--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TI LP8864/LP8866 4/6 Channel LED Driver
+ *
+ * Copyright (C) 2024 Siemens AG
+ *
+ * Based on LP8860 driver by Dan Murphy <dmurphy@ti.com>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#define LP8864_BRT_CONTROL 0x00
+#define LP8864_USER_CONFIG1 0x04
+#define LP8864_BRT_MODE_MASK GENMASK(9, 8)
+#define LP8864_BRT_MODE_REG BIT(9) /* Brightness control by DISPLAY_BRT reg */
+#define LP8864_SUPPLY_STATUS 0x0e
+#define LP8864_BOOST_STATUS 0x10
+#define LP8864_LED_STATUS 0x12
+#define LP8864_LED_STATUS_WR_MASK GENMASK(14, 9) /* Writeable bits in the LED_STATUS reg */
+
+/* Textual meaning for status bits, starting from bit 1 */
+static const char *const lp8864_supply_status_msg[] = {
+ "Vin under-voltage fault",
+ "Vin over-voltage fault",
+ "Vdd under-voltage fault",
+ "Vin over-current fault",
+ "Missing charge pump fault",
+ "Charge pump fault",
+ "Missing boost sync fault",
+ "CRC error fault ",
+};
+
+/* Textual meaning for status bits, starting from bit 1 */
+static const char *const lp8864_boost_status_msg[] = {
+ "Boost OVP low fault",
+ "Boost OVP high fault",
+ "Boost over-current fault",
+ "Missing boost FSET resistor fault",
+ "Missing MODE SEL resistor fault",
+ "Missing LED resistor fault",
+ "ISET resistor short to ground fault",
+ "Thermal shutdown fault",
+};
+
+/* Textual meaning for every register bit */
+static const char *const lp8864_led_status_msg[] = {
+ "LED 1 fault",
+ "LED 2 fault",
+ "LED 3 fault",
+ "LED 4 fault",
+ "LED 5 fault",
+ "LED 6 fault",
+ "LED open fault",
+ "LED internal short fault",
+ "LED short to GND fault",
+ NULL, NULL, NULL,
+ "Invalid string configuration fault",
+ NULL,
+ "I2C time out fault",
+};
+
+/**
+ * struct lp8864_led
+ * @client: Pointer to the I2C client
+ * @led_dev: led class device pointer
+ * @regmap: Devices register map
+ * @led_status_mask: Helps to report LED fault only once
+ */
+struct lp8864_led {
+ struct i2c_client *client;
+ struct led_classdev led_dev;
+ struct regmap *regmap;
+ u16 led_status_mask;
+};
+
+static int lp8864_fault_check(struct lp8864_led *led)
+{
+ int ret, i;
+ unsigned int val;
+
+ ret = regmap_read(led->regmap, LP8864_SUPPLY_STATUS, &val);
+ if (ret)
+ goto err;
+
+ /* Odd bits are status bits, even bits are clear bits */
+ for (i = 0; i < ARRAY_SIZE(lp8864_supply_status_msg); i++)
+ if (val & BIT(i * 2 + 1))
+ dev_warn(&led->client->dev, "%s\n", lp8864_supply_status_msg[i]);
+
+ /*
+ * Clear bits have an index preceding the corresponding Status bits;
+ * both have to be written "1" simultaneously to clear the corresponding
+ * Status bit.
+ */
+ if (val)
+ ret = regmap_write(led->regmap, LP8864_SUPPLY_STATUS, val >> 1 | val);
+ if (ret)
+ goto err;
+
+ ret = regmap_read(led->regmap, LP8864_BOOST_STATUS, &val);
+ if (ret)
+ goto err;
+
+ /* Odd bits are status bits, even bits are clear bits */
+ for (i = 0; i < ARRAY_SIZE(lp8864_boost_status_msg); i++)
+ if (val & BIT(i * 2 + 1))
+ dev_warn(&led->client->dev, "%s\n", lp8864_boost_status_msg[i]);
+
+ if (val)
+ ret = regmap_write(led->regmap, LP8864_BOOST_STATUS, val >> 1 | val);
+ if (ret)
+ goto err;
+
+ ret = regmap_read(led->regmap, LP8864_LED_STATUS, &val);
+ if (ret)
+ goto err;
+
+ /*
+ * Clear already reported faults that maintain their value until device
+ * power-down
+ */
+ val &= ~led->led_status_mask;
+
+ for (i = 0; i < ARRAY_SIZE(lp8864_led_status_msg); i++)
+ if (lp8864_led_status_msg[i] && val & BIT(i))
+ dev_warn(&led->client->dev, "%s\n", lp8864_led_status_msg[i]);
+
+ /*
+ * Mark those which maintain their value until device power-down as
+ * "already reported"
+ */
+ led->led_status_mask |= val & ~LP8864_LED_STATUS_WR_MASK;
+
+ /*
+ * Only bits 14, 12, 10 have to be cleared here, but others are RO,
+ * we don't care what we write to them.
+ */
+ if (val & LP8864_LED_STATUS_WR_MASK)
+ ret = regmap_write(led->regmap, LP8864_LED_STATUS, val >> 1 | val);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ dev_err(&led->client->dev, "Failed to read/clear faults (%pe)\n", ERR_PTR(ret));
+
+ return ret;
+}
+
+static int lp8864_brightness_set(struct led_classdev *led_cdev,
+ enum led_brightness brt_val)
+{
+ struct lp8864_led *led = container_of(led_cdev, struct lp8864_led, led_dev);
+ /* Scale 0..LED_FULL into 16-bit HW brightness */
+ unsigned int val = brt_val * 0xffff / LED_FULL;
+ int ret;
+
+ ret = lp8864_fault_check(led);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(led->regmap, LP8864_BRT_CONTROL, val);
+ if (ret)
+ dev_err(&led->client->dev, "Failed to write brightness value\n");
+
+ return ret;
+}
+
+static enum led_brightness lp8864_brightness_get(struct led_classdev *led_cdev)
+{
+ struct lp8864_led *led = container_of(led_cdev, struct lp8864_led, led_dev);
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(led->regmap, LP8864_BRT_CONTROL, &val);
+ if (ret) {
+ dev_err(&led->client->dev, "Failed to read brightness value\n");
+ return ret;
+ }
+
+ /* Scale 16-bit HW brightness into 0..LED_FULL */
+ return val * LED_FULL / 0xffff;
+}
+
+static const struct regmap_config lp8864_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+static void lp8864_disable_gpio(void *data)
+{
+ struct gpio_desc *gpio = data;
+
+ gpiod_set_value(gpio, 0);
+}
+
+static int lp8864_probe(struct i2c_client *client)
+{
+ int ret;
+ struct lp8864_led *led;
+ struct device_node *np = dev_of_node(&client->dev);
+ struct device_node *child_node;
+ struct led_init_data init_data = {};
+ struct gpio_desc *enable_gpio;
+
+ led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
+ if (!led)
+ return -ENOMEM;
+
+ child_node = of_get_next_available_child(np, NULL);
+ if (!child_node) {
+ dev_err(&client->dev, "No LED function defined\n");
+ return -EINVAL;
+ }
+
+ ret = devm_regulator_get_enable_optional(&client->dev, "vled");
+ if (ret && ret != -ENODEV)
+ return dev_err_probe(&client->dev, ret, "Failed to enable vled regulator\n");
+
+ enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH);
+ if (IS_ERR(enable_gpio))
+ return dev_err_probe(&client->dev, PTR_ERR(enable_gpio),
+ "Failed to get enable GPIO\n");
+
+ ret = devm_add_action_or_reset(&client->dev, lp8864_disable_gpio, enable_gpio);
+ if (ret)
+ return ret;
+
+ led->client = client;
+ led->led_dev.brightness_set_blocking = lp8864_brightness_set;
+ led->led_dev.brightness_get = lp8864_brightness_get;
+
+ led->regmap = devm_regmap_init_i2c(client, &lp8864_regmap_config);
+ if (IS_ERR(led->regmap))
+ return dev_err_probe(&client->dev, PTR_ERR(led->regmap),
+ "Failed to allocate regmap\n");
+
+ /* Control brightness by DISPLAY_BRT register */
+ ret = regmap_update_bits(led->regmap, LP8864_USER_CONFIG1, LP8864_BRT_MODE_MASK,
+ LP8864_BRT_MODE_REG);
+ if (ret) {
+ dev_err(&led->client->dev, "Failed to set brightness control mode\n");
+ return ret;
+ }
+
+ ret = lp8864_fault_check(led);
+ if (ret)
+ return ret;
+
+ init_data.fwnode = of_fwnode_handle(child_node);
+ init_data.devicename = "lp8864";
+ init_data.default_label = ":display_cluster";
+
+ ret = devm_led_classdev_register_ext(&client->dev, &led->led_dev, &init_data);
+ if (ret)
+ dev_err(&client->dev, "Failed to register LED device (%pe)\n", ERR_PTR(ret));
+
+ return ret;
+}
+
+static const struct i2c_device_id lp8864_id[] = {
+ { "lp8864" },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, lp8864_id);
+
+static const struct of_device_id of_lp8864_leds_match[] = {
+ { .compatible = "ti,lp8864" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, of_lp8864_leds_match);
+
+static struct i2c_driver lp8864_driver = {
+ .driver = {
+ .name = "lp8864",
+ .of_match_table = of_lp8864_leds_match,
+ },
+ .probe = lp8864_probe,
+ .id_table = lp8864_id,
+};
+module_i2c_driver(lp8864_driver);
+
+MODULE_DESCRIPTION("Texas Instruments LP8864/LP8866 LED driver");
+MODULE_AUTHOR("Alexander Sverdlin <alexander.sverdlin@siemens.com>");
+MODULE_LICENSE("GPL");
projects / thirdparty / linux.git / commitdiff
