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

   1 From 3cf717e1b077749001602a141dcdc2151e8307e1 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Thu, 9 Sep 2021 18:24:57 +0100
   4 Subject: [PATCH] regulator: rpi-panel: Convert to drive lines directly
   5
   6 The Atmel was doing a load of automatic sequencing of
   7 control lines, however it was combining the touch controller's
   8 reset with the bridge/panel control.
   9
  10 Change to control the control signals directly rather than
  11 through the automatic POWERON control.
  12
  13 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  14 ---
  15  .../regulator/rpi-panel-attiny-regulator.c    | 111 ++++++++++--------
  16  1 file changed, 60 insertions(+), 51 deletions(-)
  17
  18 --- a/drivers/regulator/rpi-panel-attiny-regulator.c
  19 +++ b/drivers/regulator/rpi-panel-attiny-regulator.c
  20 @@ -21,11 +21,28 @@
  21  /* I2C registers of the Atmel microcontroller. */
  22  #define REG_ID         0x80
  23  #define REG_PORTA      0x81
  24 -#define REG_PORTA_HF   BIT(2)
  25 -#define REG_PORTA_VF   BIT(3)
  26  #define REG_PORTB      0x82
  27 +#define REG_PORTC      0x83
  28  #define REG_POWERON    0x85
  29  #define REG_PWM                0x86
  30 +#define REG_ADDR_L     0x8c
  31 +#define REG_ADDR_H     0x8d
  32 +#define REG_WRITE_DATA_H       0x90
  33 +#define REG_WRITE_DATA_L       0x91
  34 +
  35 +#define PA_LCD_DITHB           BIT(0)
  36 +#define PA_LCD_MODE            BIT(1)
  37 +#define PA_LCD_LR              BIT(2)
  38 +#define PA_LCD_UD              BIT(3)
  39 +
  40 +#define PB_BRIDGE_PWRDNX_N     BIT(0)
  41 +#define PB_LCD_VCC_N           BIT(1)
  42 +#define PB_LCD_MAIN            BIT(7)
  43 +
  44 +#define PC_LED_EN              BIT(0)
  45 +#define PC_RST_TP_N            BIT(1)
  46 +#define PC_RST_LCD_N           BIT(2)
  47 +#define PC_RST_BRIDGE_N                BIT(3)
  48
  49  struct attiny_lcd {
  50         /* lock to serialise overall accesses to the Atmel */
  51 @@ -37,99 +54,91 @@ static const struct regmap_config attiny
  52         .reg_bits = 8,
  53         .val_bits = 8,
  54         .disable_locking = 1,
  55 -       .max_register = REG_PWM,
  56 +       .max_register = REG_WRITE_DATA_L,
  57         .cache_type = REGCACHE_NONE,
  58  };
  59
  60  static int attiny_lcd_power_enable(struct regulator_dev *rdev)
  61  {
  62 -       struct mutex *lock = rdev_get_drvdata(rdev);
  63 -       unsigned int data;
  64 -       int ret, i;
  65 +       struct attiny_lcd *state = rdev_get_drvdata(rdev);
  66
  67 -       mutex_lock(lock);
  68 -
  69 -       regmap_write(rdev->regmap, REG_POWERON, 1);
  70 -       msleep(80);
  71 +       mutex_lock(&state->lock);
  72
  73 -       /* Wait for nPWRDWN to go low to indicate poweron is done. */
  74 -       for (i = 0; i < 20; i++) {
  75 -               ret = regmap_read(rdev->regmap, REG_PORTB, &data);
  76 -               if (!ret) {
  77 -                       if (data & BIT(0))
  78 -                               break;
  79 -               }
  80 -               usleep_range(10000, 12000);
  81 -       }
  82 -       usleep_range(10000, 12000);
  83 -
  84 -       if (ret)
  85 -               pr_err("%s: regmap_read_poll_timeout failed %d\n", __func__, ret);
  86 +       /* Ensure bridge, and tp stay in reset */
  87 +       regmap_write(rdev->regmap, REG_PORTC, 0);
  88 +       usleep_range(5000, 10000);
  89
  90         /* Default to the same orientation as the closed source
  91          * firmware used for the panel.  Runtime rotation
  92          * configuration will be supported using VC4's plane
  93          * orientation bits.
  94          */
  95 -       regmap_write(rdev->regmap, REG_PORTA, BIT(2));
  96 +       regmap_write(rdev->regmap, REG_PORTA, PA_LCD_LR);
  97 +       usleep_range(5000, 10000);
  98 +       regmap_write(rdev->regmap, REG_PORTB, PB_LCD_MAIN);
  99 +       usleep_range(5000, 10000);
 100 +       /* Bring controllers out of reset */
 101 +       regmap_write(rdev->regmap, REG_PORTC,
 102 +                    PC_LED_EN | PC_RST_BRIDGE_N | PC_RST_LCD_N | PC_RST_TP_N);
 103 +
 104 +       msleep(80);
 105 +
 106 +       regmap_write(rdev->regmap, REG_ADDR_H, 0x04);
 107 +       usleep_range(5000, 8000);
 108 +       regmap_write(rdev->regmap, REG_ADDR_L, 0x7c);
 109 +       usleep_range(5000, 8000);
 110 +       regmap_write(rdev->regmap, REG_WRITE_DATA_H, 0x00);
 111 +       usleep_range(5000, 8000);
 112 +       regmap_write(rdev->regmap, REG_WRITE_DATA_L, 0x00);
 113
 114 -       mutex_unlock(lock);
 115 +       msleep(100);
 116 +
 117 +       mutex_unlock(&state->lock);
 118
 119         return 0;
 120  }
 121
 122  static int attiny_lcd_power_disable(struct regulator_dev *rdev)
 123  {
 124 -       struct mutex *lock = rdev_get_drvdata(rdev);
 125 +       struct attiny_lcd *state = rdev_get_drvdata(rdev);
 126
 127 -       mutex_lock(lock);
 128 +       mutex_lock(&state->lock);
 129
 130         regmap_write(rdev->regmap, REG_PWM, 0);
 131 -       regmap_write(rdev->regmap, REG_POWERON, 0);
 132 +       usleep_range(5000, 10000);
 133 +       regmap_write(rdev->regmap, REG_PORTA, 0);
 134 +       usleep_range(5000, 10000);
 135 +       regmap_write(rdev->regmap, REG_PORTB, PB_LCD_VCC_N);
 136 +       usleep_range(5000, 10000);
 137 +       regmap_write(rdev->regmap, REG_PORTC, 0);
 138         msleep(30);
 139
 140 -       mutex_unlock(lock);
 141 +       mutex_unlock(&state->lock);
 142
 143         return 0;
 144  }
 145
 146  static int attiny_lcd_power_is_enabled(struct regulator_dev *rdev)
 147  {
 148 -       struct mutex *lock = rdev_get_drvdata(rdev);
 149 +       struct attiny_lcd *state = rdev_get_drvdata(rdev);
 150         unsigned int data;
 151         int ret, i;
 152
 153 -       mutex_lock(lock);
 154 -
 155 -       for (i = 0; i < 10; i++) {
 156 -               ret = regmap_read(rdev->regmap, REG_POWERON, &data);
 157 -               if (!ret)
 158 -                       break;
 159 -               usleep_range(10000, 12000);
 160 -       }
 161 -       if (ret < 0) {
 162 -               mutex_unlock(lock);
 163 -               return ret;
 164 -       }
 165 -
 166 -       if (!(data & BIT(0))) {
 167 -               mutex_unlock(lock);
 168 -               return 0;
 169 -       }
 170 +       mutex_lock(&state->lock);
 171
 172         for (i = 0; i < 10; i++) {
 173 -               ret = regmap_read(rdev->regmap, REG_PORTB, &data);
 174 +               ret = regmap_read(rdev->regmap, REG_PORTC, &data);
 175                 if (!ret)
 176                         break;
 177                 usleep_range(10000, 12000);
 178         }
 179
 180 -       mutex_unlock(lock);
 181 +       mutex_unlock(&state->lock);
 182
 183         if (ret < 0)
 184                 return ret;
 185
 186 -       return data & BIT(0);
 187 +       return data & PC_RST_BRIDGE_N;
 188  }
 189
 190  static const struct regulator_init_data attiny_regulator_default = {
 191 @@ -256,7 +265,7 @@ static int attiny_i2c_probe(struct i2c_c
 192         config.regmap = regmap;
 193         config.of_node = i2c->dev.of_node;
 194         config.init_data = &attiny_regulator_default;
 195 -       config.driver_data = &state->lock;
 196 +       config.driver_data = state;
 197
 198         rdev = devm_regulator_register(&i2c->dev, &attiny_regulator, &config);
 199         if (IS_ERR(rdev)) {