1 // SPDX-License-Identifier: GPL-2.0-only
3 * Parade PS8622 eDP/LVDS bridge driver
5 * Copyright (C) 2014 Google, Inc.
8 #include <linux/backlight.h>
9 #include <linux/delay.h>
10 #include <linux/err.h>
11 #include <linux/gpio.h>
12 #include <linux/gpio/consumer.h>
13 #include <linux/i2c.h>
14 #include <linux/module.h>
16 #include <linux/of_device.h>
18 #include <linux/regulator/consumer.h>
19 #include <drm/drm_atomic_helper.h>
20 #include <drm/drm_crtc.h>
21 #include <drm/drm_of.h>
22 #include <drm/drm_panel.h>
23 #include <drm/drm_probe_helper.h>
26 /* Brightness scale on the Parade chip */
27 #define PS8622_MAX_BRIGHTNESS 0xff
29 /* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
30 #define PS8622_POWER_RISE_T1_MIN_US 10
31 #define PS8622_POWER_RISE_T1_MAX_US 10000
32 #define PS8622_RST_HIGH_T2_MIN_US 3000
33 #define PS8622_RST_HIGH_T2_MAX_US 30000
34 #define PS8622_PWMO_END_T12_MS 200
35 #define PS8622_POWER_FALL_T16_MAX_US 10000
36 #define PS8622_POWER_OFF_T17_MS 500
38 #if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
39 (PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
40 #error "T2.min + T1.max must be less than T2.max + T1.min"
43 struct ps8622_bridge {
44 struct drm_connector connector;
45 struct i2c_client *client;
46 struct drm_bridge bridge;
47 struct drm_panel *panel;
48 struct regulator *v12;
49 struct backlight_device *bl;
51 struct gpio_desc *gpio_slp;
52 struct gpio_desc *gpio_rst;
60 static inline struct ps8622_bridge *
61 bridge_to_ps8622(struct drm_bridge *bridge)
63 return container_of(bridge, struct ps8622_bridge, bridge);
66 static inline struct ps8622_bridge *
67 connector_to_ps8622(struct drm_connector *connector)
69 return container_of(connector, struct ps8622_bridge, connector);
72 static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
75 struct i2c_adapter *adap = client->adapter;
77 u8 data[] = {reg, val};
79 msg.addr = client->addr + page;
81 msg.len = sizeof(data);
84 ret = i2c_transfer(adap, &msg, 1);
86 pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
87 client->addr + page, reg, val, ret);
91 static int ps8622_send_config(struct ps8622_bridge *ps8622)
93 struct i2c_client *cl = ps8622->client;
97 err = ps8622_set(cl, 0x02, 0xa1, 0x01);
101 /* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
102 err = ps8622_set(cl, 0x04, 0x14, 0x01);
106 /* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
107 err = ps8622_set(cl, 0x04, 0xe3, 0x20);
111 /* [7] RCO SS enable */
112 err = ps8622_set(cl, 0x04, 0xe2, 0x80);
117 * [3:2] CDR tune wait cycle before measure for fine tune
118 * b00: 1us b01: 0.5us b10:2us, b11: 4us
120 err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
124 /* [3] RFD always on */
125 err = ps8622_set(cl, 0x04, 0x89, 0x08);
129 /* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
130 err = ps8622_set(cl, 0x04, 0x71, 0x2d);
134 /* 2.7G CDR settings: NOF=40LSB for HBR CDR setting */
135 err = ps8622_set(cl, 0x04, 0x7d, 0x07);
139 /* [1:0] Fmin=+4bands */
140 err = ps8622_set(cl, 0x04, 0x7b, 0x00);
144 /* [7:5] DCO_FTRNG=+-40% */
145 err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
149 /* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
150 err = ps8622_set(cl, 0x04, 0xc0, 0x12);
155 err = ps8622_set(cl, 0x04, 0xc1, 0x92);
160 err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
164 /* [7] LOS signal disable */
165 err = ps8622_set(cl, 0x04, 0x32, 0x80);
169 /* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
170 err = ps8622_set(cl, 0x04, 0x00, 0xb0);
174 /* [7:6] Right-bar GPIO output strength is 8mA */
175 err = ps8622_set(cl, 0x04, 0x15, 0x40);
179 /* EQ Training State Machine Setting, RCO calibration start */
180 err = ps8622_set(cl, 0x04, 0x54, 0x10);
184 /* Logic, needs more than 10 I2C command */
185 /* [4:0] MAX_LANE_COUNT set to max supported lanes */
186 err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count);
190 /* [4:0] LANE_COUNT_SET set to chosen lane count */
191 err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count);
195 err = ps8622_set(cl, 0x00, 0x52, 0x20);
199 /* HPD CP toggle enable */
200 err = ps8622_set(cl, 0x00, 0xf1, 0x03);
204 err = ps8622_set(cl, 0x00, 0x62, 0x41);
208 /* Counter number, add 1ms counter delay */
209 err = ps8622_set(cl, 0x00, 0xf6, 0x01);
213 /* [6]PWM function control by DPCD0040f[7], default is PWM block */
214 err = ps8622_set(cl, 0x00, 0x77, 0x06);
218 /* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
219 err = ps8622_set(cl, 0x00, 0x4c, 0x04);
223 /* DPCD00400='h00, Parade OUI ='h001cf8 */
224 err = ps8622_set(cl, 0x01, 0xc0, 0x00);
229 err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
234 err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
238 /* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
239 err = ps8622_set(cl, 0x01, 0xc3, 0x44);
244 err = ps8622_set(cl, 0x01, 0xc4, 0x32);
249 err = ps8622_set(cl, 0x01, 0xc5, 0x53);
254 err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
259 err = ps8622_set(cl, 0x01, 0xc7, 0x56);
264 err = ps8622_set(cl, 0x01, 0xc8, 0x35);
268 /* DPCD40A, Initial Code major revision '01' */
269 err = ps8622_set(cl, 0x01, 0xca, 0x01);
273 /* DPCD40B, Initial Code minor revision '05' */
274 err = ps8622_set(cl, 0x01, 0xcb, 0x05);
280 /* DPCD720, internal PWM */
281 err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
285 /* FFh for 100% brightness, 0h for 0% brightness */
286 err = ps8622_set(cl, 0x01, 0xa7,
287 ps8622->bl->props.brightness);
291 /* DPCD720, external PWM */
292 err = ps8622_set(cl, 0x01, 0xa5, 0x80);
297 /* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
298 err = ps8622_set(cl, 0x01, 0xcc, 0x13);
302 /* Enable SSC set by register */
303 err = ps8622_set(cl, 0x02, 0xb1, 0x20);
307 /* Set SSC enabled and +/-1% central spreading */
308 err = ps8622_set(cl, 0x04, 0x10, 0x16);
313 /* MPU Clock source: LC => RCO */
314 err = ps8622_set(cl, 0x04, 0x59, 0x60);
319 err = ps8622_set(cl, 0x04, 0x54, 0x14);
324 err = ps8622_set(cl, 0x02, 0xa1, 0x91);
327 return err ? -EIO : 0;
330 static int ps8622_backlight_update(struct backlight_device *bl)
332 struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
333 int ret, brightness = bl->props.brightness;
335 if (bl->props.power != FB_BLANK_UNBLANK ||
336 bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
339 if (!ps8622->enabled)
342 ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);
347 static const struct backlight_ops ps8622_backlight_ops = {
348 .update_status = ps8622_backlight_update,
351 static void ps8622_pre_enable(struct drm_bridge *bridge)
353 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
359 gpiod_set_value(ps8622->gpio_rst, 0);
362 ret = regulator_enable(ps8622->v12);
364 DRM_ERROR("fails to enable ps8622->v12");
367 if (drm_panel_prepare(ps8622->panel)) {
368 DRM_ERROR("failed to prepare panel\n");
372 gpiod_set_value(ps8622->gpio_slp, 1);
375 * T1 is the range of time that it takes for the power to rise after we
376 * enable the lcd/ps8622 fet. T2 is the range of time in which the
377 * data sheet specifies we should deassert the reset pin.
379 * If it takes T1.max for the power to rise, we need to wait atleast
380 * T2.min before deasserting the reset pin. If it takes T1.min for the
381 * power to rise, we need to wait at most T2.max before deasserting the
384 usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
385 PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);
387 gpiod_set_value(ps8622->gpio_rst, 1);
389 /* wait 20ms after RST high */
390 usleep_range(20000, 30000);
392 ret = ps8622_send_config(ps8622);
394 DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
398 ps8622->enabled = true;
401 static void ps8622_enable(struct drm_bridge *bridge)
403 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
405 if (drm_panel_enable(ps8622->panel)) {
406 DRM_ERROR("failed to enable panel\n");
411 static void ps8622_disable(struct drm_bridge *bridge)
413 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
415 if (drm_panel_disable(ps8622->panel)) {
416 DRM_ERROR("failed to disable panel\n");
419 msleep(PS8622_PWMO_END_T12_MS);
422 static void ps8622_post_disable(struct drm_bridge *bridge)
424 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
426 if (!ps8622->enabled)
429 ps8622->enabled = false;
432 * This doesn't matter if the regulators are turned off, but something
433 * else might keep them on. In that case, we want to assert the slp gpio
436 gpiod_set_value(ps8622->gpio_slp, 0);
438 if (drm_panel_unprepare(ps8622->panel)) {
439 DRM_ERROR("failed to unprepare panel\n");
444 regulator_disable(ps8622->v12);
447 * Sleep for at least the amount of time that it takes the power rail to
448 * fall to prevent asserting the rst gpio from doing anything.
450 usleep_range(PS8622_POWER_FALL_T16_MAX_US,
451 2 * PS8622_POWER_FALL_T16_MAX_US);
452 gpiod_set_value(ps8622->gpio_rst, 0);
454 msleep(PS8622_POWER_OFF_T17_MS);
457 static int ps8622_get_modes(struct drm_connector *connector)
459 struct ps8622_bridge *ps8622;
461 ps8622 = connector_to_ps8622(connector);
463 return drm_panel_get_modes(ps8622->panel);
466 static const struct drm_connector_helper_funcs ps8622_connector_helper_funcs = {
467 .get_modes = ps8622_get_modes,
470 static const struct drm_connector_funcs ps8622_connector_funcs = {
471 .fill_modes = drm_helper_probe_single_connector_modes,
472 .destroy = drm_connector_cleanup,
473 .reset = drm_atomic_helper_connector_reset,
474 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
475 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
478 static int ps8622_attach(struct drm_bridge *bridge)
480 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
483 if (!bridge->encoder) {
484 DRM_ERROR("Parent encoder object not found");
488 ps8622->connector.polled = DRM_CONNECTOR_POLL_HPD;
489 ret = drm_connector_init(bridge->dev, &ps8622->connector,
490 &ps8622_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
492 DRM_ERROR("Failed to initialize connector with drm\n");
495 drm_connector_helper_add(&ps8622->connector,
496 &ps8622_connector_helper_funcs);
497 drm_connector_register(&ps8622->connector);
498 drm_connector_attach_encoder(&ps8622->connector,
502 drm_panel_attach(ps8622->panel, &ps8622->connector);
504 drm_helper_hpd_irq_event(ps8622->connector.dev);
509 static const struct drm_bridge_funcs ps8622_bridge_funcs = {
510 .pre_enable = ps8622_pre_enable,
511 .enable = ps8622_enable,
512 .disable = ps8622_disable,
513 .post_disable = ps8622_post_disable,
514 .attach = ps8622_attach,
517 static const struct of_device_id ps8622_devices[] = {
518 {.compatible = "parade,ps8622",},
519 {.compatible = "parade,ps8625",},
522 MODULE_DEVICE_TABLE(of, ps8622_devices);
524 static int ps8622_probe(struct i2c_client *client,
525 const struct i2c_device_id *id)
527 struct device *dev = &client->dev;
528 struct ps8622_bridge *ps8622;
531 ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
535 ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &ps8622->panel, NULL);
539 ps8622->client = client;
541 ps8622->v12 = devm_regulator_get(dev, "vdd12");
542 if (IS_ERR(ps8622->v12)) {
543 dev_info(dev, "no 1.2v regulator found for PS8622\n");
547 ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH);
548 if (IS_ERR(ps8622->gpio_slp)) {
549 ret = PTR_ERR(ps8622->gpio_slp);
550 dev_err(dev, "cannot get gpio_slp %d\n", ret);
555 * Assert the reset pin high to avoid the bridge being
556 * initialized prematurely
558 ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
559 if (IS_ERR(ps8622->gpio_rst)) {
560 ret = PTR_ERR(ps8622->gpio_rst);
561 dev_err(dev, "cannot get gpio_rst %d\n", ret);
565 ps8622->max_lane_count = id->driver_data;
567 if (of_property_read_u32(dev->of_node, "lane-count",
568 &ps8622->lane_count)) {
569 ps8622->lane_count = ps8622->max_lane_count;
570 } else if (ps8622->lane_count > ps8622->max_lane_count) {
571 dev_info(dev, "lane-count property is too high,"
572 "using max_lane_count\n");
573 ps8622->lane_count = ps8622->max_lane_count;
576 if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
577 ps8622->bl = backlight_device_register("ps8622-backlight",
578 dev, ps8622, &ps8622_backlight_ops,
580 if (IS_ERR(ps8622->bl)) {
581 DRM_ERROR("failed to register backlight\n");
582 ret = PTR_ERR(ps8622->bl);
586 ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
587 ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
590 ps8622->bridge.funcs = &ps8622_bridge_funcs;
591 ps8622->bridge.of_node = dev->of_node;
592 drm_bridge_add(&ps8622->bridge);
594 i2c_set_clientdata(client, ps8622);
599 static int ps8622_remove(struct i2c_client *client)
601 struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);
603 backlight_device_unregister(ps8622->bl);
604 drm_bridge_remove(&ps8622->bridge);
609 static const struct i2c_device_id ps8622_i2c_table[] = {
610 /* Device type, max_lane_count */
615 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);
617 static struct i2c_driver ps8622_driver = {
618 .id_table = ps8622_i2c_table,
619 .probe = ps8622_probe,
620 .remove = ps8622_remove,
623 .of_match_table = ps8622_devices,
626 module_i2c_driver(ps8622_driver);
628 MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
629 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
630 MODULE_LICENSE("GPL v2");