diff options
Diffstat (limited to 'drivers/platform/x86/barco-p50-gpio.c')
| -rw-r--r-- | drivers/platform/x86/barco-p50-gpio.c | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/drivers/platform/x86/barco-p50-gpio.c b/drivers/platform/x86/barco-p50-gpio.c new file mode 100644 index 000000000000..f5c72e33f9ae --- /dev/null +++ b/drivers/platform/x86/barco-p50-gpio.c @@ -0,0 +1,436 @@ +// 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/io.h> +#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 int 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); + + return 0; +} + +static struct platform_driver p50_gpio_driver = { + .driver = { + .name = DRIVER_NAME, + }, + .probe = p50_gpio_probe, + .remove = 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); + + if (!dmi_first_match(dmi_ids)) + return -ENODEV; + + platform_driver_register(&p50_gpio_driver); + + 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"); |