// 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 <[email protected]>
*/
#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 <[email protected]>");
MODULE_DESCRIPTION("Barco P50 identify GPIOs driver");
MODULE_LICENSE("GPL");
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