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>

4 files changed, 531 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/leds/leds-lp8860.txt b/Documentation/devicetree/bindings/leds/leds-lp8860.txt
new file mode 100644
index 000000000000..aad38dd94d4b
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-lp8860.txt
@@ -0,0 +1,29 @@
+* Texas Instruments - lp8860 4-Channel LED Driver
+
+The LP8860-Q1 is an high-efficiency LED
+driver with boost controller. It has 4 high-precision
+current sinks that can be controlled by a PWM input
+signal, a SPI/I2C master, or both.
+
+Required properties:
+        - compatible:
+                "ti,lp8860"
+        - reg -  I2C slave address
+        - label - Used for naming LEDs
+
+Optional properties:
+        - enable-gpio - gpio pin to enable/disable the device.
+        - supply - "vled" - LED supply
+
+Example:
+
+leds: leds@6 {
+        compatible = "ti,lp8860";
+        reg = <0x2d>;
+        label = "display_cluster";
+        enable-gpio = <&gpio1 28 GPIO_ACTIVE_HIGH>;
+        vled-supply = <&vbatt>;
+}
+
+For more product information please see the link below:
+http://www.ti.com/product/lp8860-q1
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index a210338cfeb1..b0dce59f23e8 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -250,6 +250,16 @@ config LEDS_LP8788
         help
           This option enables support for the Keyboard LEDs on the LP8788 PMIC.
 
+config LEDS_LP8860
+        tristate "LED support for the TI LP8860 4 channel LED driver"
+        depends on LEDS_CLASS && REGMAP_I2C
+        help
+          If you say yes here you get support for the TI LP8860 4 channel
+          LED driver.
+          This option enables support for the display cluster LEDs
+          on the LP8860 4 channel LED driver using the I2C communication
+          bus.
+
 config LEDS_CLEVO_MAIL
         tristate "Mail LED on Clevo notebook"
         depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index a2b164741465..1c65a191d907 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_LEDS_LP5523)		+= leds-lp5523.o
 obj-$(CONFIG_LEDS_LP5562)               += leds-lp5562.o
 obj-$(CONFIG_LEDS_LP8501)               += leds-lp8501.o
 obj-$(CONFIG_LEDS_LP8788)               += leds-lp8788.o
+obj-$(CONFIG_LEDS_LP8860)               += leds-lp8860.o
 obj-$(CONFIG_LEDS_TCA6507)              += leds-tca6507.o
 obj-$(CONFIG_LEDS_CLEVO_MAIL)           += leds-clevo-mail.o
 obj-$(CONFIG_LEDS_IPAQ_MICRO)           += leds-ipaq-micro.o
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");