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/pm.h>
16 #include <linux/regulator/consumer.h>
17
18 #include <drm/drm_atomic_helper.h>
19 #include <drm/drm_bridge.h>
20 #include <drm/drm_crtc.h>
21 #include <drm/drm_of.h>
22 #include <drm/drm_print.h>
23 #include <drm/drm_probe_helper.h>
24
25 /* Brightness scale on the Parade chip */
26 #define PS8622_MAX_BRIGHTNESS 0xff
27
28 /* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
29 #define PS8622_POWER_RISE_T1_MIN_US 10
30 #define PS8622_POWER_RISE_T1_MAX_US 10000
31 #define PS8622_RST_HIGH_T2_MIN_US 3000
32 #define PS8622_RST_HIGH_T2_MAX_US 30000
33 #define PS8622_PWMO_END_T12_MS 200
34 #define PS8622_POWER_FALL_T16_MAX_US 10000
35 #define PS8622_POWER_OFF_T17_MS 500
36
37 #if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
38 (PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
39 #error "T2.min + T1.max must be less than T2.max + T1.min"
40 #endif
41
42 struct ps8622_bridge {
43 struct i2c_client *client;
44 struct drm_bridge bridge;
45 struct drm_bridge *panel_bridge;
46 struct regulator *v12;
47 struct backlight_device *bl;
48
49 struct gpio_desc *gpio_slp;
50 struct gpio_desc *gpio_rst;
51
52 u32 max_lane_count;
53 u32 lane_count;
54
55 bool enabled;
56 };
57
58 static inline struct ps8622_bridge *
bridge_to_ps8622(struct drm_bridge * bridge)59 bridge_to_ps8622(struct drm_bridge *bridge)
60 {
61 return container_of(bridge, struct ps8622_bridge, bridge);
62 }
63
ps8622_set(struct i2c_client * client,u8 page,u8 reg,u8 val)64 static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
65 {
66 int ret;
67 struct i2c_adapter *adap = client->adapter;
68 struct i2c_msg msg;
69 u8 data[] = {reg, val};
70
71 msg.addr = client->addr + page;
72 msg.flags = 0;
73 msg.len = sizeof(data);
74 msg.buf = data;
75
76 ret = i2c_transfer(adap, &msg, 1);
77 if (ret != 1)
78 pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
79 client->addr + page, reg, val, ret);
80 return !(ret == 1);
81 }
82
ps8622_send_config(struct ps8622_bridge * ps8622)83 static int ps8622_send_config(struct ps8622_bridge *ps8622)
84 {
85 struct i2c_client *cl = ps8622->client;
86 int err = 0;
87
88 /* HPD low */
89 err = ps8622_set(cl, 0x02, 0xa1, 0x01);
90 if (err)
91 goto error;
92
93 /* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
94 err = ps8622_set(cl, 0x04, 0x14, 0x01);
95 if (err)
96 goto error;
97
98 /* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
99 err = ps8622_set(cl, 0x04, 0xe3, 0x20);
100 if (err)
101 goto error;
102
103 /* [7] RCO SS enable */
104 err = ps8622_set(cl, 0x04, 0xe2, 0x80);
105 if (err)
106 goto error;
107
108 /* RPHY Setting
109 * [3:2] CDR tune wait cycle before measure for fine tune
110 * b00: 1us b01: 0.5us b10:2us, b11: 4us
111 */
112 err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
113 if (err)
114 goto error;
115
116 /* [3] RFD always on */
117 err = ps8622_set(cl, 0x04, 0x89, 0x08);
118 if (err)
119 goto error;
120
121 /* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
122 err = ps8622_set(cl, 0x04, 0x71, 0x2d);
123 if (err)
124 goto error;
125
126 /* 2.7G CDR settings: NOF=40LSB for HBR CDR setting */
127 err = ps8622_set(cl, 0x04, 0x7d, 0x07);
128 if (err)
129 goto error;
130
131 /* [1:0] Fmin=+4bands */
132 err = ps8622_set(cl, 0x04, 0x7b, 0x00);
133 if (err)
134 goto error;
135
136 /* [7:5] DCO_FTRNG=+-40% */
137 err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
138 if (err)
139 goto error;
140
141 /* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
142 err = ps8622_set(cl, 0x04, 0xc0, 0x12);
143 if (err)
144 goto error;
145
146 /* Gitune=-37% */
147 err = ps8622_set(cl, 0x04, 0xc1, 0x92);
148 if (err)
149 goto error;
150
151 /* Fbstep=100% */
152 err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
153 if (err)
154 goto error;
155
156 /* [7] LOS signal disable */
157 err = ps8622_set(cl, 0x04, 0x32, 0x80);
158 if (err)
159 goto error;
160
161 /* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
162 err = ps8622_set(cl, 0x04, 0x00, 0xb0);
163 if (err)
164 goto error;
165
166 /* [7:6] Right-bar GPIO output strength is 8mA */
167 err = ps8622_set(cl, 0x04, 0x15, 0x40);
168 if (err)
169 goto error;
170
171 /* EQ Training State Machine Setting, RCO calibration start */
172 err = ps8622_set(cl, 0x04, 0x54, 0x10);
173 if (err)
174 goto error;
175
176 /* Logic, needs more than 10 I2C command */
177 /* [4:0] MAX_LANE_COUNT set to max supported lanes */
178 err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count);
179 if (err)
180 goto error;
181
182 /* [4:0] LANE_COUNT_SET set to chosen lane count */
183 err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count);
184 if (err)
185 goto error;
186
187 err = ps8622_set(cl, 0x00, 0x52, 0x20);
188 if (err)
189 goto error;
190
191 /* HPD CP toggle enable */
192 err = ps8622_set(cl, 0x00, 0xf1, 0x03);
193 if (err)
194 goto error;
195
196 err = ps8622_set(cl, 0x00, 0x62, 0x41);
197 if (err)
198 goto error;
199
200 /* Counter number, add 1ms counter delay */
201 err = ps8622_set(cl, 0x00, 0xf6, 0x01);
202 if (err)
203 goto error;
204
205 /* [6]PWM function control by DPCD0040f[7], default is PWM block */
206 err = ps8622_set(cl, 0x00, 0x77, 0x06);
207 if (err)
208 goto error;
209
210 /* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
211 err = ps8622_set(cl, 0x00, 0x4c, 0x04);
212 if (err)
213 goto error;
214
215 /* DPCD00400='h00, Parade OUI ='h001cf8 */
216 err = ps8622_set(cl, 0x01, 0xc0, 0x00);
217 if (err)
218 goto error;
219
220 /* DPCD00401='h1c */
221 err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
222 if (err)
223 goto error;
224
225 /* DPCD00402='hf8 */
226 err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
227 if (err)
228 goto error;
229
230 /* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
231 err = ps8622_set(cl, 0x01, 0xc3, 0x44);
232 if (err)
233 goto error;
234
235 /* DPCD404 */
236 err = ps8622_set(cl, 0x01, 0xc4, 0x32);
237 if (err)
238 goto error;
239
240 /* DPCD405 */
241 err = ps8622_set(cl, 0x01, 0xc5, 0x53);
242 if (err)
243 goto error;
244
245 /* DPCD406 */
246 err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
247 if (err)
248 goto error;
249
250 /* DPCD407 */
251 err = ps8622_set(cl, 0x01, 0xc7, 0x56);
252 if (err)
253 goto error;
254
255 /* DPCD408 */
256 err = ps8622_set(cl, 0x01, 0xc8, 0x35);
257 if (err)
258 goto error;
259
260 /* DPCD40A, Initial Code major revision '01' */
261 err = ps8622_set(cl, 0x01, 0xca, 0x01);
262 if (err)
263 goto error;
264
265 /* DPCD40B, Initial Code minor revision '05' */
266 err = ps8622_set(cl, 0x01, 0xcb, 0x05);
267 if (err)
268 goto error;
269
270
271 if (ps8622->bl) {
272 /* DPCD720, internal PWM */
273 err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
274 if (err)
275 goto error;
276
277 /* FFh for 100% brightness, 0h for 0% brightness */
278 err = ps8622_set(cl, 0x01, 0xa7,
279 ps8622->bl->props.brightness);
280 if (err)
281 goto error;
282 } else {
283 /* DPCD720, external PWM */
284 err = ps8622_set(cl, 0x01, 0xa5, 0x80);
285 if (err)
286 goto error;
287 }
288
289 /* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
290 err = ps8622_set(cl, 0x01, 0xcc, 0x13);
291 if (err)
292 goto error;
293
294 /* Enable SSC set by register */
295 err = ps8622_set(cl, 0x02, 0xb1, 0x20);
296 if (err)
297 goto error;
298
299 /* Set SSC enabled and +/-1% central spreading */
300 err = ps8622_set(cl, 0x04, 0x10, 0x16);
301 if (err)
302 goto error;
303
304 /* Logic end */
305 /* MPU Clock source: LC => RCO */
306 err = ps8622_set(cl, 0x04, 0x59, 0x60);
307 if (err)
308 goto error;
309
310 /* LC -> RCO */
311 err = ps8622_set(cl, 0x04, 0x54, 0x14);
312 if (err)
313 goto error;
314
315 /* HPD high */
316 err = ps8622_set(cl, 0x02, 0xa1, 0x91);
317
318 error:
319 return err ? -EIO : 0;
320 }
321
ps8622_backlight_update(struct backlight_device * bl)322 static int ps8622_backlight_update(struct backlight_device *bl)
323 {
324 struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
325 int ret, brightness = backlight_get_brightness(bl);
326
327 if (!ps8622->enabled)
328 return -EINVAL;
329
330 ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);
331
332 return ret;
333 }
334
335 static const struct backlight_ops ps8622_backlight_ops = {
336 .update_status = ps8622_backlight_update,
337 };
338
ps8622_pre_enable(struct drm_bridge * bridge)339 static void ps8622_pre_enable(struct drm_bridge *bridge)
340 {
341 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
342 int ret;
343
344 if (ps8622->enabled)
345 return;
346
347 gpiod_set_value(ps8622->gpio_rst, 0);
348
349 if (ps8622->v12) {
350 ret = regulator_enable(ps8622->v12);
351 if (ret)
352 DRM_ERROR("fails to enable ps8622->v12");
353 }
354
355 gpiod_set_value(ps8622->gpio_slp, 1);
356
357 /*
358 * T1 is the range of time that it takes for the power to rise after we
359 * enable the lcd/ps8622 fet. T2 is the range of time in which the
360 * data sheet specifies we should deassert the reset pin.
361 *
362 * If it takes T1.max for the power to rise, we need to wait atleast
363 * T2.min before deasserting the reset pin. If it takes T1.min for the
364 * power to rise, we need to wait at most T2.max before deasserting the
365 * reset pin.
366 */
367 usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
368 PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);
369
370 gpiod_set_value(ps8622->gpio_rst, 1);
371
372 /* wait 20ms after RST high */
373 usleep_range(20000, 30000);
374
375 ret = ps8622_send_config(ps8622);
376 if (ret) {
377 DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
378 return;
379 }
380
381 ps8622->enabled = true;
382 }
383
ps8622_disable(struct drm_bridge * bridge)384 static void ps8622_disable(struct drm_bridge *bridge)
385 {
386 /* Delay after panel is disabled */
387 msleep(PS8622_PWMO_END_T12_MS);
388 }
389
ps8622_post_disable(struct drm_bridge * bridge)390 static void ps8622_post_disable(struct drm_bridge *bridge)
391 {
392 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
393
394 if (!ps8622->enabled)
395 return;
396
397 ps8622->enabled = false;
398
399 /*
400 * This doesn't matter if the regulators are turned off, but something
401 * else might keep them on. In that case, we want to assert the slp gpio
402 * to lower power.
403 */
404 gpiod_set_value(ps8622->gpio_slp, 0);
405
406 if (ps8622->v12)
407 regulator_disable(ps8622->v12);
408
409 /*
410 * Sleep for at least the amount of time that it takes the power rail to
411 * fall to prevent asserting the rst gpio from doing anything.
412 */
413 usleep_range(PS8622_POWER_FALL_T16_MAX_US,
414 2 * PS8622_POWER_FALL_T16_MAX_US);
415 gpiod_set_value(ps8622->gpio_rst, 0);
416
417 msleep(PS8622_POWER_OFF_T17_MS);
418 }
419
ps8622_attach(struct drm_bridge * bridge,struct drm_encoder * encoder,enum drm_bridge_attach_flags flags)420 static int ps8622_attach(struct drm_bridge *bridge,
421 struct drm_encoder *encoder,
422 enum drm_bridge_attach_flags flags)
423 {
424 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
425
426 return drm_bridge_attach(ps8622->bridge.encoder, ps8622->panel_bridge,
427 &ps8622->bridge, flags);
428 }
429
430 static const struct drm_bridge_funcs ps8622_bridge_funcs = {
431 .pre_enable = ps8622_pre_enable,
432 .disable = ps8622_disable,
433 .post_disable = ps8622_post_disable,
434 .attach = ps8622_attach,
435 };
436
437 static const struct of_device_id ps8622_devices[] = {
438 {.compatible = "parade,ps8622",},
439 {.compatible = "parade,ps8625",},
440 {}
441 };
442 MODULE_DEVICE_TABLE(of, ps8622_devices);
443
ps8622_probe(struct i2c_client * client)444 static int ps8622_probe(struct i2c_client *client)
445 {
446 const struct i2c_device_id *id = i2c_client_get_device_id(client);
447 struct device *dev = &client->dev;
448 struct ps8622_bridge *ps8622;
449 struct drm_bridge *panel_bridge;
450 int ret;
451
452 ps8622 = devm_drm_bridge_alloc(dev, struct ps8622_bridge, bridge,
453 &ps8622_bridge_funcs);
454 if (IS_ERR(ps8622))
455 return PTR_ERR(ps8622);
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_property_read_bool(dev->of_node, "use-external-pwm")) {
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.type = DRM_MODE_CONNECTOR_LVDS;
514 ps8622->bridge.of_node = dev->of_node;
515 drm_bridge_add(&ps8622->bridge);
516
517 i2c_set_clientdata(client, ps8622);
518
519 return 0;
520 }
521
ps8622_remove(struct i2c_client * client)522 static void ps8622_remove(struct i2c_client *client)
523 {
524 struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);
525
526 backlight_device_unregister(ps8622->bl);
527 drm_bridge_remove(&ps8622->bridge);
528 }
529
530 static const struct i2c_device_id ps8622_i2c_table[] = {
531 /* Device type, max_lane_count */
532 {"ps8622", 1},
533 {"ps8625", 2},
534 {},
535 };
536 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);
537
538 static struct i2c_driver ps8622_driver = {
539 .id_table = ps8622_i2c_table,
540 .probe = ps8622_probe,
541 .remove = ps8622_remove,
542 .driver = {
543 .name = "ps8622",
544 .of_match_table = ps8622_devices,
545 },
546 };
547 module_i2c_driver(ps8622_driver);
548
549 MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
550 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
551 MODULE_LICENSE("GPL v2");
552