drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c

   1 /*
   2  * Copyright © 2016-2017 Broadcom
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * Portions of this file (derived from panel-simple.c) are:
   9  *
  10  * Copyright (C) 2013, NVIDIA Corporation.  All rights reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sub license,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice (including the
  20  * next paragraph) shall be included in all copies or substantial portions
  21  * of the Software.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  24  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  25  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  26  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  27  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  28  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  29  * DEALINGS IN THE SOFTWARE.
  30  */
  31
  32 /**
  33  * Raspberry Pi 7" touchscreen panel driver.
  34  *
  35  * The 7" touchscreen consists of a DPI LCD panel, a Toshiba
  36  * TC358762XBG DSI-DPI bridge, and an I2C-connected Atmel ATTINY88-MUR
  37  * controlling power management, the LCD PWM, and initial register
  38  * setup of the Tohsiba.
  39  *
  40  * This driver controls the TC358762 and ATTINY88, presenting a DSI
  41  * device with a drm_panel.
  42  */
  43
  44 #include <linux/delay.h>
  45 #include <linux/err.h>
  46 #include <linux/fb.h>
  47 #include <linux/i2c.h>
  48 #include <linux/module.h>
  49 #include <linux/of.h>
  50 #include <linux/of_device.h>
  51 #include <linux/of_graph.h>
  52 #include <linux/pm.h>
  53
  54 #include <drm/drm_crtc.h>
  55 #include <drm/drm_device.h>
  56 #include <drm/drm_mipi_dsi.h>
  57 #include <drm/drm_panel.h>
  58
  59 #define RPI_DSI_DRIVER_NAME "rpi-ts-dsi"
  60
  61 /* I2C registers of the Atmel microcontroller. */
  62 enum REG_ADDR {
  63         REG_ID = 0x80,
  64         REG_PORTA, /* BIT(2) for horizontal flip, BIT(3) for vertical flip */
  65         REG_PORTB,
  66         REG_PORTC,
  67         REG_PORTD,
  68         REG_POWERON,
  69         REG_PWM,
  70         REG_DDRA,
  71         REG_DDRB,
  72         REG_DDRC,
  73         REG_DDRD,
  74         REG_TEST,
  75         REG_WR_ADDRL,
  76         REG_WR_ADDRH,
  77         REG_READH,
  78         REG_READL,
  79         REG_WRITEH,
  80         REG_WRITEL,
  81         REG_ID2,
  82 };
  83
  84 /* DSI D-PHY Layer Registers */
  85 #define D0W_DPHYCONTTX          0x0004
  86 #define CLW_DPHYCONTRX          0x0020
  87 #define D0W_DPHYCONTRX          0x0024
  88 #define D1W_DPHYCONTRX          0x0028
  89 #define COM_DPHYCONTRX          0x0038
  90 #define CLW_CNTRL               0x0040
  91 #define D0W_CNTRL               0x0044
  92 #define D1W_CNTRL               0x0048
  93 #define DFTMODE_CNTRL           0x0054
  94
  95 /* DSI PPI Layer Registers */
  96 #define PPI_STARTPPI            0x0104
  97 #define PPI_BUSYPPI             0x0108
  98 #define PPI_LINEINITCNT         0x0110
  99 #define PPI_LPTXTIMECNT         0x0114
 100 #define PPI_CLS_ATMR            0x0140
 101 #define PPI_D0S_ATMR            0x0144
 102 #define PPI_D1S_ATMR            0x0148
 103 #define PPI_D0S_CLRSIPOCOUNT    0x0164
 104 #define PPI_D1S_CLRSIPOCOUNT    0x0168
 105 #define CLS_PRE                 0x0180
 106 #define D0S_PRE                 0x0184
 107 #define D1S_PRE                 0x0188
 108 #define CLS_PREP                0x01A0
 109 #define D0S_PREP                0x01A4
 110 #define D1S_PREP                0x01A8
 111 #define CLS_ZERO                0x01C0
 112 #define D0S_ZERO                0x01C4
 113 #define D1S_ZERO                0x01C8
 114 #define PPI_CLRFLG              0x01E0
 115 #define PPI_CLRSIPO             0x01E4
 116 #define HSTIMEOUT               0x01F0
 117 #define HSTIMEOUTENABLE         0x01F4
 118
 119 /* DSI Protocol Layer Registers */
 120 #define DSI_STARTDSI            0x0204
 121 #define DSI_BUSYDSI             0x0208
 122 #define DSI_LANEENABLE          0x0210
 123 # define DSI_LANEENABLE_CLOCK           BIT(0)
 124 # define DSI_LANEENABLE_D0              BIT(1)
 125 # define DSI_LANEENABLE_D1              BIT(2)
 126
 127 #define DSI_LANESTATUS0         0x0214
 128 #define DSI_LANESTATUS1         0x0218
 129 #define DSI_INTSTATUS           0x0220
 130 #define DSI_INTMASK             0x0224
 131 #define DSI_INTCLR              0x0228
 132 #define DSI_LPTXTO              0x0230
 133 #define DSI_MODE                0x0260
 134 #define DSI_PAYLOAD0            0x0268
 135 #define DSI_PAYLOAD1            0x026C
 136 #define DSI_SHORTPKTDAT         0x0270
 137 #define DSI_SHORTPKTREQ         0x0274
 138 #define DSI_BTASTA              0x0278
 139 #define DSI_BTACLR              0x027C
 140
 141 /* DSI General Registers */
 142 #define DSIERRCNT               0x0300
 143 #define DSISIGMOD               0x0304
 144
 145 /* DSI Application Layer Registers */
 146 #define APLCTRL                 0x0400
 147 #define APLSTAT                 0x0404
 148 #define APLERR                  0x0408
 149 #define PWRMOD                  0x040C
 150 #define RDPKTLN                 0x0410
 151 #define PXLFMT                  0x0414
 152 #define MEMWRCMD                0x0418
 153
 154 /* LCDC/DPI Host Registers */
 155 #define LCDCTRL                 0x0420
 156 #define HSR                     0x0424
 157 #define HDISPR                  0x0428
 158 #define VSR                     0x042C
 159 #define VDISPR                  0x0430
 160 #define VFUEN                   0x0434
 161
 162 /* DBI-B Host Registers */
 163 #define DBIBCTRL                0x0440
 164
 165 /* SPI Master Registers */
 166 #define SPICMR                  0x0450
 167 #define SPITCR                  0x0454
 168
 169 /* System Controller Registers */
 170 #define SYSSTAT                 0x0460
 171 #define SYSCTRL                 0x0464
 172 #define SYSPLL1                 0x0468
 173 #define SYSPLL2                 0x046C
 174 #define SYSPLL3                 0x0470
 175 #define SYSPMCTRL               0x047C
 176
 177 /* GPIO Registers */
 178 #define GPIOC                   0x0480
 179 #define GPIOO                   0x0484
 180 #define GPIOI                   0x0488
 181
 182 /* I2C Registers */
 183 #define I2CCLKCTRL              0x0490
 184
 185 /* Chip/Rev Registers */
 186 #define IDREG                   0x04A0
 187
 188 /* Debug Registers */
 189 #define WCMDQUEUE               0x0500
 190 #define RCMDQUEUE               0x0504
 191
 192 struct rpi_touchscreen {
 193         struct drm_panel base;
 194         struct mipi_dsi_device *dsi;
 195         struct i2c_client *i2c;
 196 };
 197
 198 static const struct drm_display_mode rpi_touchscreen_modes[] = {
 199         {
 200                 /* Modeline comes from the Raspberry Pi firmware, with HFP=1
 201                  * plugged in and clock re-computed from that.
 202                  */
 203                 .clock = 25979400 / 1000,
 204                 .hdisplay = 800,
 205                 .hsync_start = 800 + 1,
 206                 .hsync_end = 800 + 1 + 2,
 207                 .htotal = 800 + 1 + 2 + 46,
 208                 .vdisplay = 480,
 209                 .vsync_start = 480 + 7,
 210                 .vsync_end = 480 + 7 + 2,
 211                 .vtotal = 480 + 7 + 2 + 21,
 212         },
 213 };
 214
 215 static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
 216 {
 217         return container_of(panel, struct rpi_touchscreen, base);
 218 }
 219
 220 static int rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
 221 {
 222         return i2c_smbus_read_byte_data(ts->i2c, reg);
 223 }
 224
 225 static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
 226                                       u8 reg, u8 val)
 227 {
 228         int ret;
 229
 230         ret = i2c_smbus_write_byte_data(ts->i2c, reg, val);
 231         if (ret)
 232                 dev_err(&ts->dsi->dev, "I2C write failed: %d\n", ret);
 233 }
 234
 235 static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
 236 {
 237         u8 msg[] = {
 238                 reg,
 239                 reg >> 8,
 240                 val,
 241                 val >> 8,
 242                 val >> 16,
 243                 val >> 24,
 244         };
 245
 246         mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));
 247
 248         return 0;
 249 }
 250
 251 static int rpi_touchscreen_disable(struct drm_panel *panel)
 252 {
 253         struct rpi_touchscreen *ts = panel_to_ts(panel);
 254
 255         rpi_touchscreen_i2c_write(ts, REG_PWM, 0);
 256
 257         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 258         udelay(1);
 259
 260         return 0;
 261 }
 262
 263 static int rpi_touchscreen_noop(struct drm_panel *panel)
 264 {
 265         return 0;
 266 }
 267
 268 static int rpi_touchscreen_enable(struct drm_panel *panel)
 269 {
 270         struct rpi_touchscreen *ts = panel_to_ts(panel);
 271         int i;
 272
 273         rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
 274         /* Wait for nPWRDWN to go low to indicate poweron is done. */
 275         for (i = 0; i < 100; i++) {
 276                 if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
 277                         break;
 278         }
 279
 280         rpi_touchscreen_write(ts, DSI_LANEENABLE,
 281                               DSI_LANEENABLE_CLOCK |
 282                               DSI_LANEENABLE_D0);
 283         rpi_touchscreen_write(ts, PPI_D0S_CLRSIPOCOUNT, 0x05);
 284         rpi_touchscreen_write(ts, PPI_D1S_CLRSIPOCOUNT, 0x05);
 285         rpi_touchscreen_write(ts, PPI_D0S_ATMR, 0x00);
 286         rpi_touchscreen_write(ts, PPI_D1S_ATMR, 0x00);
 287         rpi_touchscreen_write(ts, PPI_LPTXTIMECNT, 0x03);
 288
 289         rpi_touchscreen_write(ts, SPICMR, 0x00);
 290         rpi_touchscreen_write(ts, LCDCTRL, 0x00100150);
 291         rpi_touchscreen_write(ts, SYSCTRL, 0x040f);
 292         msleep(100);
 293
 294         rpi_touchscreen_write(ts, PPI_STARTPPI, 0x01);
 295         rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01);
 296         msleep(100);
 297
 298         /* Turn on the backlight. */
 299         rpi_touchscreen_i2c_write(ts, REG_PWM, 255);
 300
 301         /* Default to the same orientation as the closed source
 302          * firmware used for the panel.  Runtime rotation
 303          * configuration will be supported using VC4's plane
 304          * orientation bits.
 305          */
 306         rpi_touchscreen_i2c_write(ts, REG_PORTA, BIT(2));
 307
 308         return 0;
 309 }
 310
 311 static int rpi_touchscreen_get_modes(struct drm_panel *panel,
 312                                      struct drm_connector *connector)
 313 {
 314         unsigned int i, num = 0;
 315         static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 316
 317         for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
 318                 const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
 319                 struct drm_display_mode *mode;
 320
 321                 mode = drm_mode_duplicate(connector->dev, m);
 322                 if (!mode) {
 323                         dev_err(panel->dev, "failed to add mode %ux%u@%u\n",
 324                                 m->hdisplay, m->vdisplay,
 325                                 drm_mode_vrefresh(m));
 326                         continue;
 327                 }
 328
 329                 mode->type |= DRM_MODE_TYPE_DRIVER;
 330
 331                 if (i == 0)
 332                         mode->type |= DRM_MODE_TYPE_PREFERRED;
 333
 334                 drm_mode_set_name(mode);
 335
 336                 drm_mode_probed_add(connector, mode);
 337                 num++;
 338         }
 339
 340         connector->display_info.bpc = 8;
 341         connector->display_info.width_mm = 154;
 342         connector->display_info.height_mm = 86;
 343         drm_display_info_set_bus_formats(&connector->display_info,
 344                                          &bus_format, 1);
 345
 346         return num;
 347 }
 348
 349 static const struct drm_panel_funcs rpi_touchscreen_funcs = {
 350         .disable = rpi_touchscreen_disable,
 351         .unprepare = rpi_touchscreen_noop,
 352         .prepare = rpi_touchscreen_noop,
 353         .enable = rpi_touchscreen_enable,
 354         .get_modes = rpi_touchscreen_get_modes,
 355 };
 356
 357 static int rpi_touchscreen_probe(struct i2c_client *i2c,
 358                                  const struct i2c_device_id *id)
 359 {
 360         struct device *dev = &i2c->dev;
 361         struct rpi_touchscreen *ts;
 362         struct device_node *endpoint, *dsi_host_node;
 363         struct mipi_dsi_host *host;
 364         int ver;
 365         struct mipi_dsi_device_info info = {
 366                 .type = RPI_DSI_DRIVER_NAME,
 367                 .channel = 0,
 368                 .node = NULL,
 369         };
 370
 371         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 372         if (!ts)
 373                 return -ENOMEM;
 374
 375         i2c_set_clientdata(i2c, ts);
 376
 377         ts->i2c = i2c;
 378
 379         ver = rpi_touchscreen_i2c_read(ts, REG_ID);
 380         if (ver < 0) {
 381                 dev_err(dev, "Atmel I2C read failed: %d\n", ver);
 382                 return -ENODEV;
 383         }
 384
 385         switch (ver) {
 386         case 0xde: /* ver 1 */
 387         case 0xc3: /* ver 2 */
 388                 break;
 389         default:
 390                 dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
 391                 return -ENODEV;
 392         }
 393
 394         /* Turn off at boot, so we can cleanly sequence powering on. */
 395         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 396
 397         /* Look up the DSI host.  It needs to probe before we do. */
 398         endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
 399         if (!endpoint)
 400                 return -ENODEV;
 401
 402         dsi_host_node = of_graph_get_remote_port_parent(endpoint);
 403         if (!dsi_host_node)
 404                 goto error;
 405
 406         host = of_find_mipi_dsi_host_by_node(dsi_host_node);
 407         of_node_put(dsi_host_node);
 408         if (!host) {
 409                 of_node_put(endpoint);
 410                 return -EPROBE_DEFER;
 411         }
 412
 413         info.node = of_graph_get_remote_port(endpoint);
 414         if (!info.node)
 415                 goto error;
 416
 417         of_node_put(endpoint);
 418
 419         ts->dsi = mipi_dsi_device_register_full(host, &info);
 420         if (IS_ERR(ts->dsi)) {
 421                 dev_err(dev, "DSI device registration failed: %ld\n",
 422                         PTR_ERR(ts->dsi));
 423                 return PTR_ERR(ts->dsi);
 424         }
 425
 426         drm_panel_init(&ts->base, dev, &rpi_touchscreen_funcs,
 427                        DRM_MODE_CONNECTOR_DSI);
 428
 429         /* This appears last, as it's what will unblock the DSI host
 430          * driver's component bind function.
 431          */
 432         drm_panel_add(&ts->base);
 433
 434         return 0;
 435
 436 error:
 437         of_node_put(endpoint);
 438         return -ENODEV;
 439 }
 440
 441 static int rpi_touchscreen_remove(struct i2c_client *i2c)
 442 {
 443         struct rpi_touchscreen *ts = i2c_get_clientdata(i2c);
 444
 445         mipi_dsi_detach(ts->dsi);
 446
 447         drm_panel_remove(&ts->base);
 448
 449         mipi_dsi_device_unregister(ts->dsi);
 450         kfree(ts->dsi);
 451
 452         return 0;
 453 }
 454
 455 static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 456 {
 457         int ret;
 458
 459         dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
 460                            MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
 461                            MIPI_DSI_MODE_LPM);
 462         dsi->format = MIPI_DSI_FMT_RGB888;
 463         dsi->lanes = 1;
 464
 465         ret = mipi_dsi_attach(dsi);
 466
 467         if (ret)
 468                 dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);
 469
 470         return ret;
 471 }
 472
 473 static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
 474         .driver.name = RPI_DSI_DRIVER_NAME,
 475         .probe = rpi_touchscreen_dsi_probe,
 476 };
 477
 478 static const struct of_device_id rpi_touchscreen_of_ids[] = {
 479         { .compatible = "raspberrypi,7inch-touchscreen-panel" },
 480         { } /* sentinel */
 481 };
 482 MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);
 483
 484 static struct i2c_driver rpi_touchscreen_driver = {
 485         .driver = {
 486                 .name = "rpi_touchscreen",
 487                 .of_match_table = rpi_touchscreen_of_ids,
 488         },
 489         .probe = rpi_touchscreen_probe,
 490         .remove = rpi_touchscreen_remove,
 491 };
 492
 493 static int __init rpi_touchscreen_init(void)
 494 {
 495         mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
 496         return i2c_add_driver(&rpi_touchscreen_driver);
 497 }
 498 module_init(rpi_touchscreen_init);
 499
 500 static void __exit rpi_touchscreen_exit(void)
 501 {
 502         i2c_del_driver(&rpi_touchscreen_driver);
 503         mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
 504 }
 505 module_exit(rpi_touchscreen_exit);
 506
 507 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 508 MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
 509 MODULE_LICENSE("GPL v2");