[PATCH v4 7/7] leds: lm3697: Introduce the lm3697 driver

Dan Murphy
2019-05-06T19:16:45Z

Introduce the lm3697 LED driver for backlighting and display.

Datasheet location:
http://www.ti.com/lit/ds/symlink/lm3697.pdf

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---

v4 - Updated common header name - https://lore.kernel.org/patchwork/patch/1068619/

v3 - Moved TI_COMMON_LMU flag above LM3697 flag for inheritance also fixed removed
REGMAP dependency - v1 comments https://lore.kernel.org/patchwork/patch/1054503/
v2 comments https://lore.kernel.org/patchwork/patch/1058761/

v2 - Made changes to get max_brightness from ti_lmu common code, fixed commit
message extra LF otherwise no additional changes - https://lore.kernel.org/patchwork/patch/1054503/

drivers/leds/Kconfig | 7 +
drivers/leds/Makefile | 1 +
drivers/leds/leds-lm3697.c | 395 +++++++++++++++++++++++++++++++++++++
3 files changed, 403 insertions(+)
create mode 100644 drivers/leds/leds-lm3697.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index a88dad3be96c..255fdd5e8491 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -784,6 +784,13 @@ config LEDS_TI_LMU_COMMON
This supports common features between the TI LM3532, LM3631, LM3632,
LM3633, LM3695 and LM3697.

+config LEDS_LM3697
+ tristate "LED driver for LM3697"
+ depends on LEDS_TI_LMU_COMMON
+ help
+ Say Y to enable the LM3697 LED driver for TI LMU devices.
+ This supports the LED device LM3697.
+
comment "LED Triggers"
source "drivers/leds/trigger/Kconfig"

diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 9d7cdd363603..8ab825c8b5c3 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_LEDS_LM3692X) += leds-lm3692x.o
obj-$(CONFIG_LEDS_SC27XX_BLTC) += leds-sc27xx-bltc.o
obj-$(CONFIG_LEDS_LM3601X) += leds-lm3601x.o
obj-$(CONFIG_LEDS_TI_LMU_COMMON) += leds-ti-lmu-common.o
+obj-$(CONFIG_LEDS_LM3697) += leds-lm3697.o

# LED SPI Drivers
obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o
diff --git a/drivers/leds/leds-lm3697.c b/drivers/leds/leds-lm3697.c
new file mode 100644
index 000000000000..54e0e35df824
--- /dev/null
+++ b/drivers/leds/leds-lm3697.c
@@ -0,0 +1,395 @@
+// SPDX-License-Identifier: GPL-2.0
+// TI LM3697 LED chip family driver
+// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regulator/consumer.h>
+#include <linux/leds-ti-lmu-common.h>
+
+#define LM3697_REV 0x0
+#define LM3697_RESET 0x1
+#define LM3697_OUTPUT_CONFIG 0x10
+#define LM3697_CTRL_A_RAMP 0x11
+#define LM3697_CTRL_B_RAMP 0x12
+#define LM3697_CTRL_A_B_RT_RAMP 0x13
+#define LM3697_CTRL_A_B_RAMP_CFG 0x14
+#define LM3697_CTRL_A_B_BRT_CFG 0x16
+#define LM3697_CTRL_A_FS_CURR_CFG 0x17
+#define LM3697_CTRL_B_FS_CURR_CFG 0x18
+#define LM3697_PWM_CFG 0x1c
+#define LM3697_CTRL_A_BRT_LSB 0x20
+#define LM3697_CTRL_A_BRT_MSB 0x21
+#define LM3697_CTRL_B_BRT_LSB 0x22
+#define LM3697_CTRL_B_BRT_MSB 0x23
+#define LM3697_CTRL_ENABLE 0x24
+
+#define LM3697_SW_RESET BIT(0)
+
+#define LM3697_CTRL_A_EN BIT(0)
+#define LM3697_CTRL_B_EN BIT(1)
+#define LM3697_CTRL_A_B_EN (LM3697_CTRL_A_EN | LM3697_CTRL_B_EN)
+
+#define LM3697_MAX_LED_STRINGS 3
+
+#define LM3697_CONTROL_A 0
+#define LM3697_CONTROL_B 1
+#define LM3697_MAX_CONTROL_BANKS 2
+
+/**
+ * struct lm3697_led -
+ * @hvled_strings: Array of LED strings associated with a control bank
+ * @label: LED label
+ * @led_dev: LED class device
+ * @priv: Pointer to the device struct
+ * @lmu_data: Register and setting values for common code
+ * @control_bank: Control bank the LED is associated to. 0 is control bank A
+ * 1 is control bank B
+ */
+struct lm3697_led {
+ u32 hvled_strings[LM3697_MAX_LED_STRINGS];
+ char label[LED_MAX_NAME_SIZE];
+ struct led_classdev led_dev;
+ struct lm3697 *priv;
+ struct ti_lmu_bank lmu_data;
+ int control_bank;
+ int enabled;
+ int num_leds;
+};
+
+/**
+ * struct lm3697 -
+ * @enable_gpio: Hardware enable gpio
+ * @regulator: LED supply regulator pointer
+ * @client: Pointer to the I2C client
+ * @regmap: Devices register map
+ * @dev: Pointer to the devices device struct
+ * @lock: Lock for reading/writing the device
+ * @leds: Array of LED strings
+ */
+struct lm3697 {
+ struct gpio_desc *enable_gpio;
+ struct regulator *regulator;
+ struct i2c_client *client;
+ struct regmap *regmap;
+ struct device *dev;
+ struct mutex lock;
+
+ int bank_cfg;
+
+ struct lm3697_led leds[];
+};
+
+static const struct reg_default lm3697_reg_defs[] = {
+ {LM3697_OUTPUT_CONFIG, 0x6},
+ {LM3697_CTRL_A_RAMP, 0x0},
+ {LM3697_CTRL_B_RAMP, 0x0},
+ {LM3697_CTRL_A_B_RT_RAMP, 0x0},
+ {LM3697_CTRL_A_B_RAMP_CFG, 0x0},
+ {LM3697_CTRL_A_B_BRT_CFG, 0x0},
+ {LM3697_CTRL_A_FS_CURR_CFG, 0x13},
+ {LM3697_CTRL_B_FS_CURR_CFG, 0x13},
+ {LM3697_PWM_CFG, 0xc},
+ {LM3697_CTRL_A_BRT_LSB, 0x0},
+ {LM3697_CTRL_A_BRT_MSB, 0x0},
+ {LM3697_CTRL_B_BRT_LSB, 0x0},
+ {LM3697_CTRL_B_BRT_MSB, 0x0},
+ {LM3697_CTRL_ENABLE, 0x0},
+};
+
+static const struct regmap_config lm3697_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+
+ .max_register = LM3697_CTRL_ENABLE,
+ .reg_defaults = lm3697_reg_defs,
+ .num_reg_defaults = ARRAY_SIZE(lm3697_reg_defs),
+ .cache_type = REGCACHE_FLAT,
+};
+
+static int lm3697_brightness_set(struct led_classdev *led_cdev,
+ enum led_brightness brt_val)
+{
+ struct lm3697_led *led = container_of(led_cdev, struct lm3697_led,
+ led_dev);
+ int ctrl_en_val = (1 << led->control_bank);
+ int ret;
+
+ mutex_lock(&led->priv->lock);
+
+ if (brt_val == LED_OFF) {
+ ret = regmap_update_bits(led->priv->regmap, LM3697_CTRL_ENABLE,
+ ctrl_en_val, ~ctrl_en_val);
+ if (ret) {
+ dev_err(&led->priv->client->dev, "Cannot write ctrl register\n");
+ goto brightness_out;
+ }
+
+ led->enabled = LED_OFF;
+ } else {
+ ret = ti_lmu_common_set_brightness(&led->lmu_data, brt_val);
+ if (ret) {
+ dev_err(&led->priv->client->dev,
+ "Cannot write brightness\n");
+ goto brightness_out;
+ }
+
+ if (!led->enabled) {
+ ret = regmap_update_bits(led->priv->regmap,
+ LM3697_CTRL_ENABLE,
+ ctrl_en_val, ctrl_en_val);
+ if (ret) {
+ dev_err(&led->priv->client->dev,
+ "Cannot enable the device\n");
+ goto brightness_out;
+ }
+
+ led->enabled = brt_val;
+ }
+ }
+
+brightness_out:
+ mutex_unlock(&led->priv->lock);
+ return ret;
+}
+
+static int lm3697_init(struct lm3697 *priv)
+{
+ struct lm3697_led *led;
+ int i, ret;
+
+ if (priv->enable_gpio) {
+ gpiod_direction_output(priv->enable_gpio, 1);
+ } else {
+ ret = regmap_write(priv->regmap, LM3697_RESET, LM3697_SW_RESET);
+ if (ret) {
+ dev_err(&priv->client->dev, "Cannot reset the device\n");
+ goto out;
+ }
+ }
+
+ ret = regmap_write(priv->regmap, LM3697_CTRL_ENABLE, 0x0);
+ if (ret) {
+ dev_err(&priv->client->dev, "Cannot write ctrl enable\n");
+ goto out;
+ }
+
+ ret = regmap_write(priv->regmap, LM3697_OUTPUT_CONFIG, priv->bank_cfg);
+ if (ret)
+ dev_err(&priv->client->dev, "Cannot write OUTPUT config\n");
+
+ for (i = 0; i < LM3697_MAX_CONTROL_BANKS; i++) {
+ led = &priv->leds[i];
+ ret = ti_lmu_common_set_ramp(&led->lmu_data);
+ if (ret)
+ dev_err(&priv->client->dev, "Setting the ramp rate failed\n");
+ }
+out:
+ return ret;
+}
+
+static int lm3697_probe_dt(struct lm3697 *priv)
+{
+ struct fwnode_handle *child = NULL;
+ struct lm3697_led *led;
+ const char *name;
+ int control_bank;
+ size_t i = 0;
+ int ret = -EINVAL;
+ int j;
+
+ priv->enable_gpio = devm_gpiod_get_optional(&priv->client->dev,
+ "enable", GPIOD_OUT_LOW);
+ if (IS_ERR(priv->enable_gpio)) {
+ ret = PTR_ERR(priv->enable_gpio);
+ dev_err(&priv->client->dev, "Failed to get enable gpio: %d\n",
+ ret);
+ return ret;
+ }
+
+ priv->regulator = devm_regulator_get(&priv->client->dev, "vled");
+ if (IS_ERR(priv->regulator))
+ priv->regulator = NULL;
+
+ device_for_each_child_node(priv->dev, child) {
+ ret = fwnode_property_read_u32(child, "reg", &control_bank);
+ if (ret) {
+ dev_err(&priv->client->dev, "reg property missing\n");
+ fwnode_handle_put(child);
+ goto child_out;
+ }
+
+ if (control_bank > LM3697_CONTROL_B) {
+ dev_err(&priv->client->dev, "reg property is invalid\n");
+ ret = -EINVAL;
+ fwnode_handle_put(child);
+ goto child_out;
+ }
+
+ led = &priv->leds[i];
+
+ ret = ti_lmu_common_get_brt_res(&priv->client->dev,
+ child, &led->lmu_data);
+ if (ret)
+ dev_warn(&priv->client->dev, "brightness resolution property missing\n");
+
+ led->control_bank = control_bank;
+ led->lmu_data.regmap = priv->regmap;
+ led->lmu_data.runtime_ramp_reg = LM3697_CTRL_A_RAMP +
+ control_bank;
+ led->lmu_data.msb_brightness_reg = LM3697_CTRL_A_BRT_MSB +
+ led->control_bank * 2;
+ led->lmu_data.lsb_brightness_reg = LM3697_CTRL_A_BRT_LSB +
+ led->control_bank * 2;
+
+ led->num_leds = fwnode_property_read_u32_array(child,
+ "led-sources",
+ NULL, 0);
+
+ if (led->num_leds > LM3697_MAX_LED_STRINGS) {
+ dev_err(&priv->client->dev, "To many LED strings defined\n");
+ continue;
+ }
+
+ ret = fwnode_property_read_u32_array(child, "led-sources",
+ led->hvled_strings,
+ led->num_leds);
+ if (ret) {
+ dev_err(&priv->client->dev, "led-sources property missing\n");
+ fwnode_handle_put(child);
+ goto child_out;
+ }
+
+ for (j = 0; j < led->num_leds; j++)
+ priv->bank_cfg |=
+ (led->control_bank << led->hvled_strings[j]);
+
+ ret = ti_lmu_common_get_ramp_params(&priv->client->dev,
+ child, &led->lmu_data);
+ if (ret)
+ dev_warn(&priv->client->dev, "runtime-ramp properties missing\n");
+
+ fwnode_property_read_string(child, "linux,default-trigger",
+ &led->led_dev.default_trigger);
+
+ ret = fwnode_property_read_string(child, "label", &name);
+ if (ret)
+ snprintf(led->label, sizeof(led->label),
+ "%s::", priv->client->name);
+ else
+ snprintf(led->label, sizeof(led->label),
+ "%s:%s", priv->client->name, name);
+
+ led->priv = priv;
+ led->led_dev.name = led->label;
+ led->led_dev.max_brightness = led->lmu_data.max_brightness;
+ led->led_dev.brightness_set_blocking = lm3697_brightness_set;
+
+ ret = devm_led_classdev_register(priv->dev, &led->led_dev);
+ if (ret) {
+ dev_err(&priv->client->dev, "led register err: %d\n",
+ ret);
+ fwnode_handle_put(child);
+ goto child_out;
+ }
+
+ i++;
+ }
+
+child_out:
+ return ret;
+}
+
+static int lm3697_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct lm3697 *led;
+ int count;
+ int ret;
+
+ count = device_get_child_node_count(&client->dev);
+ if (!count) {
+ dev_err(&client->dev, "LEDs are not defined in device tree!");
+ return -ENODEV;
+ }
+
+ led = devm_kzalloc(&client->dev, struct_size(led, leds, count),
+ GFP_KERNEL);
+ if (!led)
+ return -ENOMEM;
+
+ mutex_init(&led->lock);
+ i2c_set_clientdata(client, led);
+
+ led->client = client;
+ led->dev = &client->dev;
+ led->regmap = devm_regmap_init_i2c(client, &lm3697_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 = lm3697_probe_dt(led);
+ if (ret)
+ return ret;
+
+ return lm3697_init(led);
+}
+
+static int lm3697_remove(struct i2c_client *client)
+{
+ struct lm3697 *led = i2c_get_clientdata(client);
+ int ret;
+
+ ret = regmap_update_bits(led->regmap, LM3697_CTRL_ENABLE,
+ LM3697_CTRL_A_B_EN, 0);
+ if (ret) {
+ dev_err(&led->client->dev, "Failed to disable the device\n");
+ return ret;
+ }
+
+ 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");
+ }
+
+ mutex_destroy(&led->lock);
+
+ return 0;
+}
+
+static const struct i2c_device_id lm3697_id[] = {
+ { "lm3697", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, lm3697_id);
+
+static const struct of_device_id of_lm3697_leds_match[] = {
+ { .compatible = "ti,lm3697", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_lm3697_leds_match);
+
+static struct i2c_driver lm3697_driver = {
+ .driver = {
+ .name = "lm3697",
+ .of_match_table = of_lm3697_leds_match,
+ },
+ .probe = lm3697_probe,
+ .remove = lm3697_remove,
+ .id_table = lm3697_id,
+};
+module_i2c_driver(lm3697_driver);
+
+MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver");
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_LICENSE("GPL v2");
--
2.21.0.5.gaeb582a983