Introducing the LM3692x Dual-String white LED driver.

Data sheet is located
http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf

Signed-off-by: Dan Murphy <dmur...@ti.com>
---
 drivers/leds/leds-lm3692x.c | 380 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 380 insertions(+)
 create mode 100644 drivers/leds/leds-lm3692x.c

diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c
new file mode 100644
index 000000000000..beb753abc7b0
--- /dev/null
+++ b/drivers/leds/leds-lm3692x.c
@@ -0,0 +1,380 @@
+/*
+ * TI lm3692x LED Driver
+ *
+ * Copyright (C) 2017 Texas Instruments
+ *
+ * Author: Dan Murphy <dmur...@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 LM3692X_LED_NAME       "lm3692x_led"
+
+#define LM3692X_REV            0x0
+#define LM3692X_RESET          0x1
+#define LM3692X_EN             0x10
+#define LM3692X_BRT_CTRL       0x11
+#define LM3692X_PWM_CTRL       0x12
+#define LM3692X_BOOST_CTRL     0x13
+#define LM3692X_AUTO_FREQ_HI   0x15
+#define LM3692X_AUTO_FREQ_LO   0x16
+#define LM3692X_BL_ADJ_THRESH  0x17
+#define LM3692X_BRT_LSB                0x18
+#define LM3692X_BRT_MSB                0x19
+#define LM3692X_FAULT_CTRL     0x1e
+#define LM3692X_FAULT_FLAGS    0x1f
+
+#define LM3692X_SW_RESET       BIT(0)
+#define LM3692X_DEVICE_EN      BIT(0)
+#define LM3692X_LED1_EN                BIT(1)
+#define LM3692X_LED2_EN                BIT(2)
+
+/* Brightness Control Bits */
+#define LM3692X_BL_ADJ_POL     BIT(0)
+#define LM3692X_RAMP_RATE_125us        0x00
+#define LM3692X_RAMP_RATE_250us        BIT(1)
+#define LM3692X_RAMP_RATE_500us BIT(2)
+#define LM3692X_RAMP_RATE_1ms  (BIT(1) | BIT(2))
+#define LM3692X_RAMP_RATE_2ms  BIT(3)
+#define LM3692X_RAMP_RATE_4ms  (BIT(3) | BIT(1))
+#define LM3692X_RAMP_RATE_8ms  (BIT(2) | BIT(3))
+#define LM3692X_RAMP_RATE_16ms (BIT(1) | BIT(2) | BIT(3))
+#define LM3692X_RAMP_EN                BIT(4)
+#define LM3692X_BRHT_MODE_REG  0x00
+#define LM3692X_BRHT_MODE_PWM  BIT(5)
+#define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
+#define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
+#define LM3692X_MAP_MODE_EXP   BIT(7)
+
+/* PWM Register Bits */
+#define LM3692X_PWM_FILTER_100 BIT(0)
+#define LM3692X_PWM_FILTER_150 BIT(1)
+#define LM3692X_PWM_FILTER_200 (BIT(0) | BIT(1))
+#define LM3692X_PWM_HYSTER_1LSB BIT(2)
+#define LM3692X_PWM_HYSTER_2LSB        BIT(3)
+#define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
+#define LM3692X_PWM_HYSTER_4LSB BIT(4)
+#define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
+#define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
+#define LM3692X_PWM_POLARITY   BIT(5)
+#define LM3692X_PWM_SAMP_4MHZ  BIT(6)
+#define LM3692X_PWM_SAMP_24MHZ BIT(7)
+
+/* Boost Control Bits */
+#define LM3692X_OCP_PROT_1A    BIT(0)
+#define LM3692X_OCP_PROT_1_25A BIT(1)
+#define LM3692X_OCP_PROT_1_5A  (BIT(0) | BIT(1))
+#define LM3692X_OVP_21V                BIT(2)
+#define LM3692X_OVP_25V                BIT(3)
+#define LM3692X_OVP_29V                (BIT(2) | BIT(3))
+#define LM3692X_MIN_IND_22UH   BIT(4)
+#define LM3692X_BOOST_SW_1MHZ  BIT(5)
+#define LM3692X_BOOST_SW_NO_SHIFT      BIT(6)
+
+/* Fault Control Bits */
+#define LM3692X_FAULT_CTRL_OVP BIT(0)
+#define LM3692X_FAULT_CTRL_OCP BIT(1)
+#define LM3692X_FAULT_CTRL_TSD BIT(2)
+#define LM3692X_FAULT_CTRL_OPEN BIT(3)
+
+/* Fault Flag Bits */
+#define LM3692X_FAULT_FLAG_OVP BIT(0)
+#define LM3692X_FAULT_FLAG_OCP BIT(1)
+#define LM3692X_FAULT_FLAG_TSD BIT(2)
+#define LM3692X_FAULT_FLAG_SHRT BIT(3)
+#define LM3692X_FAULT_FLAG_OPEN BIT(4)
+
+/**
+ * struct lm3692x_led -
+ * @lock - Lock for reading/writing the device
+ * @client - Pointer to the I2C client
+ * @led_dev - led class device pointer
+ * @regmap - Devices register map
+ * @enable_gpio - VDDIO/EN gpio to enable communication interface
+ * @regulator - LED supply regulator pointer
+ * @label - LED label
+ **/
+struct lm3692x_led {
+       struct mutex lock;
+       struct i2c_client *client;
+       struct led_classdev led_dev;
+       struct regmap *regmap;
+       struct gpio_desc *enable_gpio;
+       struct regulator *regulator;
+       const char *label;
+};
+
+static const struct reg_default lm3692x_reg_defs[] = {
+       {LM3692X_EN, 0xf},
+       {LM3692X_BRT_CTRL, 0x61},
+       {LM3692X_PWM_CTRL, 0x73},
+       {LM3692X_BOOST_CTRL, 0x6f},
+       {LM3692X_AUTO_FREQ_HI, 0x0},
+       {LM3692X_AUTO_FREQ_LO, 0x0},
+       {LM3692X_BL_ADJ_THRESH, 0x0},
+       {LM3692X_BRT_LSB, 0x7},
+       {LM3692X_BRT_MSB, 0xff},
+       {LM3692X_FAULT_CTRL, 0x7},
+};
+
+static const struct regmap_config lm3692x_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+
+       .max_register = LM3692X_FAULT_FLAGS,
+       .reg_defaults = lm3692x_reg_defs,
+       .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
+       .cache_type = REGCACHE_RBTREE,
+};
+
+static int lm3692x_fault_check(struct lm3692x_led *led)
+{
+       int ret, fault;
+       unsigned int read_buf;
+
+       ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
+       if (ret)
+               goto out;
+
+       fault = read_buf;
+
+       if (fault)
+               dev_err(&led->client->dev, "Detected a fault 0x%X\n",
+                       fault);
+out:
+       return ret;
+}
+
+static int lm3692x_brightness_set(struct led_classdev *led_cdev,
+                               enum led_brightness brt_val)
+{
+       struct lm3692x_led *led =
+                       container_of(led_cdev, struct lm3692x_led, led_dev);
+       int led_brightness = (brt_val << 4) + 7;
+       int ret;
+
+       if (brt_val == LED_OFF)
+               led_brightness = 0;
+
+       mutex_lock(&led->lock);
+
+       ret = lm3692x_fault_check(led);
+       if (ret) {
+               dev_err(&led->client->dev, "Cannot read/clear faults\n");
+               goto out;
+       }
+
+       ret = regmap_write(led->regmap, LM3692X_BRT_MSB,
+                       (led_brightness & 0xff0) >> 4);
+       if (ret) {
+               dev_err(&led->client->dev, "Cannot write MSB\n");
+               goto out;
+       }
+
+       ret = regmap_write(led->regmap, LM3692X_BRT_LSB,
+                       led_brightness & 0x07);
+       if (ret) {
+               dev_err(&led->client->dev, "Cannot write LSB\n");
+               goto out;
+       }
+out:
+       mutex_unlock(&led->lock);
+       return ret;
+}
+
+static int lm3692x_init(struct lm3692x_led *led)
+{
+       int ret;
+
+       if (led->regulator) {
+               ret = regulator_enable(led->regulator);
+               if (ret)
+                       dev_err(&led->client->dev,
+                               "Failed to enable regulator\n");
+       }
+
+       if (led->enable_gpio)
+               gpiod_direction_output(led->enable_gpio, 1);
+
+       ret = lm3692x_fault_check(led);
+       if (ret) {
+               dev_err(&led->client->dev, "Cannot read/clear faults\n");
+               goto out;
+       }
+
+       ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
+       if (ret)
+               dev_err(&led->client->dev, "Fail writing BRT CTRL\n");
+       /*
+        * For glitch free operation, the following data should
+        * only be written while device enable bit is 0
+        * Per Section 7.5.14 of the data sheet
+        */
+       ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
+               LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
+       if (ret)
+               dev_err(&led->client->dev, "Failed programming PWM CTRL\n");
+
+       ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
+                       LM3692X_BRHT_MODE_RAMP_MULTI |
+                       LM3692X_BL_ADJ_POL |
+                       LM3692X_RAMP_RATE_250us);
+       if (ret)
+               dev_err(&led->client->dev, "Failed programming BOOST CTRL\n");
+
+       ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
+       if (ret)
+               dev_err(&led->client->dev, "Failed programming AUTO HI FREQ\n");
+
+       ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
+       if (ret)
+               dev_err(&led->client->dev, "Failed programming AUTO LO FREQ\n");
+
+
+       ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
+       if (ret)
+               dev_err(&led->client->dev, "Failed programming BL Threshold\n");
+
+       ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
+                       LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB);
+       if (ret)
+               dev_err(&led->client->dev, "Failed programming BRT CTRL\n");
+
+       return ret;
+out:
+
+       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 ret;
+}
+
+static int lm3692x_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       int ret;
+       struct lm3692x_led *led;
+       struct device_node *np = client->dev.of_node;
+
+       led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
+       if (!led)
+               return -ENOMEM;
+
+       if (client->dev.of_node) {
+               ret = of_property_read_string(np, "label", &led->label);
+               if (ret)
+                       led->label = LM3692X_LED_NAME;
+       }
+
+       led->enable_gpio = devm_gpiod_get_optional(&client->dev,
+                                                  "enable", GPIOD_OUT_LOW);
+       if (IS_ERR(led->enable_gpio)) {
+               ret = PTR_ERR(led->enable_gpio);
+               dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
+               return ret;
+       }
+
+       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_blocking = lm3692x_brightness_set;
+
+       mutex_init(&led->lock);
+
+       i2c_set_clientdata(client, led);
+
+       led->regmap = devm_regmap_init_i2c(client, &lm3692x_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;
+       }
+
+       ret = lm3692x_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 lm3692x_remove(struct i2c_client *client)
+{
+       struct lm3692x_led *led = i2c_get_clientdata(client);
+       int ret;
+
+       led_classdev_unregister(&led->led_dev);
+
+       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 lm3692x_id[] = {
+       { "lm3692x", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, lm3692x_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id of_lm3692x_leds_match[] = {
+       { .compatible = "ti,lm3692x", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
+#endif
+
+static struct i2c_driver lm3692x_driver = {
+       .driver = {
+               .name   = "lm3692x",
+               .of_match_table = of_match_ptr(of_lm3692x_leds_match),
+       },
+       .probe          = lm3692x_probe,
+       .remove         = lm3692x_remove,
+       .id_table       = lm3692x_id,
+};
+module_i2c_driver(lm3692x_driver);
+
+MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
+MODULE_AUTHOR("Dan Murphy <dmur...@ti.com>");
+MODULE_LICENSE("GPL");
-- 
2.15.0.124.g7668cbc60

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