
|
|
irq_domain_remove(gpiochip->irqdomain);
|
|
}
|
|
|
|
if (gpiochip->irqchip) {
|
|
gpiochip->irqchip->irq_request_resources = NULL;
|
|
gpiochip->irqchip->irq_release_resources = NULL;
|
|
gpiochip->irqchip = NULL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gpiochip_irqchip_add() - adds an irqchip to a gpiochip
|
|
* @gpiochip: the gpiochip to add the irqchip to
|
|
* @irqchip: the irqchip to add to the gpiochip
|
|
* @first_irq: if not dynamically assigned, the base (first) IRQ to
|
|
* allocate gpiochip irqs from
|
|
* @handler: the irq handler to use (often a predefined irq core function)
|
|
* @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
|
|
* to have the core avoid setting up any default type in the hardware.
|
|
*
|
|
* This function closely associates a certain irqchip with a certain
|
|
* gpiochip, providing an irq domain to translate the local IRQs to
|
|
* global irqs in the gpiolib core, and making sure that the gpiochip
|
|
* is passed as chip data to all related functions. Driver callbacks
|
|
* need to use container_of() to get their local state containers back
|
|
* from the gpiochip passed as chip data. An irqdomain will be stored
|
|
* in the gpiochip that shall be used by the driver to handle IRQ number
|
|
* translation. The gpiochip will need to be initialized and registered
|
|
* before calling this function.
|
|
*
|
|
* This function will handle two cell:ed simple IRQs and assumes all
|
|
* the pins on the gpiochip can generate a unique IRQ. Everything else
|
|
* need to be open coded.
|
|
*/
|
|
int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
|
|
struct irq_chip *irqchip,
|
|
unsigned int first_irq,
|
|
irq_flow_handler_t handler,
|
|
unsigned int type)
|
|
{
|
|
struct device_node *of_node;
|
|
unsigned int offset;
|
|
unsigned irq_base = 0;
|
|
|
|
if (!gpiochip || !irqchip)
|
|
return -EINVAL;
|
|
|
|
if (!gpiochip->dev) {
|
|
pr_err("missing gpiochip .dev parent pointer\n");
|
|
return -EINVAL;
|
|
}
|
|
of_node = gpiochip->dev->of_node;
|
|
#ifdef CONFIG_OF_GPIO
|
|
/*
|
|
* If the gpiochip has an assigned OF node this takes precendence
|
|
* FIXME: get rid of this and use gpiochip->dev->of_node everywhere
|
|
*/
|
|
if (gpiochip->of_node)
|
|
of_node = gpiochip->of_node;
|
|
#endif
|
|
gpiochip->irqchip = irqchip;
|
|
gpiochip->irq_handler = handler;
|
|
gpiochip->irq_default_type = type;
|
|
gpiochip->to_irq = gpiochip_to_irq;
|
|
gpiochip->irqdomain = irq_domain_add_simple(of_node,
|
|
gpiochip->ngpio, first_irq,
|
|
&gpiochip_domain_ops, gpiochip);
|
|
if (!gpiochip->irqdomain) {
|
|
gpiochip->irqchip = NULL;
|
|
return -EINVAL;
|
|
}
|
|
irqchip->irq_request_resources = gpiochip_irq_reqres;
|
|
irqchip->irq_release_resources = gpiochip_irq_relres;
|
|
|
|
/*
|
|
* Prepare the mapping since the irqchip shall be orthogonal to
|
|
* any gpiochip calls. If the first_irq was zero, this is
|
|
* necessary to allocate descriptors for all IRQs.
|
|
*/
|
|
for (offset = 0; offset < gpiochip->ngpio; offset++) {
|
|
irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
|
|
if (offset == 0)
|
|
/*
|
|
* Store the base into the gpiochip to be used when
|
|
* unmapping the irqs.
|
|
*/
|
|
gpiochip->irq_base = irq_base;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_irqchip_add);
|
|
|
|
#else /* CONFIG_GPIOLIB_IRQCHIP */
|
|
|
|
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
|
|
|
|
#endif /* CONFIG_GPIOLIB_IRQCHIP */
|
|
|
|
#ifdef CONFIG_PINCTRL
|
|
|
|
/**
|
|
* gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
|
|
* @chip: the gpiochip to add the range for
|
|
* @pinctrl: the dev_name() of the pin controller to map to
|
|
* @gpio_offset: the start offset in the current gpio_chip number space
|
|
* @pin_group: name of the pin group inside the pin controller
|
|
*/
|
|
int gpiochip_add_pingroup_range(struct gpio_chip *chip,
|
|
struct pinctrl_dev *pctldev,
|
|
unsigned int gpio_offset, const char *pin_group)
|
|
{
|
|
struct gpio_pin_range *pin_range;
|
|
int ret;
|
|
|
|
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
|
|
if (!pin_range) {
|
|
chip_err(chip, "failed to allocate pin ranges\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Use local offset as range ID */
|
|
pin_range->range.id = gpio_offset;
|
|
pin_range->range.gc = chip;
|
|
pin_range->range.name = chip->label;
|
|
pin_range->range.base = chip->base + gpio_offset;
|
|
pin_range->pctldev = pctldev;
|
|
|
|
ret = pinctrl_get_group_pins(pctldev, pin_group,
|
|
&pin_range->range.pins,
|
|
&pin_range->range.npins);
|
|
if (ret < 0) {
|
|
kfree(pin_range);
|
|
return ret;
|
|
}
|
|
|
|
pinctrl_add_gpio_range(pctldev, &pin_range->range);
|
|
|
|
chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
|
|
gpio_offset, gpio_offset + pin_range->range.npins - 1,
|
|
pinctrl_dev_get_devname(pctldev), pin_group);
|
|
|
|
list_add_tail(&pin_range->node, &chip->pin_ranges);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
|
|
|
|
/**
|
|
* gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
|
|
* @chip: the gpiochip to add the range for
|
|
* @pinctrl_name: the dev_name() of the pin controller to map to
|
|
* @gpio_offset: the start offset in the current gpio_chip number space
|
|
* @pin_offset: the start offset in the pin controller number space
|
|
* @npins: the number of pins from the offset of each pin space (GPIO and
|
|
* pin controller) to accumulate in this range
|
|
*/
|
|
int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
|
|
unsigned int gpio_offset, unsigned int pin_offset,
|
|
unsigned int npins)
|
|
{
|
|
struct gpio_pin_range *pin_range;
|
|
int ret;
|
|
|
|
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
|
|
if (!pin_range) {
|
|
chip_err(chip, "failed to allocate pin ranges\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Use local offset as range ID */
|
|
pin_range->range.id = gpio_offset;
|
|
pin_range->range.gc = chip;
|
|
pin_range->range.name = chip->label;
|
|
pin_range->range.base = chip->base + gpio_offset;
|
|
pin_range->range.pin_base = pin_offset;
|
|
pin_range->range.npins = npins;
|
|
pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
|
|
&pin_range->range);
|
|
if (IS_ERR(pin_range->pctldev)) {
|
|
ret = PTR_ERR(pin_range->pctldev);
|
|
chip_err(chip, "could not create pin range\n");
|
|
kfree(pin_range);
|
|
return ret;
|
|
}
|
|
chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
|
|
gpio_offset, gpio_offset + npins - 1,
|
|
pinctl_name,
|
|
pin_offset, pin_offset + npins - 1);
|
|
|
|
list_add_tail(&pin_range->node, &chip->pin_ranges);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
|
|
|
|
/**
|
|
* gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
|
|
* @chip: the chip to remove all the mappings for
|
|
*/
|
|
void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
|
|
{
|
|
struct gpio_pin_range *pin_range, *tmp;
|
|
|
|
list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
|
|
list_del(&pin_range->node);
|
|
pinctrl_remove_gpio_range(pin_range->pctldev,
|
|
&pin_range->range);
|
|
kfree(pin_range);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
|
|
|
|
#endif /* CONFIG_PINCTRL */
|
|
|
|
/* These "optional" allocation calls help prevent drivers from stomping
|
|
* on each other, and help provide better diagnostics in debugfs.
|
|
* They're called even less than the "set direction" calls.
|
|
*/
|
|
static int __gpiod_request(struct gpio_desc *desc, const char *label)
|
|
{
|
|
struct gpio_chip *chip = desc->chip;
|
|
int status;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
/* NOTE: gpio_request() can be called in early boot,
|
|
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
|
|
*/
|
|
|
|
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
|
|
desc_set_label(desc, label ? : "?");
|
|
status = 0;
|
|
} else {
|
|
status = -EBUSY;
|
|
goto done;
|
|
}
|
|
|
|
if (chip->request) {
|
|
/* chip->request may sleep */
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
status = chip->request(chip, gpio_chip_hwgpio(desc));
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
if (status < 0) {
|
|
desc_set_label(desc, NULL);
|
|
clear_bit(FLAG_REQUESTED, &desc->flags);
|
|
goto done;
|
|
}
|
|
}
|
|
if (chip->get_direction) {
|
|
/* chip->get_direction may sleep */
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
gpiod_get_direction(desc);
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
}
|
|
done:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
return status;
|
|
}
|
|
|
|
int gpiod_request(struct gpio_desc *desc, const char *label)
|
|
{
|
|
int status = -EPROBE_DEFER;
|
|
struct gpio_chip *chip;
|
|
|
|
if (!desc) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
chip = desc->chip;
|
|
if (!chip)
|
|
goto done;
|
|
|
|
if (try_module_get(chip->owner)) {
|
|
status = __gpiod_request(desc, label);
|
|
if (status < 0)
|
|
module_put(chip->owner);
|
|
}
|
|
|
|
done:
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
return status;
|
|
}
|
|
|
|
static bool __gpiod_free(struct gpio_desc *desc)
|
|
{
|
|
bool ret = false;
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
|
|
might_sleep();
|
|
|
|
gpiod_unexport(desc);
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
chip = desc->chip;
|
|
if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
|
|
if (chip->free) {
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
might_sleep_if(chip->can_sleep);
|
|
chip->free(chip, gpio_chip_hwgpio(desc));
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
}
|
|
desc_set_label(desc, NULL);
|
|
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
clear_bit(FLAG_REQUESTED, &desc->flags);
|
|
clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
|
|
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
|
|
ret = true;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
void gpiod_free(struct gpio_desc *desc)
|
|
{
|
|
if (desc && __gpiod_free(desc))
|
|
module_put(desc->chip->owner);
|
|
else
|
|
WARN_ON(extra_checks);
|
|
}
|
|
|
|
/**
|
|
* gpiochip_is_requested - return string iff signal was requested
|
|
* @chip: controller managing the signal
|
|
* @offset: of signal within controller's 0..(ngpio - 1) range
|
|
*
|
|
* Returns NULL if the GPIO is not currently requested, else a string.
|
|
* The string returned is the label passed to gpio_request(); if none has been
|
|
* passed it is a meaningless, non-NULL constant.
|
|
*
|
|
* This function is for use by GPIO controller drivers. The label can
|
|
* help with diagnostics, and knowing that the signal is used as a GPIO
|
|
* can help avoid accidentally multiplexing it to another controller.
|
|
*/
|
|
const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
struct gpio_desc *desc;
|
|
|
|
if (!GPIO_OFFSET_VALID(chip, offset))
|
|
return NULL;
|
|
|
|
desc = &chip->desc[offset];
|
|
|
|
if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
|
|
return NULL;
|
|
return desc->label;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_is_requested);
|
|
|
|
/**
|
|
* gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
|
|
* @desc: GPIO descriptor to request
|
|
* @label: label for the GPIO
|
|
*
|
|
* Function allows GPIO chip drivers to request and use their own GPIO
|
|
* descriptors via gpiolib API. Difference to gpiod_request() is that this
|
|
* function will not increase reference count of the GPIO chip module. This
|
|
* allows the GPIO chip module to be unloaded as needed (we assume that the
|
|
* GPIO chip driver handles freeing the GPIOs it has requested).
|
|
*/
|
|
int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label)
|
|
{
|
|
if (!desc || !desc->chip)
|
|
return -EINVAL;
|
|
|
|
return __gpiod_request(desc, label);
|
|
}
|
|
|
|
/**
|
|
* gpiochip_free_own_desc - Free GPIO requested by the chip driver
|
|
* @desc: GPIO descriptor to free
|
|
*
|
|
* Function frees the given GPIO requested previously with
|
|
* gpiochip_request_own_desc().
|
|
*/
|
|
void gpiochip_free_own_desc(struct gpio_desc *desc)
|
|
{
|
|
if (desc)
|
|
__gpiod_free(desc);
|
|
}
|
|
|
|
/* Drivers MUST set GPIO direction before making get/set calls. In
|
|
* some cases this is done in early boot, before IRQs are enabled.
|
|
*
|
|
* As a rule these aren't called more than once (except for drivers
|
|
* using the open-drain emulation idiom) so these are natural places
|
|
* to accumulate extra debugging checks. Note that we can't (yet)
|
|
* rely on gpio_request() having been called beforehand.
|
|
*/
|
|
|
|
/**
|
|
* gpiod_direction_input - set the GPIO direction to input
|
|
* @desc: GPIO to set to input
|
|
*
|
|
* Set the direction of the passed GPIO to input, such as gpiod_get_value() can
|
|
* be called safely on it.
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_direction_input(struct gpio_desc *desc)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
int status = -EINVAL;
|
|
int offset;
|
|
|
|
if (!desc || !desc->chip) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
chip = desc->chip;
|
|
if (!chip->get || !chip->direction_input) {
|
|
gpiod_warn(desc,
|
|
"%s: missing get() or direction_input() operations\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
status = gpio_ensure_requested(desc);
|
|
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);
|
|
|
|
offset = gpio_chip_hwgpio(desc);
|
|
if (status) {
|
|
status = chip->request(chip, offset);
|
|
if (status < 0) {
|
|
gpiod_dbg(desc, "%s: chip request fail, %d\n",
|
|
__func__, status);
|
|
/* and it's not available to anyone else ...
|
|
* gpio_request() is the fully clean solution.
|
|
*/
|
|
goto lose;
|
|
}
|
|
}
|
|
|
|
status = chip->direction_input(chip, offset);
|
|
if (status == 0)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
|
|
trace_gpio_direction(desc_to_gpio(desc), 1, status);
|
|
lose:
|
|
return status;
|
|
fail:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_direction_input);
|
|
|
|
static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
int status = -EINVAL;
|
|
int offset;
|
|
|
|
/* GPIOs used for IRQs shall not be set as output */
|
|
if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
|
|
gpiod_err(desc,
|
|
"%s: tried to set a GPIO tied to an IRQ as output\n",
|
|
__func__);
|
|
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);
|
|
|
|
chip = desc->chip;
|
|
if (!chip->set || !chip->direction_output) {
|
|
gpiod_warn(desc,
|
|
"%s: missing set() or direction_output() operations\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
status = gpio_ensure_requested(desc);
|
|
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);
|
|
|
|
offset = gpio_chip_hwgpio(desc);
|
|
if (status) {
|
|
status = chip->request(chip, offset);
|
|
if (status < 0) {
|
|
gpiod_dbg(desc, "%s: chip request fail, %d\n",
|
|
__func__, status);
|
|
/* and it's not available to anyone else ...
|
|
* gpio_request() is the fully clean solution.
|
|
*/
|
|
goto lose;
|
|
}
|
|
}
|
|
|
|
status = chip->direction_output(chip, offset, value);
|
|
if (status == 0)
|
|
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);
|
|
lose:
|
|
return status;
|
|
fail:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status);
|
|
return status;
|
|
}
|
|
|
|
/**
|
|
* gpiod_direction_output_raw - set the GPIO direction to output
|
|
* @desc: GPIO to set to output
|
|
* @value: initial output value of the GPIO
|
|
*
|
|
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
|
|
* be called safely on it. The initial value of the output must be specified
|
|
* as raw value on the physical line without regard for the ACTIVE_LOW status.
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
|
|
{
|
|
if (!desc || !desc->chip) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
return _gpiod_direction_output_raw(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
|
|
|
|
/**
|
|
* gpiod_direction_output - set the GPIO direction to output
|
|
* @desc: GPIO to set to output
|
|
* @value: initial output value of the GPIO
|
|
*
|
|
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
|
|
* be called safely on it. The initial value of the output must be specified
|
|
* as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
|
|
* account.
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_direction_output(struct gpio_desc *desc, int value)
|
|
{
|
|
if (!desc || !desc->chip) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
return _gpiod_direction_output_raw(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_direction_output);
|
|
|
|
/**
|
|
* gpiod_set_debounce - sets @debounce time for a @gpio
|
|
* @gpio: the gpio to set debounce time
|
|
* @debounce: debounce time is microseconds
|
|
*
|
|
* returns -ENOTSUPP if the controller does not support setting
|
|
* debounce.
|
|
*/
|
|
int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
int status = -EINVAL;
|
|
int offset;
|
|
|
|
if (!desc || !desc->chip) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
chip = desc->chip;
|
|
if (!chip->set || !chip->set_debounce) {
|
|
gpiod_dbg(desc,
|
|
"%s: missing set() or set_debounce() operations\n",
|
|
__func__);
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
status = gpio_ensure_requested(desc);
|
|
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);
|
|
|
|
offset = gpio_chip_hwgpio(desc);
|
|
return chip->set_debounce(chip, offset, debounce);
|
|
|
|
fail:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_debounce);
|
|
|
|
/**
|
|
* gpiod_is_active_low - test whether a GPIO is active-low or not
|
|
* @desc: the gpio descriptor to test
|
|
*
|
|
* Returns 1 if the GPIO is active-low, 0 otherwise.
|
|
*/
|
|
int gpiod_is_active_low(const struct gpio_desc *desc)
|
|
{
|
|
return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_is_active_low);
|
|
|
|
/* I/O calls are only valid after configuration completed; the relevant
|
|
* "is this a valid GPIO" error checks should already have been done.
|
|
*
|
|
* "Get" operations are often inlinable as reading a pin value register,
|
|
* and masking the relevant bit in that register.
|
|
*
|
|
* When "set" operations are inlinable, they involve writing that mask to
|
|
* one register to set a low value, or a different register to set it high.
|
|
* Otherwise locking is needed, so there may be little value to inlining.
|
|
*
|
|
*------------------------------------------------------------------------
|
|
*
|
|
* IMPORTANT!!! The hot paths -- get/set value -- assume that callers
|
|
* have requested the GPIO. That can include implicit requesting by
|
|
* a direction setting call. Marking a gpio as requested locks its chip
|
|
* in memory, guaranteeing that these table lookups need no more locking
|
|
* and that gpiochip_remove() will fail.
|
|
*
|
|
* REVISIT when debugging, consider adding some instrumentation to ensure
|
|
* that the GPIO was actually requested.
|
|
*/
|
|
|
|
static bool _gpiod_get_raw_value(const struct gpio_desc *desc)
|
|
{
|
|
struct gpio_chip *chip;
|
|
bool value;
|
|
int offset;
|
|
|
|
chip = desc->chip;
|
|
offset = gpio_chip_hwgpio(desc);
|
|
value = chip->get ? chip->get(chip, offset) : false;
|
|
trace_gpio_value(desc_to_gpio(desc), 1, value);
|
|
return value;
|
|
}
|
|
|
|
/**
|
|
* gpiod_get_raw_value() - return a gpio's raw value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
|
|
* its ACTIVE_LOW status.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
int gpiod_get_raw_value(const struct gpio_desc *desc)
|
|
{
|
|
if (!desc)
|
|
return 0;
|
|
/* Should be using gpio_get_value_cansleep() */
|
|
WARN_ON(desc->chip->can_sleep);
|
|
return _gpiod_get_raw_value(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
|
|
|
|
/**
|
|
* gpiod_get_value() - return a gpio's value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
|
|
* account.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
int gpiod_get_value(const struct gpio_desc *desc)
|
|
{
|
|
int value;
|
|
if (!desc)
|
|
return 0;
|
|
/* Should be using gpio_get_value_cansleep() */
|
|
WARN_ON(desc->chip->can_sleep);
|
|
|
|
value = _gpiod_get_raw_value(desc);
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
|
|
return value;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_value);
|
|
|
|
/*
|
|
* _gpio_set_open_drain_value() - Set the open drain gpio's value.
|
|
* @desc: gpio descriptor whose state need to be set.
|
|
* @value: Non-zero for setting it HIGH otherise it will set to LOW.
|
|
*/
|
|
static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
|
|
{
|
|
int err = 0;
|
|
struct gpio_chip *chip = desc->chip;
|
|
int offset = gpio_chip_hwgpio(desc);
|
|
|
|
if (value) {
|
|
err = chip->direction_input(chip, offset);
|
|
if (!err)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
} else {
|
|
err = chip->direction_output(chip, offset, 0);
|
|
if (!err)
|
|
set_bit(FLAG_IS_OUT, &desc->flags);
|
|
}
|
|
trace_gpio_direction(desc_to_gpio(desc), value, err);
|
|
if (err < 0)
|
|
gpiod_err(desc,
|
|
"%s: Error in set_value for open drain err %d\n",
|
|
__func__, err);
|
|
}
|
|
|
|
/*
|
|
* _gpio_set_open_source_value() - Set the open source gpio's value.
|
|
* @desc: gpio descriptor whose state need to be set.
|
|
* @value: Non-zero for setting it HIGH otherise it will set to LOW.
|
|
*/
|
|
static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
|
|
{
|
|
int err = 0;
|
|
struct gpio_chip *chip = desc->chip;
|
|
int offset = gpio_chip_hwgpio(desc);
|
|
|
|
if (value) {
|
|
err = chip->direction_output(chip, offset, 1);
|
|
if (!err)
|
|
set_bit(FLAG_IS_OUT, &desc->flags);
|
|
} else {
|
|
err = chip->direction_input(chip, offset);
|
|
if (!err)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
}
|
|
trace_gpio_direction(desc_to_gpio(desc), !value, err);
|
|
if (err < 0)
|
|
gpiod_err(desc,
|
|
"%s: Error in set_value for open source err %d\n",
|
|
__func__, err);
|
|
}
|
|
|
|
static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
|
|
{
|
|
struct gpio_chip *chip;
|
|
|
|
chip = desc->chip;
|
|
trace_gpio_value(desc_to_gpio(desc), 0, value);
|
|
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
|
|
_gpio_set_open_drain_value(desc, value);
|
|
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
|
|
_gpio_set_open_source_value(desc, value);
|
|
else
|
|
chip->set(chip, gpio_chip_hwgpio(desc), value);
|
|
}
|
|
|
|
/**
|
|
* gpiod_set_raw_value() - assign a gpio's raw value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the raw value of the GPIO, i.e. the value of its physical line without
|
|
* regard for its ACTIVE_LOW status.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
|
|
{
|
|
if (!desc)
|
|
return;
|
|
/* Should be using gpio_set_value_cansleep() */
|
|
WARN_ON(desc->chip->can_sleep);
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
|
|
|
|
/**
|
|
* gpiod_set_value() - assign a gpio's value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
|
|
* account
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
void gpiod_set_value(struct gpio_desc *desc, int value)
|
|
{
|
|
if (!desc)
|
|
return;
|
|
/* Should be using gpio_set_value_cansleep() */
|
|
WARN_ON(desc->chip->can_sleep);
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_value);
|
|
|
|
/**
|
|
* gpiod_cansleep() - report whether gpio value access may sleep
|
|
* @desc: gpio to check
|
|
*
|
|
*/
|
|
int gpiod_cansleep(const struct gpio_desc *desc)
|
|
{
|
|
if (!desc)
|
|
return 0;
|
|
return desc->chip->can_sleep;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_cansleep);
|
|
|
|
/**
|
|
* gpiod_to_irq() - return the IRQ corresponding to a GPIO
|
|
* @desc: gpio whose IRQ will be returned (already requested)
|
|
*
|
|
* Return the IRQ corresponding to the passed GPIO, or an error code in case of
|
|
* error.
|
|
*/
|
|
int gpiod_to_irq(const struct gpio_desc *desc)
|
|
{
|
|
struct gpio_chip *chip;
|
|
int offset;
|
|
|
|
if (!desc)
|
|
return -EINVAL;
|
|
chip = desc->chip;
|
|
offset = gpio_chip_hwgpio(desc);
|
|
return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_to_irq);
|
|
|
|
/**
|
|
* gpiod_lock_as_irq() - lock a GPIO to be used as IRQ
|
|
* @gpio: the GPIO line to lock as used for IRQ
|
|
*
|
|
* This is used directly by GPIO drivers that want to lock down
|
|
* a certain GPIO line to be used for IRQs.
|
|
*/
|
|
int gpiod_lock_as_irq(struct gpio_desc *desc)
|
|
{
|
|
if (!desc)
|
|
return -EINVAL;
|
|
|
|
if (test_bit(FLAG_IS_OUT, &desc->flags)) {
|
|
gpiod_err(desc,
|
|
"%s: tried to flag a GPIO set as output for IRQ\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
set_bit(FLAG_USED_AS_IRQ, &desc->flags);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_lock_as_irq);
|
|
|
|
/**
|
|
* gpiod_unlock_as_irq() - unlock a GPIO used as IRQ
|
|
* @gpio: the GPIO line to unlock from IRQ usage
|
|
*
|
|
* This is used directly by GPIO drivers that want to indicate
|
|
* that a certain GPIO is no longer used exclusively for IRQ.
|
|
*/
|
|
void gpiod_unlock_as_irq(struct gpio_desc *desc)
|
|
{
|
|
if (!desc)
|
|
return;
|
|
|
|
clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq);
|
|
|
|
/**
|
|
* gpiod_get_raw_value_cansleep() - return a gpio's raw value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
|
|
* its ACTIVE_LOW status.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
if (!desc)
|
|
return 0;
|
|
return _gpiod_get_raw_value(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_get_value_cansleep() - return a gpio's value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
|
|
* account.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
int gpiod_get_value_cansleep(const struct gpio_desc *desc)
|
|
{
|
|
int value;
|
|
|
|
might_sleep_if(extra_checks);
|
|
if (!desc)
|
|
return 0;
|
|
|
|
value = _gpiod_get_raw_value(desc);
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
|
|
return value;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_set_raw_value_cansleep() - assign a gpio's raw value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the raw value of the GPIO, i.e. the value of its physical line without
|
|
* regard for its ACTIVE_LOW status.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
if (!desc)
|
|
return;
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_set_value_cansleep() - assign a gpio's value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
|
|
* account
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
if (!desc)
|
|
return;
|
|
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_add_lookup_table() - register GPIO device consumers
|
|
* @table: table of consumers to register
|
|
*/
|
|
void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
|
|
{
|
|
mutex_lock(&gpio_lookup_lock);
|
|
|
|
list_add_tail(&table->list, &gpio_lookup_list);
|
|
|
|
mutex_unlock(&gpio_lookup_lock);
|
|
}
|
|
|
|
static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
|
|
unsigned int idx,
|
|
enum gpio_lookup_flags *flags)
|
|
{
|
|
static const char *suffixes[] = { "gpios", "gpio" };
|
|
char prop_name[32]; /* 32 is max size of property name */
|
|
enum of_gpio_flags of_flags;
|
|
struct gpio_desc *desc;
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
|
|
if (con_id)
|
|
snprintf(prop_name, 32, "%s-%s", con_id, suffixes[i]);
|
|
else
|
|
snprintf(prop_name, 32, "%s", suffixes[i]);
|
|
|
|
desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
|
|
&of_flags);
|
|
if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
|
|
break;
|
|
}
|
|
|
|
if (IS_ERR(desc))
|
|
return desc;
|
|
|
|
if (of_flags & OF_GPIO_ACTIVE_LOW)
|
|
*flags |= GPIO_ACTIVE_LOW;
|
|
|
|
return desc;
|
|
}
|
|
|
|
static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
|
|
unsigned int idx,
|
|
enum gpio_lookup_flags *flags)
|
|
{
|
|
struct acpi_gpio_info info;
|
|
struct gpio_desc *desc;
|
|
|
|
desc = acpi_get_gpiod_by_index(dev, idx, &info);
|
|
if (IS_ERR(desc))
|
|
return desc;
|
|
|
|
if (info.gpioint && info.active_low)
|
|
*flags |= GPIO_ACTIVE_LOW;
|
|
|
|
return desc;
|
|
}
|
|
|
|
static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
|
|
{
|
|
const char *dev_id = dev ? dev_name(dev) : NULL;
|
|
struct gpiod_lookup_table *table;
|
|
|
|
mutex_lock(&gpio_lookup_lock);
|
|
|
|
list_for_each_entry(table, &gpio_lookup_list, list) {
|
|
if (table->dev_id && dev_id) {
|
|
/*
|
|
* Valid strings on both ends, must be identical to have
|
|
* a match
|
|
*/
|
|
if (!strcmp(table->dev_id, dev_id))
|
|
goto found;
|
|
} else {
|
|
/*
|
|
* One of the pointers is NULL, so both must be to have
|
|
* a match
|
|
*/
|
|
if (dev_id == table->dev_id)
|
|
goto found;
|
|
}
|
|
}
|
|
table = NULL;
|
|
|
|
found:
|
|
mutex_unlock(&gpio_lookup_lock);
|
|
return table;
|
|
}
|
|
|
|
static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
|
|
unsigned int idx,
|
|
enum gpio_lookup_flags *flags)
|
|
{
|
|
struct gpio_desc *desc = ERR_PTR(-ENOENT);
|
|
struct gpiod_lookup_table *table;
|
|
struct gpiod_lookup *p;
|
|
|
|
table = gpiod_find_lookup_table(dev);
|
|
if (!table)
|
|
return desc;
|
|
|
|
for (p = &table->table[0]; p->chip_label; p++) {
|
|
struct gpio_chip *chip;
|
|
|
|
/* idx must always match exactly */
|
|
if (p->idx != idx)
|
|
continue;
|
|
|
|
/* If the lookup entry has a con_id, require exact match */
|
|
if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
|
|
continue;
|
|
|
|
chip = find_chip_by_name(p->chip_label);
|
|
|
|
if (!chip) {
|
|
dev_err(dev, "cannot find GPIO chip %s\n",
|
|
p->chip_label);
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
if (chip->ngpio <= p->chip_hwnum) {
|
|
dev_err(dev,
|
|
"requested GPIO %d is out of range [0..%d] for chip %s\n",
|
|
idx, chip->ngpio, chip->label);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
desc = gpiochip_get_desc(chip, p->chip_hwnum);
|
|
*flags = p->flags;
|
|
|
|
return desc;
|
|
}
|
|
|
|
return desc;
|
|
}
|
|
|
|
/**
|
|
* gpiod_get - obtain a GPIO for a given GPIO function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
*
|
|
* Return the GPIO descriptor corresponding to the function con_id of device
|
|
* dev, -ENOENT if no GPIO has been assigned to the requested function, or
|
|
* another IS_ERR() code if an error occured while trying to acquire the GPIO.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id)
|
|
{
|
|
return gpiod_get_index(dev, con_id, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get);
|
|
|
|
/**
|
|
* gpiod_get_optional - obtain an optional GPIO for a given GPIO function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
*
|
|
* This is equivalent to gpiod_get(), except that when no GPIO was assigned to
|
|
* the requested function it will return NULL. This is convenient for drivers
|
|
* that need to handle optional GPIOs.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
|
|
const char *con_id)
|
|
{
|
|
return gpiod_get_index_optional(dev, con_id, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_optional);
|
|
|
|
/**
|
|
* gpiod_get_index - obtain a GPIO from a multi-index GPIO function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
* @idx: index of the GPIO to obtain in the consumer
|
|
*
|
|
* This variant of gpiod_get() allows to access GPIOs other than the first
|
|
* defined one for functions that define several GPIOs.
|
|
*
|
|
* Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
|
|
* requested function and/or index, or another IS_ERR() code if an error
|
|
* occured while trying to acquire the GPIO.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
|
|
const char *con_id,
|
|
unsigned int idx)
|
|
{
|
|
struct gpio_desc *desc = NULL;
|
|
int status;
|
|
enum gpio_lookup_flags flags = 0;
|
|
|
|
dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
|
|
|
|
/* Using device tree? */
|
|
if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) {
|
|
dev_dbg(dev, "using device tree for GPIO lookup\n");
|
|
desc = of_find_gpio(dev, con_id, idx, &flags);
|
|
} else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) {
|
|
dev_dbg(dev, "using ACPI for GPIO lookup\n");
|
|
desc = acpi_find_gpio(dev, con_id, idx, &flags);
|
|
}
|
|
|
|
/*
|
|
* Either we are not using DT or ACPI, or their lookup did not return
|
|
* a result. In that case, use platform lookup as a fallback.
|
|
*/
|
|
if (!desc || desc == ERR_PTR(-ENOENT)) {
|
|
dev_dbg(dev, "using lookup tables for GPIO lookup");
|
|
desc = gpiod_find(dev, con_id, idx, &flags);
|
|
}
|
|
|
|
if (IS_ERR(desc)) {
|
|
dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
|
|
return desc;
|
|
}
|
|
|
|
status = gpiod_request(desc, con_id);
|
|
|
|
if (status < 0)
|
|
return ERR_PTR(status);
|
|
|
|
if (flags & GPIO_ACTIVE_LOW)
|
|
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
if (flags & GPIO_OPEN_DRAIN)
|
|
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
|
|
if (flags & GPIO_OPEN_SOURCE)
|
|
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
|
|
|
|
return desc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_index);
|
|
|
|
/**
|
|
* gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
|
|
* function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
* @index: index of the GPIO to obtain in the consumer
|
|
*
|
|
* This is equivalent to gpiod_get_index(), except that when no GPIO with the
|
|
* specified index was assigned to the requested function it will return NULL.
|
|
* This is convenient for drivers that need to handle optional GPIOs.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
|
|
const char *con_id,
|
|
unsigned int index)
|
|
{
|
|
struct gpio_desc *desc;
|
|
|
|
desc = gpiod_get_index(dev, con_id, index);
|
|
if (IS_ERR(desc)) {
|
|
if (PTR_ERR(desc) == -ENOENT)
|
|
return NULL;
|
|
}
|
|
|
|
return desc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
|
|
|
|
/**
|
|
* gpiod_put - dispose of a GPIO descriptor
|
|
* @desc: GPIO descriptor to dispose of
|
|
*
|
|
* No descriptor can be used after gpiod_put() has been called on it.
|
|
*/
|
|
void gpiod_put(struct gpio_desc *desc)
|
|
{
|
|
gpiod_free(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_put);
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
|
|
static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
|
|
{
|
|
unsigned i;
|
|
unsigned gpio = chip->base;
|
|
struct gpio_desc *gdesc = &chip->desc[0];
|
|
int is_out;
|
|
int is_irq;
|
|
|
|
for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
|
|
if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
|
|
continue;
|
|
|
|
gpiod_get_direction(gdesc);
|
|
is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
|
|
is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
|
|
seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
|
|
gpio, gdesc->label,
|
|
is_out ? "out" : "in ",
|
|
chip->get
|
|
? (chip->get(chip, i) ? "hi" : "lo")
|
|
: "? ",
|
|
is_irq ? "IRQ" : " ");
|
|
seq_printf(s, "\n");
|
|
}
|
|
}
|
|
|
|
static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip = NULL;
|
|
loff_t index = *pos;
|
|
|
|
s->private = "";
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
list_for_each_entry(chip, &gpio_chips, list)
|
|
if (index-- == 0) {
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
return chip;
|
|
}
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip = v;
|
|
void *ret = NULL;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
if (list_is_last(&chip->list, &gpio_chips))
|
|
ret = NULL;
|
|
else
|
|
ret = list_entry(chip->list.next, struct gpio_chip, list);
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
s->private = "\n";
|
|
++*pos;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void gpiolib_seq_stop(struct seq_file *s, void *v)
|
|
{
|
|
}
|
|
|
|
static int gpiolib_seq_show(struct seq_file *s, void *v)
|
|
{
|
|
struct gpio_chip *chip = v;
|
|
struct device *dev;
|
|
|
|
seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
|
|
chip->base, chip->base + chip->ngpio - 1);
|
|
dev = chip->dev;
|
|
if (dev)
|
|
seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
|
|
dev_name(dev));
|
|
if (chip->label)
|
|
seq_printf(s, ", %s", chip->label);
|
|
if (chip->can_sleep)
|
|
seq_printf(s, ", can sleep");
|
|
seq_printf(s, ":\n");
|
|
|
|
if (chip->dbg_show)
|
|
chip->dbg_show(s, chip);
|
|
else
|
|
gpiolib_dbg_show(s, chip);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations gpiolib_seq_ops = {
|
|
.start = gpiolib_seq_start,
|
|
.next = gpiolib_seq_next,
|
|
.stop = gpiolib_seq_stop,
|
|
.show = gpiolib_seq_show,
|
|
};
|
|
|
|
static int gpiolib_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &gpiolib_seq_ops);
|
|
}
|
|
|
|
static const struct file_operations gpiolib_operations = {
|
|
.owner = THIS_MODULE,
|
|
.open = gpiolib_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static int __init gpiolib_debugfs_init(void)
|
|
{
|
|
/* /sys/kernel/debug/gpio */
|
|
(void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
|
|
NULL, NULL, &gpiolib_operations);
|
|
return 0;
|
|
}
|
|
subsys_initcall(gpiolib_debugfs_init);
|
|
|
|
#endif /* DEBUG_FS */
|