#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 (IS_ERR(bd))
return 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)
{
int seen_led_sources = 0;
for_each_child_of_node_scoped(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 },
{}
};
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 <paroga@paroga.com>");
MODULE_LICENSE("GPL");
