1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Parade PS8622 eDP/LVDS bridge driver
4 *
5 * Copyright (C) 2014 Google, Inc.
6 */
7
8#include <linux/backlight.h>
9#include <linux/delay.h>
10#include <linux/err.h>
11#include <linux/gpio/consumer.h>
12#include <linux/i2c.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/of_device.h>
16#include <linux/pm.h>
17#include <linux/regulator/consumer.h>
18
19#include <drm/drm_atomic_helper.h>
20#include <drm/drm_bridge.h>
21#include <drm/drm_crtc.h>
22#include <drm/drm_of.h>
23#include <drm/drm_panel.h>
24#include <drm/drm_print.h>
25#include <drm/drm_probe_helper.h>
26
27/* Brightness scale on the Parade chip */
28#define PS8622_MAX_BRIGHTNESS 0xff
29
30/* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
31#define PS8622_POWER_RISE_T1_MIN_US 10
32#define PS8622_POWER_RISE_T1_MAX_US 10000
33#define PS8622_RST_HIGH_T2_MIN_US 3000
34#define PS8622_RST_HIGH_T2_MAX_US 30000
35#define PS8622_PWMO_END_T12_MS 200
36#define PS8622_POWER_FALL_T16_MAX_US 10000
37#define PS8622_POWER_OFF_T17_MS 500
38
39#if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
40	(PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
41#error "T2.min + T1.max must be less than T2.max + T1.min"
42#endif
43
44struct ps8622_bridge {
45	struct i2c_client *client;
46	struct drm_bridge bridge;
47	struct drm_bridge *panel_bridge;
48	struct regulator *v12;
49	struct backlight_device *bl;
50
51	struct gpio_desc *gpio_slp;
52	struct gpio_desc *gpio_rst;
53
54	u32 max_lane_count;
55	u32 lane_count;
56
57	bool enabled;
58};
59
60static inline struct ps8622_bridge *
61		bridge_to_ps8622(struct drm_bridge *bridge)
62{
63	return container_of(bridge, struct ps8622_bridge, bridge);
64}
65
66static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
67{
68	int ret;
69	struct i2c_adapter *adap = client->adapter;
70	struct i2c_msg msg;
71	u8 data[] = {reg, val};
72
73	msg.addr = client->addr + page;
74	msg.flags = 0;
75	msg.len = sizeof(data);
76	msg.buf = data;
77
78	ret = i2c_transfer(adap, &msg, 1);
79	if (ret != 1)
80		pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
81			client->addr + page, reg, val, ret);
82	return !(ret == 1);
83}
84
85static int ps8622_send_config(struct ps8622_bridge *ps8622)
86{
87	struct i2c_client *cl = ps8622->client;
88	int err = 0;
89
90	/* HPD low */
91	err = ps8622_set(cl, 0x02, 0xa1, 0x01);
92	if (err)
93		goto error;
94
95	/* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
96	err = ps8622_set(cl, 0x04, 0x14, 0x01);
97	if (err)
98		goto error;
99
100	/* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
101	err = ps8622_set(cl, 0x04, 0xe3, 0x20);
102	if (err)
103		goto error;
104
105	/* [7] RCO SS enable */
106	err = ps8622_set(cl, 0x04, 0xe2, 0x80);
107	if (err)
108		goto error;
109
110	/* RPHY Setting
111	 * [3:2] CDR tune wait cycle before measure for fine tune
112	 * b00: 1us b01: 0.5us b10:2us, b11: 4us
113	 */
114	err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
115	if (err)
116		goto error;
117
118	/* [3] RFD always on */
119	err = ps8622_set(cl, 0x04, 0x89, 0x08);
120	if (err)
121		goto error;
122
123	/* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
124	err = ps8622_set(cl, 0x04, 0x71, 0x2d);
125	if (err)
126		goto error;
127
128	/* 2.7G CDR settings: NOF=40LSB for HBR CDR  setting */
129	err = ps8622_set(cl, 0x04, 0x7d, 0x07);
130	if (err)
131		goto error;
132
133	/* [1:0] Fmin=+4bands */
134	err = ps8622_set(cl, 0x04, 0x7b, 0x00);
135	if (err)
136		goto error;
137
138	/* [7:5] DCO_FTRNG=+-40% */
139	err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
140	if (err)
141		goto error;
142
143	/* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
144	err = ps8622_set(cl, 0x04, 0xc0, 0x12);
145	if (err)
146		goto error;
147
148	/* Gitune=-37% */
149	err = ps8622_set(cl, 0x04, 0xc1, 0x92);
150	if (err)
151		goto error;
152
153	/* Fbstep=100% */
154	err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
155	if (err)
156		goto error;
157
158	/* [7] LOS signal disable */
159	err = ps8622_set(cl, 0x04, 0x32, 0x80);
160	if (err)
161		goto error;
162
163	/* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
164	err = ps8622_set(cl, 0x04, 0x00, 0xb0);
165	if (err)
166		goto error;
167
168	/* [7:6] Right-bar GPIO output strength is 8mA */
169	err = ps8622_set(cl, 0x04, 0x15, 0x40);
170	if (err)
171		goto error;
172
173	/* EQ Training State Machine Setting, RCO calibration start */
174	err = ps8622_set(cl, 0x04, 0x54, 0x10);
175	if (err)
176		goto error;
177
178	/* Logic, needs more than 10 I2C command */
179	/* [4:0] MAX_LANE_COUNT set to max supported lanes */
180	err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count);
181	if (err)
182		goto error;
183
184	/* [4:0] LANE_COUNT_SET set to chosen lane count */
185	err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count);
186	if (err)
187		goto error;
188
189	err = ps8622_set(cl, 0x00, 0x52, 0x20);
190	if (err)
191		goto error;
192
193	/* HPD CP toggle enable */
194	err = ps8622_set(cl, 0x00, 0xf1, 0x03);
195	if (err)
196		goto error;
197
198	err = ps8622_set(cl, 0x00, 0x62, 0x41);
199	if (err)
200		goto error;
201
202	/* Counter number, add 1ms counter delay */
203	err = ps8622_set(cl, 0x00, 0xf6, 0x01);
204	if (err)
205		goto error;
206
207	/* [6]PWM function control by DPCD0040f[7], default is PWM block */
208	err = ps8622_set(cl, 0x00, 0x77, 0x06);
209	if (err)
210		goto error;
211
212	/* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
213	err = ps8622_set(cl, 0x00, 0x4c, 0x04);
214	if (err)
215		goto error;
216
217	/* DPCD00400='h00, Parade OUI ='h001cf8 */
218	err = ps8622_set(cl, 0x01, 0xc0, 0x00);
219	if (err)
220		goto error;
221
222	/* DPCD00401='h1c */
223	err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
224	if (err)
225		goto error;
226
227	/* DPCD00402='hf8 */
228	err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
229	if (err)
230		goto error;
231
232	/* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
233	err = ps8622_set(cl, 0x01, 0xc3, 0x44);
234	if (err)
235		goto error;
236
237	/* DPCD404 */
238	err = ps8622_set(cl, 0x01, 0xc4, 0x32);
239	if (err)
240		goto error;
241
242	/* DPCD405 */
243	err = ps8622_set(cl, 0x01, 0xc5, 0x53);
244	if (err)
245		goto error;
246
247	/* DPCD406 */
248	err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
249	if (err)
250		goto error;
251
252	/* DPCD407 */
253	err = ps8622_set(cl, 0x01, 0xc7, 0x56);
254	if (err)
255		goto error;
256
257	/* DPCD408 */
258	err = ps8622_set(cl, 0x01, 0xc8, 0x35);
259	if (err)
260		goto error;
261
262	/* DPCD40A, Initial Code major revision '01' */
263	err = ps8622_set(cl, 0x01, 0xca, 0x01);
264	if (err)
265		goto error;
266
267	/* DPCD40B, Initial Code minor revision '05' */
268	err = ps8622_set(cl, 0x01, 0xcb, 0x05);
269	if (err)
270		goto error;
271
272
273	if (ps8622->bl) {
274		/* DPCD720, internal PWM */
275		err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
276		if (err)
277			goto error;
278
279		/* FFh for 100% brightness, 0h for 0% brightness */
280		err = ps8622_set(cl, 0x01, 0xa7,
281				ps8622->bl->props.brightness);
282		if (err)
283			goto error;
284	} else {
285		/* DPCD720, external PWM */
286		err = ps8622_set(cl, 0x01, 0xa5, 0x80);
287		if (err)
288			goto error;
289	}
290
291	/* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
292	err = ps8622_set(cl, 0x01, 0xcc, 0x13);
293	if (err)
294		goto error;
295
296	/* Enable SSC set by register */
297	err = ps8622_set(cl, 0x02, 0xb1, 0x20);
298	if (err)
299		goto error;
300
301	/* Set SSC enabled and +/-1% central spreading */
302	err = ps8622_set(cl, 0x04, 0x10, 0x16);
303	if (err)
304		goto error;
305
306	/* Logic end */
307	/* MPU Clock source: LC => RCO */
308	err = ps8622_set(cl, 0x04, 0x59, 0x60);
309	if (err)
310		goto error;
311
312	/* LC -> RCO */
313	err = ps8622_set(cl, 0x04, 0x54, 0x14);
314	if (err)
315		goto error;
316
317	/* HPD high */
318	err = ps8622_set(cl, 0x02, 0xa1, 0x91);
319
320error:
321	return err ? -EIO : 0;
322}
323
324static int ps8622_backlight_update(struct backlight_device *bl)
325{
326	struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
327	int ret, brightness = bl->props.brightness;
328
329	if (bl->props.power != FB_BLANK_UNBLANK ||
330	    bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
331		brightness = 0;
332
333	if (!ps8622->enabled)
334		return -EINVAL;
335
336	ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);
337
338	return ret;
339}
340
341static const struct backlight_ops ps8622_backlight_ops = {
342	.update_status	= ps8622_backlight_update,
343};
344
345static void ps8622_pre_enable(struct drm_bridge *bridge)
346{
347	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
348	int ret;
349
350	if (ps8622->enabled)
351		return;
352
353	gpiod_set_value(ps8622->gpio_rst, 0);
354
355	if (ps8622->v12) {
356		ret = regulator_enable(ps8622->v12);
357		if (ret)
358			DRM_ERROR("fails to enable ps8622->v12");
359	}
360
361	gpiod_set_value(ps8622->gpio_slp, 1);
362
363	/*
364	 * T1 is the range of time that it takes for the power to rise after we
365	 * enable the lcd/ps8622 fet. T2 is the range of time in which the
366	 * data sheet specifies we should deassert the reset pin.
367	 *
368	 * If it takes T1.max for the power to rise, we need to wait atleast
369	 * T2.min before deasserting the reset pin. If it takes T1.min for the
370	 * power to rise, we need to wait at most T2.max before deasserting the
371	 * reset pin.
372	 */
373	usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
374		     PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);
375
376	gpiod_set_value(ps8622->gpio_rst, 1);
377
378	/* wait 20ms after RST high */
379	usleep_range(20000, 30000);
380
381	ret = ps8622_send_config(ps8622);
382	if (ret) {
383		DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
384		return;
385	}
386
387	ps8622->enabled = true;
388}
389
390static void ps8622_disable(struct drm_bridge *bridge)
391{
392	/* Delay after panel is disabled */
393	msleep(PS8622_PWMO_END_T12_MS);
394}
395
396static void ps8622_post_disable(struct drm_bridge *bridge)
397{
398	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
399
400	if (!ps8622->enabled)
401		return;
402
403	ps8622->enabled = false;
404
405	/*
406	 * This doesn't matter if the regulators are turned off, but something
407	 * else might keep them on. In that case, we want to assert the slp gpio
408	 * to lower power.
409	 */
410	gpiod_set_value(ps8622->gpio_slp, 0);
411
412	if (ps8622->v12)
413		regulator_disable(ps8622->v12);
414
415	/*
416	 * Sleep for at least the amount of time that it takes the power rail to
417	 * fall to prevent asserting the rst gpio from doing anything.
418	 */
419	usleep_range(PS8622_POWER_FALL_T16_MAX_US,
420		     2 * PS8622_POWER_FALL_T16_MAX_US);
421	gpiod_set_value(ps8622->gpio_rst, 0);
422
423	msleep(PS8622_POWER_OFF_T17_MS);
424}
425
426static int ps8622_attach(struct drm_bridge *bridge,
427			 enum drm_bridge_attach_flags flags)
428{
429	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
430
431	return drm_bridge_attach(ps8622->bridge.encoder, ps8622->panel_bridge,
432				 &ps8622->bridge, flags);
433}
434
435static const struct drm_bridge_funcs ps8622_bridge_funcs = {
436	.pre_enable = ps8622_pre_enable,
437	.disable = ps8622_disable,
438	.post_disable = ps8622_post_disable,
439	.attach = ps8622_attach,
440};
441
442static const struct of_device_id ps8622_devices[] = {
443	{.compatible = "parade,ps8622",},
444	{.compatible = "parade,ps8625",},
445	{}
446};
447MODULE_DEVICE_TABLE(of, ps8622_devices);
448
449static int ps8622_probe(struct i2c_client *client,
450					const struct i2c_device_id *id)
451{
452	struct device *dev = &client->dev;
453	struct ps8622_bridge *ps8622;
454	struct drm_bridge *panel_bridge;
455	struct drm_panel *panel;
456	int ret;
457
458	ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
459	if (!ps8622)
460		return -ENOMEM;
461
462	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &panel, NULL);
463	if (ret)
464		return ret;
465
466	panel_bridge = devm_drm_panel_bridge_add(dev, panel);
467	if (IS_ERR(panel_bridge))
468		return PTR_ERR(panel_bridge);
469
470	ps8622->panel_bridge = panel_bridge;
471	ps8622->client = client;
472
473	ps8622->v12 = devm_regulator_get(dev, "vdd12");
474	if (IS_ERR(ps8622->v12)) {
475		dev_info(dev, "no 1.2v regulator found for PS8622\n");
476		ps8622->v12 = NULL;
477	}
478
479	ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH);
480	if (IS_ERR(ps8622->gpio_slp)) {
481		ret = PTR_ERR(ps8622->gpio_slp);
482		dev_err(dev, "cannot get gpio_slp %d\n", ret);
483		return ret;
484	}
485
486	/*
487	 * Assert the reset pin high to avoid the bridge being
488	 * initialized prematurely
489	 */
490	ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
491	if (IS_ERR(ps8622->gpio_rst)) {
492		ret = PTR_ERR(ps8622->gpio_rst);
493		dev_err(dev, "cannot get gpio_rst %d\n", ret);
494		return ret;
495	}
496
497	ps8622->max_lane_count = id->driver_data;
498
499	if (of_property_read_u32(dev->of_node, "lane-count",
500						&ps8622->lane_count)) {
501		ps8622->lane_count = ps8622->max_lane_count;
502	} else if (ps8622->lane_count > ps8622->max_lane_count) {
503		dev_info(dev, "lane-count property is too high,"
504						"using max_lane_count\n");
505		ps8622->lane_count = ps8622->max_lane_count;
506	}
507
508	if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
509		ps8622->bl = backlight_device_register("ps8622-backlight",
510				dev, ps8622, &ps8622_backlight_ops,
511				NULL);
512		if (IS_ERR(ps8622->bl)) {
513			DRM_ERROR("failed to register backlight\n");
514			ret = PTR_ERR(ps8622->bl);
515			ps8622->bl = NULL;
516			return ret;
517		}
518		ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
519		ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
520	}
521
522	ps8622->bridge.funcs = &ps8622_bridge_funcs;
523	ps8622->bridge.type = DRM_MODE_CONNECTOR_LVDS;
524	ps8622->bridge.of_node = dev->of_node;
525	drm_bridge_add(&ps8622->bridge);
526
527	i2c_set_clientdata(client, ps8622);
528
529	return 0;
530}
531
532static int ps8622_remove(struct i2c_client *client)
533{
534	struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);
535
536	backlight_device_unregister(ps8622->bl);
537	drm_bridge_remove(&ps8622->bridge);
538
539	return 0;
540}
541
542static const struct i2c_device_id ps8622_i2c_table[] = {
543	/* Device type, max_lane_count */
544	{"ps8622", 1},
545	{"ps8625", 2},
546	{},
547};
548MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);
549
550static struct i2c_driver ps8622_driver = {
551	.id_table	= ps8622_i2c_table,
552	.probe		= ps8622_probe,
553	.remove		= ps8622_remove,
554	.driver		= {
555		.name	= "ps8622",
556		.of_match_table = ps8622_devices,
557	},
558};
559module_i2c_driver(ps8622_driver);
560
561MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
562MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
563MODULE_LICENSE("GPL v2");
564