meta-agl-bsp/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi/dsi/0004-drm-panel-Backport-4.15-support-for-the-Raspberry-Pi.patch

   1 From 7f745c7e13b50911424b9bbb4181d4dc72ef155f Mon Sep 17 00:00:00 2001
   2 From: Kevin Quigley <kevin@kquigley.co.uk>
   3 Date: Mon, 24 Sep 2018 12:14:41 +0000
   4 Subject: [PATCH 4/4] drm/panel: Backport 4.15 support for the Raspberry Pi 7"
   5  Touchscreen
   6
   7 ---
   8  .../drm/panel/panel-raspberrypi-touchscreen.c | 242 ++++++++----------
   9  1 file changed, 111 insertions(+), 131 deletions(-)
  10
  11 diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
  12 index 128523d8d518..2c9c9722734f 100644
  13 --- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
  14 +++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
  15 @@ -1,5 +1,5 @@
  16  /*
  17 - * Copyright © 2016 Broadcom
  18 + * Copyright © 2016-2017 Broadcom
  19   *
  20   * This program is free software; you can redistribute it and/or modify
  21   * it under the terms of the GNU General Public License version 2 as
  22 @@ -30,14 +30,15 @@
  23   */
  24
  25  /**
  26 - * DOC: Raspberry Pi 7" touchscreen panel driver.
  27 + * Raspberry Pi 7" touchscreen panel driver.
  28   *
  29   * The 7" touchscreen consists of a DPI LCD panel, a Toshiba
  30   * TC358762XBG DSI-DPI bridge, and an I2C-connected Atmel ATTINY88-MUR
  31 - * controlling power management, the LCD PWM, and the touchscreen.
  32 + * controlling power management, the LCD PWM, and initial register
  33 + * setup of the Tohsiba.
  34   *
  35 - * This driver presents this device as a MIPI DSI panel to the DRM
  36 - * driver, and should expose the touchscreen as a HID device.
  37 + * This driver controls the TC358762 and ATTINY88, presenting a DSI
  38 + * device with a drm_panel.
  39   */
  40
  41  #include <linux/delay.h>
  42 @@ -58,10 +59,12 @@
  43  #include <drm/drm_mipi_dsi.h>
  44  #include <drm/drm_panel.h>
  45
  46 +#define RPI_DSI_DRIVER_NAME "rpi-ts-dsi"
  47 +
  48  /* I2C registers of the Atmel microcontroller. */
  49  enum REG_ADDR {
  50         REG_ID = 0x80,
  51 -       REG_PORTA, // BIT(2) for horizontal flip, BIT(3) for vertical flip
  52 +       REG_PORTA, /* BIT(2) for horizontal flip, BIT(3) for vertical flip */
  53         REG_PORTB,
  54         REG_PORTC,
  55         REG_PORTD,
  56 @@ -81,9 +84,6 @@ enum REG_ADDR {
  57         REG_ID2,
  58  };
  59
  60 -/* We only turn the PWM on or off, without varying values. */
  61 -#define RPI_TOUCHSCREEN_MAX_BRIGHTNESS 1
  62 -
  63  /* DSI D-PHY Layer Registers */
  64  #define D0W_DPHYCONTTX         0x0004
  65  #define CLW_DPHYCONTRX         0x0020
  66 @@ -100,8 +100,6 @@ enum REG_ADDR {
  67  #define PPI_BUSYPPI            0x0108
  68  #define PPI_LINEINITCNT                0x0110
  69  #define PPI_LPTXTIMECNT                0x0114
  70 -//#define PPI_LANEENABLE               0x0134
  71 -//#define PPI_TX_RX_TA         0x013C
  72  #define PPI_CLS_ATMR           0x0140
  73  #define PPI_D0S_ATMR           0x0144
  74  #define PPI_D1S_ATMR           0x0148
  75 @@ -197,43 +195,23 @@ enum REG_ADDR {
  76  struct rpi_touchscreen {
  77         struct drm_panel base;
  78         struct mipi_dsi_device *dsi;
  79 -       struct i2c_client *bridge_i2c;
  80 -
  81 -       /* Version of the firmware on the bridge chip */
  82 -       int atmel_ver;
  83 +       struct i2c_client *i2c;
  84  };
  85
  86  static const struct drm_display_mode rpi_touchscreen_modes[] = {
  87         {
  88 -               /* The DSI PLL can only integer divide from the 2Ghz
  89 -                * PLLD, giving us few choices.  We pick a divide by 3
  90 -                * as our DSI HS clock, giving us a pixel clock of
  91 -                * that divided by 24 bits.  Pad out HFP to get our
  92 -                * panel to refresh at 60Hz, even if that doesn't
  93 -                * match the datasheet.
  94 -                */
  95 -#define PIXEL_CLOCK ((2000000000 / 3) / 24)
  96 -#define VREFRESH    60
  97 -#define VTOTAL      (480 + 7 + 2 + 21)
  98 -#define HACT        800
  99 -#define HSW         2
 100 -#define HBP         46
 101 -#define HFP         ((PIXEL_CLOCK / (VTOTAL * VREFRESH)) - (HACT + HSW + HBP))
 102 -
 103 -               /* Round up the pixel clock a bit (10khz), so that the
 104 -                * "don't run things faster than the requested clock
 105 -                * rate" rule of the clk driver doesn't reject the
 106 -                * divide-by-3 mode due to rounding error.
 107 +               /* Modeline comes from the Raspberry Pi firmware, with HFP=1
 108 +                * plugged in and clock re-computed from that.
 109                  */
 110 -               .clock = PIXEL_CLOCK / 1000 + 10,
 111 -               .hdisplay = HACT,
 112 -               .hsync_start = HACT + HFP,
 113 -               .hsync_end = HACT + HFP + HSW,
 114 -               .htotal = HACT + HFP + HSW + HBP,
 115 +               .clock = 25979400 / 1000,
 116 +               .hdisplay = 800,
 117 +               .hsync_start = 800 + 1,
 118 +               .hsync_end = 800 + 1 + 2,
 119 +               .htotal = 800 + 1 + 2 + 46,
 120                 .vdisplay = 480,
 121                 .vsync_start = 480 + 7,
 122                 .vsync_end = 480 + 7 + 2,
 123 -               .vtotal = VTOTAL,
 124 +               .vtotal = 480 + 7 + 2 + 21,
 125                 .vrefresh = 60,
 126         },
 127  };
 128 @@ -245,7 +223,7 @@ static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
 129
 130  static int rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
 131  {
 132 -       return i2c_smbus_read_byte_data(ts->bridge_i2c, reg);
 133 +       return i2c_smbus_read_byte_data(ts->i2c, reg);
 134  }
 135
 136  static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
 137 @@ -253,19 +231,13 @@ static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
 138  {
 139         int ret;
 140
 141 -       ret = i2c_smbus_write_byte_data(ts->bridge_i2c, reg, val);
 142 +       ret = i2c_smbus_write_byte_data(ts->i2c, reg, val);
 143         if (ret)
 144                 dev_err(&ts->dsi->dev, "I2C write failed: %d\n", ret);
 145  }
 146
 147  static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
 148  {
 149 -#if 0
 150 -       /* The firmware uses LP DSI transactions like this to bring up
 151 -        * the hardware, which should be faster than using I2C to then
 152 -        * pass to the Toshiba.  However, I was unable to get it to
 153 -        * work.
 154 -        */
 155         u8 msg[] = {
 156                 reg,
 157                 reg >> 8,
 158 @@ -275,13 +247,7 @@ static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
 159                 val >> 24,
 160         };
 161
 162 -       mipi_dsi_dcs_write_buffer(ts->dsi, msg, sizeof(msg));
 163 -#else
 164 -       rpi_touchscreen_i2c_write(ts, REG_WR_ADDRH, reg >> 8);
 165 -       rpi_touchscreen_i2c_write(ts, REG_WR_ADDRL, reg);
 166 -       rpi_touchscreen_i2c_write(ts, REG_WRITEH, val >> 8);
 167 -       rpi_touchscreen_i2c_write(ts, REG_WRITEL, val);
 168 -#endif
 169 +       mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));
 170
 171         return 0;
 172  }
 173 @@ -317,8 +283,7 @@ static int rpi_touchscreen_enable(struct drm_panel *panel)
 174
 175         rpi_touchscreen_write(ts, DSI_LANEENABLE,
 176                               DSI_LANEENABLE_CLOCK |
 177 -                             DSI_LANEENABLE_D0 |
 178 -                             (ts->dsi->lanes > 1 ? DSI_LANEENABLE_D1 : 0));
 179 +                             DSI_LANEENABLE_D0);
 180         rpi_touchscreen_write(ts, PPI_D0S_CLRSIPOCOUNT, 0x05);
 181         rpi_touchscreen_write(ts, PPI_D1S_CLRSIPOCOUNT, 0x05);
 182         rpi_touchscreen_write(ts, PPI_D0S_ATMR, 0x00);
 183 @@ -352,6 +317,7 @@ static int rpi_touchscreen_get_modes(struct drm_panel *panel)
 184         struct drm_connector *connector = panel->connector;
 185         struct drm_device *drm = panel->drm;
 186         unsigned int i, num = 0;
 187 +       static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 188
 189         for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
 190                 const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
 191 @@ -378,6 +344,8 @@ static int rpi_touchscreen_get_modes(struct drm_panel *panel)
 192         connector->display_info.bpc = 8;
 193         connector->display_info.width_mm = 154;
 194         connector->display_info.height_mm = 86;
 195 +       drm_display_info_set_bus_formats(&connector->display_info,
 196 +                                        &bus_format, 1);
 197
 198         return num;
 199  }
 200 @@ -390,51 +358,27 @@ static const struct drm_panel_funcs rpi_touchscreen_funcs = {
 201         .get_modes = rpi_touchscreen_get_modes,
 202  };
 203
 204 -static struct i2c_client *rpi_touchscreen_get_i2c(struct device *dev,
 205 -                                                 const char *name)
 206 -{
 207 -       struct device_node *node;
 208 -       struct i2c_client *client;
 209 -
 210 -       node = of_parse_phandle(dev->of_node, name, 0);
 211 -       if (!node)
 212 -               return ERR_PTR(-ENODEV);
 213 -
 214 -       client = of_find_i2c_device_by_node(node);
 215 -
 216 -       of_node_put(node);
 217 -
 218 -       if (!client)
 219 -               return ERR_PTR(-EPROBE_DEFER);
 220 -
 221 -       return client;
 222 -}
 223 -
 224 -static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 225 +static int rpi_touchscreen_probe(struct i2c_client *i2c,
 226 +                                const struct i2c_device_id *id)
 227  {
 228 -       struct device *dev = &dsi->dev;
 229 +       struct device *dev = &i2c->dev;
 230         struct rpi_touchscreen *ts;
 231 +       struct device_node *endpoint, *dsi_host_node;
 232 +       struct mipi_dsi_host *host;
 233         int ret, ver;
 234 +       struct mipi_dsi_device_info info = {
 235 +               .type = RPI_DSI_DRIVER_NAME,
 236 +               .channel = 0,
 237 +               .node = NULL,
 238 +       };
 239
 240         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 241         if (!ts)
 242                 return -ENOMEM;
 243
 244 -       dev_set_drvdata(dev, ts);
 245 +       i2c_set_clientdata(i2c, ts);
 246
 247 -       ts->dsi = dsi;
 248 -       dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
 249 -                          MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
 250 -                          MIPI_DSI_MODE_LPM);
 251 -       dsi->format = MIPI_DSI_FMT_RGB888;
 252 -       dsi->lanes = 1;
 253 -
 254 -       ts->bridge_i2c =
 255 -               rpi_touchscreen_get_i2c(dev, "raspberrypi,touchscreen-bridge");
 256 -       if (IS_ERR(ts->bridge_i2c)) {
 257 -               ret = -EPROBE_DEFER;
 258 -               return ret;
 259 -       }
 260 +       ts->i2c = i2c;
 261
 262         ver = rpi_touchscreen_i2c_read(ts, REG_ID);
 263         if (ver < 0) {
 264 @@ -443,11 +387,8 @@ static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 265         }
 266
 267         switch (ver) {
 268 -       case 0xde:
 269 -               ts->atmel_ver = 1;
 270 -               break;
 271 -       case 0xc3:
 272 -               ts->atmel_ver = 2;
 273 +       case 0xde: /* ver 1 */
 274 +       case 0xc3: /* ver 2 */
 275                 break;
 276         default:
 277                 dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
 278 @@ -457,65 +398,104 @@ static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 279         /* Turn off at boot, so we can cleanly sequence powering on. */
 280         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 281
 282 -       drm_panel_init(&ts->base);
 283 +       /* Look up the DSI host.  It needs to probe before we do. */
 284 +       endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
 285 +       dsi_host_node = of_graph_get_remote_port_parent(endpoint);
 286 +       host = of_find_mipi_dsi_host_by_node(dsi_host_node);
 287 +       of_node_put(dsi_host_node);
 288 +       if (!host) {
 289 +               of_node_put(endpoint);
 290 +               return -EPROBE_DEFER;
 291 +       }
 292 +
 293 +       info.node = of_graph_get_remote_port(endpoint);
 294 +       of_node_put(endpoint);
 295 +
 296 +       ts->dsi = mipi_dsi_device_register_full(host, &info);
 297 +       if (IS_ERR(ts->dsi)) {
 298 +               dev_err(dev, "DSI device registration failed: %ld\n",
 299 +                       PTR_ERR(ts->dsi));
 300 +               return PTR_ERR(ts->dsi);
 301 +       }
 302 +
 303         ts->base.dev = dev;
 304         ts->base.funcs = &rpi_touchscreen_funcs;
 305
 306 +       /* This appears last, as it's what will unblock the DSI host
 307 +        * driver's component bind function.
 308 +        */
 309         ret = drm_panel_add(&ts->base);
 310 -       if (ret < 0)
 311 -               goto err_release_bridge;
 312 -
 313 -       return mipi_dsi_attach(dsi);
 314 +       if (ret)
 315 +               return ret;
 316
 317 -err_release_bridge:
 318 -       put_device(&ts->bridge_i2c->dev);
 319 -       return ret;
 320 +       return 0;
 321  }
 322
 323 -static int rpi_touchscreen_dsi_remove(struct mipi_dsi_device *dsi)
 324 +static int rpi_touchscreen_remove(struct i2c_client *i2c)
 325  {
 326 -       struct device *dev = &dsi->dev;
 327 -       struct rpi_touchscreen *ts = dev_get_drvdata(dev);
 328 -       int ret;
 329 +       struct rpi_touchscreen *ts = i2c_get_clientdata(i2c);
 330
 331 -       ret = mipi_dsi_detach(dsi);
 332 -       if (ret < 0) {
 333 -               dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", ret);
 334 -               return ret;
 335 -       }
 336 +       mipi_dsi_detach(ts->dsi);
 337
 338 -       drm_panel_detach(&ts->base);
 339         drm_panel_remove(&ts->base);
 340
 341 -       put_device(&ts->bridge_i2c->dev);
 342 +       mipi_dsi_device_unregister(ts->dsi);
 343 +       kfree(ts->dsi);
 344
 345         return 0;
 346  }
 347
 348 -static void rpi_touchscreen_dsi_shutdown(struct mipi_dsi_device *dsi)
 349 +static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 350  {
 351 -       struct device *dev = &dsi->dev;
 352 -       struct rpi_touchscreen *ts = dev_get_drvdata(dev);
 353 +       int ret;
 354
 355 -       rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 356 +       dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
 357 +                          MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
 358 +                          MIPI_DSI_MODE_LPM);
 359 +       dsi->format = MIPI_DSI_FMT_RGB888;
 360 +       dsi->lanes = 1;
 361 +
 362 +       ret = mipi_dsi_attach(dsi);
 363 +
 364 +       if (ret)
 365 +               dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);
 366 +
 367 +       return ret;
 368  }
 369
 370 -static const struct of_device_id rpi_touchscreen_of_match[] = {
 371 -       { .compatible = "raspberrypi,touchscreen" },
 372 +static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
 373 +       .driver.name = RPI_DSI_DRIVER_NAME,
 374 +       .probe = rpi_touchscreen_dsi_probe,
 375 +};
 376 +
 377 +static const struct of_device_id rpi_touchscreen_of_ids[] = {
 378 +       { .compatible = "raspberrypi,7inch-touchscreen-panel" },
 379         { } /* sentinel */
 380  };
 381 -MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_match);
 382 +MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);
 383
 384 -static struct mipi_dsi_driver rpi_touchscreen_driver = {
 385 +static struct i2c_driver rpi_touchscreen_driver = {
 386         .driver = {
 387 -               .name = "raspberrypi-touchscreen",
 388 -               .of_match_table = rpi_touchscreen_of_match,
 389 +               .name = "rpi_touchscreen",
 390 +               .of_match_table = rpi_touchscreen_of_ids,
 391         },
 392 -       .probe = rpi_touchscreen_dsi_probe,
 393 -       .remove = rpi_touchscreen_dsi_remove,
 394 -       .shutdown = rpi_touchscreen_dsi_shutdown,
 395 +       .probe = rpi_touchscreen_probe,
 396 +       .remove = rpi_touchscreen_remove,
 397  };
 398 -module_mipi_dsi_driver(rpi_touchscreen_driver);
 399 +
 400 +static int __init rpi_touchscreen_init(void)
 401 +{
 402 +       mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
 403 +       return i2c_add_driver(&rpi_touchscreen_driver);
 404 +}
 405 +module_init(rpi_touchscreen_init);
 406 +
 407 +static void __exit rpi_touchscreen_exit(void)
 408 +{
 409 +       i2c_del_driver(&rpi_touchscreen_driver);
 410 +       mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
 411 +}
 412 +module_exit(rpi_touchscreen_exit);
 413
 414  MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 415  MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
 416 --
 417 2.21.0
 418