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