1/*
2 * Parade PS8622 eDP/LVDS bridge driver
3 *
4 * Copyright (C) 2014 Google, Inc.
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 */
15
16#include <linux/backlight.h>
17#include <linux/delay.h>
18#include <linux/err.h>
19#include <linux/fb.h>
20#include <linux/gpio.h>
21#include <linux/i2c.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/of_graph.h>
26#include <linux/pm.h>
27#include <linux/regulator/consumer.h>
28
29#include <drm/drm_panel.h>
30
31#include "drmP.h"
32#include "drm_crtc.h"
33#include "drm_crtc_helper.h"
34
35/* Brightness scale on the Parade chip */
36#define PS8622_MAX_BRIGHTNESS 0xff
37
38/* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
39#define PS8622_POWER_RISE_T1_MIN_US 10
40#define PS8622_POWER_RISE_T1_MAX_US 10000
41#define PS8622_RST_HIGH_T2_MIN_US 3000
42#define PS8622_RST_HIGH_T2_MAX_US 30000
43#define PS8622_PWMO_END_T12_MS 200
44#define PS8622_POWER_FALL_T16_MAX_US 10000
45#define PS8622_POWER_OFF_T17_MS 500
46
47#if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
48	(PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
49#error "T2.min + T1.max must be less than T2.max + T1.min"
50#endif
51
52struct ps8622_bridge {
53	struct drm_connector connector;
54	struct i2c_client *client;
55	struct drm_bridge bridge;
56	struct drm_panel *panel;
57	struct regulator *v12;
58	struct backlight_device *bl;
59
60	struct gpio_desc *gpio_slp;
61	struct gpio_desc *gpio_rst;
62
63	u32 max_lane_count;
64	u32 lane_count;
65
66	bool enabled;
67};
68
69static inline struct ps8622_bridge *
70		bridge_to_ps8622(struct drm_bridge *bridge)
71{
72	return container_of(bridge, struct ps8622_bridge, bridge);
73}
74
75static inline struct ps8622_bridge *
76		connector_to_ps8622(struct drm_connector *connector)
77{
78	return container_of(connector, struct ps8622_bridge, connector);
79}
80
81static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
82{
83	int ret;
84	struct i2c_adapter *adap = client->adapter;
85	struct i2c_msg msg;
86	u8 data[] = {reg, val};
87
88	msg.addr = client->addr + page;
89	msg.flags = 0;
90	msg.len = sizeof(data);
91	msg.buf = data;
92
93	ret = i2c_transfer(adap, &msg, 1);
94	if (ret != 1)
95		pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
96			client->addr + page, reg, val, ret);
97	return !(ret == 1);
98}
99
100static int ps8622_send_config(struct ps8622_bridge *ps8622)
101{
102	struct i2c_client *cl = ps8622->client;
103	int err = 0;
104
105	/* HPD low */
106	err = ps8622_set(cl, 0x02, 0xa1, 0x01);
107	if (err)
108		goto error;
109
110	/* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
111	err = ps8622_set(cl, 0x04, 0x14, 0x01);
112	if (err)
113		goto error;
114
115	/* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
116	err = ps8622_set(cl, 0x04, 0xe3, 0x20);
117	if (err)
118		goto error;
119
120	/* [7] RCO SS enable */
121	err = ps8622_set(cl, 0x04, 0xe2, 0x80);
122	if (err)
123		goto error;
124
125	/* RPHY Setting
126	 * [3:2] CDR tune wait cycle before measure for fine tune
127	 * b00: 1us b01: 0.5us b10:2us, b11: 4us
128	 */
129	err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
130	if (err)
131		goto error;
132
133	/* [3] RFD always on */
134	err = ps8622_set(cl, 0x04, 0x89, 0x08);
135	if (err)
136		goto error;
137
138	/* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
139	err = ps8622_set(cl, 0x04, 0x71, 0x2d);
140	if (err)
141		goto error;
142
143	/* 2.7G CDR settings: NOF=40LSB for HBR CDR  setting */
144	err = ps8622_set(cl, 0x04, 0x7d, 0x07);
145	if (err)
146		goto error;
147
148	/* [1:0] Fmin=+4bands */
149	err = ps8622_set(cl, 0x04, 0x7b, 0x00);
150	if (err)
151		goto error;
152
153	/* [7:5] DCO_FTRNG=+-40% */
154	err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
155	if (err)
156		goto error;
157
158	/* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
159	err = ps8622_set(cl, 0x04, 0xc0, 0x12);
160	if (err)
161		goto error;
162
163	/* Gitune=-37% */
164	err = ps8622_set(cl, 0x04, 0xc1, 0x92);
165	if (err)
166		goto error;
167
168	/* Fbstep=100% */
169	err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
170	if (err)
171		goto error;
172
173	/* [7] LOS signal disable */
174	err = ps8622_set(cl, 0x04, 0x32, 0x80);
175	if (err)
176		goto error;
177
178	/* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
179	err = ps8622_set(cl, 0x04, 0x00, 0xb0);
180	if (err)
181		goto error;
182
183	/* [7:6] Right-bar GPIO output strength is 8mA */
184	err = ps8622_set(cl, 0x04, 0x15, 0x40);
185	if (err)
186		goto error;
187
188	/* EQ Training State Machine Setting, RCO calibration start */
189	err = ps8622_set(cl, 0x04, 0x54, 0x10);
190	if (err)
191		goto error;
192
193	/* Logic, needs more than 10 I2C command */
194	/* [4:0] MAX_LANE_COUNT set to max supported lanes */
195	err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count);
196	if (err)
197		goto error;
198
199	/* [4:0] LANE_COUNT_SET set to chosen lane count */
200	err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count);
201	if (err)
202		goto error;
203
204	err = ps8622_set(cl, 0x00, 0x52, 0x20);
205	if (err)
206		goto error;
207
208	/* HPD CP toggle enable */
209	err = ps8622_set(cl, 0x00, 0xf1, 0x03);
210	if (err)
211		goto error;
212
213	err = ps8622_set(cl, 0x00, 0x62, 0x41);
214	if (err)
215		goto error;
216
217	/* Counter number, add 1ms counter delay */
218	err = ps8622_set(cl, 0x00, 0xf6, 0x01);
219	if (err)
220		goto error;
221
222	/* [6]PWM function control by DPCD0040f[7], default is PWM block */
223	err = ps8622_set(cl, 0x00, 0x77, 0x06);
224	if (err)
225		goto error;
226
227	/* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
228	err = ps8622_set(cl, 0x00, 0x4c, 0x04);
229	if (err)
230		goto error;
231
232	/* DPCD00400='h00, Parade OUI ='h001cf8 */
233	err = ps8622_set(cl, 0x01, 0xc0, 0x00);
234	if (err)
235		goto error;
236
237	/* DPCD00401='h1c */
238	err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
239	if (err)
240		goto error;
241
242	/* DPCD00402='hf8 */
243	err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
244	if (err)
245		goto error;
246
247	/* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
248	err = ps8622_set(cl, 0x01, 0xc3, 0x44);
249	if (err)
250		goto error;
251
252	/* DPCD404 */
253	err = ps8622_set(cl, 0x01, 0xc4, 0x32);
254	if (err)
255		goto error;
256
257	/* DPCD405 */
258	err = ps8622_set(cl, 0x01, 0xc5, 0x53);
259	if (err)
260		goto error;
261
262	/* DPCD406 */
263	err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
264	if (err)
265		goto error;
266
267	/* DPCD407 */
268	err = ps8622_set(cl, 0x01, 0xc7, 0x56);
269	if (err)
270		goto error;
271
272	/* DPCD408 */
273	err = ps8622_set(cl, 0x01, 0xc8, 0x35);
274	if (err)
275		goto error;
276
277	/* DPCD40A, Initial Code major revision '01' */
278	err = ps8622_set(cl, 0x01, 0xca, 0x01);
279	if (err)
280		goto error;
281
282	/* DPCD40B, Initial Code minor revision '05' */
283	err = ps8622_set(cl, 0x01, 0xcb, 0x05);
284	if (err)
285		goto error;
286
287
288	if (ps8622->bl) {
289		/* DPCD720, internal PWM */
290		err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
291		if (err)
292			goto error;
293
294		/* FFh for 100% brightness, 0h for 0% brightness */
295		err = ps8622_set(cl, 0x01, 0xa7,
296				ps8622->bl->props.brightness);
297		if (err)
298			goto error;
299	} else {
300		/* DPCD720, external PWM */
301		err = ps8622_set(cl, 0x01, 0xa5, 0x80);
302		if (err)
303			goto error;
304	}
305
306	/* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
307	err = ps8622_set(cl, 0x01, 0xcc, 0x13);
308	if (err)
309		goto error;
310
311	/* Enable SSC set by register */
312	err = ps8622_set(cl, 0x02, 0xb1, 0x20);
313	if (err)
314		goto error;
315
316	/* Set SSC enabled and +/-1% central spreading */
317	err = ps8622_set(cl, 0x04, 0x10, 0x16);
318	if (err)
319		goto error;
320
321	/* Logic end */
322	/* MPU Clock source: LC => RCO */
323	err = ps8622_set(cl, 0x04, 0x59, 0x60);
324	if (err)
325		goto error;
326
327	/* LC -> RCO */
328	err = ps8622_set(cl, 0x04, 0x54, 0x14);
329	if (err)
330		goto error;
331
332	/* HPD high */
333	err = ps8622_set(cl, 0x02, 0xa1, 0x91);
334
335error:
336	return err ? -EIO : 0;
337}
338
339static int ps8622_backlight_update(struct backlight_device *bl)
340{
341	struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
342	int ret, brightness = bl->props.brightness;
343
344	if (bl->props.power != FB_BLANK_UNBLANK ||
345	    bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
346		brightness = 0;
347
348	if (!ps8622->enabled)
349		return -EINVAL;
350
351	ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);
352
353	return ret;
354}
355
356static const struct backlight_ops ps8622_backlight_ops = {
357	.update_status	= ps8622_backlight_update,
358};
359
360static void ps8622_pre_enable(struct drm_bridge *bridge)
361{
362	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
363	int ret;
364
365	if (ps8622->enabled)
366		return;
367
368	gpiod_set_value(ps8622->gpio_rst, 0);
369
370	if (ps8622->v12) {
371		ret = regulator_enable(ps8622->v12);
372		if (ret)
373			DRM_ERROR("fails to enable ps8622->v12");
374	}
375
376	if (drm_panel_prepare(ps8622->panel)) {
377		DRM_ERROR("failed to prepare panel\n");
378		return;
379	}
380
381	gpiod_set_value(ps8622->gpio_slp, 1);
382
383	/*
384	 * T1 is the range of time that it takes for the power to rise after we
385	 * enable the lcd/ps8622 fet. T2 is the range of time in which the
386	 * data sheet specifies we should deassert the reset pin.
387	 *
388	 * If it takes T1.max for the power to rise, we need to wait atleast
389	 * T2.min before deasserting the reset pin. If it takes T1.min for the
390	 * power to rise, we need to wait at most T2.max before deasserting the
391	 * reset pin.
392	 */
393	usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
394		     PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);
395
396	gpiod_set_value(ps8622->gpio_rst, 1);
397
398	/* wait 20ms after RST high */
399	usleep_range(20000, 30000);
400
401	ret = ps8622_send_config(ps8622);
402	if (ret) {
403		DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
404		return;
405	}
406
407	ps8622->enabled = true;
408}
409
410static void ps8622_enable(struct drm_bridge *bridge)
411{
412	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
413
414	if (drm_panel_enable(ps8622->panel)) {
415		DRM_ERROR("failed to enable panel\n");
416		return;
417	}
418}
419
420static void ps8622_disable(struct drm_bridge *bridge)
421{
422	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
423
424	if (drm_panel_disable(ps8622->panel)) {
425		DRM_ERROR("failed to disable panel\n");
426		return;
427	}
428	msleep(PS8622_PWMO_END_T12_MS);
429}
430
431static void ps8622_post_disable(struct drm_bridge *bridge)
432{
433	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
434
435	if (!ps8622->enabled)
436		return;
437
438	ps8622->enabled = false;
439
440	/*
441	 * This doesn't matter if the regulators are turned off, but something
442	 * else might keep them on. In that case, we want to assert the slp gpio
443	 * to lower power.
444	 */
445	gpiod_set_value(ps8622->gpio_slp, 0);
446
447	if (drm_panel_unprepare(ps8622->panel)) {
448		DRM_ERROR("failed to unprepare panel\n");
449		return;
450	}
451
452	if (ps8622->v12)
453		regulator_disable(ps8622->v12);
454
455	/*
456	 * Sleep for at least the amount of time that it takes the power rail to
457	 * fall to prevent asserting the rst gpio from doing anything.
458	 */
459	usleep_range(PS8622_POWER_FALL_T16_MAX_US,
460		     2 * PS8622_POWER_FALL_T16_MAX_US);
461	gpiod_set_value(ps8622->gpio_rst, 0);
462
463	msleep(PS8622_POWER_OFF_T17_MS);
464}
465
466static int ps8622_get_modes(struct drm_connector *connector)
467{
468	struct ps8622_bridge *ps8622;
469
470	ps8622 = connector_to_ps8622(connector);
471
472	return drm_panel_get_modes(ps8622->panel);
473}
474
475static struct drm_encoder *ps8622_best_encoder(struct drm_connector *connector)
476{
477	struct ps8622_bridge *ps8622;
478
479	ps8622 = connector_to_ps8622(connector);
480
481	return ps8622->bridge.encoder;
482}
483
484static const struct drm_connector_helper_funcs ps8622_connector_helper_funcs = {
485	.get_modes = ps8622_get_modes,
486	.best_encoder = ps8622_best_encoder,
487};
488
489static enum drm_connector_status ps8622_detect(struct drm_connector *connector,
490								bool force)
491{
492	return connector_status_connected;
493}
494
495static void ps8622_connector_destroy(struct drm_connector *connector)
496{
497	drm_connector_cleanup(connector);
498}
499
500static const struct drm_connector_funcs ps8622_connector_funcs = {
501	.dpms = drm_helper_connector_dpms,
502	.fill_modes = drm_helper_probe_single_connector_modes,
503	.detect = ps8622_detect,
504	.destroy = ps8622_connector_destroy,
505};
506
507static int ps8622_attach(struct drm_bridge *bridge)
508{
509	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
510	int ret;
511
512	if (!bridge->encoder) {
513		DRM_ERROR("Parent encoder object not found");
514		return -ENODEV;
515	}
516
517	ps8622->connector.polled = DRM_CONNECTOR_POLL_HPD;
518	ret = drm_connector_init(bridge->dev, &ps8622->connector,
519			&ps8622_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
520	if (ret) {
521		DRM_ERROR("Failed to initialize connector with drm\n");
522		return ret;
523	}
524	drm_connector_helper_add(&ps8622->connector,
525					&ps8622_connector_helper_funcs);
526	drm_connector_register(&ps8622->connector);
527	drm_mode_connector_attach_encoder(&ps8622->connector,
528							bridge->encoder);
529
530	if (ps8622->panel)
531		drm_panel_attach(ps8622->panel, &ps8622->connector);
532
533	drm_helper_hpd_irq_event(ps8622->connector.dev);
534
535	return ret;
536}
537
538static const struct drm_bridge_funcs ps8622_bridge_funcs = {
539	.pre_enable = ps8622_pre_enable,
540	.enable = ps8622_enable,
541	.disable = ps8622_disable,
542	.post_disable = ps8622_post_disable,
543	.attach = ps8622_attach,
544};
545
546static const struct of_device_id ps8622_devices[] = {
547	{.compatible = "parade,ps8622",},
548	{.compatible = "parade,ps8625",},
549	{}
550};
551MODULE_DEVICE_TABLE(of, ps8622_devices);
552
553static int ps8622_probe(struct i2c_client *client,
554					const struct i2c_device_id *id)
555{
556	struct device *dev = &client->dev;
557	struct device_node *endpoint, *panel_node;
558	struct ps8622_bridge *ps8622;
559	int ret;
560
561	ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
562	if (!ps8622)
563		return -ENOMEM;
564
565	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
566	if (endpoint) {
567		panel_node = of_graph_get_remote_port_parent(endpoint);
568		if (panel_node) {
569			ps8622->panel = of_drm_find_panel(panel_node);
570			of_node_put(panel_node);
571			if (!ps8622->panel)
572				return -EPROBE_DEFER;
573		}
574	}
575
576	ps8622->client = client;
577
578	ps8622->v12 = devm_regulator_get(dev, "vdd12");
579	if (IS_ERR(ps8622->v12)) {
580		dev_info(dev, "no 1.2v regulator found for PS8622\n");
581		ps8622->v12 = NULL;
582	}
583
584	ps8622->gpio_slp = devm_gpiod_get(dev, "sleep");
585	if (IS_ERR(ps8622->gpio_slp)) {
586		ret = PTR_ERR(ps8622->gpio_slp);
587		dev_err(dev, "cannot get gpio_slp %d\n", ret);
588		return ret;
589	}
590	ret = gpiod_direction_output(ps8622->gpio_slp, 1);
591	if (ret) {
592		dev_err(dev, "cannot configure gpio_slp\n");
593		return ret;
594	}
595
596	ps8622->gpio_rst = devm_gpiod_get(dev, "reset");
597	if (IS_ERR(ps8622->gpio_rst)) {
598		ret = PTR_ERR(ps8622->gpio_rst);
599		dev_err(dev, "cannot get gpio_rst %d\n", ret);
600		return ret;
601	}
602	/*
603	 * Assert the reset pin high to avoid the bridge being
604	 * initialized prematurely
605	 */
606	ret = gpiod_direction_output(ps8622->gpio_rst, 1);
607	if (ret) {
608		dev_err(dev, "cannot configure gpio_rst\n");
609		return ret;
610	}
611
612	ps8622->max_lane_count = id->driver_data;
613
614	if (of_property_read_u32(dev->of_node, "lane-count",
615						&ps8622->lane_count)) {
616		ps8622->lane_count = ps8622->max_lane_count;
617	} else if (ps8622->lane_count > ps8622->max_lane_count) {
618		dev_info(dev, "lane-count property is too high,"
619						"using max_lane_count\n");
620		ps8622->lane_count = ps8622->max_lane_count;
621	}
622
623	if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
624		ps8622->bl = backlight_device_register("ps8622-backlight",
625				dev, ps8622, &ps8622_backlight_ops,
626				NULL);
627		if (IS_ERR(ps8622->bl)) {
628			DRM_ERROR("failed to register backlight\n");
629			ret = PTR_ERR(ps8622->bl);
630			ps8622->bl = NULL;
631			return ret;
632		}
633		ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
634		ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
635	}
636
637	ps8622->bridge.funcs = &ps8622_bridge_funcs;
638	ps8622->bridge.of_node = dev->of_node;
639	ret = drm_bridge_add(&ps8622->bridge);
640	if (ret) {
641		DRM_ERROR("Failed to add bridge\n");
642		return ret;
643	}
644
645	i2c_set_clientdata(client, ps8622);
646
647	return 0;
648}
649
650static int ps8622_remove(struct i2c_client *client)
651{
652	struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);
653
654	if (ps8622->bl)
655		backlight_device_unregister(ps8622->bl);
656
657	drm_bridge_remove(&ps8622->bridge);
658
659	return 0;
660}
661
662static const struct i2c_device_id ps8622_i2c_table[] = {
663	/* Device type, max_lane_count */
664	{"ps8622", 1},
665	{"ps8625", 2},
666	{},
667};
668MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);
669
670static struct i2c_driver ps8622_driver = {
671	.id_table	= ps8622_i2c_table,
672	.probe		= ps8622_probe,
673	.remove		= ps8622_remove,
674	.driver		= {
675		.name	= "ps8622",
676		.owner	= THIS_MODULE,
677		.of_match_table = ps8622_devices,
678	},
679};
680module_i2c_driver(ps8622_driver);
681
682MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
683MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
684MODULE_LICENSE("GPL v2");
685