linux/drivers/platform/x86/barco-p50-gpio.c
Uwe Kleine-König f4278cc877 platform/x86: barco-p50-gpio: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230302144732.1903781-8-u.kleine-koenig@pengutronix.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2023-03-07 12:19:45 +01:00

437 lines
9.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Support for EC-connected GPIOs for identify
* LED/button on Barco P50 board
*
* Copyright (C) 2021 Barco NV
* Author: Santosh Kumar Yadav <santoshkumar.yadav@barco.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio_keys.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/input.h>
#define DRIVER_NAME "barco-p50-gpio"
/* GPIO lines */
#define P50_GPIO_LINE_LED 0
#define P50_GPIO_LINE_BTN 1
/* GPIO IO Ports */
#define P50_GPIO_IO_PORT_BASE 0x299
#define P50_PORT_DATA 0x00
#define P50_PORT_CMD 0x01
#define P50_STATUS_OBF 0x01 /* EC output buffer full */
#define P50_STATUS_IBF 0x02 /* EC input buffer full */
#define P50_CMD_READ 0xa0
#define P50_CMD_WRITE 0x50
/* EC mailbox registers */
#define P50_MBOX_REG_CMD 0x00
#define P50_MBOX_REG_STATUS 0x01
#define P50_MBOX_REG_PARAM 0x02
#define P50_MBOX_REG_DATA 0x03
#define P50_MBOX_CMD_READ_GPIO 0x11
#define P50_MBOX_CMD_WRITE_GPIO 0x12
#define P50_MBOX_CMD_CLEAR 0xff
#define P50_MBOX_STATUS_SUCCESS 0x01
#define P50_MBOX_PARAM_LED 0x12
#define P50_MBOX_PARAM_BTN 0x13
struct p50_gpio {
struct gpio_chip gc;
struct mutex lock;
unsigned long base;
struct platform_device *leds_pdev;
struct platform_device *keys_pdev;
};
static struct platform_device *gpio_pdev;
static int gpio_params[] = {
[P50_GPIO_LINE_LED] = P50_MBOX_PARAM_LED,
[P50_GPIO_LINE_BTN] = P50_MBOX_PARAM_BTN,
};
static const char * const gpio_names[] = {
[P50_GPIO_LINE_LED] = "identify-led",
[P50_GPIO_LINE_BTN] = "identify-button",
};
static struct gpiod_lookup_table p50_gpio_led_table = {
.dev_id = "leds-gpio",
.table = {
GPIO_LOOKUP_IDX(DRIVER_NAME, P50_GPIO_LINE_LED, NULL, 0, GPIO_ACTIVE_HIGH),
{}
}
};
/* GPIO LEDs */
static struct gpio_led leds[] = {
{ .name = "identify" }
};
static struct gpio_led_platform_data leds_pdata = {
.num_leds = ARRAY_SIZE(leds),
.leds = leds,
};
/* GPIO keyboard */
static struct gpio_keys_button buttons[] = {
{
.code = KEY_VENDOR,
.gpio = P50_GPIO_LINE_BTN,
.active_low = 1,
.type = EV_KEY,
.value = 1,
},
};
static struct gpio_keys_platform_data keys_pdata = {
.buttons = buttons,
.nbuttons = ARRAY_SIZE(buttons),
.poll_interval = 100,
.rep = 0,
.name = "identify",
};
/* low level access routines */
static int p50_wait_ec(struct p50_gpio *p50, int mask, int expected)
{
int i, val;
for (i = 0; i < 100; i++) {
val = inb(p50->base + P50_PORT_CMD) & mask;
if (val == expected)
return 0;
usleep_range(500, 2000);
}
dev_err(p50->gc.parent, "Timed out waiting for EC (0x%x)\n", val);
return -ETIMEDOUT;
}
static int p50_read_mbox_reg(struct p50_gpio *p50, int reg)
{
int ret;
ret = p50_wait_ec(p50, P50_STATUS_IBF, 0);
if (ret)
return ret;
/* clear output buffer flag, prevent unfinished commands */
inb(p50->base + P50_PORT_DATA);
/* cmd/address */
outb(P50_CMD_READ | reg, p50->base + P50_PORT_CMD);
ret = p50_wait_ec(p50, P50_STATUS_OBF, P50_STATUS_OBF);
if (ret)
return ret;
return inb(p50->base + P50_PORT_DATA);
}
static int p50_write_mbox_reg(struct p50_gpio *p50, int reg, int val)
{
int ret;
ret = p50_wait_ec(p50, P50_STATUS_IBF, 0);
if (ret)
return ret;
/* cmd/address */
outb(P50_CMD_WRITE | reg, p50->base + P50_PORT_CMD);
ret = p50_wait_ec(p50, P50_STATUS_IBF, 0);
if (ret)
return ret;
/* data */
outb(val, p50->base + P50_PORT_DATA);
return 0;
}
/* mbox routines */
static int p50_wait_mbox_idle(struct p50_gpio *p50)
{
int i, val;
for (i = 0; i < 1000; i++) {
val = p50_read_mbox_reg(p50, P50_MBOX_REG_CMD);
/* cmd is 0 when idle */
if (val <= 0)
return val;
usleep_range(500, 2000);
}
dev_err(p50->gc.parent, "Timed out waiting for EC mbox idle (CMD: 0x%x)\n", val);
return -ETIMEDOUT;
}
static int p50_send_mbox_cmd(struct p50_gpio *p50, int cmd, int param, int data)
{
int ret;
ret = p50_wait_mbox_idle(p50);
if (ret)
return ret;
ret = p50_write_mbox_reg(p50, P50_MBOX_REG_DATA, data);
if (ret)
return ret;
ret = p50_write_mbox_reg(p50, P50_MBOX_REG_PARAM, param);
if (ret)
return ret;
ret = p50_write_mbox_reg(p50, P50_MBOX_REG_CMD, cmd);
if (ret)
return ret;
ret = p50_wait_mbox_idle(p50);
if (ret)
return ret;
ret = p50_read_mbox_reg(p50, P50_MBOX_REG_STATUS);
if (ret < 0)
return ret;
if (ret == P50_MBOX_STATUS_SUCCESS)
return 0;
dev_err(p50->gc.parent, "Mbox command failed (CMD=0x%x STAT=0x%x PARAM=0x%x DATA=0x%x)\n",
cmd, ret, param, data);
return -EIO;
}
/* gpio routines */
static int p50_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
switch (offset) {
case P50_GPIO_LINE_BTN:
return GPIO_LINE_DIRECTION_IN;
case P50_GPIO_LINE_LED:
return GPIO_LINE_DIRECTION_OUT;
default:
return -EINVAL;
}
}
static int p50_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
struct p50_gpio *p50 = gpiochip_get_data(gc);
int ret;
mutex_lock(&p50->lock);
ret = p50_send_mbox_cmd(p50, P50_MBOX_CMD_READ_GPIO, gpio_params[offset], 0);
if (ret == 0)
ret = p50_read_mbox_reg(p50, P50_MBOX_REG_DATA);
mutex_unlock(&p50->lock);
return ret;
}
static void p50_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
{
struct p50_gpio *p50 = gpiochip_get_data(gc);
mutex_lock(&p50->lock);
p50_send_mbox_cmd(p50, P50_MBOX_CMD_WRITE_GPIO, gpio_params[offset], value);
mutex_unlock(&p50->lock);
}
static int p50_gpio_probe(struct platform_device *pdev)
{
struct p50_gpio *p50;
struct resource *res;
int ret;
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (!res) {
dev_err(&pdev->dev, "Cannot get I/O ports\n");
return -ENODEV;
}
if (!devm_request_region(&pdev->dev, res->start, resource_size(res), pdev->name)) {
dev_err(&pdev->dev, "Unable to reserve I/O region\n");
return -EBUSY;
}
p50 = devm_kzalloc(&pdev->dev, sizeof(*p50), GFP_KERNEL);
if (!p50)
return -ENOMEM;
platform_set_drvdata(pdev, p50);
mutex_init(&p50->lock);
p50->base = res->start;
p50->gc.owner = THIS_MODULE;
p50->gc.parent = &pdev->dev;
p50->gc.label = dev_name(&pdev->dev);
p50->gc.ngpio = ARRAY_SIZE(gpio_names);
p50->gc.names = gpio_names;
p50->gc.can_sleep = true;
p50->gc.base = -1;
p50->gc.get_direction = p50_gpio_get_direction;
p50->gc.get = p50_gpio_get;
p50->gc.set = p50_gpio_set;
/* reset mbox */
ret = p50_wait_mbox_idle(p50);
if (ret)
return ret;
ret = p50_write_mbox_reg(p50, P50_MBOX_REG_CMD, P50_MBOX_CMD_CLEAR);
if (ret)
return ret;
ret = p50_wait_mbox_idle(p50);
if (ret)
return ret;
ret = devm_gpiochip_add_data(&pdev->dev, &p50->gc, p50);
if (ret < 0) {
dev_err(&pdev->dev, "Could not register gpiochip: %d\n", ret);
return ret;
}
gpiod_add_lookup_table(&p50_gpio_led_table);
p50->leds_pdev = platform_device_register_data(&pdev->dev,
"leds-gpio", PLATFORM_DEVID_NONE, &leds_pdata, sizeof(leds_pdata));
if (IS_ERR(p50->leds_pdev)) {
ret = PTR_ERR(p50->leds_pdev);
dev_err(&pdev->dev, "Could not register leds-gpio: %d\n", ret);
goto err_leds;
}
/* gpio-keys-polled uses old-style gpio interface, pass the right identifier */
buttons[0].gpio += p50->gc.base;
p50->keys_pdev =
platform_device_register_data(&pdev->dev, "gpio-keys-polled",
PLATFORM_DEVID_NONE,
&keys_pdata, sizeof(keys_pdata));
if (IS_ERR(p50->keys_pdev)) {
ret = PTR_ERR(p50->keys_pdev);
dev_err(&pdev->dev, "Could not register gpio-keys-polled: %d\n", ret);
goto err_keys;
}
return 0;
err_keys:
platform_device_unregister(p50->leds_pdev);
err_leds:
gpiod_remove_lookup_table(&p50_gpio_led_table);
return ret;
}
static void p50_gpio_remove(struct platform_device *pdev)
{
struct p50_gpio *p50 = platform_get_drvdata(pdev);
platform_device_unregister(p50->keys_pdev);
platform_device_unregister(p50->leds_pdev);
gpiod_remove_lookup_table(&p50_gpio_led_table);
}
static struct platform_driver p50_gpio_driver = {
.driver = {
.name = DRIVER_NAME,
},
.probe = p50_gpio_probe,
.remove_new = p50_gpio_remove,
};
/* Board setup */
static const struct dmi_system_id dmi_ids[] __initconst = {
{
.matches = {
DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Barco"),
DMI_EXACT_MATCH(DMI_PRODUCT_FAMILY, "P50")
},
},
{}
};
MODULE_DEVICE_TABLE(dmi, dmi_ids);
static int __init p50_module_init(void)
{
struct resource res = DEFINE_RES_IO(P50_GPIO_IO_PORT_BASE, P50_PORT_CMD + 1);
int ret;
if (!dmi_first_match(dmi_ids))
return -ENODEV;
ret = platform_driver_register(&p50_gpio_driver);
if (ret)
return ret;
gpio_pdev = platform_device_register_simple(DRIVER_NAME, PLATFORM_DEVID_NONE, &res, 1);
if (IS_ERR(gpio_pdev)) {
pr_err("failed registering %s: %ld\n", DRIVER_NAME, PTR_ERR(gpio_pdev));
platform_driver_unregister(&p50_gpio_driver);
return PTR_ERR(gpio_pdev);
}
return 0;
}
static void __exit p50_module_exit(void)
{
platform_device_unregister(gpio_pdev);
platform_driver_unregister(&p50_gpio_driver);
}
module_init(p50_module_init);
module_exit(p50_module_exit);
MODULE_AUTHOR("Santosh Kumar Yadav, Barco NV <santoshkumar.yadav@barco.com>");
MODULE_DESCRIPTION("Barco P50 identify GPIOs driver");
MODULE_LICENSE("GPL");