On Fri, Oct 20, 2023 at 03:54:34PM +0200, Flavio Suligoi wrote: > 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> > --- > > v5: > - checked and resend for updated kernel 6.6.0-rc1 Why is this v5 patch attached to a 1 patch "series" that only purports to contain a binding patch? Thanks, Conor. > v4: > - add brightness-levels property > - force fixed 32 brightness levels (0..31) in analog-i2c dimming mode > - remove useless irq and reset_gpio from mp3309c_chip structure > v3: > - fix SPDX obsolete spelling > - in mp3309c_bl_update_status, change from msleep_interruptible() to msleep() > and improve the related comment > v2: > - fix dependecies in Kconfig > - fix Kconfig MP3309C entry order > - remove switch-on-delay-ms property > - remove optional gpio property to reset external devices > - remove dimming-mode property (the analog-i2c dimming mode is the default; the > presence of the pwms property, in DT, selects automatically the pwm dimming > mode) > - substitute three boolean properties, used for the overvoltage-protection > values, with a single enum property > - drop simple tracing messages > - use dev_err_probe() in probe function > - change device name from mp3309c_bl to the simple mp3309c > - remove shutdown function > v1: > - first version > > MAINTAINERS | 7 + > drivers/video/backlight/Kconfig | 11 + > drivers/video/backlight/Makefile | 1 + > drivers/video/backlight/mp3309c.c | 443 ++++++++++++++++++++++++++++++ > 4 files changed, 462 insertions(+) > create mode 100644 drivers/video/backlight/mp3309c.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 90f13281d297..3d23b869e2aa 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -14474,6 +14474,13 @@ S: Maintained > F: Documentation/driver-api/tty/moxa-smartio.rst > F: drivers/tty/mxser.* > > +MP3309C BACKLIGHT DRIVER > +M: Flavio Suligoi <f.suligoi@xxxxxxx> > +L: dri-devel@xxxxxxxxxxxxxxxxxxxxx > +S: Maintained > +F: Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml > +F: drivers/video/backlight/mp3309c.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..1144a54a35c0 100644 > --- a/drivers/video/backlight/Kconfig > +++ b/drivers/video/backlight/Kconfig > @@ -402,6 +402,17 @@ config BACKLIGHT_LP8788 > help > This supports TI LP8788 backlight driver. > > +config BACKLIGHT_MP3309C > + tristate "Backlight Driver for MPS MP3309C" > + depends on I2C && PWM > + select REGMAP_I2C > + 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. > + > config BACKLIGHT_PANDORA > tristate "Backlight driver for Pandora console" > depends on TWL4030_CORE > diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile > index f72e1c3c59e9..1af583de665b 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-$(CONFIG_BACKLIGHT_MP3309C) += mp3309c.o > obj-$(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.c b/drivers/video/backlight/mp3309c.c > new file mode 100644 > index 000000000000..3fe4469ef43f > --- /dev/null > +++ b/drivers/video/backlight/mp3309c.c > @@ -0,0 +1,443 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Driver for MPS MP3309C White LED driver with I2C interface > + * > + * This driver support both analog (by I2C commands) and PWM dimming control > + * modes. > + * > + * Copyright (C) 2023 ASEM Srl > + * Author: Flavio Suligoi <f.suligoi@xxxxxxx> > + * > + * Based on pwm_bl.c > + */ > + > +#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> > + > +#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_I2C_NUM_LEVELS 32 /* 0..31 */ > +#define ANALOG_I2C_REG_MASK 0x7c > + > +#define MP3309C_PWM_DEFAULT_NUM_LEVELS 256 /* 0..255 */ > + > +enum mp3309c_status_value { > + FIRST_POWER_ON, > + BACKLIGHT_OFF, > + BACKLIGHT_ON, > +}; > + > +enum mp3309c_dimming_mode_value { > + DIMMING_PWM, > + DIMMING_ANALOG_I2C, > +}; > + > +struct mp3309c_platform_data { > + unsigned int max_brightness; > + unsigned int default_brightness; > + unsigned int *levels; > + u8 dimming_mode; > + u8 over_voltage_protection; > + bool sync_mode; > + u8 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; > +}; > + > +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 mp3309c_enable_device(struct mp3309c_chip *chip) > +{ > + u8 reg_val; > + 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/disable synchronous mode > + * - set overvoltage protection (OVP) > + */ > + reg_val = 0x00; > + if (chip->pdata->dimming_mode == DIMMING_PWM) > + reg_val |= REG_I2C_1_DIMS; > + if (chip->pdata->sync_mode) > + reg_val |= REG_I2C_1_SYNC; > + reg_val |= chip->pdata->over_voltage_protection; > + ret = regmap_write(chip->regmap, REG_I2C_1, reg_val); > + if (ret) > + return ret; > + > + return 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 control mode > + */ > + pwm_get_state(chip->pwmd, &pwmstate); > + pwm_set_relative_duty_cycle(&pwmstate, > + chip->pdata->levels[brightness], > + chip->pdata->levels[chip->pdata->max_brightness]); > + pwmstate.enabled = true; > + ret = pwm_apply_state(chip->pwmd, &pwmstate); > + if (ret) > + return ret; > + > + switch (chip->pdata->status) { > + case FIRST_POWER_ON: > + case BACKLIGHT_OFF: > + /* > + * After 20ms of low pwm signal level, the chip turns > + * off automatically. In this case, before enabling the > + * chip again, we must wait about 10ms for pwm signal to > + * stabilize. > + */ > + if (brightness > 0) { > + msleep(10); > + mp3309c_enable_device(chip); > + chip->pdata->status = BACKLIGHT_ON; > + } else { > + chip->pdata->status = BACKLIGHT_OFF; > + } > + break; > + case BACKLIGHT_ON: > + if (brightness == 0) > + chip->pdata->status = BACKLIGHT_OFF; > + break; > + } > + } else { > + /* > + * Analog (by I2C command) control mode > + * > + * The first time, before setting brightness, we must enable the > + * device > + */ > + if (chip->pdata->status == FIRST_POWER_ON) > + mp3309c_enable_device(chip); > + > + /* > + * Dimming mode I2C command (fixed dimming range 0..31) > + * > + * 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 = 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_I2C_REG_MASK, bits_val); > + if (ret) > + return ret; > + > + if (brightness > 0) > + chip->pdata->status = BACKLIGHT_ON; > + else > + chip->pdata->status = BACKLIGHT_OFF; > + } > + > + return 0; > +} > + > +static const struct backlight_ops mp3309c_bl_ops = { > + .update_status = mp3309c_bl_update_status, > +}; > + > +static int pm3309c_parse_dt_node(struct mp3309c_chip *chip, > + struct mp3309c_platform_data *pdata) > +{ > + struct device_node *node = chip->dev->of_node; > + struct property *prop_pwms, *prop_levels; > + int length = 0; > + int ret, i; > + unsigned int num_levels, tmp_value; > + > + if (!node) { > + dev_err(chip->dev, "failed to get DT node\n"); > + return -ENODEV; > + } > + > + /* > + * Dimming mode: the MP3309C provides two dimming control mode: > + * > + * - PWM mode > + * - Analog by I2C control mode (default) > + * > + * I2C control mode is assumed as default but, if the pwms property is > + * found in the backlight node, the mode switches to PWM mode. > + */ > + pdata->dimming_mode = DIMMING_ANALOG_I2C; > + prop_pwms = of_find_property(node, "pwms", &length); > + if (prop_pwms) { > + chip->pwmd = devm_pwm_get(chip->dev, NULL); > + if (IS_ERR(chip->pwmd)) > + return dev_err_probe(chip->dev, PTR_ERR(chip->pwmd), > + "error getting pwm data\n"); > + pdata->dimming_mode = DIMMING_PWM; > + pwm_apply_args(chip->pwmd); > + } > + > + /* > + * In I2C control mode the dimming levels (0..31) are fixed by the > + * hardware, while in PWM control mode they can be chosen by the user, > + * to allow nonlinear mappings. > + */ > + if (pdata->dimming_mode == DIMMING_ANALOG_I2C) { > + /* > + * Analog (by I2C commands) control mode: fixed 0..31 brightness > + * levels > + */ > + num_levels = ANALOG_I2C_NUM_LEVELS; > + > + /* Enable GPIO used in I2C dimming mode only */ > + chip->enable_gpio = devm_gpiod_get(chip->dev, "enable", > + GPIOD_OUT_HIGH); > + if (IS_ERR(chip->enable_gpio)) > + return dev_err_probe(chip->dev, > + PTR_ERR(chip->enable_gpio), > + "error getting enable gpio\n"); > + } else { > + /* > + * PWM control mode: check for brightness level in DT > + */ > + prop_levels = of_find_property(node, "brightness-levels", > + &length); > + if (prop_levels) { > + /* Read brightness levels from DT */ > + num_levels = length / sizeof(u32); > + if (num_levels < 2) > + return -EINVAL; > + } else { > + /* Use default brightness levels */ > + num_levels = MP3309C_PWM_DEFAULT_NUM_LEVELS; > + } > + } > + > + /* Fill brightness levels array */ > + pdata->levels = devm_kcalloc(chip->dev, num_levels, > + sizeof(*pdata->levels), GFP_KERNEL); > + if (!pdata->levels) > + return -ENOMEM; > + if (prop_levels) { > + ret = of_property_read_u32_array(node, "brightness-levels", > + pdata->levels, > + num_levels); > + if (ret < 0) > + return ret; > + } else { > + for (i = 0; i < num_levels; i++) > + pdata->levels[i] = i; > + } > + > + pdata->max_brightness = num_levels - 1; > + > + ret = of_property_read_u32(node, "default-brightness", > + &pdata->default_brightness); > + if (ret) > + pdata->default_brightness = pdata->max_brightness; > + if (pdata->default_brightness > pdata->max_brightness) { > + dev_err(chip->dev, > + "default brightness exceeds max brightness\n"); > + pdata->default_brightness = pdata->max_brightness; > + } > + > + /* > + * Over-voltage protection (OVP) > + * > + * This (optional) property values are: > + * > + * - 13.5V > + * - 24V > + * - 35.5V (hardware default setting) > + * > + * If missing, the default value for OVP is 35.5V > + */ > + pdata->over_voltage_protection = REG_I2C_1_OVP1; > + if (!of_property_read_u32(node, "mps,overvoltage-protection-microvolt", > + &tmp_value)) { > + switch (tmp_value) { > + case 13500000: > + pdata->over_voltage_protection = 0x00; > + break; > + case 24000000: > + pdata->over_voltage_protection = REG_I2C_1_OVP0; > + break; > + case 35500000: > + pdata->over_voltage_protection = REG_I2C_1_OVP1; > + break; > + default: > + return -EINVAL; > + } > + } > + > + /* Synchronous (default) and non-synchronous mode */ > + pdata->sync_mode = true; > + if (of_property_read_bool(node, "mps,no-sync-mode")) > + pdata->sync_mode = false; > + > + return 0; > +} > + > +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; > + struct pwm_state pwmstate; > + 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(*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)) > + return dev_err_probe(&client->dev, PTR_ERR(chip->regmap), > + "failed to allocate register map\n"); > + > + i2c_set_clientdata(client, chip); > + > + if (!pdata) { > + pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL); > + if (!pdata) > + return -ENOMEM; > + > + ret = pm3309c_parse_dt_node(chip, pdata); > + if (ret) > + return ret; > + } > + chip->pdata = pdata; > + > + /* Backlight properties */ > + props.brightness = pdata->default_brightness; > + props.max_brightness = pdata->max_brightness; > + props.scale = BACKLIGHT_SCALE_LINEAR; > + props.type = BACKLIGHT_RAW; > + props.power = FB_BLANK_UNBLANK; > + props.fb_blank = FB_BLANK_UNBLANK; > + chip->bl = devm_backlight_device_register(chip->dev, "mp3309c", > + chip->dev, chip, > + &mp3309c_bl_ops, &props); > + if (IS_ERR(chip->bl)) > + return dev_err_probe(chip->dev, PTR_ERR(chip->bl), > + "error registering backlight device\n"); > + > + /* In PWM dimming mode, enable pwm device */ > + if (chip->pdata->dimming_mode == DIMMING_PWM) { > + pwm_init_state(chip->pwmd, &pwmstate); > + pwm_set_relative_duty_cycle(&pwmstate, > + chip->pdata->default_brightness, > + chip->pdata->max_brightness); > + pwmstate.enabled = true; > + ret = pwm_apply_state(chip->pwmd, &pwmstate); > + if (ret) > + return dev_err_probe(chip->dev, ret, > + "error setting pwm device\n"); > + } > + > + chip->pdata->status = FIRST_POWER_ON; > + backlight_update_status(chip->bl); > + > + return 0; > +} > + > +static void mp3309c_remove(struct i2c_client *client) > +{ > + struct mp3309c_chip *chip = i2c_get_clientdata(client); > + struct backlight_device *bl = chip->bl; > + > + bl->props.power = FB_BLANK_POWERDOWN; > + bl->props.brightness = 0; > + backlight_update_status(chip->bl); > +} > + > +static const struct of_device_id mp3309c_match_table[] = { > + { .compatible = "mps,mp3309c", }, > + { }, > +}; > +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 = KBUILD_MODNAME, > + .of_match_table = mp3309c_match_table, > + }, > + .probe = mp3309c_probe, > + .remove = mp3309c_remove, > + .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 >
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