// SPDX-License-Identifier: GPL-2.0
// TI LM3532 LED driver
// Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/
// https://www.ti.com/lit/ds/symlink/lm3532.pdf
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include <linux/regmap.h>
#include <linux/types.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>
#include <uapi/linux/uleds.h>
#include <linux/gpio/consumer.h>
#define LM3532_NAME "lm3532-led"
#define LM3532_BL_MODE_MANUAL 0x00
#define LM3532_BL_MODE_ALS 0x01
#define LM3532_REG_OUTPUT_CFG 0x10
#define LM3532_REG_STARTSHUT_RAMP 0x11
#define LM3532_REG_RT_RAMP 0x12
#define LM3532_REG_PWM_A_CFG 0x13
#define LM3532_REG_PWM_B_CFG 0x14
#define LM3532_REG_PWM_C_CFG 0x15
#define LM3532_REG_ZONE_CFG_A 0x16
#define LM3532_REG_CTRL_A_FS_CURR 0x17
#define LM3532_REG_ZONE_CFG_B 0x18
#define LM3532_REG_CTRL_B_FS_CURR 0x19
#define LM3532_REG_ZONE_CFG_C 0x1a
#define LM3532_REG_CTRL_C_FS_CURR 0x1b
#define LM3532_REG_ENABLE 0x1d
#define LM3532_ALS_CONFIG 0x23
#define LM3532_REG_ZN_0_HI 0x60
#define LM3532_REG_ZN_0_LO 0x61
#define LM3532_REG_ZN_1_HI 0x62
#define LM3532_REG_ZN_1_LO 0x63
#define LM3532_REG_ZN_2_HI 0x64
#define LM3532_REG_ZN_2_LO 0x65
#define LM3532_REG_ZN_3_HI 0x66
#define LM3532_REG_ZN_3_LO 0x67
#define LM3532_REG_ZONE_TRGT_A 0x70
#define LM3532_REG_ZONE_TRGT_B 0x75
#define LM3532_REG_ZONE_TRGT_C 0x7a
#define LM3532_REG_MAX 0x7e
/* Control Enable */
#define LM3532_CTRL_A_ENABLE BIT(0)
#define LM3532_CTRL_B_ENABLE BIT(1)
#define LM3532_CTRL_C_ENABLE BIT(2)
/* PWM Zone Control */
#define LM3532_PWM_ZONE_MASK 0x7c
#define LM3532_PWM_ZONE_0_EN BIT(2)
#define LM3532_PWM_ZONE_1_EN BIT(3)
#define LM3532_PWM_ZONE_2_EN BIT(4)
#define LM3532_PWM_ZONE_3_EN BIT(5)
#define LM3532_PWM_ZONE_4_EN BIT(6)
/* Brightness Configuration */
#define LM3532_I2C_CTRL BIT(0)
#define LM3532_ALS_CTRL 0
#define LM3532_LINEAR_MAP BIT(1)
#define LM3532_ZONE_MASK (BIT(2) | BIT(3) | BIT(4))
#define LM3532_ZONE_0 0
#define LM3532_ZONE_1 BIT(2)
#define LM3532_ZONE_2 BIT(3)
#define LM3532_ZONE_3 (BIT(2) | BIT(3))
#define LM3532_ZONE_4 BIT(4)
#define LM3532_ENABLE_ALS BIT(3)
#define LM3532_ALS_SEL_SHIFT 6
/* Zone Boundary Register */
#define LM3532_ALS_WINDOW_mV 2000
#define LM3532_ALS_ZB_MAX 4
#define LM3532_ALS_OFFSET_mV 2
#define LM3532_CONTROL_A 0
#define LM3532_CONTROL_B 1
#define LM3532_CONTROL_C 2
#define LM3532_MAX_CONTROL_BANKS 3
#define LM3532_MAX_LED_STRINGS 3
#define LM3532_OUTPUT_CFG_MASK 0x3
#define LM3532_BRT_VAL_ADJUST 8
#define LM3532_RAMP_DOWN_SHIFT 3
#define LM3532_NUM_RAMP_VALS 8
#define LM3532_NUM_AVG_VALS 8
#define LM3532_NUM_IMP_VALS 32
#define LM3532_FS_CURR_MIN 5000
#define LM3532_FS_CURR_MAX 29800
#define LM3532_FS_CURR_STEP 800
/*
* struct lm3532_als_data
* @config: value of ALS configuration register
* @als1_imp_sel: value of ALS1 resistor select register
* @als2_imp_sel: value of ALS2 resistor select register
* @als_avrg_time: ALS averaging time
* @als_input_mode: ALS input mode for brightness control
* @als_vmin: Minimum ALS voltage
* @als_vmax: Maximum ALS voltage
* @zone_lo: values of ALS lo ZB(Zone Boundary) registers
* @zone_hi: values of ALS hi ZB(Zone Boundary) registers
*/
struct lm3532_als_data {
u8 config;
u8 als1_imp_sel;
u8 als2_imp_sel;
u8 als_avrg_time;
u8 als_input_mode;
u32 als_vmin;
u32 als_vmax;
u8 zones_lo[LM3532_ALS_ZB_MAX];
u8 zones_hi[LM3532_ALS_ZB_MAX];
};
/**
* struct lm3532_led
* @led_dev: led class device
* @priv: Pointer the device data structure
* @control_bank: Control bank the LED is associated to
* @mode: Mode of the LED string
* @ctrl_brt_pointer: Zone target register that controls the sink
* @num_leds: Number of LED strings are supported in this array
* @full_scale_current: The full-scale current setting for the current sink.
* @led_strings: The LED strings supported in this array
* @enabled: Enabled status
*/
struct lm3532_led {
struct led_classdev led_dev;
struct lm3532_data *priv;
int control_bank;
int mode;
int ctrl_brt_pointer;
int num_leds;
int full_scale_current;
unsigned int enabled:1;
u32 led_strings[LM3532_MAX_CONTROL_BANKS];
};
/**
* struct lm3532_data
* @enable_gpio: Hardware enable gpio
* @regulator: regulator
* @client: i2c client
* @regmap: Devices register map
* @dev: Pointer to the devices device struct
* @lock: Lock for reading/writing the device
* @als_data: Pointer to the als data struct
* @runtime_ramp_up: Runtime ramp up setting
* @runtime_ramp_down: Runtime ramp down setting
* @leds: Array of LED strings
*/
struct lm3532_data {
struct gpio_desc *enable_gpio;
struct regulator *regulator;
struct i2c_client *client;
struct regmap *regmap;
struct device *dev;
struct mutex lock;
struct lm3532_als_data *als_data;
u32 runtime_ramp_up;
u32 runtime_ramp_down;
struct lm3532_led leds[];
};
static const struct reg_default lm3532_reg_defs[] = {
{LM3532_REG_OUTPUT_CFG, 0xe4},
{LM3532_REG_STARTSHUT_RAMP, 0xc0},
{LM3532_REG_RT_RAMP, 0xc0},
{LM3532_REG_PWM_A_CFG, 0x82},
{LM3532_REG_PWM_B_CFG, 0x82},
{LM3532_REG_PWM_C_CFG, 0x82},
{LM3532_REG_ZONE_CFG_A, 0xf1},
{LM3532_REG_CTRL_A_FS_CURR, 0xf3},
{LM3532_REG_ZONE_CFG_B, 0xf1},
{LM3532_REG_CTRL_B_FS_CURR, 0xf3},
{LM3532_REG_ZONE_CFG_C, 0xf1},
{LM3532_REG_CTRL_C_FS_CURR, 0xf3},
{LM3532_REG_ENABLE, 0xf8},
{LM3532_ALS_CONFIG, 0x44},
{LM3532_REG_ZN_0_HI, 0x35},
{LM3532_REG_ZN_0_LO, 0x33},
{LM3532_REG_ZN_1_HI, 0x6a},
{LM3532_REG_ZN_1_LO, 0x66},
{LM3532_REG_ZN_2_HI, 0xa1},
{LM3532_REG_ZN_2_LO, 0x99},
{LM3532_REG_ZN_3_HI, 0xdc},
{LM3532_REG_ZN_3_LO, 0xcc},
};
static const struct regmap_config lm3532_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = LM3532_REG_MAX,
.reg_defaults = lm3532_reg_defs,
.num_reg_defaults = ARRAY_SIZE(lm3532_reg_defs),
.cache_type = REGCACHE_FLAT,
};
static const int als_imp_table[LM3532_NUM_IMP_VALS] = {37000, 18500, 12330,
92500, 7400, 6170, 5290,
4630, 4110, 3700, 3360,
3080, 2850, 2640, 2440,
2310, 2180, 2060, 1950,
1850, 1760, 1680, 1610,
1540, 1480, 1420, 1370,
1320, 1280, 1230, 1190};
static int lm3532_get_als_imp_index(int als_imped)
{
int i;
if (als_imped > als_imp_table[1])
return 0;
if (als_imped < als_imp_table[LM3532_NUM_IMP_VALS - 1])
return LM3532_NUM_IMP_VALS - 1;
for (i = 1; i < LM3532_NUM_IMP_VALS; i++) {
if (als_imped == als_imp_table[i])
return i;
/* Find an approximate index by looking up the table */
if (als_imped < als_imp_table[i - 1] &&
als_imped > als_imp_table[i]) {
if (als_imped - als_imp_table[i - 1] <
als_imp_table[i] - als_imped)
return i + 1;
else
return i;
}
}
return -EINVAL;
}
static int lm3532_get_index(const int table[], int size, int value)
{
int i;
for (i = 1; i < size; i++) {
if (value == table[i])
return i;
/* Find an approximate index by looking up the table */
if (value > table[i - 1] &&
value < table[i]) {
if (value - table[i - 1] < table[i] - value)
return i - 1;
else
return i;
}
}
return -EINVAL;
}
static const int als_avrg_table[LM3532_NUM_AVG_VALS] = {17920, 35840, 71680,
1433360, 286720, 573440,
1146880, 2293760};
static int lm3532_get_als_avg_index(int avg_time)
{
if (avg_time <= als_avrg_table[0])
return 0;
if (avg_time > als_avrg_table[LM3532_NUM_AVG_VALS - 1])
return LM3532_NUM_AVG_VALS - 1;
return lm3532_get_index(&als_avrg_table[0], LM3532_NUM_AVG_VALS,
avg_time);
}
static const int ramp_table[LM3532_NUM_RAMP_VALS] = { 8, 1024, 2048, 4096, 8192,
16384, 32768, 65536};
static int lm3532_get_ramp_index(int ramp_time)
{
if (ramp_time <= ramp_table[0])
return 0;
if (ramp_time > ramp_table[LM3532_NUM_RAMP_VALS - 1])
return LM3532_NUM_RAMP_VALS - 1;
return lm3532_get_index(&ramp_table[0], LM3532_NUM_RAMP_VALS,
ramp_time);
}
/* Caller must take care of locking */
static int lm3532_led_enable(struct lm3532_led *led_data)
{
int ctrl_en_val = BIT(led_data->control_bank);
int ret;
if (led_data->enabled)
return 0;
ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE,
ctrl_en_val, ctrl_en_val);
if (ret) {
dev_err(led_data->priv->dev, "Failed to set ctrl:%d\n", ret);
return ret;
}
ret = regulator_enable(led_data->priv->regulator);
if (ret < 0)
return ret;
led_data->enabled = 1;
return 0;
}
/* Caller must take care of locking */
static int lm3532_led_disable(struct lm3532_led *led_data)
{
int ctrl_en_val = BIT(led_data->control_bank);
int ret;
if (!led_data->enabled)
return 0;
ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE,
ctrl_en_val, 0);
if (ret) {
dev_err(led_data->priv->dev, "Failed to set ctrl:%d\n", ret);
return ret;
}
ret = regulator_disable(led_data->priv->regulator);
if (ret < 0)
return ret;
led_data->enabled = 0;
return 0;
}
static int lm3532_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brt_val)
{
struct lm3532_led *led =
container_of(led_cdev, struct lm3532_led, led_dev);
u8 brightness_reg;
int ret;
mutex_lock(&led->priv->lock);
if (led->mode == LM3532_ALS_CTRL) {
if (brt_val > LED_OFF)
ret = lm3532_led_enable(led);
else
ret = lm3532_led_disable(led);
goto unlock;
}
if (brt_val == LED_OFF) {
ret = lm3532_led_disable(led);
goto unlock;
}
ret = lm3532_led_enable(led);
if (ret)
goto unlock;
brightness_reg = LM3532_REG_ZONE_TRGT_A + led->control_bank * 5 +
(led->ctrl_brt_pointer >> 2);
ret = regmap_write(led->priv->regmap, brightness_reg, brt_val);
unlock:
mutex_unlock(&led->priv->lock);
return ret;
}
static int lm3532_init_registers(struct lm3532_led *led)
{
struct lm3532_data *drvdata = led->priv;
unsigned int runtime_ramp_val;
unsigned int output_cfg_val = 0;
unsigned int output_cfg_shift = 0;
unsigned int output_cfg_mask = 0;
unsigned int brightness_config_reg;
unsigned int brightness_config_val;
int fs_current_reg;
int fs_current_val;
int ret, i;
if (drvdata->enable_gpio)
gpiod_direction_output(drvdata->enable_gpio, 1);
brightness_config_reg = LM3532_REG_ZONE_CFG_A + led->control_bank * 2;
/*
* This could be hard coded to the default value but the control
* brightness register may have changed during boot.
*/
ret = regmap_read(drvdata->regmap, brightness_config_reg,
&led->ctrl_brt_pointer);
if (ret)
return ret;
led->ctrl_brt_pointer &= LM3532_ZONE_MASK;
brightness_config_val = led->ctrl_brt_pointer | led->mode;
ret = regmap_write(drvdata->regmap, brightness_config_reg,
brightness_config_val);
if (ret)
return ret;
if (led->full_scale_current) {
fs_current_reg = LM3532_REG_CTRL_A_FS_CURR + led->control_bank * 2;
fs_current_val = (led->full_scale_current - LM3532_FS_CURR_MIN) /
LM3532_FS_CURR_STEP;
ret = regmap_write(drvdata->regmap, fs_current_reg,
fs_current_val);
if (ret)
return ret;
}
for (i = 0; i < led->num_leds; i++) {
output_cfg_shift = led->led_strings[i] * 2;
output_cfg_val |= (led->control_bank << output_cfg_shift);
output_cfg_mask |= LM3532_OUTPUT_CFG_MASK << output_cfg_shift;
}
ret = regmap_update_bits(drvdata->regmap, LM3532_REG_OUTPUT_CFG,
output_cfg_mask, output_cfg_val);
if (ret)
return ret;
runtime_ramp_val = drvdata->runtime_ramp_up |
(drvdata->runtime_ramp_down << LM3532_RAMP_DOWN_SHIFT);
return regmap_write(drvdata->regmap, LM3532_REG_RT_RAMP,
runtime_ramp_val);
}
static int lm3532_als_configure(struct lm3532_data *priv,
struct lm3532_led *led)
{
struct lm3532_als_data *als = priv->als_data;
u32 als_vmin, als_vmax, als_vstep;
int zone_reg = LM3532_REG_ZN_0_HI;
int ret;
int i;
als_vmin = als->als_vmin;
als_vmax = als->als_vmax;
als_vstep = (als_vmax - als_vmin) / ((LM3532_ALS_ZB_MAX + 1) * 2);
for (i = 0; i < LM3532_ALS_ZB_MAX; i++) {
als->zones_lo[i] = ((als_vmin + als_vstep + (i * als_vstep)) *
LED_FULL) / 1000;
als->zones_hi[i] = ((als_vmin + LM3532_ALS_OFFSET_mV +
als_vstep + (i * als_vstep)) * LED_FULL) / 1000;
zone_reg = LM3532_REG_ZN_0_HI + i * 2;
ret = regmap_write(priv->regmap, zone_reg, als->zones_lo[i]);
if (ret)
return ret;
zone_reg += 1;
ret = regmap_write(priv->regmap, zone_reg, als->zones_hi[i]);
if (ret)
return ret;
}
als->config = (als->als_avrg_time | (LM3532_ENABLE_ALS) |
(als->als_input_mode << LM3532_ALS_SEL_SHIFT));
return regmap_write(priv->regmap, LM3532_ALS_CONFIG, als->config);
}
static int lm3532_parse_als(struct lm3532_data *priv)
{
struct lm3532_als_data *als;
int als_avg_time;
int als_impedance;
int ret;
als = devm_kzalloc(priv->dev, sizeof(*als), GFP_KERNEL);
if (als == NULL)
return -ENOMEM;
ret = device_property_read_u32(&priv->client->dev, "ti,als-vmin",
&als->als_vmin);
if (ret)
als->als_vmin = 0;
ret = device_property_read_u32(&priv->client->dev, "ti,als-vmax",
&als->als_vmax);
if (ret)
als->als_vmax = LM3532_ALS_WINDOW_mV;
if (als->als_vmax > LM3532_ALS_WINDOW_mV) {
ret = -EINVAL;
return ret;
}
ret = device_property_read_u32(&priv->client->dev, "ti,als1-imp-sel",
&als_impedance);
if (ret)
als->als1_imp_sel = 0;
else
als->als1_imp_sel = lm3532_get_als_imp_index(als_impedance);
ret = device_property_read_u32(&priv->client->dev, "ti,als2-imp-sel",
&als_impedance);
if (ret)
als->als2_imp_sel = 0;
else
als->als2_imp_sel = lm3532_get_als_imp_index(als_impedance);
ret = device_property_read_u32(&priv->client->dev, "ti,als-avrg-time-us",
&als_avg_time);
if (ret)
als->als_avrg_time = 0;
else
als->als_avrg_time = lm3532_get_als_avg_index(als_avg_time);
ret = device_property_read_u8(&priv->client->dev, "ti,als-input-mode",
&als->als_input_mode);
if (ret)
als->als_input_mode = 0;
if (als->als_input_mode > LM3532_BL_MODE_ALS) {
ret = -EINVAL;
return ret;
}
priv->als_data = als;
return ret;
}
static void gpio_set_low_action(void *data)
{
struct lm3532_data *priv = data;
gpiod_direction_output(priv->enable_gpio, 0);
}
static int lm3532_parse_node(struct lm3532_data *priv)
{
struct fwnode_handle *child = NULL;
struct lm3532_led *led;
int control_bank;
u32 ramp_time;
size_t i = 0;
int ret;
priv->enable_gpio = devm_gpiod_get_optional(&priv->client->dev,
"enable", GPIOD_OUT_LOW);
if (IS_ERR(priv->enable_gpio))
priv->enable_gpio = NULL;
if (priv->enable_gpio) {
ret = devm_add_action(&priv->client->dev, gpio_set_low_action, priv);
if (ret)
return ret;
}
priv->regulator = devm_regulator_get(&priv->client->dev, "vin");
if (IS_ERR(priv->regulator))
priv->regulator = NULL;
ret = device_property_read_u32(&priv->client->dev, "ramp-up-us",
&ramp_time);
if (ret)
dev_info(&priv->client->dev, "ramp-up-ms property missing\n");
else
priv->runtime_ramp_up = lm3532_get_ramp_index(ramp_time);
ret = device_property_read_u32(&priv->client->dev, "ramp-down-us",
&ramp_time);
if (ret)
dev_info(&priv->client->dev, "ramp-down-ms property missing\n");
else
priv->runtime_ramp_down = lm3532_get_ramp_index(ramp_time);
device_for_each_child_node(priv->dev, child) {
struct led_init_data idata = {
.fwnode = child,
.default_label = ":",
.devicename = priv->client->name,
};
led = &priv->leds[i];
ret = fwnode_property_read_u32(child, "reg", &control_bank);
if (ret) {
dev_err(&priv->client->dev, "reg property missing\n");
goto child_out;
}
if (control_bank > LM3532_CONTROL_C) {
dev_err(&priv->client->dev, "Control bank invalid\n");
continue;
}
led->control_bank = control_bank;
ret = fwnode_property_read_u32(child, "ti,led-mode",
&led->mode);
if (ret) {
dev_err(&priv->client->dev, "ti,led-mode property missing\n");
goto child_out;
}
if (fwnode_property_present(child, "led-max-microamp") &&
fwnode_property_read_u32(child, "led-max-microamp",
&led->full_scale_current))
dev_err(&priv->client->dev,
"Failed getting led-max-microamp\n");
else
led->full_scale_current = min(led->full_scale_current,
LM3532_FS_CURR_MAX);
if (led->mode == LM3532_BL_MODE_ALS) {
led->mode = LM3532_ALS_CTRL;
ret = lm3532_parse_als(priv);
if (ret)
dev_err(&priv->client->dev, "Failed to parse als\n");
else
lm3532_als_configure(priv, led);
} else {
led->mode = LM3532_I2C_CTRL;
}
led->num_leds = fwnode_property_count_u32(child, "led-sources");
if (led->num_leds > LM3532_MAX_LED_STRINGS) {
dev_err(&priv->client->dev, "Too many LED string defined\n");
continue;
}
ret = fwnode_property_read_u32_array(child, "led-sources",
led->led_strings,
led->num_leds);
if (ret) {
dev_err(&priv->client->dev, "led-sources property missing\n");
goto child_out;
}
led->priv = priv;
led->led_dev.brightness_set_blocking = lm3532_brightness_set;
ret = devm_led_classdev_register_ext(priv->dev, &led->led_dev, &idata);
if (ret) {
dev_err(&priv->client->dev, "led register err: %d\n",
ret);
goto child_out;
}
ret = lm3532_init_registers(led);
if (ret) {
dev_err(&priv->client->dev, "register init err: %d\n",
ret);
goto child_out;
}
i++;
}
return 0;
child_out:
fwnode_handle_put(child);
return ret;
}
static int lm3532_probe(struct i2c_client *client)
{
struct lm3532_data *drvdata;
int ret = 0;
int count;
count = device_get_child_node_count(&client->dev);
if (!count) {
dev_err(&client->dev, "LEDs are not defined in device tree!");
return -ENODEV;
}
drvdata = devm_kzalloc(&client->dev, struct_size(drvdata, leds, count),
GFP_KERNEL);
if (drvdata == NULL)
return -ENOMEM;
drvdata->client = client;
drvdata->dev = &client->dev;
drvdata->regmap = devm_regmap_init_i2c(client, &lm3532_regmap_config);
if (IS_ERR(drvdata->regmap)) {
ret = PTR_ERR(drvdata->regmap);
dev_err(&client->dev, "Failed to allocate register map: %d\n",
ret);
return ret;
}
ret = devm_mutex_init(&client->dev, &drvdata->lock);
if (ret)
return ret;
i2c_set_clientdata(client, drvdata);
ret = lm3532_parse_node(drvdata);
if (ret) {
dev_err(&client->dev, "Failed to parse node\n");
return ret;
}
return ret;
}
static const struct of_device_id of_lm3532_leds_match[] = {
{ .compatible = "ti,lm3532", },
{},
};
MODULE_DEVICE_TABLE(of, of_lm3532_leds_match);
static const struct i2c_device_id lm3532_id[] = {
{ LM3532_NAME },
{}
};
MODULE_DEVICE_TABLE(i2c, lm3532_id);
static struct i2c_driver lm3532_i2c_driver = {
.probe = lm3532_probe,
.id_table = lm3532_id,
.driver = {
.name = LM3532_NAME,
.of_match_table = of_lm3532_leds_match,
},
};
module_i2c_driver(lm3532_i2c_driver);
MODULE_DESCRIPTION("Back Light driver for LM3532");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Dan Murphy <[email protected]>");
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