This is a general driver for LM3509 backlight chip of TI.
LM3509 is High Efficiency Boost for White LEDs and/or OLED Displays with
Dual Current Sinks. This driver supports OLED/White LED select, brightness
control and sub/main control.
The datasheet can be found at http://www.ti.com/product/lm3509.
Signed-off-by: Patrick Gansterer <par...@paroga.com>
Reviewed-by: Daniel Thompson <daniel.thomp...@linaro.org>
---
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/lm3509_bl.c | 340 ++++++++++++++++++++++++++++
3 files changed, 348 insertions(+)
create mode 100644 drivers/video/backlight/lm3509_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 230bca07b09d..3614a5d29c71 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -373,6 +373,13 @@ config BACKLIGHT_AAT2870
If you have a AnalogicTech AAT2870 say Y to enable the
backlight driver.
+config BACKLIGHT_LM3509
+ tristate "Backlight Driver for LM3509"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ This supports TI LM3509 Backlight Driver
+
config BACKLIGHT_LM3630A
tristate "Backlight Driver for LM3630A"
depends on I2C && PWM
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 8d2cb252042d..8fc98f760a8a 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_BACKLIGHT_IPAQ_MICRO) += ipaq_micro_bl.o
obj-$(CONFIG_BACKLIGHT_KTD253) += ktd253-backlight.o
obj-$(CONFIG_BACKLIGHT_KTD2801) += ktd2801-backlight.o
obj-$(CONFIG_BACKLIGHT_KTZ8866) += ktz8866.o
+obj-$(CONFIG_BACKLIGHT_LM3509) += lm3509_bl.o
obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o
obj-$(CONFIG_BACKLIGHT_LM3630A) += lm3630a_bl.o
obj-$(CONFIG_BACKLIGHT_LM3639) += lm3639_bl.o
diff --git a/drivers/video/backlight/lm3509_bl.c
b/drivers/video/backlight/lm3509_bl.c
new file mode 100644
index 000000000000..ab57f79ffe23
--- /dev/null
+++ b/drivers/video/backlight/lm3509_bl.c
@@ -0,0 +1,340 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define LM3509_NAME "lm3509_bl"
+
+#define LM3509_SINK_MAIN 0
+#define LM3509_SINK_SUB 1
+#define LM3509_NUM_SINKS 2
+
+#define LM3509_DEF_BRIGHTNESS 0x12
+#define LM3509_MAX_BRIGHTNESS 0x1F
+
+#define REG_GP 0x10
+#define REG_BMAIN 0xA0
+#define REG_BSUB 0xB0
+#define REG_MAX 0xFF
+
+enum {
+ REG_GP_ENM_BIT = 0,
+ REG_GP_ENS_BIT,
+ REG_GP_UNI_BIT,
+ REG_GP_RMP0_BIT,
+ REG_GP_RMP1_BIT,
+ REG_GP_OLED_BIT,
+};
+
+struct lm3509_bl {
+ struct regmap *regmap;
+ struct backlight_device *bl_main;
+ struct backlight_device *bl_sub;
+ struct gpio_desc *reset_gpio;
+};
+
+struct lm3509_bl_led_data {
+ const char *label;
+ int led_sources;
+ u32 brightness;
+ u32 max_brightness;
+};
+
+static void lm3509_reset(struct lm3509_bl *data)
+{
+ if (data->reset_gpio) {
+ gpiod_set_value(data->reset_gpio, 1);
+ udelay(1);
+ gpiod_set_value(data->reset_gpio, 0);
+ udelay(10);
+ }
+}
+
+static int lm3509_update_status(struct backlight_device *bl,
+ unsigned int en_mask, unsigned int br_reg)
+{
+ struct lm3509_bl *data = bl_get_data(bl);
+ int ret;
+ bool en;
+
+ ret = regmap_write(data->regmap, br_reg, backlight_get_brightness(bl));
+ if (ret < 0)
+ return ret;
+
+ en = !backlight_is_blank(bl);
+ return regmap_update_bits(data->regmap, REG_GP, en_mask,
+ en ? en_mask : 0);
+}
+
+static int lm3509_main_update_status(struct backlight_device *bl)
+{
+ return lm3509_update_status(bl, BIT(REG_GP_ENM_BIT), REG_BMAIN);
+}
+
+static const struct backlight_ops lm3509_main_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = lm3509_main_update_status,
+};
+
+static int lm3509_sub_update_status(struct backlight_device *bl)
+{
+ return lm3509_update_status(bl, BIT(REG_GP_ENS_BIT), REG_BSUB);
+}
+
+static const struct backlight_ops lm3509_sub_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = lm3509_sub_update_status,
+};
+
+static struct backlight_device *
+lm3509_backlight_register(struct device *dev, const char *name_suffix,
+ struct lm3509_bl *data,
+ const struct backlight_ops *ops,
+ const struct lm3509_bl_led_data *led_data)
+
+{
+ struct backlight_device *bd;
+ struct backlight_properties props;
+ const char *label = led_data->label;
+ char name[64];
+
+ memset(&props, 0, sizeof(props));
+ props.type = BACKLIGHT_RAW;
+ props.brightness = led_data->brightness;
+ props.max_brightness = led_data->max_brightness;
+ props.scale = BACKLIGHT_SCALE_NON_LINEAR;
+
+ if (!label) {
+ snprintf(name, sizeof(name), "lm3509-%s-%s", dev_name(dev),
+ name_suffix);
+ label = name;
+ }
+
+ bd = devm_backlight_device_register(dev, label, dev, data, ops, &props);
+ if (bd)
+ backlight_update_status(bd);
+
+ return bd;
+}
+
+static const struct regmap_config lm3509_regmap = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = REG_MAX,
+};
+
+static int lm3509_parse_led_sources(struct device_node *node,
+ int default_led_sources)
+{
+ u32 sources[LM3509_NUM_SINKS];
+ int ret, num_sources, i;
+
+ num_sources = of_property_count_u32_elems(node, "led-sources");
+ if (num_sources < 0)
+ return default_led_sources;
+ else if (num_sources > ARRAY_SIZE(sources))
+ return -EINVAL;
+
+ ret = of_property_read_u32_array(node, "led-sources", sources,
+ num_sources);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < num_sources; i++) {
+ if (sources[i] >= LM3509_NUM_SINKS)
+ return -EINVAL;
+
+ ret |= BIT(sources[i]);
+ }
+
+ return ret;
+}
+
+static int lm3509_parse_dt_node(struct device *dev,
+ struct lm3509_bl_led_data *led_data)
+{
+ struct device_node *child;
+ int seen_led_sources = 0;
+
+ for_each_child_of_node(dev->of_node, child) {
+ struct lm3509_bl_led_data *ld;
+ int ret;
+ u32 reg;
+ int valid_led_sources;
+
+ ret = of_property_read_u32(child, "reg", ®);
+ if (ret < 0)
+ return ret;
+ if (reg >= LM3509_NUM_SINKS)
+ return -EINVAL;
+ ld = &led_data[reg];
+
+ ld->led_sources = lm3509_parse_led_sources(child, BIT(reg));
+ if (ld->led_sources < 0)
+ return ld->led_sources;
+
+ if (reg == 0)
+ valid_led_sources = BIT(LM3509_SINK_MAIN) |
+ BIT(LM3509_SINK_SUB);
+ else
+ valid_led_sources = BIT(LM3509_SINK_SUB);
+
+ if (ld->led_sources != (ld->led_sources & valid_led_sources))
+ return -EINVAL;
+
+ if (seen_led_sources & ld->led_sources)
+ return -EINVAL;
+
+ seen_led_sources |= ld->led_sources;
+
+ ld->label = NULL;
+ of_property_read_string(child, "label", &ld->label);
+
+ ld->max_brightness = LM3509_MAX_BRIGHTNESS;
+ of_property_read_u32(child, "max-brightness",
+ &ld->max_brightness);
+ ld->max_brightness =
+ min_t(u32, ld->max_brightness, LM3509_MAX_BRIGHTNESS);
+
+ ld->brightness = LM3509_DEF_BRIGHTNESS;
+ of_property_read_u32(child, "default-brightness",
+ &ld->brightness);
+ ld->brightness = min_t(u32, ld->brightness, ld->max_brightness);
+ }
+
+ return 0;
+}
+
+static int lm3509_probe(struct i2c_client *client)
+{
+ struct lm3509_bl *data;
+ struct device *dev = &client->dev;
+ int ret;
+ bool oled_mode = false;
+ unsigned int reg_gp_val = 0;
+ struct lm3509_bl_led_data led_data[LM3509_NUM_SINKS];
+ u32 rate_of_change = 0;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(dev, "i2c functionality check failed\n");
+ return -EOPNOTSUPP;
+ }
+
+ data = devm_kzalloc(dev, sizeof(struct lm3509_bl), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->regmap = devm_regmap_init_i2c(client, &lm3509_regmap);
+ if (IS_ERR(data->regmap))
+ return PTR_ERR(data->regmap);
+ i2c_set_clientdata(client, data);
+
+ data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(data->reset_gpio))
+ return dev_err_probe(dev, PTR_ERR(data->reset_gpio),
+ "Failed to get 'reset' gpio\n");
+
+ lm3509_reset(data);
+
+ memset(led_data, 0, sizeof(led_data));
+ ret = lm3509_parse_dt_node(dev, led_data);
+ if (ret)
+ return ret;
+
+ oled_mode = of_property_read_bool(dev->of_node, "ti,oled-mode");
+
+ if (!of_property_read_u32(dev->of_node,
+ "ti,brightness-rate-of-change-us",
+ &rate_of_change)) {
+ switch (rate_of_change) {
+ case 51:
+ reg_gp_val = 0;
+ break;
+ case 13000:
+ reg_gp_val = BIT(REG_GP_RMP1_BIT);
+ break;
+ case 26000:
+ reg_gp_val = BIT(REG_GP_RMP0_BIT);
+ break;
+ case 52000:
+ reg_gp_val = BIT(REG_GP_RMP0_BIT) |
+ BIT(REG_GP_RMP1_BIT);
+ break;
+ default:
+ dev_warn(dev, "invalid rate of change %u\n",
+ rate_of_change);
+ break;
+ }
+ }
+
+ if (led_data[0].led_sources ==
+ (BIT(LM3509_SINK_MAIN) | BIT(LM3509_SINK_SUB)))
+ reg_gp_val |= BIT(REG_GP_UNI_BIT);
+ if (oled_mode)
+ reg_gp_val |= BIT(REG_GP_OLED_BIT);
+
+ ret = regmap_write(data->regmap, REG_GP, reg_gp_val);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "failed to write register\n");
+
+ if (led_data[0].led_sources) {
+ data->bl_main = lm3509_backlight_register(
+ dev, "main", data, &lm3509_main_ops, &led_data[0]);
+ if (IS_ERR(data->bl_main)) {
+ return dev_err_probe(
+ dev, PTR_ERR(data->bl_main),
+ "failed to register main backlight\n");
+ }
+ }
+
+ if (led_data[1].led_sources) {
+ data->bl_sub = lm3509_backlight_register(
+ dev, "sub", data, &lm3509_sub_ops, &led_data[1]);
+ if (IS_ERR(data->bl_sub)) {
+ return dev_err_probe(
+ dev, PTR_ERR(data->bl_sub),
+ "failed to register secondary backlight\n");
+ }
+ }
+
+ return 0;
+}
+
+static void lm3509_remove(struct i2c_client *client)
+{
+ struct lm3509_bl *data = i2c_get_clientdata(client);
+
+ regmap_write(data->regmap, REG_GP, 0x00);
+}
+
+static const struct i2c_device_id lm3509_id[] = { { LM3509_NAME, 0 }, {} };
+
+MODULE_DEVICE_TABLE(i2c, lm3509_id);
+
+static const struct of_device_id lm3509_match_table[] = {
+ {
+ .compatible = "ti,lm3509",
+ },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, lm3509_match_table);
+
+static struct i2c_driver lm3509_i2c_driver = {
+ .driver = {
+ .name = LM3509_NAME,
+ .of_match_table = lm3509_match_table,
+ },
+ .probe = lm3509_probe,
+ .remove = lm3509_remove,
+ .id_table = lm3509_id,
+};
+
+module_i2c_driver(lm3509_i2c_driver);
+
+MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3509");
+MODULE_AUTHOR("Patrick Gansterer <par...@paroga.com>");
+MODULE_LICENSE("GPL");
--
2.45.1
