backlight: mp3309c: Add support for MPS MP3309C
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@asem.it> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20231116105319.957600-3-f.suligoi@asem.it Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Flavio Suligoi
Lee Jones
parent
87f33a1b8f
commit
2e914516a5
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@ -14658,6 +14658,13 @@ S: Maintained
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F: Documentation/driver-api/tty/moxa-smartio.rst
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F: drivers/tty/mxser.*
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MP3309C BACKLIGHT DRIVER
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M: Flavio Suligoi <f.suligoi@asem.it>
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L: dri-devel@lists.freedesktop.org
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S: Maintained
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F: Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
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F: drivers/video/backlight/mp3309c.c
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MR800 AVERMEDIA USB FM RADIO DRIVER
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M: Alexey Klimov <klimov.linux@gmail.com>
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L: linux-media@vger.kernel.org
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@ -402,6 +402,17 @@ config BACKLIGHT_LP8788
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help
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This supports TI LP8788 backlight driver.
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config BACKLIGHT_MP3309C
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tristate "Backlight Driver for MPS MP3309C"
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depends on I2C && PWM
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select REGMAP_I2C
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help
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This supports MPS MP3309C backlight WLED driver in both PWM and
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analog/I2C dimming modes.
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To compile this driver as a module, choose M here: the module will
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be called mp3309c.
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config BACKLIGHT_PANDORA
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tristate "Backlight driver for Pandora console"
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depends on TWL4030_CORE
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@ -44,6 +44,7 @@ obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o
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obj-$(CONFIG_BACKLIGHT_LP8788) += lp8788_bl.o
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obj-$(CONFIG_BACKLIGHT_LV5207LP) += lv5207lp.o
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obj-$(CONFIG_BACKLIGHT_MAX8925) += max8925_bl.o
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obj-$(CONFIG_BACKLIGHT_MP3309C) += mp3309c.o
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obj-$(CONFIG_BACKLIGHT_MT6370) += mt6370-backlight.o
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obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o
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obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o
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@ -0,0 +1,443 @@
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Driver for MPS MP3309C White LED driver with I2C interface
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*
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* This driver support both analog (by I2C commands) and PWM dimming control
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* modes.
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*
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* Copyright (C) 2023 ASEM Srl
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* Author: Flavio Suligoi <f.suligoi@asem.it>
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*
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* Based on pwm_bl.c
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*/
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#include <linux/backlight.h>
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#include <linux/delay.h>
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#include <linux/gpio/consumer.h>
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#include <linux/i2c.h>
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#include <linux/pwm.h>
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#include <linux/regmap.h>
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#define REG_I2C_0 0x00
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#define REG_I2C_1 0x01
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#define REG_I2C_0_EN 0x80
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#define REG_I2C_0_D0 0x40
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#define REG_I2C_0_D1 0x20
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#define REG_I2C_0_D2 0x10
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#define REG_I2C_0_D3 0x08
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#define REG_I2C_0_D4 0x04
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#define REG_I2C_0_RSRV1 0x02
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#define REG_I2C_0_RSRV2 0x01
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#define REG_I2C_1_RSRV1 0x80
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#define REG_I2C_1_DIMS 0x40
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#define REG_I2C_1_SYNC 0x20
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#define REG_I2C_1_OVP0 0x10
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#define REG_I2C_1_OVP1 0x08
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#define REG_I2C_1_VOS 0x04
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#define REG_I2C_1_LEDO 0x02
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#define REG_I2C_1_OTP 0x01
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#define ANALOG_I2C_NUM_LEVELS 32 /* 0..31 */
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#define ANALOG_I2C_REG_MASK 0x7c
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#define MP3309C_PWM_DEFAULT_NUM_LEVELS 256 /* 0..255 */
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enum mp3309c_status_value {
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FIRST_POWER_ON,
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BACKLIGHT_OFF,
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BACKLIGHT_ON,
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};
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enum mp3309c_dimming_mode_value {
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DIMMING_PWM,
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DIMMING_ANALOG_I2C,
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};
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struct mp3309c_platform_data {
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unsigned int max_brightness;
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unsigned int default_brightness;
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unsigned int *levels;
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u8 dimming_mode;
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u8 over_voltage_protection;
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bool sync_mode;
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u8 status;
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};
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struct mp3309c_chip {
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struct device *dev;
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struct mp3309c_platform_data *pdata;
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struct backlight_device *bl;
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struct gpio_desc *enable_gpio;
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struct regmap *regmap;
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struct pwm_device *pwmd;
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};
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static const struct regmap_config mp3309c_regmap = {
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.name = "mp3309c_regmap",
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.reg_bits = 8,
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.reg_stride = 1,
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.val_bits = 8,
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.max_register = REG_I2C_1,
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};
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static int mp3309c_enable_device(struct mp3309c_chip *chip)
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{
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u8 reg_val;
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int ret;
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/* I2C register #0 - Device enable */
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ret = regmap_update_bits(chip->regmap, REG_I2C_0, REG_I2C_0_EN,
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REG_I2C_0_EN);
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if (ret)
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return ret;
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/*
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* I2C register #1 - Set working mode:
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* - set one of the two dimming mode:
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* - PWM dimming using an external PWM dimming signal
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* - analog dimming using I2C commands
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* - enable/disable synchronous mode
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* - set overvoltage protection (OVP)
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*/
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reg_val = 0x00;
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if (chip->pdata->dimming_mode == DIMMING_PWM)
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reg_val |= REG_I2C_1_DIMS;
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if (chip->pdata->sync_mode)
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reg_val |= REG_I2C_1_SYNC;
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reg_val |= chip->pdata->over_voltage_protection;
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ret = regmap_write(chip->regmap, REG_I2C_1, reg_val);
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if (ret)
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return ret;
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return 0;
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}
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static int mp3309c_bl_update_status(struct backlight_device *bl)
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{
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struct mp3309c_chip *chip = bl_get_data(bl);
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int brightness = backlight_get_brightness(bl);
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struct pwm_state pwmstate;
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unsigned int analog_val, bits_val;
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int i, ret;
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if (chip->pdata->dimming_mode == DIMMING_PWM) {
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/*
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* PWM control mode
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*/
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pwm_get_state(chip->pwmd, &pwmstate);
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pwm_set_relative_duty_cycle(&pwmstate,
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chip->pdata->levels[brightness],
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chip->pdata->levels[chip->pdata->max_brightness]);
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pwmstate.enabled = true;
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ret = pwm_apply_state(chip->pwmd, &pwmstate);
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if (ret)
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return ret;
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switch (chip->pdata->status) {
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case FIRST_POWER_ON:
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case BACKLIGHT_OFF:
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/*
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* After 20ms of low pwm signal level, the chip turns
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* off automatically. In this case, before enabling the
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* chip again, we must wait about 10ms for pwm signal to
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* stabilize.
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*/
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if (brightness > 0) {
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msleep(10);
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mp3309c_enable_device(chip);
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chip->pdata->status = BACKLIGHT_ON;
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} else {
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chip->pdata->status = BACKLIGHT_OFF;
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}
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break;
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case BACKLIGHT_ON:
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if (brightness == 0)
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chip->pdata->status = BACKLIGHT_OFF;
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break;
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}
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} else {
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/*
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* Analog (by I2C command) control mode
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*
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* The first time, before setting brightness, we must enable the
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* device
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*/
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if (chip->pdata->status == FIRST_POWER_ON)
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mp3309c_enable_device(chip);
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/*
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* Dimming mode I2C command (fixed dimming range 0..31)
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*
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* The 5 bits of the dimming analog value D4..D0 is allocated
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* in the I2C register #0, in the following way:
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*
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* +--+--+--+--+--+--+--+--+
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* |EN|D0|D1|D2|D3|D4|XX|XX|
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* +--+--+--+--+--+--+--+--+
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*/
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analog_val = brightness;
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bits_val = 0;
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for (i = 0; i <= 5; i++)
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bits_val += ((analog_val >> i) & 0x01) << (6 - i);
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ret = regmap_update_bits(chip->regmap, REG_I2C_0,
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ANALOG_I2C_REG_MASK, bits_val);
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if (ret)
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return ret;
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if (brightness > 0)
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chip->pdata->status = BACKLIGHT_ON;
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else
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chip->pdata->status = BACKLIGHT_OFF;
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}
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return 0;
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}
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static const struct backlight_ops mp3309c_bl_ops = {
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.update_status = mp3309c_bl_update_status,
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};
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static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
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struct mp3309c_platform_data *pdata)
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{
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struct device_node *node = chip->dev->of_node;
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struct property *prop_pwms, *prop_levels;
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int length = 0;
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int ret, i;
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unsigned int num_levels, tmp_value;
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if (!node) {
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dev_err(chip->dev, "failed to get DT node\n");
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return -ENODEV;
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}
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/*
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* Dimming mode: the MP3309C provides two dimming control mode:
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*
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* - PWM mode
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* - Analog by I2C control mode (default)
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*
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* I2C control mode is assumed as default but, if the pwms property is
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* found in the backlight node, the mode switches to PWM mode.
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*/
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pdata->dimming_mode = DIMMING_ANALOG_I2C;
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prop_pwms = of_find_property(node, "pwms", &length);
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if (prop_pwms) {
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chip->pwmd = devm_pwm_get(chip->dev, NULL);
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if (IS_ERR(chip->pwmd))
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return dev_err_probe(chip->dev, PTR_ERR(chip->pwmd),
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"error getting pwm data\n");
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pdata->dimming_mode = DIMMING_PWM;
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pwm_apply_args(chip->pwmd);
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}
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/*
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* In I2C control mode the dimming levels (0..31) are fixed by the
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* hardware, while in PWM control mode they can be chosen by the user,
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* to allow nonlinear mappings.
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*/
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if (pdata->dimming_mode == DIMMING_ANALOG_I2C) {
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/*
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* Analog (by I2C commands) control mode: fixed 0..31 brightness
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* levels
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*/
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num_levels = ANALOG_I2C_NUM_LEVELS;
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/* Enable GPIO used in I2C dimming mode only */
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chip->enable_gpio = devm_gpiod_get(chip->dev, "enable",
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GPIOD_OUT_HIGH);
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if (IS_ERR(chip->enable_gpio))
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return dev_err_probe(chip->dev,
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PTR_ERR(chip->enable_gpio),
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"error getting enable gpio\n");
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} else {
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/*
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* PWM control mode: check for brightness level in DT
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*/
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prop_levels = of_find_property(node, "brightness-levels",
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&length);
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if (prop_levels) {
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/* Read brightness levels from DT */
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num_levels = length / sizeof(u32);
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if (num_levels < 2)
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return -EINVAL;
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} else {
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/* Use default brightness levels */
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num_levels = MP3309C_PWM_DEFAULT_NUM_LEVELS;
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}
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}
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/* Fill brightness levels array */
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pdata->levels = devm_kcalloc(chip->dev, num_levels,
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sizeof(*pdata->levels), GFP_KERNEL);
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if (!pdata->levels)
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return -ENOMEM;
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if (prop_levels) {
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ret = of_property_read_u32_array(node, "brightness-levels",
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pdata->levels,
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num_levels);
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if (ret < 0)
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return ret;
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} else {
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for (i = 0; i < num_levels; i++)
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pdata->levels[i] = i;
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}
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pdata->max_brightness = num_levels - 1;
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ret = of_property_read_u32(node, "default-brightness",
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&pdata->default_brightness);
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if (ret)
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pdata->default_brightness = pdata->max_brightness;
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if (pdata->default_brightness > pdata->max_brightness) {
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dev_err(chip->dev,
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"default brightness exceeds max brightness\n");
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pdata->default_brightness = pdata->max_brightness;
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}
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/*
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* Over-voltage protection (OVP)
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*
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* This (optional) property values are:
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*
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* - 13.5V
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* - 24V
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* - 35.5V (hardware default setting)
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*
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* If missing, the default value for OVP is 35.5V
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*/
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pdata->over_voltage_protection = REG_I2C_1_OVP1;
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if (!of_property_read_u32(node, "mps,overvoltage-protection-microvolt",
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&tmp_value)) {
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switch (tmp_value) {
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case 13500000:
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pdata->over_voltage_protection = 0x00;
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break;
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case 24000000:
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pdata->over_voltage_protection = REG_I2C_1_OVP0;
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break;
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case 35500000:
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pdata->over_voltage_protection = REG_I2C_1_OVP1;
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break;
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default:
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return -EINVAL;
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}
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}
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/* Synchronous (default) and non-synchronous mode */
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pdata->sync_mode = true;
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if (of_property_read_bool(node, "mps,no-sync-mode"))
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pdata->sync_mode = false;
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return 0;
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}
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static int mp3309c_probe(struct i2c_client *client)
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{
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struct mp3309c_platform_data *pdata = dev_get_platdata(&client->dev);
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struct mp3309c_chip *chip;
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struct backlight_properties props;
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struct pwm_state pwmstate;
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int ret;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
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dev_err(&client->dev, "failed to check i2c functionality\n");
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return -EOPNOTSUPP;
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}
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chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
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if (!chip)
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return -ENOMEM;
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chip->dev = &client->dev;
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chip->regmap = devm_regmap_init_i2c(client, &mp3309c_regmap);
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if (IS_ERR(chip->regmap))
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return dev_err_probe(&client->dev, PTR_ERR(chip->regmap),
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"failed to allocate register map\n");
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i2c_set_clientdata(client, chip);
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if (!pdata) {
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pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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ret = pm3309c_parse_dt_node(chip, pdata);
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if (ret)
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return ret;
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}
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chip->pdata = pdata;
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/* Backlight properties */
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props.brightness = pdata->default_brightness;
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props.max_brightness = pdata->max_brightness;
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props.scale = BACKLIGHT_SCALE_LINEAR;
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props.type = BACKLIGHT_RAW;
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props.power = FB_BLANK_UNBLANK;
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props.fb_blank = FB_BLANK_UNBLANK;
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chip->bl = devm_backlight_device_register(chip->dev, "mp3309c",
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chip->dev, chip,
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&mp3309c_bl_ops, &props);
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if (IS_ERR(chip->bl))
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return dev_err_probe(chip->dev, PTR_ERR(chip->bl),
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"error registering backlight device\n");
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/* In PWM dimming mode, enable pwm device */
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if (chip->pdata->dimming_mode == DIMMING_PWM) {
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pwm_init_state(chip->pwmd, &pwmstate);
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pwm_set_relative_duty_cycle(&pwmstate,
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chip->pdata->default_brightness,
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chip->pdata->max_brightness);
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pwmstate.enabled = true;
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ret = pwm_apply_state(chip->pwmd, &pwmstate);
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if (ret)
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return dev_err_probe(chip->dev, ret,
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"error setting pwm device\n");
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}
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||||
|
||||
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@asem.it>");
|
||||
MODULE_LICENSE("GPL");
|
||||
Loading…
Reference in New Issue