summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
blob: 79f852465a846c0d9589a248c8bceb2c752f9591 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
/*
 * Copyright © 2016-2017 Broadcom
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Portions of this file (derived from panel-simple.c) are:
 *
 * Copyright (C) 2013, NVIDIA Corporation.  All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sub license,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

/*
 * Raspberry Pi 7" touchscreen panel driver.
 *
 * The 7" touchscreen consists of a DPI LCD panel, a Toshiba
 * TC358762XBG DSI-DPI bridge, and an I2C-connected Atmel ATTINY88-MUR
 * controlling power management, the LCD PWM, and initial register
 * setup of the Tohsiba.
 *
 * This driver controls the TC358762 and ATTINY88, presenting a DSI
 * device with a drm_panel.
 */

#include <linux/delay.h>
#include <linux/err.h>
#include <linux/fb.h>
#include <linux/i2c.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_graph.h>
#include <linux/pm.h>

#include <drm/drm_crtc.h>
#include <drm/drm_device.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_panel.h>

#define RPI_DSI_DRIVER_NAME "rpi-ts-dsi"

/* I2C registers of the Atmel microcontroller. */
enum REG_ADDR {
	REG_ID = 0x80,
	REG_PORTA, /* BIT(2) for horizontal flip, BIT(3) for vertical flip */
	REG_PORTB,
	REG_PORTC,
	REG_PORTD,
	REG_POWERON,
	REG_PWM,
	REG_DDRA,
	REG_DDRB,
	REG_DDRC,
	REG_DDRD,
	REG_TEST,
	REG_WR_ADDRL,
	REG_WR_ADDRH,
	REG_READH,
	REG_READL,
	REG_WRITEH,
	REG_WRITEL,
	REG_ID2,
};

/* DSI D-PHY Layer Registers */
#define D0W_DPHYCONTTX		0x0004
#define CLW_DPHYCONTRX		0x0020
#define D0W_DPHYCONTRX		0x0024
#define D1W_DPHYCONTRX		0x0028
#define COM_DPHYCONTRX		0x0038
#define CLW_CNTRL		0x0040
#define D0W_CNTRL		0x0044
#define D1W_CNTRL		0x0048
#define DFTMODE_CNTRL		0x0054

/* DSI PPI Layer Registers */
#define PPI_STARTPPI		0x0104
#define PPI_BUSYPPI		0x0108
#define PPI_LINEINITCNT		0x0110
#define PPI_LPTXTIMECNT		0x0114
#define PPI_CLS_ATMR		0x0140
#define PPI_D0S_ATMR		0x0144
#define PPI_D1S_ATMR		0x0148
#define PPI_D0S_CLRSIPOCOUNT	0x0164
#define PPI_D1S_CLRSIPOCOUNT	0x0168
#define CLS_PRE			0x0180
#define D0S_PRE			0x0184
#define D1S_PRE			0x0188
#define CLS_PREP		0x01A0
#define D0S_PREP		0x01A4
#define D1S_PREP		0x01A8
#define CLS_ZERO		0x01C0
#define D0S_ZERO		0x01C4
#define D1S_ZERO		0x01C8
#define PPI_CLRFLG		0x01E0
#define PPI_CLRSIPO		0x01E4
#define HSTIMEOUT		0x01F0
#define HSTIMEOUTENABLE		0x01F4

/* DSI Protocol Layer Registers */
#define DSI_STARTDSI		0x0204
#define DSI_BUSYDSI		0x0208
#define DSI_LANEENABLE		0x0210
# define DSI_LANEENABLE_CLOCK		BIT(0)
# define DSI_LANEENABLE_D0		BIT(1)
# define DSI_LANEENABLE_D1		BIT(2)

#define DSI_LANESTATUS0		0x0214
#define DSI_LANESTATUS1		0x0218
#define DSI_INTSTATUS		0x0220
#define DSI_INTMASK		0x0224
#define DSI_INTCLR		0x0228
#define DSI_LPTXTO		0x0230
#define DSI_MODE		0x0260
#define DSI_PAYLOAD0		0x0268
#define DSI_PAYLOAD1		0x026C
#define DSI_SHORTPKTDAT		0x0270
#define DSI_SHORTPKTREQ		0x0274
#define DSI_BTASTA		0x0278
#define DSI_BTACLR		0x027C

/* DSI General Registers */
#define DSIERRCNT		0x0300
#define DSISIGMOD		0x0304

/* DSI Application Layer Registers */
#define APLCTRL			0x0400
#define APLSTAT			0x0404
#define APLERR			0x0408
#define PWRMOD			0x040C
#define RDPKTLN			0x0410
#define PXLFMT			0x0414
#define MEMWRCMD		0x0418

/* LCDC/DPI Host Registers */
#define LCDCTRL			0x0420
#define HSR			0x0424
#define HDISPR			0x0428
#define VSR			0x042C
#define VDISPR			0x0430
#define VFUEN			0x0434

/* DBI-B Host Registers */
#define DBIBCTRL		0x0440

/* SPI Master Registers */
#define SPICMR			0x0450
#define SPITCR			0x0454

/* System Controller Registers */
#define SYSSTAT			0x0460
#define SYSCTRL			0x0464
#define SYSPLL1			0x0468
#define SYSPLL2			0x046C
#define SYSPLL3			0x0470
#define SYSPMCTRL		0x047C

/* GPIO Registers */
#define GPIOC			0x0480
#define GPIOO			0x0484
#define GPIOI			0x0488

/* I2C Registers */
#define I2CCLKCTRL		0x0490

/* Chip/Rev Registers */
#define IDREG			0x04A0

/* Debug Registers */
#define WCMDQUEUE		0x0500
#define RCMDQUEUE		0x0504

struct rpi_touchscreen {
	struct drm_panel base;
	struct mipi_dsi_device *dsi;
	struct i2c_client *i2c;
};

static const struct drm_display_mode rpi_touchscreen_modes[] = {
	{
		/* Modeline comes from the Raspberry Pi firmware, with HFP=1
		 * plugged in and clock re-computed from that.
		 */
		.clock = 25979400 / 1000,
		.hdisplay = 800,
		.hsync_start = 800 + 1,
		.hsync_end = 800 + 1 + 2,
		.htotal = 800 + 1 + 2 + 46,
		.vdisplay = 480,
		.vsync_start = 480 + 7,
		.vsync_end = 480 + 7 + 2,
		.vtotal = 480 + 7 + 2 + 21,
	},
};

static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
{
	return container_of(panel, struct rpi_touchscreen, base);
}

static int rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
{
	return i2c_smbus_read_byte_data(ts->i2c, reg);
}

static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
				      u8 reg, u8 val)
{
	int ret;

	ret = i2c_smbus_write_byte_data(ts->i2c, reg, val);
	if (ret)
		dev_err(&ts->i2c->dev, "I2C write failed: %d\n", ret);
}

static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
{
	u8 msg[] = {
		reg,
		reg >> 8,
		val,
		val >> 8,
		val >> 16,
		val >> 24,
	};

	mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));

	return 0;
}

static int rpi_touchscreen_disable(struct drm_panel *panel)
{
	struct rpi_touchscreen *ts = panel_to_ts(panel);

	rpi_touchscreen_i2c_write(ts, REG_PWM, 0);

	rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
	udelay(1);

	return 0;
}

static int rpi_touchscreen_noop(struct drm_panel *panel)
{
	return 0;
}

static int rpi_touchscreen_prepare(struct drm_panel *panel)
{
	struct rpi_touchscreen *ts = panel_to_ts(panel);
	int i;

	rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
	/* Wait for nPWRDWN to go low to indicate poweron is done. */
	for (i = 0; i < 100; i++) {
		if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
			break;
	}

	rpi_touchscreen_write(ts, DSI_LANEENABLE,
			      DSI_LANEENABLE_CLOCK |
			      DSI_LANEENABLE_D0);
	rpi_touchscreen_write(ts, PPI_D0S_CLRSIPOCOUNT, 0x05);
	rpi_touchscreen_write(ts, PPI_D1S_CLRSIPOCOUNT, 0x05);
	rpi_touchscreen_write(ts, PPI_D0S_ATMR, 0x00);
	rpi_touchscreen_write(ts, PPI_D1S_ATMR, 0x00);
	rpi_touchscreen_write(ts, PPI_LPTXTIMECNT, 0x03);

	rpi_touchscreen_write(ts, SPICMR, 0x00);
	rpi_touchscreen_write(ts, LCDCTRL, 0x00100150);
	rpi_touchscreen_write(ts, SYSCTRL, 0x040f);
	msleep(100);

	rpi_touchscreen_write(ts, PPI_STARTPPI, 0x01);
	rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01);
	msleep(100);

	return 0;
}

static int rpi_touchscreen_enable(struct drm_panel *panel)
{
	struct rpi_touchscreen *ts = panel_to_ts(panel);

	/* Turn on the backlight. */
	rpi_touchscreen_i2c_write(ts, REG_PWM, 255);

	/* Default to the same orientation as the closed source
	 * firmware used for the panel.  Runtime rotation
	 * configuration will be supported using VC4's plane
	 * orientation bits.
	 */
	rpi_touchscreen_i2c_write(ts, REG_PORTA, BIT(2));

	return 0;
}

static int rpi_touchscreen_get_modes(struct drm_panel *panel,
				     struct drm_connector *connector)
{
	unsigned int i, num = 0;
	static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;

	for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
		const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
		struct drm_display_mode *mode;

		mode = drm_mode_duplicate(connector->dev, m);
		if (!mode) {
			dev_err(panel->dev, "failed to add mode %ux%u@%u\n",
				m->hdisplay, m->vdisplay,
				drm_mode_vrefresh(m));
			continue;
		}

		mode->type |= DRM_MODE_TYPE_DRIVER;

		if (i == 0)
			mode->type |= DRM_MODE_TYPE_PREFERRED;

		drm_mode_set_name(mode);

		drm_mode_probed_add(connector, mode);
		num++;
	}

	connector->display_info.bpc = 8;
	connector->display_info.width_mm = 154;
	connector->display_info.height_mm = 86;
	drm_display_info_set_bus_formats(&connector->display_info,
					 &bus_format, 1);

	return num;
}

static const struct drm_panel_funcs rpi_touchscreen_funcs = {
	.disable = rpi_touchscreen_disable,
	.unprepare = rpi_touchscreen_noop,
	.prepare = rpi_touchscreen_prepare,
	.enable = rpi_touchscreen_enable,
	.get_modes = rpi_touchscreen_get_modes,
};

static int rpi_touchscreen_probe(struct i2c_client *i2c,
				 const struct i2c_device_id *id)
{
	struct device *dev = &i2c->dev;
	struct rpi_touchscreen *ts;
	struct device_node *endpoint, *dsi_host_node;
	struct mipi_dsi_host *host;
	int ver;
	struct mipi_dsi_device_info info = {
		.type = RPI_DSI_DRIVER_NAME,
		.channel = 0,
		.node = NULL,
	};

	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
	if (!ts)
		return -ENOMEM;

	i2c_set_clientdata(i2c, ts);

	ts->i2c = i2c;

	ver = rpi_touchscreen_i2c_read(ts, REG_ID);
	if (ver < 0) {
		dev_err(dev, "Atmel I2C read failed: %d\n", ver);
		return -ENODEV;
	}

	switch (ver) {
	case 0xde: /* ver 1 */
	case 0xc3: /* ver 2 */
		break;
	default:
		dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
		return -ENODEV;
	}

	/* Turn off at boot, so we can cleanly sequence powering on. */
	rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);

	/* Look up the DSI host.  It needs to probe before we do. */
	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
	if (!endpoint)
		return -ENODEV;

	dsi_host_node = of_graph_get_remote_port_parent(endpoint);
	if (!dsi_host_node)
		goto error;

	host = of_find_mipi_dsi_host_by_node(dsi_host_node);
	of_node_put(dsi_host_node);
	if (!host) {
		of_node_put(endpoint);
		return -EPROBE_DEFER;
	}

	info.node = of_graph_get_remote_port(endpoint);
	if (!info.node)
		goto error;

	of_node_put(endpoint);

	ts->dsi = mipi_dsi_device_register_full(host, &info);
	if (IS_ERR(ts->dsi)) {
		dev_err(dev, "DSI device registration failed: %ld\n",
			PTR_ERR(ts->dsi));
		return PTR_ERR(ts->dsi);
	}

	drm_panel_init(&ts->base, dev, &rpi_touchscreen_funcs,
		       DRM_MODE_CONNECTOR_DSI);

	/* This appears last, as it's what will unblock the DSI host
	 * driver's component bind function.
	 */
	drm_panel_add(&ts->base);

	return 0;

error:
	of_node_put(endpoint);
	return -ENODEV;
}

static void rpi_touchscreen_remove(struct i2c_client *i2c)
{
	struct rpi_touchscreen *ts = i2c_get_clientdata(i2c);

	mipi_dsi_detach(ts->dsi);

	drm_panel_remove(&ts->base);

	mipi_dsi_device_unregister(ts->dsi);
}

static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
{
	int ret;

	dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
			   MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
			   MIPI_DSI_MODE_LPM);
	dsi->format = MIPI_DSI_FMT_RGB888;
	dsi->lanes = 1;

	ret = mipi_dsi_attach(dsi);

	if (ret)
		dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);

	return ret;
}

static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
	.driver.name = RPI_DSI_DRIVER_NAME,
	.probe = rpi_touchscreen_dsi_probe,
};

static const struct of_device_id rpi_touchscreen_of_ids[] = {
	{ .compatible = "raspberrypi,7inch-touchscreen-panel" },
	{ } /* sentinel */
};
MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);

static struct i2c_driver rpi_touchscreen_driver = {
	.driver = {
		.name = "rpi_touchscreen",
		.of_match_table = rpi_touchscreen_of_ids,
	},
	.probe = rpi_touchscreen_probe,
	.remove = rpi_touchscreen_remove,
};

static int __init rpi_touchscreen_init(void)
{
	mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
	return i2c_add_driver(&rpi_touchscreen_driver);
}
module_init(rpi_touchscreen_init);

static void __exit rpi_touchscreen_exit(void)
{
	i2c_del_driver(&rpi_touchscreen_driver);
	mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
}
module_exit(rpi_touchscreen_exit);

MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
MODULE_LICENSE("GPL v2");