linux/net/rfkill/rfkill-gpio.c
Rouven Czerwinski 23484d8170 net: rfkill: gpio: set GPIO direction
Fix the undefined usage of the GPIO consumer API after retrieving the
GPIO description with GPIO_ASIS. The API documentation mentions that
GPIO_ASIS won't set a GPIO direction and requires the user to set a
direction before using the GPIO.

This can be confirmed on i.MX6 hardware, where rfkill-gpio is no longer
able to enabled/disable a device, presumably because the GPIO controller
was never configured for the output direction.

Fixes: b2f750c3a8 ("net: rfkill: gpio: prevent value glitch during probe")
Cc: stable@vger.kernel.org
Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
Link: https://msgid.link/20231207075835.3091694-1-r.czerwinski@pengutronix.de
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-12-12 10:14:57 +01:00

199 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2011, NVIDIA Corporation.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/rfkill.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/gpio/consumer.h>
struct rfkill_gpio_data {
const char *name;
enum rfkill_type type;
struct gpio_desc *reset_gpio;
struct gpio_desc *shutdown_gpio;
struct rfkill *rfkill_dev;
struct clk *clk;
bool clk_enabled;
};
static int rfkill_gpio_set_power(void *data, bool blocked)
{
struct rfkill_gpio_data *rfkill = data;
if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
clk_enable(rfkill->clk);
gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
clk_disable(rfkill->clk);
rfkill->clk_enabled = !blocked;
return 0;
}
static const struct rfkill_ops rfkill_gpio_ops = {
.set_block = rfkill_gpio_set_power,
};
static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
{ "reset-gpios", &reset_gpios, 1 },
{ "shutdown-gpios", &shutdown_gpios, 1 },
{ },
};
static int rfkill_gpio_acpi_probe(struct device *dev,
struct rfkill_gpio_data *rfkill)
{
const struct acpi_device_id *id;
id = acpi_match_device(dev->driver->acpi_match_table, dev);
if (!id)
return -ENODEV;
rfkill->type = (unsigned)id->driver_data;
return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
}
static int rfkill_gpio_probe(struct platform_device *pdev)
{
struct rfkill_gpio_data *rfkill;
struct gpio_desc *gpio;
const char *name_property;
const char *type_property;
const char *type_name;
int ret;
rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
if (!rfkill)
return -ENOMEM;
if (dev_of_node(&pdev->dev)) {
name_property = "label";
type_property = "radio-type";
} else {
name_property = "name";
type_property = "type";
}
device_property_read_string(&pdev->dev, name_property, &rfkill->name);
device_property_read_string(&pdev->dev, type_property, &type_name);
if (!rfkill->name)
rfkill->name = dev_name(&pdev->dev);
rfkill->type = rfkill_find_type(type_name);
if (ACPI_HANDLE(&pdev->dev)) {
ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
if (ret)
return ret;
}
rfkill->clk = devm_clk_get(&pdev->dev, NULL);
gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS);
if (IS_ERR(gpio))
return PTR_ERR(gpio);
rfkill->reset_gpio = gpio;
gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS);
if (IS_ERR(gpio))
return PTR_ERR(gpio);
rfkill->shutdown_gpio = gpio;
/* Make sure at-least one GPIO is defined for this instance */
if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
dev_err(&pdev->dev, "invalid platform data\n");
return -EINVAL;
}
ret = gpiod_direction_output(rfkill->reset_gpio, true);
if (ret)
return ret;
ret = gpiod_direction_output(rfkill->shutdown_gpio, true);
if (ret)
return ret;
rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
rfkill->type, &rfkill_gpio_ops,
rfkill);
if (!rfkill->rfkill_dev)
return -ENOMEM;
ret = rfkill_register(rfkill->rfkill_dev);
if (ret < 0)
goto err_destroy;
platform_set_drvdata(pdev, rfkill);
dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
return 0;
err_destroy:
rfkill_destroy(rfkill->rfkill_dev);
return ret;
}
static int rfkill_gpio_remove(struct platform_device *pdev)
{
struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
rfkill_unregister(rfkill->rfkill_dev);
rfkill_destroy(rfkill->rfkill_dev);
return 0;
}
#ifdef CONFIG_ACPI
static const struct acpi_device_id rfkill_acpi_match[] = {
{ "BCM4752", RFKILL_TYPE_GPS },
{ "LNV4752", RFKILL_TYPE_GPS },
{ },
};
MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
#endif
static const struct of_device_id rfkill_of_match[] __maybe_unused = {
{ .compatible = "rfkill-gpio", },
{ },
};
MODULE_DEVICE_TABLE(of, rfkill_of_match);
static struct platform_driver rfkill_gpio_driver = {
.probe = rfkill_gpio_probe,
.remove = rfkill_gpio_remove,
.driver = {
.name = "rfkill_gpio",
.acpi_match_table = ACPI_PTR(rfkill_acpi_match),
.of_match_table = of_match_ptr(rfkill_of_match),
},
};
module_platform_driver(rfkill_gpio_driver);
MODULE_DESCRIPTION("gpio rfkill");
MODULE_AUTHOR("NVIDIA");
MODULE_LICENSE("GPL");