Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 202 insertions, 0 deletions

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 <daniel@zonque.org>
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/leds.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <uapi/linux/uleds.h>
+
+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 <daniel@zonque.org>");
+MODULE_DESCRIPTION("LED driver for LT3593 controllers");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:leds-lt3593");