From e47bee270ad0ac0d32af91acfc5d8a84c4039787 Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Mon, 30 Nov 2020 16:45:23 +0000 Subject: [PATCH 0944/1085] regulator: Add a regulator for the new LCD panels The newer Raspberry Pi 5" and 7" panels have a slightly different register map to the original one. Add a new driver for this regulator. Signed-off-by: Dave Stevenson --- drivers/regulator/Kconfig | 10 ++ drivers/regulator/Makefile | 1 + drivers/regulator/rpi-panel-v2-regulator.c | 189 +++++++++++++++++++++ 3 files changed, 200 insertions(+) create mode 100644 drivers/regulator/rpi-panel-v2-regulator.c --- a/drivers/regulator/Kconfig +++ b/drivers/regulator/Kconfig @@ -1097,6 +1097,16 @@ config REGULATOR_RASPBERRYPI_TOUCHSCREEN touchscreen unit. The regulator is used to enable power to the TC358762, display and to control backlight. +config REGULATOR_RASPBERRYPI_TOUCHSCREEN_V2 + tristate "Raspberry Pi 7-inch touchscreen panel V2 regulator" + depends on BACKLIGHT_CLASS_DEVICE + depends on I2C + select REGMAP_I2C + help + This driver supports regulator on the V2 Raspberry Pi + touchscreen unit. The regulator is used to enable power to the + display and to control backlight. + config REGULATOR_RC5T583 tristate "RICOH RC5T583 Power regulators" depends on MFD_RC5T583 --- a/drivers/regulator/Makefile +++ b/drivers/regulator/Makefile @@ -130,6 +130,7 @@ obj-$(CONFIG_REGULATOR_PCAP) += pcap-reg obj-$(CONFIG_REGULATOR_PCF50633) += pcf50633-regulator.o obj-$(CONFIG_REGULATOR_RAA215300) += raa215300.o obj-$(CONFIG_REGULATOR_RASPBERRYPI_TOUCHSCREEN_ATTINY) += rpi-panel-attiny-regulator.o +obj-$(CONFIG_REGULATOR_RASPBERRYPI_TOUCHSCREEN_V2) += rpi-panel-v2-regulator.o obj-$(CONFIG_REGULATOR_RC5T583) += rc5t583-regulator.o obj-$(CONFIG_REGULATOR_RK808) += rk808-regulator.o obj-$(CONFIG_REGULATOR_RN5T618) += rn5t618-regulator.o --- /dev/null +++ b/drivers/regulator/rpi-panel-v2-regulator.c @@ -0,0 +1,189 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2022 Raspberry Pi Ltd. + * + * Based on rpi-panel-attiny-regulator.c by Marek Vasut + */ + +#include +#include +#include +#include +#include +#include +#include + +/* I2C registers of the microcontroller. */ +#define REG_ID 0x01 +#define REG_POWERON 0x02 +#define REG_PWM 0x03 + +// bits for poweron register +#define LCD_RESET_BIT BIT(0) +#define CTP_RESET_BIT BIT(1) + +//bits for the PWM register +#define PWM_BL_ENABLE BIT(7) +#define PWM_VALUE GENMASK(4, 0) + +#define NUM_GPIO 2 /* Treat LCD_RESET and CTP_RESET as GPIOs */ + +struct rpi_panel_v2_lcd { + /* lock to serialise overall accesses to the Atmel */ + struct mutex lock; + struct regmap *regmap; + u8 poweron_state; + + struct gpio_chip gc; +}; + +static const struct regmap_config rpi_panel_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = REG_PWM, +}; + +static int rpi_panel_v2_gpio_get_direction(struct gpio_chip *gc, unsigned int off) +{ + return GPIO_LINE_DIRECTION_OUT; +} + +static void rpi_panel_v2_gpio_set(struct gpio_chip *gc, unsigned int off, int val) +{ + struct rpi_panel_v2_lcd *state = gpiochip_get_data(gc); + u8 last_val; + + if (off >= NUM_GPIO) + return; + + mutex_lock(&state->lock); + + last_val = state->poweron_state; + if (val) + last_val |= (1 << off); + else + last_val &= ~(1 << off); + + state->poweron_state = last_val; + + regmap_write(state->regmap, REG_POWERON, last_val); + + mutex_unlock(&state->lock); +} + +static int rpi_panel_v2_update_status(struct backlight_device *bl) +{ + struct regmap *regmap = bl_get_data(bl); + int brightness = bl->props.brightness; + + if (bl->props.power != FB_BLANK_UNBLANK || + bl->props.fb_blank != FB_BLANK_UNBLANK) + brightness = 0; + + return regmap_write(regmap, REG_PWM, brightness | PWM_BL_ENABLE); +} + +static const struct backlight_ops rpi_panel_v2_bl = { + .update_status = rpi_panel_v2_update_status, +}; + +/* + * I2C driver interface functions + */ +static int rpi_panel_v2_i2c_probe(struct i2c_client *i2c) +{ + struct backlight_properties props = { }; + struct backlight_device *bl; + struct rpi_panel_v2_lcd *state; + struct regmap *regmap; + unsigned int data; + int ret; + + state = devm_kzalloc(&i2c->dev, sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + + mutex_init(&state->lock); + + regmap = devm_regmap_init_i2c(i2c, &rpi_panel_regmap_config); + if (IS_ERR(regmap)) { + ret = PTR_ERR(regmap); + dev_err(&i2c->dev, "Failed to allocate register map: %d\n", + ret); + goto error; + } + + ret = regmap_read(regmap, REG_ID, &data); + if (ret < 0) { + dev_err(&i2c->dev, "Failed to read REG_ID reg: %d\n", ret); + goto error; + } + + switch (data & 0x0f) { + case 0x01: /* 7 inch */ + case 0x04: /* 7 inch - old */ + case 0x08: /* 5 inch - old */ + case 0x09: /* 5 inch */ + break; + default: + dev_err(&i2c->dev, "Unknown revision: 0x%02x\n", + data & 0x0f); + ret = -ENODEV; + goto error; + } + + regmap_write(regmap, REG_POWERON, 0); + + state->regmap = regmap; + state->gc.parent = &i2c->dev; + state->gc.label = i2c->name; + state->gc.owner = THIS_MODULE; + state->gc.base = -1; + state->gc.ngpio = NUM_GPIO; + + state->gc.set = rpi_panel_v2_gpio_set; + state->gc.get_direction = rpi_panel_v2_gpio_get_direction; + state->gc.can_sleep = true; + + ret = devm_gpiochip_add_data(&i2c->dev, &state->gc, state); + if (ret) { + dev_err(&i2c->dev, "Failed to create gpiochip: %d\n", ret); + goto error; + } + + props.type = BACKLIGHT_RAW; + props.max_brightness = PWM_VALUE; + bl = devm_backlight_device_register(&i2c->dev, dev_name(&i2c->dev), + &i2c->dev, regmap, &rpi_panel_v2_bl, + &props); + if (IS_ERR(bl)) + return PTR_ERR(bl); + + bl->props.brightness = PWM_VALUE; + + return 0; + +error: + mutex_destroy(&state->lock); + return ret; +} + +static const struct of_device_id rpi_panel_v2_dt_ids[] = { + { .compatible = "raspberrypi,v2-touchscreen-panel-regulator" }, + {}, +}; +MODULE_DEVICE_TABLE(of, rpi_panel_v2_dt_ids); + +static struct i2c_driver rpi_panel_v2_regulator_driver = { + .driver = { + .name = "rpi_touchscreen_v2", + .of_match_table = of_match_ptr(rpi_panel_v2_dt_ids), + }, + .probe = rpi_panel_v2_i2c_probe, +}; + +module_i2c_driver(rpi_panel_v2_regulator_driver); + +MODULE_AUTHOR("Dave Stevenson "); +MODULE_DESCRIPTION("Regulator device driver for Raspberry Pi 7-inch V2 touchscreen"); +MODULE_LICENSE("GPL");