diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/video/backlight/mp3309c.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/video/backlight/mp3309c.c')
| -rw-r--r-- | drivers/video/backlight/mp3309c.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/drivers/video/backlight/mp3309c.c b/drivers/video/backlight/mp3309c.c new file mode 100644 index 000000000..752a45798 --- /dev/null +++ b/drivers/video/backlight/mp3309c.c @@ -0,0 +1,421 @@ +// 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@asem.it> + * + * Based on pwm_bl.c + */ + +#include <linux/backlight.h> +#include <linux/delay.h> +#include <linux/gpio/consumer.h> +#include <linux/i2c.h> +#include <linux/property.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: + * - enable/disable synchronous mode + * - set overvoltage protection (OVP) + */ + reg_val = 0x00; + 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_might_sleep(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 mp3309c_parse_fwnode(struct mp3309c_chip *chip, + struct mp3309c_platform_data *pdata) +{ + int ret, i; + unsigned int tmp_value; + struct device *dev = chip->dev; + int num_levels; + + if (!dev_fwnode(dev)) + return dev_err_probe(dev, -ENODEV, "failed to get firmware node\n"); + + /* + * 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; + if (device_property_present(dev, "pwms")) { + chip->pwmd = devm_pwm_get(dev, NULL); + if (IS_ERR(chip->pwmd)) + return dev_err_probe(dev, PTR_ERR(chip->pwmd), "error getting pwm data\n"); + pdata->dimming_mode = DIMMING_PWM; + } + + /* + * 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(dev, "enable", GPIOD_OUT_HIGH); + if (IS_ERR(chip->enable_gpio)) + return dev_err_probe(dev, PTR_ERR(chip->enable_gpio), + "error getting enable gpio\n"); + } else { + /* + * PWM control mode: check for brightness level in DT + */ + if (device_property_present(dev, "brightness-levels")) { + /* Read brightness levels from DT */ + num_levels = device_property_count_u32(dev, "brightness-levels"); + 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(dev, num_levels, sizeof(*pdata->levels), GFP_KERNEL); + if (!pdata->levels) + return -ENOMEM; + if (device_property_present(dev, "brightness-levels")) { + ret = device_property_read_u32_array(dev, "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 = device_property_read_u32(dev, "default-brightness", &pdata->default_brightness); + if (ret) + pdata->default_brightness = pdata->max_brightness; + if (pdata->default_brightness > pdata->max_brightness) { + dev_err_probe(dev, -ERANGE, "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; + ret = device_property_read_u32(dev, "mps,overvoltage-protection-microvolt", &tmp_value); + if (!ret) { + 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 = !device_property_read_bool(dev, "mps,no-sync-mode"); + + return 0; +} + +static int mp3309c_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct mp3309c_platform_data *pdata = dev_get_platdata(dev); + struct mp3309c_chip *chip; + struct backlight_properties props; + struct pwm_state pwmstate; + int ret; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return dev_err_probe(dev, -EOPNOTSUPP, "failed to check i2c functionality\n"); + + chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->dev = dev; + + chip->regmap = devm_regmap_init_i2c(client, &mp3309c_regmap); + if (IS_ERR(chip->regmap)) + return dev_err_probe(dev, PTR_ERR(chip->regmap), + "failed to allocate register map\n"); + + i2c_set_clientdata(client, chip); + + if (!pdata) { + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + ret = mp3309c_parse_fwnode(chip, pdata); + if (ret) + return ret; + } + chip->pdata = pdata; + + /* Backlight properties */ + props = (typeof(props)){ + .brightness = pdata->default_brightness, + .max_brightness = pdata->max_brightness, + .scale = BACKLIGHT_SCALE_LINEAR, + .type = BACKLIGHT_RAW, + .power = BACKLIGHT_POWER_ON, + }; + chip->bl = devm_backlight_device_register(dev, "mp3309c", dev, chip, + &mp3309c_bl_ops, &props); + if (IS_ERR(chip->bl)) + return dev_err_probe(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_might_sleep(chip->pwmd, &pwmstate); + if (ret) + return dev_err_probe(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 = BACKLIGHT_POWER_OFF; + 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[] = { + { .name = "mp3309c" }, + { } +}; +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"); |
