The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a programmable switching frequency to optimize efficiency. The brightness can be controlled either by I2C commands (called "analog" mode) or by a PWM input signal (PWM mode). This driver supports both modes. For DT configuration details, please refer to: - Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml The datasheet is available at: - https://www.monolithicpower.com/en/mp3309c.html Signed-off-by: Flavio Suligoi <f.suligoi@xxxxxxx> --- MAINTAINERS | 6 + drivers/video/backlight/Kconfig | 13 + drivers/video/backlight/Makefile | 1 + drivers/video/backlight/mp3309c_bl.c | 491 +++++++++++++++++++++++++++ 4 files changed, 511 insertions(+) create mode 100644 drivers/video/backlight/mp3309c_bl.c diff --git a/MAINTAINERS b/MAINTAINERS index 3be1bdfe8ecc..895c56ff4f1e 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14333,6 +14333,12 @@ S: Maintained F: Documentation/driver-api/tty/moxa-smartio.rst F: drivers/tty/mxser.* +MP3309C BACKLIGHT DRIVER +M: Flavio Suligoi <f.suligoi@xxxxxxx> +S: Maintained +F: Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml +F: drivers/video/backlight/mp3309c_bl.c + MR800 AVERMEDIA USB FM RADIO DRIVER M: Alexey Klimov <klimov.linux@xxxxxxxxx> L: linux-media@xxxxxxxxxxxxxxx diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 51387b1ef012..65d0ac9f611d 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -389,6 +389,19 @@ config BACKLIGHT_LM3639 help This supports TI LM3639 Backlight + 1.5A Flash LED Driver +config BACKLIGHT_MP3309C + tristate "Backlight Driver for MPS MP3309C" + depends on I2C + select REGMAP_I2C + select NEW_LEDS + select LEDS_CLASS + help + This supports MPS MP3309C backlight WLED Driver in both PWM and + analog/I2C dimming modes. + + To compile this driver as a module, choose M here: the module will + be called mp3309c_bl. + config BACKLIGHT_LP855X tristate "Backlight driver for TI LP855X" depends on I2C && PWM diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index f72e1c3c59e9..c42c5bccc5ac 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o obj-$(CONFIG_BACKLIGHT_LP8788) += lp8788_bl.o obj-$(CONFIG_BACKLIGHT_LV5207LP) += lv5207lp.o obj-$(CONFIG_BACKLIGHT_MAX8925) += max8925_bl.o +obj-$(CONFIG_BACKLIGHT_MP3309C) += mp3309c_bl.o obj-$(CONFIG_BACKLIGHT_MT6370) += mt6370-backlight.o obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o diff --git a/drivers/video/backlight/mp3309c_bl.c b/drivers/video/backlight/mp3309c_bl.c new file mode 100644 index 000000000000..7cb7a542ceca --- /dev/null +++ b/drivers/video/backlight/mp3309c_bl.c @@ -0,0 +1,491 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for MPS MP3309C White LED driver with I2C interface + * + * Copyright (C) 2023 ASEM Srl + * Author: Flavio Suligoi <f.suligoi@xxxxxxx> + */ + +#include <linux/backlight.h> +#include <linux/delay.h> +#include <linux/gpio/consumer.h> +#include <linux/i2c.h> +#include <linux/pwm.h> +#include <linux/regmap.h> +#include <linux/workqueue.h> + +#define REG_I2C_0 0x00 +#define REG_I2C_1 0x01 + +#define REG_I2C_0_EN 0x80 +#define REG_I2C_0_D0 0x40 +#define REG_I2C_0_D1 0x20 +#define REG_I2C_0_D2 0x10 +#define REG_I2C_0_D3 0x08 +#define REG_I2C_0_D4 0x04 +#define REG_I2C_0_RSRV1 0x02 +#define REG_I2C_0_RSRV2 0x01 + +#define REG_I2C_1_RSRV1 0x80 +#define REG_I2C_1_DIMS 0x40 +#define REG_I2C_1_SYNC 0x20 +#define REG_I2C_1_OVP0 0x10 +#define REG_I2C_1_OVP1 0x08 +#define REG_I2C_1_VOS 0x04 +#define REG_I2C_1_LEDO 0x02 +#define REG_I2C_1_OTP 0x01 + +#define ANALOG_MAX_VAL 31 +#define ANALOG_REG_MASK 0x7c + +enum backlight_status { + FIRST_POWER_ON, + BACKLIGHT_OFF, + BACKLIGHT_ON, +}; + +enum dimming_mode_value { + DIMMING_PWM, + DIMMING_ANALOG_I2C, +}; + +struct mp3309c_platform_data { + u32 max_brightness; + u32 brightness; + u32 switch_on_delay_ms; + u32 switch_off_delay_ms; + u32 reset_on_delay_ms; + u32 reset_on_length_ms; + u8 dimming_mode; + u8 reset_pulse_enable; + u8 over_voltage_protection; + + unsigned int status; +}; + +struct mp3309c_chip { + struct device *dev; + struct mp3309c_platform_data *pdata; + struct backlight_device *bl; + struct gpio_desc *enable_gpio; + struct regmap *regmap; + struct pwm_device *pwmd; + + struct delayed_work enable_work; + struct delayed_work reset_gpio_work; + int irq; + + struct gpio_desc *reset_gpio; +}; + +static const struct regmap_config mp3309c_regmap = { + .name = "mp3309c_regmap", + .reg_bits = 8, + .reg_stride = 1, + .val_bits = 8, + .max_register = REG_I2C_1, +}; + +static int pm3309c_parse_dt_node(struct mp3309c_chip *chip, + struct mp3309c_platform_data *pdata) +{ + struct device_node *node = chip->dev->of_node; + const char *tmp_string; + int ret; + + if (!node) { + dev_err(chip->dev, "failed to get DT node\n"); + return -ENODEV; + } + + /* + * Dimming mode: the MP3309C provides two dimming methods: + * + * - PWM mode + * - Analog by I2C control mode + */ + ret = of_property_read_string(node, "mps,dimming-mode", &tmp_string); + if (ret < 0) { + dev_err(chip->dev, "missed dimming-mode in DT\n"); + return ret; + } + if (!strcmp(tmp_string, "pwm")) { + dev_info(chip->dev, "dimming method: PWM\n"); + pdata->dimming_mode = DIMMING_PWM; + } + if (!strcmp(tmp_string, "analog-i2c")) { + dev_info(chip->dev, "dimming method: analog by I2C commands\n"); + pdata->dimming_mode = DIMMING_ANALOG_I2C; + } + + /* PWM steps (levels): 0 .. max_brightness */ + ret = of_property_read_u32(node, "max-brightness", + &pdata->max_brightness); + if (ret < 0) { + dev_err(chip->dev, "failed to get max-brightness from DT\n"); + return ret; + } + + /* Default brightness at startup */ + ret = of_property_read_u32(node, "default-brightness", + &pdata->brightness); + if (ret < 0) { + dev_err(chip->dev, + "failed to get default-brightness from DT\n"); + return ret; + } + + /* + * Optional backlight switch-on/off delay + * + * Note: set 10ms as minimal value for switch-on delay, to stabilize + * video data + */ + pdata->switch_on_delay_ms = 50; + of_property_read_u32(node, "mps,switch-on-delay-ms", + &pdata->switch_on_delay_ms); + if (pdata->switch_on_delay_ms < 10) { + pdata->switch_on_delay_ms = 10; + dev_warn(chip->dev, + "switch-on-delay-ms set to 10ms as minimal value\n"); + } + pdata->switch_off_delay_ms = 0; + of_property_read_u32(node, "mps,switch-off-delay-ms", + &pdata->switch_off_delay_ms); + + /* + * Reset: GPIO, initial delay and pulse length + * + * Use this optional GPIO to reset an external device (LCD panel, video + * FPGA, etc) when the backlight is switched on + */ + pdata->reset_pulse_enable = 0; + chip->reset_gpio = devm_gpiod_get_optional(chip->dev, "mps,reset", + GPIOD_OUT_LOW); + if (IS_ERR(chip->reset_gpio)) { + ret = PTR_ERR(chip->reset_gpio); + dev_err(chip->dev, "error acquiring reset gpio: %d\n", ret); + return ret; + } + if (chip->reset_gpio) { + pdata->reset_pulse_enable = 1; + + pdata->reset_on_delay_ms = 10; + of_property_read_u32(node, "mps,reset-on-delay-ms", + &pdata->reset_on_delay_ms); + pdata->reset_on_length_ms = 10; + of_property_read_u32(node, "mps,reset-on-length-ms", + &pdata->reset_on_length_ms); + } + + /* + * Over-voltage protection (OVP) + * + * These (optional) properties are: + * + * - overvoltage-protection-13v --> OVP point set to 13.5V + * - overvoltage-protection-24v --> OVP point set to 24V + * - overvoltage-protection-35v --> OVP point set to 35.5V + * + * If not chosen, the hw default value for OVP is 35.5V + */ + pdata->over_voltage_protection = REG_I2C_1_OVP1; + if (of_property_read_bool(node, "mps,overvoltage-protection-13v")) + pdata->over_voltage_protection = 0x00; + if (of_property_read_bool(node, "mps,overvoltage-protection-24v")) + pdata->over_voltage_protection = REG_I2C_1_OVP0; + if (of_property_read_bool(node, "mps,overvoltage-protection-35v")) + pdata->over_voltage_protection = REG_I2C_1_OVP1; + + return 0; +} + +static int mp3309c_enable_device(struct mp3309c_chip *chip) +{ + u8 reg_val = 0; /* Configuration for analog by I2C commands */ + int ret; + + /* I2C register #0 - Device enable */ + ret = regmap_update_bits(chip->regmap, REG_I2C_0, REG_I2C_0_EN, + REG_I2C_0_EN); + if (ret) + return ret; + + /* + * I2C register #1 - Set working mode: + * - set one of the two dimming mode: + * - PWM dimming using an external PWM dimming signal + * - analog dimming using I2C commands + * - enable synchronous mode (fixed for now) + * - set overvoltage protection (OVP) + */ + if (chip->pdata->dimming_mode == DIMMING_PWM) + reg_val = REG_I2C_1_DIMS; + ret = regmap_write(chip->regmap, REG_I2C_1, reg_val | REG_I2C_1_SYNC | + chip->pdata->over_voltage_protection); + if (ret) + return ret; + + return 0; +} + +/* For delayed backlight enabled */ +static void mp3309c_enable(struct work_struct *work) +{ + struct mp3309c_chip *chip = container_of(work, struct mp3309c_chip, + enable_work.work); + if (mp3309c_enable_device(chip)) + dev_err(chip->dev, "failed writing I2C register\n"); +} + +static void mp3309c_reset_gpio(struct work_struct *work) +{ + struct mp3309c_chip *chip = container_of(work, struct mp3309c_chip, + reset_gpio_work.work); + + if (chip->reset_gpio) { + gpiod_set_value_cansleep(chip->reset_gpio, 0); + usleep_range(100, 150); + gpiod_set_value_cansleep(chip->reset_gpio, 1); + usleep_range(chip->pdata->reset_on_length_ms * 1000, + (chip->pdata->reset_on_length_ms * 1000) + 100); + gpiod_set_value_cansleep(chip->reset_gpio, 0); + } +} + +static int mp3309c_bl_update_status(struct backlight_device *bl) +{ + struct mp3309c_chip *chip = bl_get_data(bl); + int brightness = backlight_get_brightness(bl); + struct pwm_state pwmstate; + unsigned int analog_val, bits_val; + int i, ret; + + if (chip->pdata->dimming_mode == DIMMING_PWM) { + /* + * PWM dimming mode + */ + pwm_init_state(chip->pwmd, &pwmstate); + pwm_set_relative_duty_cycle(&pwmstate, brightness, + chip->pdata->max_brightness); + pwmstate.enabled = true; + ret = pwm_apply_state(chip->pwmd, &pwmstate); + if (ret) + return ret; + } else { + /* + * Analog dimming mode by I2C commands + * + * The 5 bits of the dimming analog value D4..D0 is allocated + * in the I2C register #0, in the following way: + * + * +--+--+--+--+--+--+--+--+ + * |EN|D0|D1|D2|D3|D4|XX|XX| + * +--+--+--+--+--+--+--+--+ + */ + analog_val = DIV_ROUND_UP(ANALOG_MAX_VAL * brightness, + chip->pdata->max_brightness); + bits_val = 0; + for (i = 0; i <= 5; i++) + bits_val += ((analog_val >> i) & 0x01) << (6 - i); + ret = regmap_update_bits(chip->regmap, REG_I2C_0, + ANALOG_REG_MASK, bits_val); + if (ret) + return ret; + } + + if (brightness > 0) { + switch (chip->pdata->status) { + case FIRST_POWER_ON: + /* + * Only for the first time, wait for the optional + * switch-on delay and then enable the device. + * Otherwise enable the backlight immediately. + */ + schedule_delayed_work(&chip->enable_work, + msecs_to_jiffies(chip->pdata->switch_on_delay_ms)); + /* + * Optional external device GPIO reset, with + * delay pulse length + */ + if (chip->pdata->reset_pulse_enable) + schedule_delayed_work(&chip->reset_gpio_work, + msecs_to_jiffies(chip->pdata->reset_on_delay_ms)); + break; + case BACKLIGHT_OFF: + /* Enable the backlight immediately */ + if (chip->pdata->reset_pulse_enable) + cancel_delayed_work(&chip->reset_gpio_work); + mp3309c_enable_device(chip); + break; + } + + chip->pdata->status = BACKLIGHT_ON; + } else { + /* Wait for the optional switch-off delay */ + if (chip->pdata->switch_off_delay_ms > 0) { + usleep_range(chip->pdata->switch_off_delay_ms * 1000, + (chip->pdata->switch_off_delay_ms + 1) * + 1000); + } + + chip->pdata->status = BACKLIGHT_OFF; + } + + return 0; +} + +static const struct backlight_ops mp3309c_bl_ops = { + .update_status = mp3309c_bl_update_status, +}; + +static int mp3309c_probe(struct i2c_client *client) +{ + struct mp3309c_platform_data *pdata = dev_get_platdata(&client->dev); + struct mp3309c_chip *chip; + struct backlight_properties props; + int ret; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { + dev_err(&client->dev, "failed to check i2c functionality\n"); + return -EOPNOTSUPP; + } + + chip = devm_kzalloc(&client->dev, sizeof(struct mp3309c_chip), + GFP_KERNEL); + if (!chip) + return -ENOMEM; + chip->dev = &client->dev; + + chip->regmap = devm_regmap_init_i2c(client, &mp3309c_regmap); + if (IS_ERR(chip->regmap)) { + ret = PTR_ERR(chip->regmap); + dev_err(&client->dev, "failed to allocate register map\n"); + return ret; + } + + i2c_set_clientdata(client, chip); + + if (!pdata) { + pdata = devm_kzalloc(chip->dev, + sizeof(struct mp3309c_platform_data), + GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + ret = pm3309c_parse_dt_node(chip, pdata); + if (ret) { + dev_err(&client->dev, "failed parsing DT node\n"); + return ret; + } + } + chip->pdata = pdata; + + chip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", + GPIOD_OUT_HIGH); + if (IS_ERR(chip->enable_gpio)) { + ret = PTR_ERR(chip->enable_gpio); + return ret; + } + + /* Backlight */ + props.type = BACKLIGHT_RAW; + props.brightness = pdata->brightness; + props.max_brightness = pdata->max_brightness; + props.scale = BACKLIGHT_SCALE_LINEAR; + chip->bl = + devm_backlight_device_register(chip->dev, "mp3309c_bl", + chip->dev, chip, &mp3309c_bl_ops, + &props); + if (IS_ERR(chip->bl)) { + dev_err(&client->dev, "failed registering backlight\n"); + return PTR_ERR(chip->bl); + } + pdata->status = FIRST_POWER_ON; + + /* Enable PWM, if required */ + if (pdata->dimming_mode == DIMMING_PWM) { + chip->pwmd = devm_pwm_get(chip->dev, NULL); + if (IS_ERR(chip->pwmd)) { + dev_err(&client->dev, "failed getting pwm device\n"); + return PTR_ERR(chip->pwmd); + } + pwm_apply_args(chip->pwmd); + } + + /* + * Workqueue for delayed backlight enabling + */ + INIT_DELAYED_WORK(&chip->enable_work, mp3309c_enable); + + /* + * Workqueue for (optional) external device GPIO reset + */ + if (pdata->reset_pulse_enable) { + dev_info(&client->dev, "reset pulse enabled\n"); + INIT_DELAYED_WORK(&chip->reset_gpio_work, mp3309c_reset_gpio); + } + + dev_info(&client->dev, "MP3309C backlight initialized"); + return 0; +} + +static int mp3309c_backlight_switch_off(struct pwm_device *pwmd) +{ + struct pwm_state pwmstate; + + /* Switch-off the backlight */ + pwm_get_state(pwmd, &pwmstate); + pwmstate.duty_cycle = 0; + pwmstate.enabled = false; + pwm_apply_state(pwmd, &pwmstate); + + return 0; +} + +static void mp3309c_remove(struct i2c_client *client) +{ + struct mp3309c_chip *chip = i2c_get_clientdata(client); + + if (chip->pdata->dimming_mode == DIMMING_PWM) + mp3309c_backlight_switch_off(chip->pwmd); + if (chip->pdata->reset_pulse_enable) + cancel_delayed_work(&chip->reset_gpio_work); +} + +static void mp3309c_shutdown(struct i2c_client *client) +{ + struct mp3309c_chip *chip = i2c_get_clientdata(client); + + if (chip->pdata->dimming_mode == DIMMING_PWM) + mp3309c_backlight_switch_off(chip->pwmd); +} + +static const struct of_device_id mp3309c_match_table[] = { + { .compatible = "mps,mp3309c-backlight", }, + { }, +}; +MODULE_DEVICE_TABLE(of, mp3309c_match_table); + +static const struct i2c_device_id mp3309c_id[] = { + { "mp3309c", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, mp3309c_id); + +static struct i2c_driver mp3309c_i2c_driver = { + .driver = { + .name = "mp3309c-backlight", + .of_match_table = mp3309c_match_table, + }, + .probe = mp3309c_probe, + .remove = mp3309c_remove, + .shutdown = mp3309c_shutdown, + .id_table = mp3309c_id, +}; + +module_i2c_driver(mp3309c_i2c_driver); + +MODULE_DESCRIPTION("Backlight Driver for MPS MP3309C"); +MODULE_AUTHOR("Flavio Suligoi <f.suligoi@xxxxxxx>"); +MODULE_LICENSE("GPL"); -- 2.34.1
