leds: lp8860: Introduce TI lp8860 4 channel LED driver

Introduce the Texas Instruments lp8860
4 channel LED driver.

This driver configures the device in display cluster mode
as this seems to be the most used configuration at the
time of the driver configuration.

For more product information please see the link below:
http://www.ti.com/product/lp8860-q1

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

1 files changed, 491 insertions, 0 deletions

diff --git a/drivers/leds/leds-lp8860.c b/drivers/leds/leds-lp8860.c
new file mode 100644
index 000000000000..840e93f3ab3e
--- /dev/null
+++ b/drivers/leds/leds-lp8860.c
@@ -0,0 +1,491 @@
+/*
+ * TI LP8860 4-Channel LED Driver
+ *
+ * Copyright (C) 2014 Texas Instruments
+ *
+ * Author: Dan Murphy <dmurphy@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/slab.h>
+
+#define LP8860_DISP_CL1_BRT_MSB		0x00
+#define LP8860_DISP_CL1_BRT_LSB		0x01
+#define LP8860_DISP_CL1_CURR_MSB	0x02
+#define LP8860_DISP_CL1_CURR_LSB	0x03
+#define LP8860_CL2_BRT_MSB		0x04
+#define LP8860_CL2_BRT_LSB		0x05
+#define LP8860_CL2_CURRENT		0x06
+#define LP8860_CL3_BRT_MSB		0x07
+#define LP8860_CL3_BRT_LSB		0x08
+#define LP8860_CL3_CURRENT		0x09
+#define LP8860_CL4_BRT_MSB		0x0a
+#define LP8860_CL4_BRT_LSB		0x0b
+#define LP8860_CL4_CURRENT		0x0c
+#define LP8860_CONFIG			0x0d
+#define LP8860_STATUS			0x0e
+#define LP8860_FAULT			0x0f
+#define LP8860_LED_FAULT		0x10
+#define LP8860_FAULT_CLEAR		0x11
+#define LP8860_ID			0x12
+#define LP8860_TEMP_MSB			0x13
+#define LP8860_TEMP_LSB			0x14
+#define LP8860_DISP_LED_CURR_MSB	0x15
+#define LP8860_DISP_LED_CURR_LSB	0x16
+#define LP8860_DISP_LED_PWM_MSB		0x17
+#define LP8860_DISP_LED_PWM_LSB		0x18
+#define LP8860_EEPROM_CNTRL		0x19
+#define LP8860_EEPROM_UNLOCK		0x1a
+
+#define LP8860_EEPROM_REG_0		0x60
+#define LP8860_EEPROM_REG_1		0x61
+#define LP8860_EEPROM_REG_2		0x62
+#define LP8860_EEPROM_REG_3		0x63
+#define LP8860_EEPROM_REG_4		0x64
+#define LP8860_EEPROM_REG_5		0x65
+#define LP8860_EEPROM_REG_6		0x66
+#define LP8860_EEPROM_REG_7		0x67
+#define LP8860_EEPROM_REG_8		0x68
+#define LP8860_EEPROM_REG_9		0x69
+#define LP8860_EEPROM_REG_10		0x6a
+#define LP8860_EEPROM_REG_11		0x6b
+#define LP8860_EEPROM_REG_12		0x6c
+#define LP8860_EEPROM_REG_13		0x6d
+#define LP8860_EEPROM_REG_14		0x6e
+#define LP8860_EEPROM_REG_15		0x6f
+#define LP8860_EEPROM_REG_16		0x70
+#define LP8860_EEPROM_REG_17		0x71
+#define LP8860_EEPROM_REG_18		0x72
+#define LP8860_EEPROM_REG_19		0x73
+#define LP8860_EEPROM_REG_20		0x74
+#define LP8860_EEPROM_REG_21		0x75
+#define LP8860_EEPROM_REG_22		0x76
+#define LP8860_EEPROM_REG_23		0x77
+#define LP8860_EEPROM_REG_24		0x78
+
+#define LP8860_LOCK_EEPROM		0x00
+#define LP8860_UNLOCK_EEPROM		0x01
+#define LP8860_PROGRAM_EEPROM		0x02
+#define LP8860_EEPROM_CODE_1		0x08
+#define LP8860_EEPROM_CODE_2		0xba
+#define LP8860_EEPROM_CODE_3		0xef
+
+#define LP8860_CLEAR_FAULTS		0x01
+
+#define LP8860_DISP_LED_NAME		"display_cluster"
+
+/**
+ * struct lp8860_led -
+ * @lock - Lock for reading/writing the device
+ * @work - Work item used to off load the brightness register writes
+ * @client - Pointer to the I2C client
+ * @led_dev - led class device pointer
+ * @regmap - Devices register map
+ * @eeprom_regmap - EEPROM register map
+ * @enable_gpio - VDDIO/EN gpio to enable communication interface
+ * @regulator - LED supply regulator pointer
+ * @brightness - Current brightness value requested
+ * @label - LED label
+**/
+struct lp8860_led {
+	struct mutex lock;
+	struct work_struct work;
+	struct i2c_client *client;
+	struct led_classdev led_dev;
+	struct regmap *regmap;
+	struct regmap *eeprom_regmap;
+	struct gpio_desc *enable_gpio;
+	struct regulator *regulator;
+	enum led_brightness brightness;
+	const char *label;
+};
+
+struct lp8860_eeprom_reg {
+	uint8_t reg;
+	uint8_t value;
+};
+
+static struct lp8860_eeprom_reg lp8860_eeprom_disp_regs[] = {
+	{ LP8860_EEPROM_REG_0, 0xed },
+	{ LP8860_EEPROM_REG_1, 0xdf },
+	{ LP8860_EEPROM_REG_2, 0xdc },
+	{ LP8860_EEPROM_REG_3, 0xf0 },
+	{ LP8860_EEPROM_REG_4, 0xdf },
+	{ LP8860_EEPROM_REG_5, 0xe5 },
+	{ LP8860_EEPROM_REG_6, 0xf2 },
+	{ LP8860_EEPROM_REG_7, 0x77 },
+	{ LP8860_EEPROM_REG_8, 0x77 },
+	{ LP8860_EEPROM_REG_9, 0x71 },
+	{ LP8860_EEPROM_REG_10, 0x3f },
+	{ LP8860_EEPROM_REG_11, 0xb7 },
+	{ LP8860_EEPROM_REG_12, 0x17 },
+	{ LP8860_EEPROM_REG_13, 0xef },
+	{ LP8860_EEPROM_REG_14, 0xb0 },
+	{ LP8860_EEPROM_REG_15, 0x87 },
+	{ LP8860_EEPROM_REG_16, 0xce },
+	{ LP8860_EEPROM_REG_17, 0x72 },
+	{ LP8860_EEPROM_REG_18, 0xe5 },
+	{ LP8860_EEPROM_REG_19, 0xdf },
+	{ LP8860_EEPROM_REG_20, 0x35 },
+	{ LP8860_EEPROM_REG_21, 0x06 },
+	{ LP8860_EEPROM_REG_22, 0xdc },
+	{ LP8860_EEPROM_REG_23, 0x88 },
+	{ LP8860_EEPROM_REG_24, 0x3E },
+};
+
+static int lp8860_unlock_eeprom(struct lp8860_led *led, int lock)
+{
+	int ret;
+
+	mutex_lock(&led->lock);
+
+	if (lock == LP8860_UNLOCK_EEPROM) {
+		ret = regmap_write(led->regmap,
+			LP8860_EEPROM_UNLOCK,
+			LP8860_EEPROM_CODE_1);
+		if (ret) {
+			dev_err(&led->client->dev, "EEPROM Unlock failed\n");
+			goto out;
+		}
+
+		ret = regmap_write(led->regmap,
+			LP8860_EEPROM_UNLOCK,
+			LP8860_EEPROM_CODE_2);
+		if (ret) {
+			dev_err(&led->client->dev, "EEPROM Unlock failed\n");
+			goto out;
+		}
+		ret = regmap_write(led->regmap,
+			LP8860_EEPROM_UNLOCK,
+			LP8860_EEPROM_CODE_3);
+		if (ret) {
+			dev_err(&led->client->dev, "EEPROM Unlock failed\n");
+			goto out;
+		}
+	} else {
+		ret = regmap_write(led->regmap,
+			LP8860_EEPROM_UNLOCK,
+			LP8860_LOCK_EEPROM);
+	}
+
+out:
+	mutex_unlock(&led->lock);
+	return ret;
+}
+
+static int lp8860_fault_check(struct lp8860_led *led)
+{
+	int ret, fault;
+	unsigned int read_buf;
+
+	ret = regmap_read(led->regmap, LP8860_LED_FAULT, &read_buf);
+	if (ret)
+		goto out;
+
+	fault = read_buf;
+
+	ret = regmap_read(led->regmap, LP8860_FAULT, &read_buf);
+	if (ret)
+		goto out;
+
+	fault |= read_buf;
+
+	/* Attempt to clear any faults */
+	if (fault)
+		ret = regmap_write(led->regmap, LP8860_FAULT_CLEAR,
+			LP8860_CLEAR_FAULTS);
+out:
+	return ret;
+}
+
+static void lp8860_led_brightness_work(struct work_struct *work)
+{
+	struct lp8860_led *led = container_of(work, struct lp8860_led, work);
+	int ret;
+	int disp_brightness = led->brightness * 255;
+
+	mutex_lock(&led->lock);
+
+	ret = lp8860_fault_check(led);
+	if (ret) {
+		dev_err(&led->client->dev, "Cannot read/clear faults\n");
+		goto out;
+	}
+
+	ret = regmap_write(led->regmap, LP8860_DISP_CL1_BRT_MSB,
+			(disp_brightness & 0xff00) >> 8);
+	if (ret) {
+		dev_err(&led->client->dev, "Cannot write CL1 MSB\n");
+		goto out;
+	}
+
+	ret = regmap_write(led->regmap, LP8860_DISP_CL1_BRT_LSB,
+			disp_brightness & 0xff);
+	if (ret) {
+		dev_err(&led->client->dev, "Cannot write CL1 LSB\n");
+		goto out;
+	}
+out:
+	mutex_unlock(&led->lock);
+}
+
+static void lp8860_brightness_set(struct led_classdev *led_cdev,
+				enum led_brightness brt_val)
+{
+	struct lp8860_led *led =
+			container_of(led_cdev, struct lp8860_led, led_dev);
+
+	led->brightness = brt_val;
+	schedule_work(&led->work);
+}
+
+static int lp8860_init(struct lp8860_led *led)
+{
+	unsigned int read_buf;
+	int ret, i, reg_count;
+
+	if (led->enable_gpio)
+		gpiod_direction_output(led->enable_gpio, 1);
+
+	ret = lp8860_fault_check(led);
+	if (ret)
+		goto out;
+
+	ret = regmap_read(led->regmap, LP8860_STATUS, &read_buf);
+	if (ret)
+		goto out;
+
+	ret = lp8860_unlock_eeprom(led, LP8860_UNLOCK_EEPROM);
+	if (ret) {
+		dev_err(&led->client->dev, "Failed unlocking EEPROM\n");
+		goto out;
+	}
+
+	reg_count = ARRAY_SIZE(lp8860_eeprom_disp_regs) / sizeof(lp8860_eeprom_disp_regs[0]);
+	for (i = 0; i < reg_count; i++) {
+		ret = regmap_write(led->eeprom_regmap,
+				lp8860_eeprom_disp_regs[i].reg,
+				lp8860_eeprom_disp_regs[i].value);
+		if (ret) {
+			dev_err(&led->client->dev, "Failed writing EEPROM\n");
+			goto out;
+		}
+	}
+
+	ret = lp8860_unlock_eeprom(led, LP8860_LOCK_EEPROM);
+	if (ret)
+		goto out;
+
+	ret = regmap_write(led->regmap,
+			LP8860_EEPROM_CNTRL,
+			LP8860_PROGRAM_EEPROM);
+	if (ret)
+		dev_err(&led->client->dev, "Failed programming EEPROM\n");
+out:
+	if (ret)
+		if (led->enable_gpio)
+			gpiod_direction_output(led->enable_gpio, 0);
+	return ret;
+}
+
+static struct reg_default lp8860_reg_defs[] = {
+	{ LP8860_DISP_CL1_BRT_MSB, 0x00},
+	{ LP8860_DISP_CL1_BRT_LSB, 0x00},
+	{ LP8860_DISP_CL1_CURR_MSB, 0x00},
+	{ LP8860_DISP_CL1_CURR_LSB, 0x00},
+	{ LP8860_CL2_BRT_MSB, 0x00},
+	{ LP8860_CL2_BRT_LSB, 0x00},
+	{ LP8860_CL2_CURRENT, 0x00},
+	{ LP8860_CL3_BRT_MSB, 0x00},
+	{ LP8860_CL3_BRT_LSB, 0x00},
+	{ LP8860_CL3_CURRENT, 0x00},
+	{ LP8860_CL4_BRT_MSB, 0x00},
+	{ LP8860_CL4_BRT_LSB, 0x00},
+	{ LP8860_CL4_CURRENT, 0x00},
+	{ LP8860_CONFIG, 0x00},
+	{ LP8860_FAULT_CLEAR, 0x00},
+	{ LP8860_EEPROM_CNTRL, 0x80},
+	{ LP8860_EEPROM_UNLOCK, 0x00},
+};
+
+static const struct regmap_config lp8860_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = LP8860_EEPROM_UNLOCK,
+	.reg_defaults = lp8860_reg_defs,
+	.num_reg_defaults = ARRAY_SIZE(lp8860_reg_defs),
+	.cache_type = REGCACHE_NONE,
+};
+
+static struct reg_default lp8860_eeprom_defs[] = {
+	{ LP8860_EEPROM_REG_0, 0x00 },
+	{ LP8860_EEPROM_REG_1, 0x00 },
+	{ LP8860_EEPROM_REG_2, 0x00 },
+	{ LP8860_EEPROM_REG_3, 0x00 },
+	{ LP8860_EEPROM_REG_4, 0x00 },
+	{ LP8860_EEPROM_REG_5, 0x00 },
+	{ LP8860_EEPROM_REG_6, 0x00 },
+	{ LP8860_EEPROM_REG_7, 0x00 },
+	{ LP8860_EEPROM_REG_8, 0x00 },
+	{ LP8860_EEPROM_REG_9, 0x00 },
+	{ LP8860_EEPROM_REG_10, 0x00 },
+	{ LP8860_EEPROM_REG_11, 0x00 },
+	{ LP8860_EEPROM_REG_12, 0x00 },
+	{ LP8860_EEPROM_REG_13, 0x00 },
+	{ LP8860_EEPROM_REG_14, 0x00 },
+	{ LP8860_EEPROM_REG_15, 0x00 },
+	{ LP8860_EEPROM_REG_16, 0x00 },
+	{ LP8860_EEPROM_REG_17, 0x00 },
+	{ LP8860_EEPROM_REG_18, 0x00 },
+	{ LP8860_EEPROM_REG_19, 0x00 },
+	{ LP8860_EEPROM_REG_20, 0x00 },
+	{ LP8860_EEPROM_REG_21, 0x00 },
+	{ LP8860_EEPROM_REG_22, 0x00 },
+	{ LP8860_EEPROM_REG_23, 0x00 },
+	{ LP8860_EEPROM_REG_24, 0x00 },
+};
+
+static const struct regmap_config lp8860_eeprom_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = LP8860_EEPROM_REG_24,
+	.reg_defaults = lp8860_eeprom_defs,
+	.num_reg_defaults = ARRAY_SIZE(lp8860_eeprom_defs),
+	.cache_type = REGCACHE_NONE,
+};
+
+static int lp8860_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	int ret;
+	struct lp8860_led *led;
+	struct device_node *np = client->dev.of_node;
+
+	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	led->label = LP8860_DISP_LED_NAME;
+
+	if (client->dev.of_node) {
+		ret = of_property_read_string(np, "label", &led->label);
+		if (ret) {
+			dev_err(&client->dev, "Missing label in dt\n");
+			return -EINVAL;
+		}
+	}
+
+	led->enable_gpio = devm_gpiod_get(&client->dev, "enable");
+	if (IS_ERR(led->enable_gpio))
+		led->enable_gpio = NULL;
+	else
+		gpiod_direction_output(led->enable_gpio, 0);
+
+	led->regulator = devm_regulator_get(&client->dev, "vled");
+	if (IS_ERR(led->regulator))
+		led->regulator = NULL;
+
+	led->client = client;
+	led->led_dev.name = led->label;
+	led->led_dev.max_brightness = LED_FULL;
+	led->led_dev.brightness_set = lp8860_brightness_set;
+
+	mutex_init(&led->lock);
+	INIT_WORK(&led->work, lp8860_led_brightness_work);
+
+	i2c_set_clientdata(client, led);
+
+	led->regmap = devm_regmap_init_i2c(client, &lp8860_regmap_config);
+	if (IS_ERR(led->regmap)) {
+		ret = PTR_ERR(led->regmap);
+		dev_err(&client->dev, "Failed to allocate register map: %d\n",
+			ret);
+		return ret;
+	}
+
+	led->eeprom_regmap = devm_regmap_init_i2c(client, &lp8860_eeprom_regmap_config);
+	if (IS_ERR(led->eeprom_regmap)) {
+		ret = PTR_ERR(led->eeprom_regmap);
+		dev_err(&client->dev, "Failed to allocate register map: %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = lp8860_init(led);
+	if (ret)
+		return ret;
+
+	ret = led_classdev_register(&client->dev, &led->led_dev);
+	if (ret) {
+		dev_err(&client->dev, "led register err: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int lp8860_remove(struct i2c_client *client)
+{
+	struct lp8860_led *led = i2c_get_clientdata(client);
+	int ret;
+
+	led_classdev_unregister(&led->led_dev);
+	cancel_work_sync(&led->work);
+
+	if (led->enable_gpio)
+		gpiod_direction_output(led->enable_gpio, 0);
+
+	if (led->regulator) {
+		ret = regulator_disable(led->regulator);
+		if (ret)
+			dev_err(&led->client->dev,
+				"Failed to disable regulator\n");
+	}
+
+	return 0;
+}
+
+static const struct i2c_device_id lp8860_id[] = {
+	{ "lp8860", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lp8860_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id of_lp8860_leds_match[] = {
+	{ .compatible = "ti,lp8860", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_lp8860_leds_match);
+#endif
+
+static struct i2c_driver lp8860_driver = {
+	.driver = {
+		.name	= "lp8860",
+		.of_match_table = of_match_ptr(of_lp8860_leds_match),
+	},
+	.probe		= lp8860_probe,
+	.remove		= lp8860_remove,
+	.id_table	= lp8860_id,
+};
+module_i2c_driver(lp8860_driver);
+
+MODULE_DESCRIPTION("Texas Instruments LP8860 LED drvier");
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_LICENSE("GPL");