git.openwrt.org Git - openwrt/staging/neocturne.git/blob

   1 From 6486bb50b96f359844b9c34f0978c69bbdcda140 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Fri, 10 Sep 2021 13:50:28 +0100
   4 Subject: [PATCH] regulator: rpi-panel: Add GPIO control for panel and
   5  touch resets
   6
   7 We need independent control of the resets for the panel&bridge,
   8 vs the touch controller.
   9
  10 Expose the reset lines that are on the Atmel's port C via the GPIO
  11 API so that they can be controlled appropriately.
  12
  13 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  14 ---
  15  .../regulator/rpi-panel-attiny-regulator.c    | 115 +++++++++++++++---
  16  1 file changed, 97 insertions(+), 18 deletions(-)
  17
  18 --- a/drivers/regulator/rpi-panel-attiny-regulator.c
  19 +++ b/drivers/regulator/rpi-panel-attiny-regulator.c
  20 @@ -8,6 +8,7 @@
  21  #include <linux/backlight.h>
  22  #include <linux/err.h>
  23  #include <linux/gpio.h>
  24 +#include <linux/gpio/driver.h>
  25  #include <linux/i2c.h>
  26  #include <linux/init.h>
  27  #include <linux/interrupt.h>
  28 @@ -44,10 +45,30 @@
  29  #define PC_RST_LCD_N           BIT(2)
  30  #define PC_RST_BRIDGE_N                BIT(3)
  31
  32 +enum gpio_signals {
  33 +       RST_BRIDGE_N,   /* TC358762 bridge reset */
  34 +       RST_TP_N,       /* Touch controller reset */
  35 +       NUM_GPIO
  36 +};
  37 +
  38 +struct gpio_signal_mappings {
  39 +       unsigned int reg;
  40 +       unsigned int mask;
  41 +};
  42 +
  43 +static const struct gpio_signal_mappings mappings[NUM_GPIO] = {
  44 +       [RST_BRIDGE_N] = { REG_PORTC, PC_RST_BRIDGE_N | PC_RST_LCD_N  },
  45 +       [RST_TP_N] = { REG_PORTC, PC_RST_TP_N },
  46 +};
  47 +
  48  struct attiny_lcd {
  49         /* lock to serialise overall accesses to the Atmel */
  50         struct mutex    lock;
  51         struct regmap   *regmap;
  52 +       bool gpio_states[NUM_GPIO];
  53 +       u8 port_states[3];
  54 +
  55 +       struct gpio_chip gc;
  56  };
  57
  58  static const struct regmap_config attiny_regmap_config = {
  59 @@ -58,6 +79,17 @@ static const struct regmap_config attiny
  60         .cache_type = REGCACHE_NONE,
  61  };
  62
  63 +static int attiny_set_port_state(struct attiny_lcd *state, int reg, u8 val)
  64 +{
  65 +       state->port_states[reg - REG_PORTA] = val;
  66 +       return regmap_write(state->regmap, reg, val);
  67 +};
  68 +
  69 +static u8 attiny_get_port_state(struct attiny_lcd *state, int reg)
  70 +{
  71 +       return state->port_states[reg - REG_PORTA];
  72 +};
  73 +
  74  static int attiny_lcd_power_enable(struct regulator_dev *rdev)
  75  {
  76         struct attiny_lcd *state = rdev_get_drvdata(rdev);
  77 @@ -65,7 +97,7 @@ static int attiny_lcd_power_enable(struc
  78         mutex_lock(&state->lock);
  79
  80         /* Ensure bridge, and tp stay in reset */
  81 -       regmap_write(rdev->regmap, REG_PORTC, 0);
  82 +       attiny_set_port_state(state, REG_PORTC, 0);
  83         usleep_range(5000, 10000);
  84
  85         /* Default to the same orientation as the closed source
  86 @@ -73,26 +105,16 @@ static int attiny_lcd_power_enable(struc
  87          * configuration will be supported using VC4's plane
  88          * orientation bits.
  89          */
  90 -       regmap_write(rdev->regmap, REG_PORTA, PA_LCD_LR);
  91 +       attiny_set_port_state(state, REG_PORTA, PA_LCD_LR);
  92         usleep_range(5000, 10000);
  93 -       regmap_write(rdev->regmap, REG_PORTB, PB_LCD_MAIN);
  94 +       /* Main regulator on, and power to the panel (LCD_VCC_N) */
  95 +       attiny_set_port_state(state, REG_PORTB, PB_LCD_MAIN);
  96         usleep_range(5000, 10000);
  97         /* Bring controllers out of reset */
  98 -       regmap_write(rdev->regmap, REG_PORTC,
  99 -                    PC_LED_EN | PC_RST_BRIDGE_N | PC_RST_LCD_N | PC_RST_TP_N);
 100 +       attiny_set_port_state(state, REG_PORTC, PC_LED_EN);
 101
 102         msleep(80);
 103
 104 -       regmap_write(rdev->regmap, REG_ADDR_H, 0x04);
 105 -       usleep_range(5000, 8000);
 106 -       regmap_write(rdev->regmap, REG_ADDR_L, 0x7c);
 107 -       usleep_range(5000, 8000);
 108 -       regmap_write(rdev->regmap, REG_WRITE_DATA_H, 0x00);
 109 -       usleep_range(5000, 8000);
 110 -       regmap_write(rdev->regmap, REG_WRITE_DATA_L, 0x00);
 111 -
 112 -       msleep(100);
 113 -
 114         mutex_unlock(&state->lock);
 115
 116         return 0;
 117 @@ -106,11 +128,12 @@ static int attiny_lcd_power_disable(stru
 118
 119         regmap_write(rdev->regmap, REG_PWM, 0);
 120         usleep_range(5000, 10000);
 121 -       regmap_write(rdev->regmap, REG_PORTA, 0);
 122 +
 123 +       attiny_set_port_state(state, REG_PORTA, 0);
 124         usleep_range(5000, 10000);
 125 -       regmap_write(rdev->regmap, REG_PORTB, PB_LCD_VCC_N);
 126 +       attiny_set_port_state(state, REG_PORTB, PB_LCD_VCC_N);
 127         usleep_range(5000, 10000);
 128 -       regmap_write(rdev->regmap, REG_PORTC, 0);
 129 +       attiny_set_port_state(state, REG_PORTC, 0);
 130         msleep(30);
 131
 132         mutex_unlock(&state->lock);
 133 @@ -211,6 +234,45 @@ static const struct backlight_ops attiny
 134         .get_brightness = attiny_get_brightness,
 135  };
 136
 137 +static int attiny_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
 138 +{
 139 +       return GPIO_LINE_DIRECTION_OUT;
 140 +}
 141 +
 142 +static void attiny_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
 143 +{
 144 +       struct attiny_lcd *state = gpiochip_get_data(gc);
 145 +       u8 last_val;
 146 +
 147 +       if (off >= NUM_GPIO)
 148 +               return;
 149 +
 150 +       mutex_lock(&state->lock);
 151 +
 152 +       last_val = attiny_get_port_state(state, mappings[off].reg);
 153 +       if (val)
 154 +               last_val |= mappings[off].mask;
 155 +       else
 156 +               last_val &= ~mappings[off].mask;
 157 +
 158 +       attiny_set_port_state(state, mappings[off].reg, last_val);
 159 +
 160 +       if (off == RST_BRIDGE_N && val) {
 161 +               usleep_range(5000, 8000);
 162 +               regmap_write(state->regmap, REG_ADDR_H, 0x04);
 163 +               usleep_range(5000, 8000);
 164 +               regmap_write(state->regmap, REG_ADDR_L, 0x7c);
 165 +               usleep_range(5000, 8000);
 166 +               regmap_write(state->regmap, REG_WRITE_DATA_H, 0x00);
 167 +               usleep_range(5000, 8000);
 168 +               regmap_write(state->regmap, REG_WRITE_DATA_L, 0x00);
 169 +
 170 +               msleep(100);
 171 +       }
 172 +
 173 +       mutex_unlock(&state->lock);
 174 +}
 175 +
 176  /*
 177   * I2C driver interface functions
 178   */
 179 @@ -289,6 +351,23 @@ static int attiny_i2c_probe(struct i2c_c
 180
 181         bl->props.brightness = 0xff;
 182
 183 +       state->gc.parent = &i2c->dev;
 184 +       state->gc.label = i2c->name;
 185 +       state->gc.owner = THIS_MODULE;
 186 +       state->gc.of_node = i2c->dev.of_node;
 187 +       state->gc.base = -1;
 188 +       state->gc.ngpio = NUM_GPIO;
 189 +
 190 +       state->gc.set = attiny_gpio_set;
 191 +       state->gc.get_direction = attiny_gpio_get_direction;
 192 +       state->gc.can_sleep = true;
 193 +
 194 +       ret = devm_gpiochip_add_data(&i2c->dev, &state->gc, state);
 195 +       if (ret) {
 196 +               dev_err(&i2c->dev, "Failed to create gpiochip: %d\n", ret);
 197 +               goto error;
 198 +       }
 199 +
 200         return 0;
 201
 202  error: