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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 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
436error:
437 of_node_put(endpoint);
438 return -ENODEV;
439}
440
441static 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
451 return 0;
452}
453
454static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
455{
456 int ret;
457
458 dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
459 MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
460 MIPI_DSI_MODE_LPM);
461 dsi->format = MIPI_DSI_FMT_RGB888;
462 dsi->lanes = 1;
463
464 ret = mipi_dsi_attach(dsi);
465
466 if (ret)
467 dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);
468
469 return ret;
470}
471
472static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
473 .driver.name = RPI_DSI_DRIVER_NAME,
474 .probe = rpi_touchscreen_dsi_probe,
475};
476
477static const struct of_device_id rpi_touchscreen_of_ids[] = {
478 { .compatible = "raspberrypi,7inch-touchscreen-panel" },
479 { } /* sentinel */
480};
481MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);
482
483static struct i2c_driver rpi_touchscreen_driver = {
484 .driver = {
485 .name = "rpi_touchscreen",
486 .of_match_table = rpi_touchscreen_of_ids,
487 },
488 .probe = rpi_touchscreen_probe,
489 .remove = rpi_touchscreen_remove,
490};
491
492static int __init rpi_touchscreen_init(void)
493{
494 mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
495 return i2c_add_driver(&rpi_touchscreen_driver);
496}
497module_init(rpi_touchscreen_init);
498
499static void __exit rpi_touchscreen_exit(void)
500{
501 i2c_del_driver(&rpi_touchscreen_driver);
502 mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
503}
504module_exit(rpi_touchscreen_exit);
505
506MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
507MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
508MODULE_LICENSE("GPL v2");