LXR linux/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. */
  62enum 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
 192struct rpi_touchscreen {
 193        struct drm_panel base;
 194        struct mipi_dsi_device *dsi;
 195        struct i2c_client *i2c;
 196};
 197
 198static 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
 215static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
 216{
 217        return container_of(panel, struct rpi_touchscreen, base);
 218}
 219
 220static int rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
 221{
 222        return i2c_smbus_read_byte_data(ts->i2c, reg);
 223}
 224
 225static 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
 235static 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
 251static 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
 263static int rpi_touchscreen_noop(struct drm_panel *panel)
 264{
 265        return 0;
 266}
 267
 268static 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
 311static 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
 349static 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
 357static 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 ret, 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        ret = drm_panel_add(&ts->base);
 433        if (ret)
 434                return ret;
 435
 436        return 0;
 437
 438error:
 439        of_node_put(endpoint);
 440        return -ENODEV;
 441}
 442
 443static int rpi_touchscreen_remove(struct i2c_client *i2c)
 444{
 445        struct rpi_touchscreen *ts = i2c_get_clientdata(i2c);
 446
 447        mipi_dsi_detach(ts->dsi);
 448
 449        drm_panel_remove(&ts->base);
 450
 451        mipi_dsi_device_unregister(ts->dsi);
 452        kfree(ts->dsi);
 453
 454        return 0;
 455}
 456
 457static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 458{
 459        int ret;
 460
 461        dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
 462                           MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
 463                           MIPI_DSI_MODE_LPM);
 464        dsi->format = MIPI_DSI_FMT_RGB888;
 465        dsi->lanes = 1;
 466
 467        ret = mipi_dsi_attach(dsi);
 468
 469        if (ret)
 470                dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);
 471
 472        return ret;
 473}
 474
 475static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
 476        .driver.name = RPI_DSI_DRIVER_NAME,
 477        .probe = rpi_touchscreen_dsi_probe,
 478};
 479
 480static const struct of_device_id rpi_touchscreen_of_ids[] = {
 481        { .compatible = "raspberrypi,7inch-touchscreen-panel" },
 482        { } /* sentinel */
 483};
 484MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);
 485
 486static struct i2c_driver rpi_touchscreen_driver = {
 487        .driver = {
 488                .name = "rpi_touchscreen",
 489                .of_match_table = rpi_touchscreen_of_ids,
 490        },
 491        .probe = rpi_touchscreen_probe,
 492        .remove = rpi_touchscreen_remove,
 493};
 494
 495static int __init rpi_touchscreen_init(void)
 496{
 497        mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
 498        return i2c_add_driver(&rpi_touchscreen_driver);
 499}
 500module_init(rpi_touchscreen_init);
 501
 502static void __exit rpi_touchscreen_exit(void)
 503{
 504        i2c_del_driver(&rpi_touchscreen_driver);
 505        mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
 506}
 507module_exit(rpi_touchscreen_exit);
 508
 509MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 510MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
 511MODULE_LICENSE("GPL v2");
 512