From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- drivers/leds/leds-lt3593.c | 202 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 drivers/leds/leds-lt3593.c (limited to 'drivers/leds/leds-lt3593.c') diff --git a/drivers/leds/leds-lt3593.c b/drivers/leds/leds-lt3593.c new file mode 100644 index 000000000..de3623e0d --- /dev/null +++ b/drivers/leds/leds-lt3593.c @@ -0,0 +1,202 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2009,2018 Daniel Mack + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct lt3593_led_data { + char name[LED_MAX_NAME_SIZE]; + struct led_classdev cdev; + struct gpio_desc *gpiod; +}; + +static int lt3593_led_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + struct lt3593_led_data *led_dat = + container_of(led_cdev, struct lt3593_led_data, cdev); + int pulses; + + /* + * The LT3593 resets its internal current level register to the maximum + * level on the first falling edge on the control pin. Each following + * falling edge decreases the current level by 625uA. Up to 32 pulses + * can be sent, so the maximum power reduction is 20mA. + * After a timeout of 128us, the value is taken from the register and + * applied is to the output driver. + */ + + if (value == 0) { + gpiod_set_value_cansleep(led_dat->gpiod, 0); + return 0; + } + + pulses = 32 - (value * 32) / 255; + + if (pulses == 0) { + gpiod_set_value_cansleep(led_dat->gpiod, 0); + mdelay(1); + gpiod_set_value_cansleep(led_dat->gpiod, 1); + return 0; + } + + gpiod_set_value_cansleep(led_dat->gpiod, 1); + + while (pulses--) { + gpiod_set_value_cansleep(led_dat->gpiod, 0); + udelay(1); + gpiod_set_value_cansleep(led_dat->gpiod, 1); + udelay(1); + } + + return 0; +} + +static struct lt3593_led_data *lt3593_led_probe_pdata(struct device *dev) +{ + struct gpio_led_platform_data *pdata = dev_get_platdata(dev); + const struct gpio_led *template = &pdata->leds[0]; + struct lt3593_led_data *led_data; + int ret, state; + + if (pdata->num_leds != 1) + return ERR_PTR(-EINVAL); + + led_data = devm_kzalloc(dev, sizeof(*led_data), GFP_KERNEL); + if (!led_data) + return ERR_PTR(-ENOMEM); + + led_data->cdev.name = template->name; + led_data->cdev.default_trigger = template->default_trigger; + led_data->cdev.brightness_set_blocking = lt3593_led_set; + + state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); + led_data->cdev.brightness = state ? LED_FULL : LED_OFF; + + if (!template->retain_state_suspended) + led_data->cdev.flags |= LED_CORE_SUSPENDRESUME; + + ret = devm_gpio_request_one(dev, template->gpio, state ? + GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, + template->name); + if (ret < 0) + return ERR_PTR(ret); + + led_data->gpiod = gpio_to_desc(template->gpio); + if (!led_data->gpiod) + return ERR_PTR(-EPROBE_DEFER); + + ret = devm_led_classdev_register(dev, &led_data->cdev); + if (ret < 0) + return ERR_PTR(ret); + + dev_info(dev, "registered LT3593 LED '%s' at GPIO %d\n", + template->name, template->gpio); + + return led_data; +} + +static int lt3593_led_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct lt3593_led_data *led_data; + struct fwnode_handle *child; + int ret, state = LEDS_GPIO_DEFSTATE_OFF; + enum gpiod_flags flags = GPIOD_OUT_LOW; + const char *tmp; + + if (dev_get_platdata(dev)) { + led_data = lt3593_led_probe_pdata(dev); + if (IS_ERR(led_data)) + return PTR_ERR(led_data); + + goto out; + } + + if (!dev->of_node) + return -ENODEV; + + led_data = devm_kzalloc(dev, sizeof(*led_data), GFP_KERNEL); + if (!led_data) + return -ENOMEM; + + if (device_get_child_node_count(dev) != 1) { + dev_err(dev, "Device must have exactly one LED sub-node."); + return -EINVAL; + } + + led_data->gpiod = devm_gpiod_get(dev, "lltc,ctrl", 0); + if (IS_ERR(led_data->gpiod)) + return PTR_ERR(led_data->gpiod); + + child = device_get_next_child_node(dev, NULL); + + ret = fwnode_property_read_string(child, "label", &tmp); + if (ret < 0) + snprintf(led_data->name, sizeof(led_data->name), + "lt3593::"); + else + snprintf(led_data->name, sizeof(led_data->name), + "lt3593:%s", tmp); + + fwnode_property_read_string(child, "linux,default-trigger", + &led_data->cdev.default_trigger); + + if (!fwnode_property_read_string(child, "default-state", &tmp)) { + if (!strcmp(tmp, "keep")) { + state = LEDS_GPIO_DEFSTATE_KEEP; + flags = GPIOD_ASIS; + } else if (!strcmp(tmp, "on")) { + state = LEDS_GPIO_DEFSTATE_ON; + flags = GPIOD_OUT_HIGH; + } + } + + led_data->cdev.name = led_data->name; + led_data->cdev.brightness_set_blocking = lt3593_led_set; + led_data->cdev.brightness = state ? LED_FULL : LED_OFF; + + ret = devm_led_classdev_register(dev, &led_data->cdev); + if (ret < 0) { + fwnode_handle_put(child); + return ret; + } + + led_data->cdev.dev->of_node = dev->of_node; + +out: + platform_set_drvdata(pdev, led_data); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id of_lt3593_leds_match[] = { + { .compatible = "lltc,lt3593", }, + {}, +}; +MODULE_DEVICE_TABLE(of, of_lt3593_leds_match); +#endif + +static struct platform_driver lt3593_led_driver = { + .probe = lt3593_led_probe, + .driver = { + .name = "leds-lt3593", + .of_match_table = of_match_ptr(of_lt3593_leds_match), + }, +}; + +module_platform_driver(lt3593_led_driver); + +MODULE_AUTHOR("Daniel Mack "); +MODULE_DESCRIPTION("LED driver for LT3593 controllers"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:leds-lt3593"); -- cgit v1.2.3