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
44 struct 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
60 static inline struct ps8622_bridge *
bridge_to_ps8622(struct drm_bridge * bridge)61 bridge_to_ps8622(struct drm_bridge *bridge)
62 {
63 return container_of(bridge, struct ps8622_bridge, bridge);
64 }
65
ps8622_set(struct i2c_client * client,u8 page,u8 reg,u8 val)66 static 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
ps8622_send_config(struct ps8622_bridge * ps8622)85 static 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
320 error:
321 return err ? -EIO : 0;
322 }
323
ps8622_backlight_update(struct backlight_device * bl)324 static int ps8622_backlight_update(struct backlight_device *bl)
325 {
326 struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
327 int ret, brightness = backlight_get_brightness(bl);
328
329 if (!ps8622->enabled)
330 return -EINVAL;
331
332 ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);
333
334 return ret;
335 }
336
337 static const struct backlight_ops ps8622_backlight_ops = {
338 .update_status = ps8622_backlight_update,
339 };
340
ps8622_pre_enable(struct drm_bridge * bridge)341 static void ps8622_pre_enable(struct drm_bridge *bridge)
342 {
343 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
344 int ret;
345
346 if (ps8622->enabled)
347 return;
348
349 gpiod_set_value(ps8622->gpio_rst, 0);
350
351 if (ps8622->v12) {
352 ret = regulator_enable(ps8622->v12);
353 if (ret)
354 DRM_ERROR("fails to enable ps8622->v12");
355 }
356
357 gpiod_set_value(ps8622->gpio_slp, 1);
358
359 /*
360 * T1 is the range of time that it takes for the power to rise after we
361 * enable the lcd/ps8622 fet. T2 is the range of time in which the
362 * data sheet specifies we should deassert the reset pin.
363 *
364 * If it takes T1.max for the power to rise, we need to wait atleast
365 * T2.min before deasserting the reset pin. If it takes T1.min for the
366 * power to rise, we need to wait at most T2.max before deasserting the
367 * reset pin.
368 */
369 usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
370 PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);
371
372 gpiod_set_value(ps8622->gpio_rst, 1);
373
374 /* wait 20ms after RST high */
375 usleep_range(20000, 30000);
376
377 ret = ps8622_send_config(ps8622);
378 if (ret) {
379 DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
380 return;
381 }
382
383 ps8622->enabled = true;
384 }
385
ps8622_disable(struct drm_bridge * bridge)386 static void ps8622_disable(struct drm_bridge *bridge)
387 {
388 /* Delay after panel is disabled */
389 msleep(PS8622_PWMO_END_T12_MS);
390 }
391
ps8622_post_disable(struct drm_bridge * bridge)392 static void ps8622_post_disable(struct drm_bridge *bridge)
393 {
394 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
395
396 if (!ps8622->enabled)
397 return;
398
399 ps8622->enabled = false;
400
401 /*
402 * This doesn't matter if the regulators are turned off, but something
403 * else might keep them on. In that case, we want to assert the slp gpio
404 * to lower power.
405 */
406 gpiod_set_value(ps8622->gpio_slp, 0);
407
408 if (ps8622->v12)
409 regulator_disable(ps8622->v12);
410
411 /*
412 * Sleep for at least the amount of time that it takes the power rail to
413 * fall to prevent asserting the rst gpio from doing anything.
414 */
415 usleep_range(PS8622_POWER_FALL_T16_MAX_US,
416 2 * PS8622_POWER_FALL_T16_MAX_US);
417 gpiod_set_value(ps8622->gpio_rst, 0);
418
419 msleep(PS8622_POWER_OFF_T17_MS);
420 }
421
ps8622_attach(struct drm_bridge * bridge,enum drm_bridge_attach_flags flags)422 static int ps8622_attach(struct drm_bridge *bridge,
423 enum drm_bridge_attach_flags flags)
424 {
425 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
426
427 return drm_bridge_attach(ps8622->bridge.encoder, ps8622->panel_bridge,
428 &ps8622->bridge, flags);
429 }
430
431 static const struct drm_bridge_funcs ps8622_bridge_funcs = {
432 .pre_enable = ps8622_pre_enable,
433 .disable = ps8622_disable,
434 .post_disable = ps8622_post_disable,
435 .attach = ps8622_attach,
436 };
437
438 static const struct of_device_id ps8622_devices[] = {
439 {.compatible = "parade,ps8622",},
440 {.compatible = "parade,ps8625",},
441 {}
442 };
443 MODULE_DEVICE_TABLE(of, ps8622_devices);
444
ps8622_probe(struct i2c_client * client)445 static int ps8622_probe(struct i2c_client *client)
446 {
447 const struct i2c_device_id *id = i2c_client_get_device_id(client);
448 struct device *dev = &client->dev;
449 struct ps8622_bridge *ps8622;
450 struct drm_bridge *panel_bridge;
451 int ret;
452
453 ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
454 if (!ps8622)
455 return -ENOMEM;
456
457 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
458 if (IS_ERR(panel_bridge))
459 return PTR_ERR(panel_bridge);
460
461 ps8622->panel_bridge = panel_bridge;
462 ps8622->client = client;
463
464 ps8622->v12 = devm_regulator_get(dev, "vdd12");
465 if (IS_ERR(ps8622->v12)) {
466 dev_info(dev, "no 1.2v regulator found for PS8622\n");
467 ps8622->v12 = NULL;
468 }
469
470 ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH);
471 if (IS_ERR(ps8622->gpio_slp)) {
472 ret = PTR_ERR(ps8622->gpio_slp);
473 dev_err(dev, "cannot get gpio_slp %d\n", ret);
474 return ret;
475 }
476
477 /*
478 * Assert the reset pin high to avoid the bridge being
479 * initialized prematurely
480 */
481 ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
482 if (IS_ERR(ps8622->gpio_rst)) {
483 ret = PTR_ERR(ps8622->gpio_rst);
484 dev_err(dev, "cannot get gpio_rst %d\n", ret);
485 return ret;
486 }
487
488 ps8622->max_lane_count = id->driver_data;
489
490 if (of_property_read_u32(dev->of_node, "lane-count",
491 &ps8622->lane_count)) {
492 ps8622->lane_count = ps8622->max_lane_count;
493 } else if (ps8622->lane_count > ps8622->max_lane_count) {
494 dev_info(dev, "lane-count property is too high,"
495 "using max_lane_count\n");
496 ps8622->lane_count = ps8622->max_lane_count;
497 }
498
499 if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
500 ps8622->bl = backlight_device_register("ps8622-backlight",
501 dev, ps8622, &ps8622_backlight_ops,
502 NULL);
503 if (IS_ERR(ps8622->bl)) {
504 DRM_ERROR("failed to register backlight\n");
505 ret = PTR_ERR(ps8622->bl);
506 ps8622->bl = NULL;
507 return ret;
508 }
509 ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
510 ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
511 }
512
513 ps8622->bridge.funcs = &ps8622_bridge_funcs;
514 ps8622->bridge.type = DRM_MODE_CONNECTOR_LVDS;
515 ps8622->bridge.of_node = dev->of_node;
516 drm_bridge_add(&ps8622->bridge);
517
518 i2c_set_clientdata(client, ps8622);
519
520 return 0;
521 }
522
ps8622_remove(struct i2c_client * client)523 static void ps8622_remove(struct i2c_client *client)
524 {
525 struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);
526
527 backlight_device_unregister(ps8622->bl);
528 drm_bridge_remove(&ps8622->bridge);
529 }
530
531 static const struct i2c_device_id ps8622_i2c_table[] = {
532 /* Device type, max_lane_count */
533 {"ps8622", 1},
534 {"ps8625", 2},
535 {},
536 };
537 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);
538
539 static struct i2c_driver ps8622_driver = {
540 .id_table = ps8622_i2c_table,
541 .probe_new = ps8622_probe,
542 .remove = ps8622_remove,
543 .driver = {
544 .name = "ps8622",
545 .of_match_table = ps8622_devices,
546 },
547 };
548 module_i2c_driver(ps8622_driver);
549
550 MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
551 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
552 MODULE_LICENSE("GPL v2");
553