diff options
Diffstat (limited to 'drivers/regulator/rpi-panel-attiny-regulator.c')
-rw-r--r-- | drivers/regulator/rpi-panel-attiny-regulator.c | 291 |
1 files changed, 247 insertions, 44 deletions
diff --git a/drivers/regulator/rpi-panel-attiny-regulator.c b/drivers/regulator/rpi-panel-attiny-regulator.c index ee46bfbf5eee..f7df0f4b2f87 100644 --- a/drivers/regulator/rpi-panel-attiny-regulator.c +++ b/drivers/regulator/rpi-panel-attiny-regulator.c @@ -8,6 +8,7 @@ #include <linux/backlight.h> #include <linux/err.h> #include <linux/gpio.h> +#include <linux/gpio/driver.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/interrupt.h> @@ -21,63 +22,146 @@ /* I2C registers of the Atmel microcontroller. */ #define REG_ID 0x80 #define REG_PORTA 0x81 -#define REG_PORTA_HF BIT(2) -#define REG_PORTA_VF BIT(3) #define REG_PORTB 0x82 +#define REG_PORTC 0x83 #define REG_POWERON 0x85 #define REG_PWM 0x86 +#define REG_ADDR_L 0x8c +#define REG_ADDR_H 0x8d +#define REG_WRITE_DATA_H 0x90 +#define REG_WRITE_DATA_L 0x91 + +#define PA_LCD_DITHB BIT(0) +#define PA_LCD_MODE BIT(1) +#define PA_LCD_LR BIT(2) +#define PA_LCD_UD BIT(3) + +#define PB_BRIDGE_PWRDNX_N BIT(0) +#define PB_LCD_VCC_N BIT(1) +#define PB_LCD_MAIN BIT(7) + +#define PC_LED_EN BIT(0) +#define PC_RST_TP_N BIT(1) +#define PC_RST_LCD_N BIT(2) +#define PC_RST_BRIDGE_N BIT(3) + +enum gpio_signals { + RST_BRIDGE_N, /* TC358762 bridge reset */ + RST_TP_N, /* Touch controller reset */ + NUM_GPIO +}; + +struct gpio_signal_mappings { + unsigned int reg; + unsigned int mask; +}; + +static const struct gpio_signal_mappings mappings[NUM_GPIO] = { + [RST_BRIDGE_N] = { REG_PORTC, PC_RST_BRIDGE_N | PC_RST_LCD_N }, + [RST_TP_N] = { REG_PORTC, PC_RST_TP_N }, +}; + +struct attiny_lcd { + /* lock to serialise overall accesses to the Atmel */ + struct mutex lock; + struct regmap *regmap; + bool gpio_states[NUM_GPIO]; + u8 port_states[3]; + + struct gpio_chip gc; +}; static const struct regmap_config attiny_regmap_config = { .reg_bits = 8, .val_bits = 8, - .max_register = REG_PWM, - .cache_type = REGCACHE_NONE, + .disable_locking = 1, + .max_register = REG_WRITE_DATA_L, + .cache_type = REGCACHE_RBTREE, +}; + +static int attiny_set_port_state(struct attiny_lcd *state, int reg, u8 val) +{ + state->port_states[reg - REG_PORTA] = val; + return regmap_write(state->regmap, reg, val); +}; + +static u8 attiny_get_port_state(struct attiny_lcd *state, int reg) +{ + return state->port_states[reg - REG_PORTA]; }; static int attiny_lcd_power_enable(struct regulator_dev *rdev) { - unsigned int data; + struct attiny_lcd *state = rdev_get_drvdata(rdev); - regmap_write(rdev->regmap, REG_POWERON, 1); - /* Wait for nPWRDWN to go low to indicate poweron is done. */ - regmap_read_poll_timeout(rdev->regmap, REG_PORTB, data, - data & BIT(0), 10, 1000000); + mutex_lock(&state->lock); + + /* Ensure bridge, and tp stay in reset */ + attiny_set_port_state(state, REG_PORTC, 0); + usleep_range(5000, 10000); /* Default to the same orientation as the closed source * firmware used for the panel. Runtime rotation * configuration will be supported using VC4's plane * orientation bits. */ - regmap_write(rdev->regmap, REG_PORTA, BIT(2)); + attiny_set_port_state(state, REG_PORTA, PA_LCD_LR); + usleep_range(5000, 10000); + /* Main regulator on, and power to the panel (LCD_VCC_N) */ + attiny_set_port_state(state, REG_PORTB, PB_LCD_MAIN); + usleep_range(5000, 10000); + /* Bring controllers out of reset */ + attiny_set_port_state(state, REG_PORTC, PC_LED_EN); + + msleep(80); + + mutex_unlock(&state->lock); return 0; } static int attiny_lcd_power_disable(struct regulator_dev *rdev) { + struct attiny_lcd *state = rdev_get_drvdata(rdev); + + mutex_lock(&state->lock); + regmap_write(rdev->regmap, REG_PWM, 0); - regmap_write(rdev->regmap, REG_POWERON, 0); - udelay(1); + usleep_range(5000, 10000); + + attiny_set_port_state(state, REG_PORTA, 0); + usleep_range(5000, 10000); + attiny_set_port_state(state, REG_PORTB, PB_LCD_VCC_N); + usleep_range(5000, 10000); + attiny_set_port_state(state, REG_PORTC, 0); + msleep(30); + + mutex_unlock(&state->lock); + return 0; } static int attiny_lcd_power_is_enabled(struct regulator_dev *rdev) { + struct attiny_lcd *state = rdev_get_drvdata(rdev); unsigned int data; - int ret; + int ret, i; - ret = regmap_read(rdev->regmap, REG_POWERON, &data); - if (ret < 0) - return ret; + mutex_lock(&state->lock); - if (!(data & BIT(0))) - return 0; + for (i = 0; i < 10; i++) { + ret = regmap_read(rdev->regmap, REG_PORTC, &data); + if (!ret) + break; + usleep_range(10000, 12000); + } + + mutex_unlock(&state->lock); - ret = regmap_read(rdev->regmap, REG_PORTB, &data); if (ret < 0) return ret; - return data & BIT(0); + return data & PC_RST_BRIDGE_N; } static const struct regulator_init_data attiny_regulator_default = { @@ -101,33 +185,104 @@ static const struct regulator_desc attiny_regulator = { static int attiny_update_status(struct backlight_device *bl) { - struct regmap *regmap = bl_get_data(bl); + struct attiny_lcd *state = bl_get_data(bl); + struct regmap *regmap = state->regmap; int brightness = bl->props.brightness; + int ret, i; + + mutex_lock(&state->lock); if (bl->props.power != FB_BLANK_UNBLANK || bl->props.fb_blank != FB_BLANK_UNBLANK) brightness = 0; - return regmap_write(regmap, REG_PWM, brightness); -} - -static int attiny_get_brightness(struct backlight_device *bl) -{ - struct regmap *regmap = bl_get_data(bl); - int ret, brightness; + for (i = 0; i < 10; i++) { + ret = regmap_write(regmap, REG_PWM, brightness); + if (!ret) + break; + } - ret = regmap_read(regmap, REG_PWM, &brightness); - if (ret) - return ret; + mutex_unlock(&state->lock); - return brightness; + return ret; } static const struct backlight_ops attiny_bl = { .update_status = attiny_update_status, - .get_brightness = attiny_get_brightness, }; +static int attiny_gpio_get_direction(struct gpio_chip *gc, unsigned int off) +{ + return GPIO_LINE_DIRECTION_OUT; +} + +static void attiny_gpio_set(struct gpio_chip *gc, unsigned int off, int val) +{ + struct attiny_lcd *state = gpiochip_get_data(gc); + u8 last_val; + + if (off >= NUM_GPIO) + return; + + mutex_lock(&state->lock); + + last_val = attiny_get_port_state(state, mappings[off].reg); + if (val) + last_val |= mappings[off].mask; + else + last_val &= ~mappings[off].mask; + + attiny_set_port_state(state, mappings[off].reg, last_val); + + if (off == RST_BRIDGE_N && val) { + usleep_range(5000, 8000); + regmap_write(state->regmap, REG_ADDR_H, 0x04); + usleep_range(5000, 8000); + regmap_write(state->regmap, REG_ADDR_L, 0x7c); + usleep_range(5000, 8000); + regmap_write(state->regmap, REG_WRITE_DATA_H, 0x00); + usleep_range(5000, 8000); + regmap_write(state->regmap, REG_WRITE_DATA_L, 0x00); + + msleep(100); + } + + mutex_unlock(&state->lock); +} + +static int attiny_i2c_read(struct i2c_client *client, u8 reg, unsigned int *buf) +{ + struct i2c_msg msgs[1]; + u8 addr_buf[1] = { reg }; + u8 data_buf[1] = { 0, }; + int ret; + + /* Write register address */ + msgs[0].addr = client->addr; + msgs[0].flags = 0; + msgs[0].len = ARRAY_SIZE(addr_buf); + msgs[0].buf = addr_buf; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret != ARRAY_SIZE(msgs)) + return -EIO; + + usleep_range(5000, 10000); + + /* Read data from register */ + msgs[0].addr = client->addr; + msgs[0].flags = I2C_M_RD; + msgs[0].len = 1; + msgs[0].buf = data_buf; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret != ARRAY_SIZE(msgs)) + return -EIO; + + *buf = data_buf[0]; + return 0; +} + /* * I2C driver interface functions */ @@ -138,22 +293,30 @@ static int attiny_i2c_probe(struct i2c_client *i2c, struct regulator_config config = { }; struct backlight_device *bl; struct regulator_dev *rdev; + struct attiny_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); + i2c_set_clientdata(i2c, state); + regmap = devm_regmap_init_i2c(i2c, &attiny_regmap_config); if (IS_ERR(regmap)) { ret = PTR_ERR(regmap); dev_err(&i2c->dev, "Failed to allocate register map: %d\n", ret); - return ret; + goto error; } - ret = regmap_read(regmap, REG_ID, &data); + ret = attiny_i2c_read(i2c, REG_ID, &data); if (ret < 0) { dev_err(&i2c->dev, "Failed to read REG_ID reg: %d\n", ret); - return ret; + goto error; } switch (data) { @@ -162,34 +325,73 @@ static int attiny_i2c_probe(struct i2c_client *i2c, break; default: dev_err(&i2c->dev, "Unknown Atmel firmware revision: 0x%02x\n", data); - return -ENODEV; + ret = -ENODEV; + goto error; } regmap_write(regmap, REG_POWERON, 0); - mdelay(1); + msleep(30); + regmap_write(regmap, REG_PWM, 0); config.dev = &i2c->dev; config.regmap = regmap; config.of_node = i2c->dev.of_node; config.init_data = &attiny_regulator_default; + config.driver_data = state; rdev = devm_regulator_register(&i2c->dev, &attiny_regulator, &config); if (IS_ERR(rdev)) { dev_err(&i2c->dev, "Failed to register ATTINY regulator\n"); - return PTR_ERR(rdev); + ret = PTR_ERR(rdev); + goto error; } props.type = BACKLIGHT_RAW; props.max_brightness = 0xff; - bl = devm_backlight_device_register(&i2c->dev, - "7inch-touchscreen-panel-bl", - &i2c->dev, regmap, &attiny_bl, + + state->regmap = regmap; + + bl = devm_backlight_device_register(&i2c->dev, dev_name(&i2c->dev), + &i2c->dev, state, &attiny_bl, &props); - if (IS_ERR(bl)) - return PTR_ERR(bl); + if (IS_ERR(bl)) { + ret = PTR_ERR(bl); + goto error; + } bl->props.brightness = 0xff; + state->gc.parent = &i2c->dev; + state->gc.label = i2c->name; + state->gc.owner = THIS_MODULE; + state->gc.of_node = i2c->dev.of_node; + state->gc.base = -1; + state->gc.ngpio = NUM_GPIO; + + state->gc.set = attiny_gpio_set; + state->gc.get_direction = attiny_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; + } + + return 0; + +error: + mutex_destroy(&state->lock); + + return ret; +} + +static int attiny_i2c_remove(struct i2c_client *client) +{ + struct attiny_lcd *state = i2c_get_clientdata(client); + + mutex_destroy(&state->lock); + return 0; } @@ -205,6 +407,7 @@ static struct i2c_driver attiny_regulator_driver = { .of_match_table = of_match_ptr(attiny_dt_ids), }, .probe = attiny_i2c_probe, + .remove = attiny_i2c_remove, }; module_i2c_driver(attiny_regulator_driver); |