mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 20:48:49 +08:00
b7b56e64a3
We're porting all users of gpiochip_find() to using gpio_device_find(). Update the swnode GPIO code. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
124 lines
3.2 KiB
C
124 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Software Node helpers for the GPIO API
|
|
*
|
|
* Copyright 2022 Google LLC
|
|
*/
|
|
#include <linux/err.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/printk.h>
|
|
#include <linux/property.h>
|
|
#include <linux/string.h>
|
|
|
|
#include <linux/gpio/consumer.h>
|
|
#include <linux/gpio/driver.h>
|
|
|
|
#include "gpiolib.h"
|
|
#include "gpiolib-swnode.h"
|
|
|
|
static void swnode_format_propname(const char *con_id, char *propname,
|
|
size_t max_size)
|
|
{
|
|
/*
|
|
* Note we do not need to try both -gpios and -gpio suffixes,
|
|
* as, unlike OF and ACPI, we can fix software nodes to conform
|
|
* to the proper binding.
|
|
*/
|
|
if (con_id)
|
|
snprintf(propname, max_size, "%s-gpios", con_id);
|
|
else
|
|
strscpy(propname, "gpios", max_size);
|
|
}
|
|
|
|
static struct gpio_device *swnode_get_gpio_device(struct fwnode_handle *fwnode)
|
|
{
|
|
const struct software_node *gdev_node;
|
|
struct gpio_device *gdev;
|
|
|
|
gdev_node = to_software_node(fwnode);
|
|
if (!gdev_node || !gdev_node->name)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
gdev = gpio_device_find_by_label(gdev_node->name);
|
|
return gdev ?: ERR_PTR(-EPROBE_DEFER);
|
|
}
|
|
|
|
struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode,
|
|
const char *con_id, unsigned int idx,
|
|
unsigned long *flags)
|
|
{
|
|
const struct software_node *swnode;
|
|
struct fwnode_reference_args args;
|
|
struct gpio_desc *desc;
|
|
char propname[32]; /* 32 is max size of property name */
|
|
int error;
|
|
|
|
swnode = to_software_node(fwnode);
|
|
if (!swnode)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
swnode_format_propname(con_id, propname, sizeof(propname));
|
|
|
|
/*
|
|
* We expect all swnode-described GPIOs have GPIO number and
|
|
* polarity arguments, hence nargs is set to 2.
|
|
*/
|
|
error = fwnode_property_get_reference_args(fwnode, propname, NULL, 2, idx, &args);
|
|
if (error) {
|
|
pr_debug("%s: can't parse '%s' property of node '%pfwP[%d]'\n",
|
|
__func__, propname, fwnode, idx);
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
struct gpio_device *gdev __free(gpio_device_put) =
|
|
swnode_get_gpio_device(args.fwnode);
|
|
fwnode_handle_put(args.fwnode);
|
|
if (IS_ERR(gdev))
|
|
return ERR_CAST(gdev);
|
|
|
|
/*
|
|
* FIXME: The GPIO device reference is put at return but the descriptor
|
|
* is passed on. Find a proper solution.
|
|
*/
|
|
desc = gpio_device_get_desc(gdev, args.args[0]);
|
|
*flags = args.args[1]; /* We expect native GPIO flags */
|
|
|
|
pr_debug("%s: parsed '%s' property of node '%pfwP[%d]' - status (%d)\n",
|
|
__func__, propname, fwnode, idx, PTR_ERR_OR_ZERO(desc));
|
|
|
|
return desc;
|
|
}
|
|
|
|
/**
|
|
* swnode_gpio_count - count the GPIOs associated with a device / function
|
|
* @fwnode: firmware node of the GPIO consumer, can be %NULL for
|
|
* system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
*
|
|
* Return:
|
|
* The number of GPIOs associated with a device / function or %-ENOENT,
|
|
* if no GPIO has been assigned to the requested function.
|
|
*/
|
|
int swnode_gpio_count(const struct fwnode_handle *fwnode, const char *con_id)
|
|
{
|
|
struct fwnode_reference_args args;
|
|
char propname[32];
|
|
int count;
|
|
|
|
swnode_format_propname(con_id, propname, sizeof(propname));
|
|
|
|
/*
|
|
* This is not very efficient, but GPIO lists usually have only
|
|
* 1 or 2 entries.
|
|
*/
|
|
count = 0;
|
|
while (fwnode_property_get_reference_args(fwnode, propname, NULL, 0,
|
|
count, &args) == 0) {
|
|
fwnode_handle_put(args.fwnode);
|
|
count++;
|
|
}
|
|
|
|
return count ?: -ENOENT;
|
|
}
|