[PATCH v9 2/2] leds: lm3601x: Introduce the lm3601x LED driver

From: Dan Murphy
Date: Wed May 23 2018 - 06:58:28 EST

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

Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
---

v9 - Changed "strobe" to flash in some cases, removed some redundant variable
assignments, updated a couple of line to make them more readable, converted to
probe_new from old probe, and change err to ret - https://patchwork.kernel.org/patch/10418731/

v8 - Removed OF Kconfig dependency, change strobe to flash, updated label generation,
fixed brightness calculation, added mutex_destroy and flash_unregister - https://patchwork.kernel.org/patch/10416163/
v7 - Numerous fixes to many to list. Highlights are moved from OF APIs to device_property
APIs, updated LED registration, timeout to reg algorithim, and fixed label generation -
https://patchwork.kernel.org/patch/10401437/
v6 - This driver has been heavily modified from v5. There is no longer reading
of individual child nodes. There are too many changes to list here see -
https://patchwork.kernel.org/patch/10392123/
v5 - Fixed magic numbers, change reg cache type, added of_put_node to release
the dt node ref, and I did not change the remove function to leave the LED in its
state on driver removal - https://patchwork.kernel.org/patch/10391741/
v4 - Fixed Cocci issue using ARRAY_SIZE - https://patchwork.kernel.org/patch/10389259/
v3 - removed wildcard dt compatible, fixed copyright, fixed struct doc, removed
RO registers from default, added regmap volatile for FLAGS_REG, updated regmap cache type,
fixed unlock and extra semi colon in strobe_set, removed unnecessary out label
in led register and fixed checking of the ret in brightness_set - https://patchwork.kernel.org/patch/10386243/
v2 - Fixed kbuild issue and removed unused cdev_strobe - https://patchwork.kernel.org/patch/10384585/

drivers/leds/Kconfig | 9 +
drivers/leds/Makefile | 1 +
drivers/leds/leds-lm3601x.c | 487 ++++++++++++++++++++++++++++++++++++
3 files changed, 497 insertions(+)
create mode 100644 drivers/leds/leds-lm3601x.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 2c896c0e69e1..d95d436e6089 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -145,6 +145,15 @@ 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
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 91eca81cae82..b79807fe1b67 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -76,6 +76,7 @@ obj-$(CONFIG_LEDS_MLXREG) += leds-mlxreg.o
obj-$(CONFIG_LEDS_NIC78BX) += leds-nic78bx.o
obj-$(CONFIG_LEDS_MT6323) += leds-mt6323.o
obj-$(CONFIG_LEDS_LM3692X) += leds-lm3692x.o
+obj-$(CONFIG_LEDS_LM3601X) += leds-lm3601x.o

# LED SPI Drivers
obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
diff --git a/drivers/leds/leds-lm3601x.c b/drivers/leds/leds-lm3601x.c
new file mode 100644
index 000000000000..081aa71e43a3
--- /dev/null
+++ b/drivers/leds/leds-lm3601x.c
@@ -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@xxxxxx>");
+MODULE_LICENSE("GPL v2");
--
2.17.0.582.gccdcbd54c