2 * Parade PS8622 eDP/LVDS bridge driver
4 * Copyright (C) 2014 Google, Inc.
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
16 #include <linux/backlight.h>
17 #include <linux/delay.h>
18 #include <linux/err.h>
20 #include <linux/gpio.h>
21 #include <linux/i2c.h>
22 #include <linux/module.h>
24 #include <linux/of_device.h>
25 #include <linux/of_graph.h>
27 #include <linux/regulator/consumer.h>
29 #include <drm/drm_panel.h>
33 #include "drm_crtc_helper.h"
35 /* Brightness scale on the Parade chip */
36 #define PS8622_MAX_BRIGHTNESS 0xff
38 /* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
39 #define PS8622_POWER_RISE_T1_MIN_US 10
40 #define PS8622_POWER_RISE_T1_MAX_US 10000
41 #define PS8622_RST_HIGH_T2_MIN_US 3000
42 #define PS8622_RST_HIGH_T2_MAX_US 30000
43 #define PS8622_PWMO_END_T12_MS 200
44 #define PS8622_POWER_FALL_T16_MAX_US 10000
45 #define PS8622_POWER_OFF_T17_MS 500
47 #if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
48 (PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
49 #error "T2.min + T1.max must be less than T2.max + T1.min"
52 struct ps8622_bridge {
53 struct drm_connector connector;
54 struct i2c_client *client;
55 struct drm_bridge bridge;
56 struct drm_panel *panel;
57 struct regulator *v12;
58 struct backlight_device *bl;
60 struct gpio_desc *gpio_slp;
61 struct gpio_desc *gpio_rst;
69 static inline struct ps8622_bridge *
70 bridge_to_ps8622(struct drm_bridge *bridge)
72 return container_of(bridge, struct ps8622_bridge, bridge);
75 static inline struct ps8622_bridge *
76 connector_to_ps8622(struct drm_connector *connector)
78 return container_of(connector, struct ps8622_bridge, connector);
81 static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
84 struct i2c_adapter *adap = client->adapter;
86 u8 data[] = {reg, val};
88 msg.addr = client->addr + page;
90 msg.len = sizeof(data);
93 ret = i2c_transfer(adap, &msg, 1);
95 pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
96 client->addr + page, reg, val, ret);
100 static int ps8622_send_config(struct ps8622_bridge *ps8622)
102 struct i2c_client *cl = ps8622->client;
106 err = ps8622_set(cl, 0x02, 0xa1, 0x01);
110 /* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
111 err = ps8622_set(cl, 0x04, 0x14, 0x01);
115 /* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
116 err = ps8622_set(cl, 0x04, 0xe3, 0x20);
120 /* [7] RCO SS enable */
121 err = ps8622_set(cl, 0x04, 0xe2, 0x80);
126 * [3:2] CDR tune wait cycle before measure for fine tune
127 * b00: 1us b01: 0.5us b10:2us, b11: 4us
129 err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
133 /* [3] RFD always on */
134 err = ps8622_set(cl, 0x04, 0x89, 0x08);
138 /* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
139 err = ps8622_set(cl, 0x04, 0x71, 0x2d);
143 /* 2.7G CDR settings: NOF=40LSB for HBR CDR setting */
144 err = ps8622_set(cl, 0x04, 0x7d, 0x07);
148 /* [1:0] Fmin=+4bands */
149 err = ps8622_set(cl, 0x04, 0x7b, 0x00);
153 /* [7:5] DCO_FTRNG=+-40% */
154 err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
158 /* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
159 err = ps8622_set(cl, 0x04, 0xc0, 0x12);
164 err = ps8622_set(cl, 0x04, 0xc1, 0x92);
169 err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
173 /* [7] LOS signal disable */
174 err = ps8622_set(cl, 0x04, 0x32, 0x80);
178 /* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
179 err = ps8622_set(cl, 0x04, 0x00, 0xb0);
183 /* [7:6] Right-bar GPIO output strength is 8mA */
184 err = ps8622_set(cl, 0x04, 0x15, 0x40);
188 /* EQ Training State Machine Setting, RCO calibration start */
189 err = ps8622_set(cl, 0x04, 0x54, 0x10);
193 /* Logic, needs more than 10 I2C command */
194 /* [4:0] MAX_LANE_COUNT set to max supported lanes */
195 err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count);
199 /* [4:0] LANE_COUNT_SET set to chosen lane count */
200 err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count);
204 err = ps8622_set(cl, 0x00, 0x52, 0x20);
208 /* HPD CP toggle enable */
209 err = ps8622_set(cl, 0x00, 0xf1, 0x03);
213 err = ps8622_set(cl, 0x00, 0x62, 0x41);
217 /* Counter number, add 1ms counter delay */
218 err = ps8622_set(cl, 0x00, 0xf6, 0x01);
222 /* [6]PWM function control by DPCD0040f[7], default is PWM block */
223 err = ps8622_set(cl, 0x00, 0x77, 0x06);
227 /* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
228 err = ps8622_set(cl, 0x00, 0x4c, 0x04);
232 /* DPCD00400='h00, Parade OUI ='h001cf8 */
233 err = ps8622_set(cl, 0x01, 0xc0, 0x00);
238 err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
243 err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
247 /* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
248 err = ps8622_set(cl, 0x01, 0xc3, 0x44);
253 err = ps8622_set(cl, 0x01, 0xc4, 0x32);
258 err = ps8622_set(cl, 0x01, 0xc5, 0x53);
263 err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
268 err = ps8622_set(cl, 0x01, 0xc7, 0x56);
273 err = ps8622_set(cl, 0x01, 0xc8, 0x35);
277 /* DPCD40A, Initial Code major revision '01' */
278 err = ps8622_set(cl, 0x01, 0xca, 0x01);
282 /* DPCD40B, Initial Code minor revision '05' */
283 err = ps8622_set(cl, 0x01, 0xcb, 0x05);
289 /* DPCD720, internal PWM */
290 err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
294 /* FFh for 100% brightness, 0h for 0% brightness */
295 err = ps8622_set(cl, 0x01, 0xa7,
296 ps8622->bl->props.brightness);
300 /* DPCD720, external PWM */
301 err = ps8622_set(cl, 0x01, 0xa5, 0x80);
306 /* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
307 err = ps8622_set(cl, 0x01, 0xcc, 0x13);
311 /* Enable SSC set by register */
312 err = ps8622_set(cl, 0x02, 0xb1, 0x20);
316 /* Set SSC enabled and +/-1% central spreading */
317 err = ps8622_set(cl, 0x04, 0x10, 0x16);
322 /* MPU Clock source: LC => RCO */
323 err = ps8622_set(cl, 0x04, 0x59, 0x60);
328 err = ps8622_set(cl, 0x04, 0x54, 0x14);
333 err = ps8622_set(cl, 0x02, 0xa1, 0x91);
336 return err ? -EIO : 0;
339 static int ps8622_backlight_update(struct backlight_device *bl)
341 struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
342 int ret, brightness = bl->props.brightness;
344 if (bl->props.power != FB_BLANK_UNBLANK ||
345 bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
348 if (!ps8622->enabled)
351 ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);
356 static const struct backlight_ops ps8622_backlight_ops = {
357 .update_status = ps8622_backlight_update,
360 static void ps8622_pre_enable(struct drm_bridge *bridge)
362 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
368 gpiod_set_value(ps8622->gpio_rst, 0);
371 ret = regulator_enable(ps8622->v12);
373 DRM_ERROR("fails to enable ps8622->v12");
376 if (drm_panel_prepare(ps8622->panel)) {
377 DRM_ERROR("failed to prepare panel\n");
381 gpiod_set_value(ps8622->gpio_slp, 1);
384 * T1 is the range of time that it takes for the power to rise after we
385 * enable the lcd/ps8622 fet. T2 is the range of time in which the
386 * data sheet specifies we should deassert the reset pin.
388 * If it takes T1.max for the power to rise, we need to wait atleast
389 * T2.min before deasserting the reset pin. If it takes T1.min for the
390 * power to rise, we need to wait at most T2.max before deasserting the
393 usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
394 PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);
396 gpiod_set_value(ps8622->gpio_rst, 1);
398 /* wait 20ms after RST high */
399 usleep_range(20000, 30000);
401 ret = ps8622_send_config(ps8622);
403 DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
407 ps8622->enabled = true;
410 static void ps8622_enable(struct drm_bridge *bridge)
412 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
414 if (drm_panel_enable(ps8622->panel)) {
415 DRM_ERROR("failed to enable panel\n");
420 static void ps8622_disable(struct drm_bridge *bridge)
422 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
424 if (drm_panel_disable(ps8622->panel)) {
425 DRM_ERROR("failed to disable panel\n");
428 msleep(PS8622_PWMO_END_T12_MS);
431 static void ps8622_post_disable(struct drm_bridge *bridge)
433 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
435 if (!ps8622->enabled)
438 ps8622->enabled = false;
441 * This doesn't matter if the regulators are turned off, but something
442 * else might keep them on. In that case, we want to assert the slp gpio
445 gpiod_set_value(ps8622->gpio_slp, 0);
447 if (drm_panel_unprepare(ps8622->panel)) {
448 DRM_ERROR("failed to unprepare panel\n");
453 regulator_disable(ps8622->v12);
456 * Sleep for at least the amount of time that it takes the power rail to
457 * fall to prevent asserting the rst gpio from doing anything.
459 usleep_range(PS8622_POWER_FALL_T16_MAX_US,
460 2 * PS8622_POWER_FALL_T16_MAX_US);
461 gpiod_set_value(ps8622->gpio_rst, 0);
463 msleep(PS8622_POWER_OFF_T17_MS);
466 static int ps8622_get_modes(struct drm_connector *connector)
468 struct ps8622_bridge *ps8622;
470 ps8622 = connector_to_ps8622(connector);
472 return drm_panel_get_modes(ps8622->panel);
475 static struct drm_encoder *ps8622_best_encoder(struct drm_connector *connector)
477 struct ps8622_bridge *ps8622;
479 ps8622 = connector_to_ps8622(connector);
481 return ps8622->bridge.encoder;
484 static const struct drm_connector_helper_funcs ps8622_connector_helper_funcs = {
485 .get_modes = ps8622_get_modes,
486 .best_encoder = ps8622_best_encoder,
489 static enum drm_connector_status ps8622_detect(struct drm_connector *connector,
492 return connector_status_connected;
495 static void ps8622_connector_destroy(struct drm_connector *connector)
497 drm_connector_cleanup(connector);
500 static const struct drm_connector_funcs ps8622_connector_funcs = {
501 .dpms = drm_helper_connector_dpms,
502 .fill_modes = drm_helper_probe_single_connector_modes,
503 .detect = ps8622_detect,
504 .destroy = ps8622_connector_destroy,
507 int ps8622_attach(struct drm_bridge *bridge)
509 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
512 if (!bridge->encoder) {
513 DRM_ERROR("Parent encoder object not found");
517 ps8622->connector.polled = DRM_CONNECTOR_POLL_HPD;
518 ret = drm_connector_init(bridge->dev, &ps8622->connector,
519 &ps8622_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
521 DRM_ERROR("Failed to initialize connector with drm\n");
524 drm_connector_helper_add(&ps8622->connector,
525 &ps8622_connector_helper_funcs);
526 drm_connector_register(&ps8622->connector);
527 drm_mode_connector_attach_encoder(&ps8622->connector,
531 drm_panel_attach(ps8622->panel, &ps8622->connector);
533 drm_helper_hpd_irq_event(ps8622->connector.dev);
538 static const struct drm_bridge_funcs ps8622_bridge_funcs = {
539 .pre_enable = ps8622_pre_enable,
540 .enable = ps8622_enable,
541 .disable = ps8622_disable,
542 .post_disable = ps8622_post_disable,
543 .attach = ps8622_attach,
546 static const struct of_device_id ps8622_devices[] = {
547 {.compatible = "parade,ps8622",},
548 {.compatible = "parade,ps8625",},
551 MODULE_DEVICE_TABLE(of, ps8622_devices);
553 static int ps8622_probe(struct i2c_client *client,
554 const struct i2c_device_id *id)
556 struct device *dev = &client->dev;
557 struct device_node *endpoint, *panel_node;
558 struct ps8622_bridge *ps8622;
561 ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
565 endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
567 panel_node = of_graph_get_remote_port_parent(endpoint);
569 ps8622->panel = of_drm_find_panel(panel_node);
570 of_node_put(panel_node);
572 return -EPROBE_DEFER;
576 ps8622->client = client;
578 ps8622->v12 = devm_regulator_get(dev, "vdd12");
579 if (IS_ERR(ps8622->v12)) {
580 dev_info(dev, "no 1.2v regulator found for PS8622\n");
584 ps8622->gpio_slp = devm_gpiod_get(dev, "sleep");
585 if (IS_ERR(ps8622->gpio_slp)) {
586 ret = PTR_ERR(ps8622->gpio_slp);
587 dev_err(dev, "cannot get gpio_slp %d\n", ret);
590 ret = gpiod_direction_output(ps8622->gpio_slp, 1);
592 dev_err(dev, "cannot configure gpio_slp\n");
596 ps8622->gpio_rst = devm_gpiod_get(dev, "reset");
597 if (IS_ERR(ps8622->gpio_rst)) {
598 ret = PTR_ERR(ps8622->gpio_rst);
599 dev_err(dev, "cannot get gpio_rst %d\n", ret);
603 * Assert the reset pin high to avoid the bridge being
604 * initialized prematurely
606 ret = gpiod_direction_output(ps8622->gpio_rst, 1);
608 dev_err(dev, "cannot configure gpio_rst\n");
612 ps8622->max_lane_count = id->driver_data;
614 if (of_property_read_u32(dev->of_node, "lane-count",
615 &ps8622->lane_count)) {
616 ps8622->lane_count = ps8622->max_lane_count;
617 } else if (ps8622->lane_count > ps8622->max_lane_count) {
618 dev_info(dev, "lane-count property is too high,"
619 "using max_lane_count\n");
620 ps8622->lane_count = ps8622->max_lane_count;
623 if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
624 ps8622->bl = backlight_device_register("ps8622-backlight",
625 dev, ps8622, &ps8622_backlight_ops,
627 if (IS_ERR(ps8622->bl)) {
628 DRM_ERROR("failed to register backlight\n");
629 ret = PTR_ERR(ps8622->bl);
633 ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
634 ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
637 ps8622->bridge.funcs = &ps8622_bridge_funcs;
638 ps8622->bridge.of_node = dev->of_node;
639 ret = drm_bridge_add(&ps8622->bridge);
641 DRM_ERROR("Failed to add bridge\n");
645 i2c_set_clientdata(client, ps8622);
650 static int ps8622_remove(struct i2c_client *client)
652 struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);
655 backlight_device_unregister(ps8622->bl);
657 drm_bridge_remove(&ps8622->bridge);
662 static const struct i2c_device_id ps8622_i2c_table[] = {
663 /* Device type, max_lane_count */
668 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);
670 struct i2c_driver ps8622_driver = {
671 .id_table = ps8622_i2c_table,
672 .probe = ps8622_probe,
673 .remove = ps8622_remove,
676 .owner = THIS_MODULE,
677 .of_match_table = ps8622_devices,
680 module_i2c_driver(ps8622_driver);
682 MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
683 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
684 MODULE_LICENSE("GPL v2");