leds: lm3697: Introduce the lm3697 driver
authorDan Murphy <dmurphy@ti.com>
Mon, 6 May 2019 19:16:14 +0000 (14:16 -0500)
committerJacek Anaszewski <jacek.anaszewski@gmail.com>
Fri, 24 May 2019 20:40:47 +0000 (22:40 +0200)
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>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
drivers/leds/Kconfig
drivers/leds/Makefile
drivers/leds/leds-lm3697.c [new file with mode: 0644]

index 4e26269..ba14b48 100644 (file)
@@ -792,6 +792,14 @@ 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
+       depends on I2C && OF
+       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"
 
index 84c4933..6c33504 100644 (file)
@@ -82,6 +82,7 @@ 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 (file)
index 0000000..54e0e35
--- /dev/null
@@ -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");