[PATCH v4 2/2] leds: lm3601x: Introduce the lm3601x LED driver

From: Dan Murphy
Date: Thu May 10 2018 - 08:27:40 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

Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
---

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 | 611 ++++++++++++++++++++++++++++++++++++
3 files changed, 621 insertions(+)
create mode 100644 drivers/leds/leds-lm3601x.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 2c896c0e69e1..50ae536f343f 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 && OF
+ 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..4104c259c65d
--- /dev/null
+++ b/drivers/leds/leds-lm3601x.c
@@ -0,0 +1,611 @@
+// 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_TORCH 0x0
+#define LM3601X_LED_STROBE 0x1
+#define LM3601X_LED_IR 0x2
+
+/* 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_LVL_TRIG ~BIT(3)
+#define LM3601X_STRB_EDGE_TRIG BIT(3)
+#define LM3601X_IVFM_EN BIT(4)
+
+#define LM36010_BOOST_LIMIT_19 ~BIT(5)
+#define LM36010_BOOST_LIMIT_28 BIT(5)
+#define LM36010_BOOST_FREQ_2MHZ ~BIT(6)
+#define LM36010_BOOST_FREQ_4MHZ BIT(6)
+#define LM36010_BOOST_MODE_NORM ~BIT(7)
+#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_MIN_TORCH_I_UA 2400
+#define LM3601X_MIN_STROBE_I_MA 11
+
+enum lm3601x_type {
+ CHIP_LM36010 = 0,
+ CHIP_LM36011,
+};
+
+/**
+ * struct lm3601x_max_timeouts -
+ * @timeout: timeout value in ms
+ * @regval: the value of the register to write
+ */
+struct lm3601x_max_timeouts {
+ int timeout;
+ int reg_val;
+};
+
+/**
+ * struct lm3601x_led -
+ * @lock: Lock for reading/writing the device
+ * @regmap: Devices register map
+ * @client: Pointer to the I2C client
+ * @cdev_torch: led class device pointer for the torch
+ * @cdev_ir: led class device pointer for infrared
+ * @fled_cdev: flash led class device pointer
+ * @strobe_node: DT device node for the strobe
+ * @torch: LED label for the torch
+ * @strobe: LED label for the strobe
+ * @ir: LED label for the infrared
+ * @last_flag: last known flags register value
+ * @strobe_timeout: the timeout for the strobe
+ * @torch_current_max: maximum current for the torch
+ * @strobe_current_max: maximum current for the strobe
+ * @max_strobe_timeout: maximum timeout for the strobe
+ */
+struct lm3601x_led {
+ struct mutex lock;
+ struct regmap *regmap;
+ struct i2c_client *client;
+
+ struct led_classdev cdev_torch;
+ struct led_classdev cdev_ir;
+
+ struct led_classdev_flash fled_cdev;
+
+ struct device_node *strobe_node;
+ struct device_node *torch_node;
+ struct device_node *ir_node;
+
+ char torch[LED_MAX_NAME_SIZE];
+ char strobe[LED_MAX_NAME_SIZE];
+ char ir[LED_MAX_NAME_SIZE];
+
+ unsigned int last_flag;
+ unsigned int strobe_timeout;
+
+ u32 torch_current_max;
+ u32 strobe_current_max;
+ u32 max_strobe_timeout;
+};
+
+static const struct lm3601x_max_timeouts strobe_timeouts[] = {
+ { 40, 0x00 },
+ { 80, 0x01 },
+ { 120, 0x02 },
+ { 160, 0x03 },
+ { 200, 0x04 },
+ { 240, 0x05 },
+ { 280, 0x06 },
+ { 320, 0x07 },
+ { 360, 0x08 },
+ { 400, 0x09 },
+ { 600, 0x0a },
+ { 800, 0x0b },
+ { 1000, 0x0c },
+ { 1200, 0x0d },
+ { 1400, 0x0e },
+ { 1600, 0x0f },
+};
+
+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_FLAT,
+ .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 = flags_val;
+
+ return led->last_flag;
+}
+
+static int lm3601x_torch_brightness_set(struct led_classdev *cdev,
+ enum led_brightness brightness)
+{
+ struct lm3601x_led *led =
+ container_of(cdev, struct lm3601x_led, cdev_torch);
+ int ret;
+ u8 brightness_val;
+
+ 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_TORCH, LED_OFF);
+ goto out;
+ }
+
+ if (brightness == LED_ON)
+ brightness_val = LED_ON;
+ else
+ brightness_val = (brightness/2);
+
+ ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness_val);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+ LM3601X_MODE_TORCH,
+ LM3601X_MODE_TORCH);
+
+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 ret;
+ int current_timeout;
+ int reg_count;
+ int i;
+ int timeout_reg_val = 0;
+
+ mutex_lock(&led->lock);
+
+ ret = regmap_read(led->regmap, LM3601X_CFG_REG, &current_timeout);
+ if (ret < 0)
+ goto out;
+
+ reg_count = ARRAY_SIZE(strobe_timeouts);
+ for (i = 0; i < reg_count; i++) {
+ if (led->strobe_timeout > strobe_timeouts[i].timeout)
+ continue;
+
+ if (led->strobe_timeout <= strobe_timeouts[i].timeout) {
+ timeout_reg_val = (strobe_timeouts[i].reg_val << 1);
+ break;
+ }
+
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (led->strobe_timeout != current_timeout)
+ ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,
+ 0x1e, timeout_reg_val);
+
+ if (state)
+ ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+ LM3601X_MODE_STROBE,
+ 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_strobe_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;
+ u8 brightness_val;
+
+ 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;
+ }
+
+ if (brightness == LED_ON)
+ brightness_val = LED_ON;
+ else
+ brightness_val = (brightness/2);
+
+ ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
+
+out:
+ mutex_unlock(&led->lock);
+ return ret;
+}
+
+static int lm3601x_strobe_timeout_set(struct led_classdev_flash *fled_cdev,
+ u32 timeout)
+{
+ struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+ int ret = 0;
+
+ mutex_lock(&led->lock);
+
+ if (timeout > led->max_strobe_timeout)
+ ret = -EINVAL;
+ else
+ led->strobe_timeout = timeout;
+
+ mutex_unlock(&led->lock);
+
+ return ret;
+}
+
+static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev,
+ bool *state)
+{
+ struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+ int ret;
+ int strobe_state;
+
+ 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_ir_brightness_set(struct led_classdev *cdev,
+ enum led_brightness brightness)
+{
+ struct lm3601x_led *led =
+ container_of(cdev, struct lm3601x_led, cdev_ir);
+ int ret;
+ u8 brightness_val;
+
+ 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,
+ 0xfe, LED_OFF);
+ goto out;
+ }
+
+ if (brightness == LED_ON)
+ brightness_val = LED_ON;
+ else
+ brightness_val = (brightness/2);
+
+ ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+ LM3601X_MODE_IR_DRV,
+ LM3601X_MODE_IR_DRV);
+
+out:
+ mutex_unlock(&led->lock);
+ return ret;
+}
+
+static int lm3601x_strobe_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 strobe_ops = {
+ .strobe_set = lm3601x_strobe_set,
+ .strobe_get = lm3601x_strobe_get,
+ .timeout_set = lm3601x_strobe_timeout_set,
+ .fault_get = lm3601x_strobe_fault_get,
+};
+
+static int lm3601x_register_leds(struct lm3601x_led *led)
+{
+ struct led_classdev_flash *fled_cdev;
+ struct led_classdev *led_cdev;
+ int err = -ENODEV;
+
+ if (led->torch_node) {
+ led->cdev_torch.name = led->torch;
+ led->cdev_torch.max_brightness = LED_FULL;
+ led->cdev_torch.brightness_set_blocking = lm3601x_torch_brightness_set;
+ err = devm_led_classdev_register(&led->client->dev,
+ &led->cdev_torch);
+ if (err < 0)
+ return err;
+ }
+
+ if (led->strobe_node) {
+ fled_cdev = &led->fled_cdev;
+ fled_cdev->ops = &strobe_ops;
+
+ led_cdev = &fled_cdev->led_cdev;
+ led_cdev->name = led->strobe;
+ led_cdev->max_brightness = LED_FULL;
+ led_cdev->brightness_set_blocking = lm3601x_strobe_brightness_set;
+ led_cdev->flags |= LED_DEV_CAP_FLASH;
+
+ err = led_classdev_flash_register(&led->client->dev,
+ fled_cdev);
+ if (err < 0)
+ return err;
+ }
+
+ if (led->ir_node) {
+ led->cdev_ir.name = led->ir;
+ led->cdev_ir.max_brightness = LED_FULL;
+ led->cdev_ir.brightness_set_blocking =
+ lm3601x_ir_brightness_set;
+
+ err = devm_led_classdev_register(&led->client->dev,
+ &led->cdev_ir);
+ }
+
+ return err;
+}
+
+static void lm3601x_init_flash_timeout(struct lm3601x_led *led)
+{
+ struct led_flash_setting *setting;
+
+ setting = &led->fled_cdev.timeout;
+ setting->min = strobe_timeouts[0].timeout;
+ setting->max = led->max_strobe_timeout;
+ setting->step = 40;
+ setting->val = led->max_strobe_timeout;
+}
+
+static int lm3601x_parse_node(struct lm3601x_led *led,
+ struct device_node *node)
+{
+ struct device_node *child_node;
+ const char *name;
+ int ret = -ENODEV;
+
+ for_each_available_child_of_node(node, child_node) {
+ u32 id = 0;
+
+ of_property_read_u32(child_node, "reg", &id);
+
+ switch (id) {
+ case LM3601X_LED_TORCH:
+ led->torch_node = of_node_get(child_node);
+ break;
+ case LM3601X_LED_STROBE:
+ led->strobe_node = of_node_get(child_node);
+ break;
+ case LM3601X_LED_IR:
+ led->ir_node = of_node_get(child_node);
+ break;
+ default:
+ dev_warn(&led->client->dev,
+ "unknown LED %u encountered, ignoring\n", id);
+ break;
+ }
+ }
+
+ if (led->torch_node) {
+ ret = of_property_read_string(led->torch_node, "label", &name);
+ if (!ret)
+ snprintf(led->torch, sizeof(led->torch),
+ "%s:%s", led->torch_node->name, name);
+ else
+ snprintf(led->torch, sizeof(led->torch),
+ "%s:torch", led->torch_node->name);
+ ret = of_property_read_u32(led->torch_node, "led-max-microamp",
+ &led->torch_current_max);
+ if (ret < 0) {
+ led->torch_current_max = LM3601X_MIN_TORCH_I_UA;
+ dev_warn(&led->client->dev,
+ "led-max-microamp DT property missing\n");
+ }
+ }
+
+ if (led->strobe_node) {
+ ret = of_property_read_string(led->strobe_node, "label", &name);
+ if (!ret)
+ snprintf(led->strobe, sizeof(led->strobe),
+ "%s:%s", led->strobe_node->name, name);
+ else
+ snprintf(led->strobe, sizeof(led->strobe),
+ "%s::strobe", led->strobe_node->name);
+
+ ret = of_property_read_u32(led->strobe_node,
+ "flash-max-microamp",
+ &led->strobe_current_max);
+ if (ret < 0) {
+ led->strobe_current_max = LM3601X_MIN_STROBE_I_MA;
+ dev_warn(&led->client->dev,
+ "flash-max-microamp DT property missing\n");
+ }
+
+ ret = of_property_read_u32(led->strobe_node,
+ "flash-max-timeout-us",
+ &led->max_strobe_timeout);
+ if (ret < 0) {
+ led->max_strobe_timeout = strobe_timeouts[0].reg_val;
+ dev_warn(&led->client->dev,
+ "flash-max-timeout-us DT property missing\n");
+ }
+
+ lm3601x_init_flash_timeout(led);
+
+ }
+
+ if (led->ir_node) {
+ ret = of_property_read_string(led->ir_node, "label", &name);
+ if (!ret)
+ snprintf(led->ir, sizeof(led->ir),
+ "%s:%s", led->ir_node->name, name);
+ else
+ snprintf(led->ir, sizeof(led->ir),
+ "%s::infrared", led->ir_node->name);
+ }
+
+ return ret;
+}
+
+static int lm3601x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct lm3601x_led *led;
+ int err;
+
+ led = devm_kzalloc(&client->dev,
+ sizeof(struct lm3601x_led), GFP_KERNEL);
+ if (!led)
+ return -ENOMEM;
+
+ err = lm3601x_parse_node(led, client->dev.of_node);
+ if (err < 0)
+ return -ENODEV;
+
+ led->client = client;
+ led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);
+ if (IS_ERR(led->regmap)) {
+ err = PTR_ERR(led->regmap);
+ dev_err(&client->dev,
+ "Failed to allocate register map: %d\n", err);
+ return err;
+ }
+
+ mutex_init(&led->lock);
+ i2c_set_clientdata(client, led);
+ err = lm3601x_register_leds(led);
+
+ return err;
+}
+
+static int lm3601x_remove(struct i2c_client *client)
+{
+ struct lm3601x_led *led = i2c_get_clientdata(client);
+
+ regmap_write(led->regmap, LM3601X_ENABLE_REG, 0);
+
+ return 0;
+}
+
+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 = 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