leds: lm3601x: Introduce the lm3601x LED driver
authorDan Murphy <dmurphy@ti.com>
Wed, 23 May 2018 11:51:29 +0000 (06:51 -0500)
committerJacek Anaszewski <jacek.anaszewski@gmail.com>
Wed, 23 May 2018 19:44:47 +0000 (21:44 +0200)
Introduce the family of LED devices that can
drive a torch, strobe or IR LED.

The LED driver can be configured with a strobe
timer to execute a strobe flash.  The IR LED
brightness is controlled via the torch brightness
register.

The data sheet for each the LM36010 and LM36011
LED drivers can be found here:
http://www.ti.com/product/LM36010
http://www.ti.com/product/LM36011

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
drivers/leds/Kconfig
drivers/leds/Makefile
drivers/leds/leds-lm3601x.c [new file with mode: 0644]

index cfeb5fb28c2d6e3f730562fc143bbbc18e0c5676..6e3a998f337096bf09588df53924d15e499279d0 100644 (file)
@@ -158,6 +158,15 @@ config LEDS_LM3692X
          This option enables support for the TI LM3692x family
          of white LED string drivers used for backlighting.
 
+config LEDS_LM3601X
+       tristate "LED support for LM3601x Chips"
+       depends on LEDS_CLASS && I2C
+       depends on LEDS_CLASS_FLASH
+       select REGMAP_I2C
+       help
+         This option enables support for the TI LM3601x family
+         of flash, torch and indicator classes.
+
 config LEDS_LOCOMO
        tristate "LED Support for Locomo device"
        depends on LEDS_CLASS
index 2f7b5c31dc9897843ecceef140849660593a1033..420b5d2cfa6275445df39c254e0719ddf03a4f17 100644 (file)
@@ -77,6 +77,7 @@ obj-$(CONFIG_LEDS_NIC78BX)            += leds-nic78bx.o
 obj-$(CONFIG_LEDS_MT6323)              += leds-mt6323.o
 obj-$(CONFIG_LEDS_LM3692X)             += leds-lm3692x.o
 obj-$(CONFIG_LEDS_SC27XX_BLTC)         += leds-sc27xx-bltc.o
+obj-$(CONFIG_LEDS_LM3601X)             += leds-lm3601x.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_CR0014114)           += leds-cr0014114.o
diff --git a/drivers/leds/leds-lm3601x.c b/drivers/leds/leds-lm3601x.c
new file mode 100644 (file)
index 0000000..081aa71
--- /dev/null
@@ -0,0 +1,487 @@
+// SPDX-License-Identifier: GPL-2.0
+// Flash and torch driver for Texas Instruments LM3601X LED
+// Flash driver chip family
+// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <uapi/linux/uleds.h>
+
+#define LM3601X_LED_IR         0x0
+#define LM3601X_LED_TORCH      0x1
+
+/* Registers */
+#define LM3601X_ENABLE_REG     0x01
+#define LM3601X_CFG_REG                0x02
+#define LM3601X_LED_FLASH_REG  0x03
+#define LM3601X_LED_TORCH_REG  0x04
+#define LM3601X_FLAGS_REG      0x05
+#define LM3601X_DEV_ID_REG     0x06
+
+#define LM3601X_SW_RESET       BIT(7)
+
+/* Enable Mode bits */
+#define LM3601X_MODE_STANDBY   0x00
+#define LM3601X_MODE_IR_DRV    BIT(0)
+#define LM3601X_MODE_TORCH     BIT(1)
+#define LM3601X_MODE_STROBE    (BIT(0) | BIT(1))
+#define LM3601X_STRB_EN                BIT(2)
+#define LM3601X_STRB_EDGE_TRIG BIT(3)
+#define LM3601X_IVFM_EN                BIT(4)
+
+#define LM36010_BOOST_LIMIT_28 BIT(5)
+#define LM36010_BOOST_FREQ_4MHZ        BIT(6)
+#define LM36010_BOOST_MODE_PASS        BIT(7)
+
+/* Flag Mask */
+#define LM3601X_FLASH_TIME_OUT BIT(0)
+#define LM3601X_UVLO_FAULT     BIT(1)
+#define LM3601X_THERM_SHUTDOWN BIT(2)
+#define LM3601X_THERM_CURR     BIT(3)
+#define LM36010_CURR_LIMIT     BIT(4)
+#define LM3601X_SHORT_FAULT    BIT(5)
+#define LM3601X_IVFM_TRIP      BIT(6)
+#define LM36010_OVP_FAULT      BIT(7)
+
+#define LM3601X_MAX_TORCH_I_UA 376000
+#define LM3601X_MIN_TORCH_I_UA 2400
+#define LM3601X_TORCH_REG_DIV  2965
+
+#define LM3601X_MAX_STROBE_I_UA        1500000
+#define LM3601X_MIN_STROBE_I_UA        11000
+#define LM3601X_STROBE_REG_DIV 11800
+
+#define LM3601X_TIMEOUT_MASK   0x1e
+#define LM3601X_ENABLE_MASK    (LM3601X_MODE_IR_DRV | LM3601X_MODE_TORCH)
+
+#define LM3601X_LOWER_STEP_US  40000
+#define LM3601X_UPPER_STEP_US  200000
+#define LM3601X_MIN_TIMEOUT_US 40000
+#define LM3601X_MAX_TIMEOUT_US 1600000
+#define LM3601X_TIMEOUT_XOVER_US 400000
+
+enum lm3601x_type {
+       CHIP_LM36010 = 0,
+       CHIP_LM36011,
+};
+
+/**
+ * struct lm3601x_led -
+ * @fled_cdev: flash LED class device pointer
+ * @client: Pointer to the I2C client
+ * @regmap: Devices register map
+ * @lock: Lock for reading/writing the device
+ * @led_name: LED label for the Torch or IR LED
+ * @flash_timeout: the timeout for the flash
+ * @last_flag: last known flags register value
+ * @torch_current_max: maximum current for the torch
+ * @flash_current_max: maximum current for the flash
+ * @max_flash_timeout: maximum timeout for the flash
+ * @led_mode: The mode to enable either IR or Torch
+ */
+struct lm3601x_led {
+       struct led_classdev_flash fled_cdev;
+       struct i2c_client *client;
+       struct regmap *regmap;
+       struct mutex lock;
+
+       char led_name[LED_MAX_NAME_SIZE];
+
+       unsigned int flash_timeout;
+       unsigned int last_flag;
+
+       u32 torch_current_max;
+       u32 flash_current_max;
+       u32 max_flash_timeout;
+
+       u32 led_mode;
+};
+
+static const struct reg_default lm3601x_regmap_defs[] = {
+       { LM3601X_ENABLE_REG, 0x20 },
+       { LM3601X_CFG_REG, 0x15 },
+       { LM3601X_LED_FLASH_REG, 0x00 },
+       { LM3601X_LED_TORCH_REG, 0x00 },
+};
+
+static bool lm3601x_volatile_reg(struct device *dev, unsigned int reg)
+{
+       switch (reg) {
+       case LM3601X_FLAGS_REG:
+               return true;
+       default:
+               return false;
+       }
+}
+
+static const struct regmap_config lm3601x_regmap = {
+       .reg_bits = 8,
+       .val_bits = 8,
+
+       .max_register = LM3601X_DEV_ID_REG,
+       .reg_defaults = lm3601x_regmap_defs,
+       .num_reg_defaults = ARRAY_SIZE(lm3601x_regmap_defs),
+       .cache_type = REGCACHE_RBTREE,
+       .volatile_reg = lm3601x_volatile_reg,
+};
+
+static struct lm3601x_led *fled_cdev_to_led(struct led_classdev_flash *fled_cdev)
+{
+       return container_of(fled_cdev, struct lm3601x_led, fled_cdev);
+}
+
+static int lm3601x_read_faults(struct lm3601x_led *led)
+{
+       int flags_val;
+       int ret;
+
+       ret = regmap_read(led->regmap, LM3601X_FLAGS_REG, &flags_val);
+       if (ret < 0)
+               return -EIO;
+
+       led->last_flag = 0;
+
+       if (flags_val & LM36010_OVP_FAULT)
+               led->last_flag |= LED_FAULT_OVER_VOLTAGE;
+
+       if (flags_val & (LM3601X_THERM_SHUTDOWN | LM3601X_THERM_CURR))
+               led->last_flag |= LED_FAULT_OVER_TEMPERATURE;
+
+       if (flags_val & LM3601X_SHORT_FAULT)
+               led->last_flag |= LED_FAULT_SHORT_CIRCUIT;
+
+       if (flags_val & LM36010_CURR_LIMIT)
+               led->last_flag |= LED_FAULT_OVER_CURRENT;
+
+       if (flags_val & LM3601X_UVLO_FAULT)
+               led->last_flag |= LED_FAULT_UNDER_VOLTAGE;
+
+       if (flags_val & LM3601X_IVFM_TRIP)
+               led->last_flag |= LED_FAULT_INPUT_VOLTAGE;
+
+       if (flags_val & LM3601X_THERM_SHUTDOWN)
+               led->last_flag |= LED_FAULT_LED_OVER_TEMPERATURE;
+
+       return led->last_flag;
+}
+
+static int lm3601x_brightness_set(struct led_classdev *cdev,
+                                       enum led_brightness brightness)
+{
+       struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
+       struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+       int ret, led_mode_val;
+
+       mutex_lock(&led->lock);
+
+       ret = lm3601x_read_faults(led);
+       if (ret < 0)
+               goto out;
+
+       if (led->led_mode == LM3601X_LED_TORCH)
+               led_mode_val = LM3601X_MODE_TORCH;
+       else
+               led_mode_val = LM3601X_MODE_IR_DRV;
+
+       if (brightness == LED_OFF) {
+               ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+                                       led_mode_val, LED_OFF);
+               goto out;
+       }
+
+       ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness);
+       if (ret < 0)
+               goto out;
+
+       ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+                               LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
+                               led_mode_val);
+out:
+       mutex_unlock(&led->lock);
+       return ret;
+}
+
+static int lm3601x_strobe_set(struct led_classdev_flash *fled_cdev,
+                               bool state)
+{
+       struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+       int timeout_reg_val;
+       int current_timeout;
+       int ret;
+
+       mutex_lock(&led->lock);
+
+       ret = regmap_read(led->regmap, LM3601X_CFG_REG, &current_timeout);
+       if (ret < 0)
+               goto out;
+
+       if (led->flash_timeout >= LM3601X_TIMEOUT_XOVER_US)
+               timeout_reg_val = led->flash_timeout / LM3601X_UPPER_STEP_US + 0x07;
+       else
+               timeout_reg_val = led->flash_timeout / LM3601X_LOWER_STEP_US - 0x01;
+
+       if (led->flash_timeout != current_timeout)
+               ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,
+                                       LM3601X_TIMEOUT_MASK, timeout_reg_val);
+
+       if (state)
+               ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+                                       LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
+                                       LM3601X_MODE_STROBE);
+       else
+               ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+                                       LM3601X_MODE_STROBE, LED_OFF);
+
+       ret = lm3601x_read_faults(led);
+out:
+       mutex_unlock(&led->lock);
+       return ret;
+}
+
+static int lm3601x_flash_brightness_set(struct led_classdev_flash *fled_cdev,
+                                       u32 brightness)
+{
+       struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+       u8 brightness_val;
+       int ret;
+
+       mutex_lock(&led->lock);
+       ret = lm3601x_read_faults(led);
+       if (ret < 0)
+               goto out;
+
+       if (brightness == LED_OFF) {
+               ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+                                       LM3601X_MODE_STROBE, LED_OFF);
+               goto out;
+       }
+
+       brightness_val = brightness / LM3601X_STROBE_REG_DIV;
+
+       ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
+out:
+       mutex_unlock(&led->lock);
+       return ret;
+}
+
+static int lm3601x_flash_timeout_set(struct led_classdev_flash *fled_cdev,
+                               u32 timeout)
+{
+       struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+
+       mutex_lock(&led->lock);
+
+       led->flash_timeout = timeout;
+
+       mutex_unlock(&led->lock);
+
+       return 0;
+}
+
+static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
+{
+       struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+       int strobe_state;
+       int ret;
+
+       mutex_lock(&led->lock);
+
+       ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &strobe_state);
+       if (ret < 0)
+               goto out;
+
+       *state = strobe_state & LM3601X_MODE_STROBE;
+
+out:
+       mutex_unlock(&led->lock);
+       return ret;
+}
+
+static int lm3601x_flash_fault_get(struct led_classdev_flash *fled_cdev,
+                               u32 *fault)
+{
+       struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+
+       lm3601x_read_faults(led);
+
+       *fault = led->last_flag;
+
+       return 0;
+}
+
+static const struct led_flash_ops flash_ops = {
+       .flash_brightness_set   = lm3601x_flash_brightness_set,
+       .strobe_set             = lm3601x_strobe_set,
+       .strobe_get             = lm3601x_strobe_get,
+       .timeout_set            = lm3601x_flash_timeout_set,
+       .fault_get              = lm3601x_flash_fault_get,
+};
+
+static int lm3601x_register_leds(struct lm3601x_led *led)
+{
+       struct led_classdev *led_cdev;
+       struct led_flash_setting *setting;
+
+       led->fled_cdev.ops = &flash_ops;
+
+       setting = &led->fled_cdev.timeout;
+       setting->min = LM3601X_MIN_TIMEOUT_US;
+       setting->max = led->max_flash_timeout;
+       setting->step = LM3601X_LOWER_STEP_US;
+       setting->val = led->max_flash_timeout;
+
+       setting = &led->fled_cdev.brightness;
+       setting->min = LM3601X_MIN_STROBE_I_UA;
+       setting->max = led->flash_current_max;
+       setting->step = LM3601X_TORCH_REG_DIV;
+       setting->val = led->flash_current_max;
+
+       led_cdev = &led->fled_cdev.led_cdev;
+       led_cdev->name = led->led_name;
+       led_cdev->brightness_set_blocking = lm3601x_brightness_set;
+       led_cdev->max_brightness = DIV_ROUND_UP(led->torch_current_max,
+                                               LM3601X_TORCH_REG_DIV);
+       led_cdev->flags |= LED_DEV_CAP_FLASH;
+
+       return led_classdev_flash_register(&led->client->dev, &led->fled_cdev);
+}
+
+static int lm3601x_parse_node(struct lm3601x_led *led)
+{
+       struct fwnode_handle *child = NULL;
+       int ret = -ENODEV;
+       const char *name;
+
+       child = device_get_next_child_node(&led->client->dev, child);
+       if (!child) {
+               dev_err(&led->client->dev, "No LED Child node\n");
+               return ret;
+       }
+
+       ret = fwnode_property_read_u32(child, "reg", &led->led_mode);
+       if (ret) {
+               dev_err(&led->client->dev, "reg DT property missing\n");
+               goto out_err;
+       }
+
+       if (led->led_mode > LM3601X_LED_TORCH ||
+           led->led_mode < LM3601X_LED_IR) {
+               dev_warn(&led->client->dev, "Invalid led mode requested\n");
+               ret = -EINVAL;
+               goto out_err;
+       }
+
+       ret = fwnode_property_read_string(child, "label", &name);
+       if (ret) {
+               if (led->led_mode == LM3601X_LED_TORCH)
+                       name = "torch";
+               else
+                       name = "infrared";
+       }
+
+       snprintf(led->led_name, sizeof(led->led_name),
+               "%s:%s", led->client->name, name);
+
+       ret = fwnode_property_read_u32(child, "led-max-microamp",
+                                       &led->torch_current_max);
+       if (ret) {
+               dev_warn(&led->client->dev,
+                       "led-max-microamp DT property missing\n");
+               goto out_err;
+       }
+
+       ret = fwnode_property_read_u32(child, "flash-max-microamp",
+                               &led->flash_current_max);
+       if (ret) {
+               dev_warn(&led->client->dev,
+                        "flash-max-microamp DT property missing\n");
+               goto out_err;
+       }
+
+       ret = fwnode_property_read_u32(child, "flash-max-timeout-us",
+                               &led->max_flash_timeout);
+       if (ret) {
+               dev_warn(&led->client->dev,
+                        "flash-max-timeout-us DT property missing\n");
+               goto out_err;
+       }
+
+out_err:
+       fwnode_handle_put(child);
+       return ret;
+}
+
+static int lm3601x_probe(struct i2c_client *client)
+{
+       struct lm3601x_led *led;
+       int ret;
+
+       led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
+       if (!led)
+               return -ENOMEM;
+
+       led->client = client;
+       i2c_set_clientdata(client, led);
+
+       ret = lm3601x_parse_node(led);
+       if (ret)
+               return -ENODEV;
+
+       led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);
+       if (IS_ERR(led->regmap)) {
+               ret = PTR_ERR(led->regmap);
+               dev_err(&client->dev,
+                       "Failed to allocate register map: %d\n", ret);
+               return ret;
+       }
+
+       mutex_init(&led->lock);
+
+       return lm3601x_register_leds(led);
+}
+
+static int lm3601x_remove(struct i2c_client *client)
+{
+       struct lm3601x_led *led = i2c_get_clientdata(client);
+
+       led_classdev_flash_unregister(&led->fled_cdev);
+       mutex_destroy(&led->lock);
+
+       return regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+                          LM3601X_ENABLE_MASK,
+                          LM3601X_MODE_STANDBY);
+}
+
+static const struct i2c_device_id lm3601x_id[] = {
+       { "LM36010", CHIP_LM36010 },
+       { "LM36011", CHIP_LM36011 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, lm3601x_id);
+
+static const struct of_device_id of_lm3601x_leds_match[] = {
+       { .compatible = "ti,lm36010", },
+       { .compatible = "ti,lm36011", },
+       { }
+};
+MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);
+
+static struct i2c_driver lm3601x_i2c_driver = {
+       .driver = {
+               .name = "lm3601x",
+               .of_match_table = of_lm3601x_leds_match,
+       },
+       .probe_new = lm3601x_probe,
+       .remove = lm3601x_remove,
+       .id_table = lm3601x_id,
+};
+module_i2c_driver(lm3601x_i2c_driver);
+
+MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_LICENSE("GPL v2");