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