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