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/media-bus-format.h>
  49 #include <linux/module.h>
  50 #include <linux/of.h>
  51 #include <linux/of_device.h>
  52 #include <linux/of_graph.h>
  53 #include <linux/pm.h>
  54
  55 #include <drm/drm_crtc.h>
  56 #include <drm/drm_device.h>
  57 #include <drm/drm_mipi_dsi.h>
  58 #include <drm/drm_panel.h>
  59
  60 #define RPI_DSI_DRIVER_NAME "rpi-ts-dsi"
  61
  62 /* I2C registers of the Atmel microcontroller. */
  63 enum REG_ADDR {
  64         REG_ID = 0x80,
  65         REG_PORTA, /* BIT(2) for horizontal flip, BIT(3) for vertical flip */
  66         REG_PORTB,
  67         REG_PORTC,
  68         REG_PORTD,
  69         REG_POWERON,
  70         REG_PWM,
  71         REG_DDRA,
  72         REG_DDRB,
  73         REG_DDRC,
  74         REG_DDRD,
  75         REG_TEST,
  76         REG_WR_ADDRL,
  77         REG_WR_ADDRH,
  78         REG_READH,
  79         REG_READL,
  80         REG_WRITEH,
  81         REG_WRITEL,
  82         REG_ID2,
  83 };
  84
  85 /* DSI D-PHY Layer Registers */
  86 #define D0W_DPHYCONTTX          0x0004
  87 #define CLW_DPHYCONTRX          0x0020
  88 #define D0W_DPHYCONTRX          0x0024
  89 #define D1W_DPHYCONTRX          0x0028
  90 #define COM_DPHYCONTRX          0x0038
  91 #define CLW_CNTRL               0x0040
  92 #define D0W_CNTRL               0x0044
  93 #define D1W_CNTRL               0x0048
  94 #define DFTMODE_CNTRL           0x0054
  95
  96 /* DSI PPI Layer Registers */
  97 #define PPI_STARTPPI            0x0104
  98 #define PPI_BUSYPPI             0x0108
  99 #define PPI_LINEINITCNT         0x0110
 100 #define PPI_LPTXTIMECNT         0x0114
 101 #define PPI_CLS_ATMR            0x0140
 102 #define PPI_D0S_ATMR            0x0144
 103 #define PPI_D1S_ATMR            0x0148
 104 #define PPI_D0S_CLRSIPOCOUNT    0x0164
 105 #define PPI_D1S_CLRSIPOCOUNT    0x0168
 106 #define CLS_PRE                 0x0180
 107 #define D0S_PRE                 0x0184
 108 #define D1S_PRE                 0x0188
 109 #define CLS_PREP                0x01A0
 110 #define D0S_PREP                0x01A4
 111 #define D1S_PREP                0x01A8
 112 #define CLS_ZERO                0x01C0
 113 #define D0S_ZERO                0x01C4
 114 #define D1S_ZERO                0x01C8
 115 #define PPI_CLRFLG              0x01E0
 116 #define PPI_CLRSIPO             0x01E4
 117 #define HSTIMEOUT               0x01F0
 118 #define HSTIMEOUTENABLE         0x01F4
 119
 120 /* DSI Protocol Layer Registers */
 121 #define DSI_STARTDSI            0x0204
 122 #define DSI_BUSYDSI             0x0208
 123 #define DSI_LANEENABLE          0x0210
 124 # define DSI_LANEENABLE_CLOCK           BIT(0)
 125 # define DSI_LANEENABLE_D0              BIT(1)
 126 # define DSI_LANEENABLE_D1              BIT(2)
 127
 128 #define DSI_LANESTATUS0         0x0214
 129 #define DSI_LANESTATUS1         0x0218
 130 #define DSI_INTSTATUS           0x0220
 131 #define DSI_INTMASK             0x0224
 132 #define DSI_INTCLR              0x0228
 133 #define DSI_LPTXTO              0x0230
 134 #define DSI_MODE                0x0260
 135 #define DSI_PAYLOAD0            0x0268
 136 #define DSI_PAYLOAD1            0x026C
 137 #define DSI_SHORTPKTDAT         0x0270
 138 #define DSI_SHORTPKTREQ         0x0274
 139 #define DSI_BTASTA              0x0278
 140 #define DSI_BTACLR              0x027C
 141
 142 /* DSI General Registers */
 143 #define DSIERRCNT               0x0300
 144 #define DSISIGMOD               0x0304
 145
 146 /* DSI Application Layer Registers */
 147 #define APLCTRL                 0x0400
 148 #define APLSTAT                 0x0404
 149 #define APLERR                  0x0408
 150 #define PWRMOD                  0x040C
 151 #define RDPKTLN                 0x0410
 152 #define PXLFMT                  0x0414
 153 #define MEMWRCMD                0x0418
 154
 155 /* LCDC/DPI Host Registers */
 156 #define LCDCTRL                 0x0420
 157 #define HSR                     0x0424
 158 #define HDISPR                  0x0428
 159 #define VSR                     0x042C
 160 #define VDISPR                  0x0430
 161 #define VFUEN                   0x0434
 162
 163 /* DBI-B Host Registers */
 164 #define DBIBCTRL                0x0440
 165
 166 /* SPI Master Registers */
 167 #define SPICMR                  0x0450
 168 #define SPITCR                  0x0454
 169
 170 /* System Controller Registers */
 171 #define SYSSTAT                 0x0460
 172 #define SYSCTRL                 0x0464
 173 #define SYSPLL1                 0x0468
 174 #define SYSPLL2                 0x046C
 175 #define SYSPLL3                 0x0470
 176 #define SYSPMCTRL               0x047C
 177
 178 /* GPIO Registers */
 179 #define GPIOC                   0x0480
 180 #define GPIOO                   0x0484
 181 #define GPIOI                   0x0488
 182
 183 /* I2C Registers */
 184 #define I2CCLKCTRL              0x0490
 185
 186 /* Chip/Rev Registers */
 187 #define IDREG                   0x04A0
 188
 189 /* Debug Registers */
 190 #define WCMDQUEUE               0x0500
 191 #define RCMDQUEUE               0x0504
 192
 193 struct rpi_touchscreen {
 194         struct drm_panel base;
 195         struct mipi_dsi_device *dsi;
 196         struct i2c_client *i2c;
 197 };
 198
 199 static const struct drm_display_mode rpi_touchscreen_modes[] = {
 200         {
 201                 /* Modeline comes from the Raspberry Pi firmware, with HFP=1
 202                  * plugged in and clock re-computed from that.
 203                  */
 204                 .clock = 25979400 / 1000,
 205                 .hdisplay = 800,
 206                 .hsync_start = 800 + 1,
 207                 .hsync_end = 800 + 1 + 2,
 208                 .htotal = 800 + 1 + 2 + 46,
 209                 .vdisplay = 480,
 210                 .vsync_start = 480 + 7,
 211                 .vsync_end = 480 + 7 + 2,
 212                 .vtotal = 480 + 7 + 2 + 21,
 213         },
 214 };
 215
 216 static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
 217 {
 218         return container_of(panel, struct rpi_touchscreen, base);
 219 }
 220
 221 static int rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
 222 {
 223         return i2c_smbus_read_byte_data(ts->i2c, reg);
 224 }
 225
 226 static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
 227                                       u8 reg, u8 val)
 228 {
 229         int ret;
 230
 231         ret = i2c_smbus_write_byte_data(ts->i2c, reg, val);
 232         if (ret)
 233                 dev_err(&ts->i2c->dev, "I2C write failed: %d\n", ret);
 234 }
 235
 236 static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
 237 {
 238         u8 msg[] = {
 239                 reg,
 240                 reg >> 8,
 241                 val,
 242                 val >> 8,
 243                 val >> 16,
 244                 val >> 24,
 245         };
 246
 247         mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));
 248
 249         return 0;
 250 }
 251
 252 static int rpi_touchscreen_disable(struct drm_panel *panel)
 253 {
 254         struct rpi_touchscreen *ts = panel_to_ts(panel);
 255
 256         rpi_touchscreen_i2c_write(ts, REG_PWM, 0);
 257
 258         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 259         udelay(1);
 260
 261         return 0;
 262 }
 263
 264 static int rpi_touchscreen_noop(struct drm_panel *panel)
 265 {
 266         return 0;
 267 }
 268
 269 static int rpi_touchscreen_prepare(struct drm_panel *panel)
 270 {
 271         struct rpi_touchscreen *ts = panel_to_ts(panel);
 272         int i;
 273
 274         rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
 275         /* Wait for nPWRDWN to go low to indicate poweron is done. */
 276         for (i = 0; i < 100; i++) {
 277                 if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
 278                         break;
 279         }
 280
 281         rpi_touchscreen_write(ts, DSI_LANEENABLE,
 282                               DSI_LANEENABLE_CLOCK |
 283                               DSI_LANEENABLE_D0);
 284         rpi_touchscreen_write(ts, PPI_D0S_CLRSIPOCOUNT, 0x05);
 285         rpi_touchscreen_write(ts, PPI_D1S_CLRSIPOCOUNT, 0x05);
 286         rpi_touchscreen_write(ts, PPI_D0S_ATMR, 0x00);
 287         rpi_touchscreen_write(ts, PPI_D1S_ATMR, 0x00);
 288         rpi_touchscreen_write(ts, PPI_LPTXTIMECNT, 0x03);
 289
 290         rpi_touchscreen_write(ts, SPICMR, 0x00);
 291         rpi_touchscreen_write(ts, LCDCTRL, 0x00100150);
 292         rpi_touchscreen_write(ts, SYSCTRL, 0x040f);
 293         msleep(100);
 294
 295         rpi_touchscreen_write(ts, PPI_STARTPPI, 0x01);
 296         rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01);
 297         msleep(100);
 298
 299         return 0;
 300 }
 301
 302 static int rpi_touchscreen_enable(struct drm_panel *panel)
 303 {
 304         struct rpi_touchscreen *ts = panel_to_ts(panel);
 305
 306         /* Turn on the backlight. */
 307         rpi_touchscreen_i2c_write(ts, REG_PWM, 255);
 308
 309         /* Default to the same orientation as the closed source
 310          * firmware used for the panel.  Runtime rotation
 311          * configuration will be supported using VC4's plane
 312          * orientation bits.
 313          */
 314         rpi_touchscreen_i2c_write(ts, REG_PORTA, BIT(2));
 315
 316         return 0;
 317 }
 318
 319 static int rpi_touchscreen_get_modes(struct drm_panel *panel,
 320                                      struct drm_connector *connector)
 321 {
 322         unsigned int i, num = 0;
 323         static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 324
 325         for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
 326                 const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
 327                 struct drm_display_mode *mode;
 328
 329                 mode = drm_mode_duplicate(connector->dev, m);
 330                 if (!mode) {
 331                         dev_err(panel->dev, "failed to add mode %ux%u@%u\n",
 332                                 m->hdisplay, m->vdisplay,
 333                                 drm_mode_vrefresh(m));
 334                         continue;
 335                 }
 336
 337                 mode->type |= DRM_MODE_TYPE_DRIVER;
 338
 339                 if (i == 0)
 340                         mode->type |= DRM_MODE_TYPE_PREFERRED;
 341
 342                 drm_mode_set_name(mode);
 343
 344                 drm_mode_probed_add(connector, mode);
 345                 num++;
 346         }
 347
 348         connector->display_info.bpc = 8;
 349         connector->display_info.width_mm = 154;
 350         connector->display_info.height_mm = 86;
 351         drm_display_info_set_bus_formats(&connector->display_info,
 352                                          &bus_format, 1);
 353
 354         return num;
 355 }
 356
 357 static const struct drm_panel_funcs rpi_touchscreen_funcs = {
 358         .disable = rpi_touchscreen_disable,
 359         .unprepare = rpi_touchscreen_noop,
 360         .prepare = rpi_touchscreen_prepare,
 361         .enable = rpi_touchscreen_enable,
 362         .get_modes = rpi_touchscreen_get_modes,
 363 };
 364
 365 static int rpi_touchscreen_probe(struct i2c_client *i2c,
 366                                  const struct i2c_device_id *id)
 367 {
 368         struct device *dev = &i2c->dev;
 369         struct rpi_touchscreen *ts;
 370         struct device_node *endpoint, *dsi_host_node;
 371         struct mipi_dsi_host *host;
 372         int ver;
 373         struct mipi_dsi_device_info info = {
 374                 .type = RPI_DSI_DRIVER_NAME,
 375                 .channel = 0,
 376                 .node = NULL,
 377         };
 378
 379         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 380         if (!ts)
 381                 return -ENOMEM;
 382
 383         i2c_set_clientdata(i2c, ts);
 384
 385         ts->i2c = i2c;
 386
 387         ver = rpi_touchscreen_i2c_read(ts, REG_ID);
 388         if (ver < 0) {
 389                 dev_err(dev, "Atmel I2C read failed: %d\n", ver);
 390                 return -ENODEV;
 391         }
 392
 393         switch (ver) {
 394         case 0xde: /* ver 1 */
 395         case 0xc3: /* ver 2 */
 396                 break;
 397         default:
 398                 dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
 399                 return -ENODEV;
 400         }
 401
 402         /* Turn off at boot, so we can cleanly sequence powering on. */
 403         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 404
 405         /* Look up the DSI host.  It needs to probe before we do. */
 406         endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
 407         if (!endpoint)
 408                 return -ENODEV;
 409
 410         dsi_host_node = of_graph_get_remote_port_parent(endpoint);
 411         if (!dsi_host_node)
 412                 goto error;
 413
 414         host = of_find_mipi_dsi_host_by_node(dsi_host_node);
 415         of_node_put(dsi_host_node);
 416         if (!host) {
 417                 of_node_put(endpoint);
 418                 return -EPROBE_DEFER;
 419         }
 420
 421         info.node = of_graph_get_remote_port(endpoint);
 422         if (!info.node)
 423                 goto error;
 424
 425         of_node_put(endpoint);
 426
 427         ts->dsi = mipi_dsi_device_register_full(host, &info);
 428         if (IS_ERR(ts->dsi)) {
 429                 dev_err(dev, "DSI device registration failed: %ld\n",
 430                         PTR_ERR(ts->dsi));
 431                 return PTR_ERR(ts->dsi);
 432         }
 433
 434         drm_panel_init(&ts->base, dev, &rpi_touchscreen_funcs,
 435                        DRM_MODE_CONNECTOR_DSI);
 436
 437         /* This appears last, as it's what will unblock the DSI host
 438          * driver's component bind function.
 439          */
 440         drm_panel_add(&ts->base);
 441
 442         return 0;
 443
 444 error:
 445         of_node_put(endpoint);
 446         return -ENODEV;
 447 }
 448
 449 static int rpi_touchscreen_remove(struct i2c_client *i2c)
 450 {
 451         struct rpi_touchscreen *ts = i2c_get_clientdata(i2c);
 452
 453         mipi_dsi_detach(ts->dsi);
 454
 455         drm_panel_remove(&ts->base);
 456
 457         mipi_dsi_device_unregister(ts->dsi);
 458
 459         return 0;
 460 }
 461
 462 static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 463 {
 464         int ret;
 465
 466         dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
 467                            MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
 468                            MIPI_DSI_MODE_LPM);
 469         dsi->format = MIPI_DSI_FMT_RGB888;
 470         dsi->lanes = 1;
 471
 472         ret = mipi_dsi_attach(dsi);
 473
 474         if (ret)
 475                 dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);
 476
 477         return ret;
 478 }
 479
 480 static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
 481         .driver.name = RPI_DSI_DRIVER_NAME,
 482         .probe = rpi_touchscreen_dsi_probe,
 483 };
 484
 485 static const struct of_device_id rpi_touchscreen_of_ids[] = {
 486         { .compatible = "raspberrypi,7inch-touchscreen-panel" },
 487         { } /* sentinel */
 488 };
 489 MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);
 490
 491 static struct i2c_driver rpi_touchscreen_driver = {
 492         .driver = {
 493                 .name = "rpi_touchscreen",
 494                 .of_match_table = rpi_touchscreen_of_ids,
 495         },
 496         .probe = rpi_touchscreen_probe,
 497         .remove = rpi_touchscreen_remove,
 498 };
 499
 500 static int __init rpi_touchscreen_init(void)
 501 {
 502         mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
 503         return i2c_add_driver(&rpi_touchscreen_driver);
 504 }
 505 module_init(rpi_touchscreen_init);
 506
 507 static void __exit rpi_touchscreen_exit(void)
 508 {
 509         i2c_del_driver(&rpi_touchscreen_driver);
 510         mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
 511 }
 512 module_exit(rpi_touchscreen_exit);
 513
 514 MODULE_AUTHOR("Eric Anholt <[email protected]>");
 515 MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
 516 MODULE_LICENSE("GPL v2");