gpio: Rework of_gpiochip_set_names() to use device property accessors

In order to use "gpio-line-names" property in systems not having DT as
their boot firmware, rework of_gpiochip_set_names() to use device property
accessors. This reworked function is placed in a separate file making it
clear it deals with universal device properties.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Mika Westerberg 2016-10-21 17:21:31 +03:00 committed by Linus Walleij
parent c80f1ba75d
commit 9427ecbed4
4 changed files with 66 additions and 46 deletions

View File

@ -5,6 +5,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG
obj-$(CONFIG_GPIO_DEVRES) += devres.o
obj-$(CONFIG_GPIOLIB) += gpiolib.o
obj-$(CONFIG_GPIOLIB) += gpiolib-legacy.o
obj-$(CONFIG_GPIOLIB) += gpiolib-devprop.o
obj-$(CONFIG_OF_GPIO) += gpiolib-of.o
obj-$(CONFIG_GPIO_SYSFS) += gpiolib-sysfs.o
obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o

View File

@ -0,0 +1,62 @@
/*
* Device property helpers for GPIO chips.
*
* Copyright (C) 2016, Intel Corporation
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include "gpiolib.h"
/**
* devprop_gpiochip_set_names - Set GPIO line names using device properties
* @chip: GPIO chip whose lines should be named, if possible
*
* Looks for device property "gpio-line-names" and if it exists assigns
* GPIO line names for the chip. The memory allocated for the assigned
* names belong to the underlying firmware node and should not be released
* by the caller.
*/
void devprop_gpiochip_set_names(struct gpio_chip *chip)
{
struct gpio_device *gdev = chip->gpiodev;
const char **names;
int ret, i;
ret = device_property_read_string_array(chip->parent, "gpio-line-names",
NULL, 0);
if (ret < 0)
return;
if (ret != gdev->ngpio) {
dev_warn(chip->parent,
"names %d do not match number of GPIOs %d\n", ret,
gdev->ngpio);
return;
}
names = kcalloc(gdev->ngpio, sizeof(*names), GFP_KERNEL);
if (!names)
return;
ret = device_property_read_string_array(chip->parent, "gpio-line-names",
names, gdev->ngpio);
if (ret < 0) {
dev_warn(chip->parent, "failed to read GPIO line names\n");
kfree(names);
return;
}
for (i = 0; i < gdev->ngpio; i++)
gdev->descs[i].name = names[i];
kfree(names);
}

View File

@ -221,51 +221,6 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
return desc;
}
/**
* of_gpiochip_set_names() - set up the names of the lines
* @chip: GPIO chip whose lines should be named, if possible
*/
static void of_gpiochip_set_names(struct gpio_chip *gc)
{
struct gpio_device *gdev = gc->gpiodev;
struct device_node *np = gc->of_node;
int i;
int nstrings;
nstrings = of_property_count_strings(np, "gpio-line-names");
if (nstrings <= 0)
/* Lines names not present */
return;
/* This is normally not what you want */
if (gdev->ngpio != nstrings)
dev_info(&gdev->dev, "gpio-line-names specifies %d line "
"names but there are %d lines on the chip\n",
nstrings, gdev->ngpio);
/*
* Make sure to not index beyond the end of the number of descriptors
* of the GPIO device.
*/
for (i = 0; i < gdev->ngpio; i++) {
const char *name;
int ret;
ret = of_property_read_string_index(np,
"gpio-line-names",
i,
&name);
if (ret) {
if (ret != -ENODATA)
dev_err(&gdev->dev,
"unable to name line %d: %d\n",
i, ret);
break;
}
gdev->descs[i].name = name;
}
}
/**
* of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
* @chip: gpio chip to act on
@ -522,7 +477,7 @@ int of_gpiochip_add(struct gpio_chip *chip)
/* If the chip defines names itself, these take precedence */
if (!chip->names)
of_gpiochip_set_names(chip);
devprop_gpiochip_set_names(chip);
of_node_get(chip->of_node);

View File

@ -209,6 +209,8 @@ static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
return desc - &desc->gdev->descs[0];
}
void devprop_gpiochip_set_names(struct gpio_chip *chip);
/* With descriptor prefix */
#define gpiod_emerg(desc, fmt, ...) \