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/gpio/consumer.h>
22 #include <linux/i2c.h>
23 #include <linux/module.h>
25 #include <linux/of_device.h>
26 #include <linux/of_graph.h>
28 #include <linux/regulator/consumer.h>
30 #include <drm/drm_panel.h>
34 #include "drm_crtc_helper.h"
35 #include "drm_atomic_helper.h"
37 /* Brightness scale on the Parade chip */
38 #define PS8622_MAX_BRIGHTNESS 0xff
40 /* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
41 #define PS8622_POWER_RISE_T1_MIN_US 10
42 #define PS8622_POWER_RISE_T1_MAX_US 10000
43 #define PS8622_RST_HIGH_T2_MIN_US 3000
44 #define PS8622_RST_HIGH_T2_MAX_US 30000
45 #define PS8622_PWMO_END_T12_MS 200
46 #define PS8622_POWER_FALL_T16_MAX_US 10000
47 #define PS8622_POWER_OFF_T17_MS 500
49 #if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
50 (PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
51 #error "T2.min + T1.max must be less than T2.max + T1.min"
54 struct ps8622_bridge {
55 struct drm_connector connector;
56 struct i2c_client *client;
57 struct drm_bridge bridge;
58 struct drm_panel *panel;
59 struct regulator *v12;
60 struct backlight_device *bl;
62 struct gpio_desc *gpio_slp;
63 struct gpio_desc *gpio_rst;
71 static inline struct ps8622_bridge *
72 bridge_to_ps8622(struct drm_bridge *bridge)
74 return container_of(bridge, struct ps8622_bridge, bridge);
77 static inline struct ps8622_bridge *
78 connector_to_ps8622(struct drm_connector *connector)
80 return container_of(connector, struct ps8622_bridge, connector);
83 static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
86 struct i2c_adapter *adap = client->adapter;
88 u8 data[] = {reg, val};
90 msg.addr = client->addr + page;
92 msg.len = sizeof(data);
95 ret = i2c_transfer(adap, &msg, 1);
97 pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
98 client->addr + page, reg, val, ret);
102 static int ps8622_send_config(struct ps8622_bridge *ps8622)
104 struct i2c_client *cl = ps8622->client;
108 err = ps8622_set(cl, 0x02, 0xa1, 0x01);
112 /* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
113 err = ps8622_set(cl, 0x04, 0x14, 0x01);
117 /* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
118 err = ps8622_set(cl, 0x04, 0xe3, 0x20);
122 /* [7] RCO SS enable */
123 err = ps8622_set(cl, 0x04, 0xe2, 0x80);
128 * [3:2] CDR tune wait cycle before measure for fine tune
129 * b00: 1us b01: 0.5us b10:2us, b11: 4us
131 err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
135 /* [3] RFD always on */
136 err = ps8622_set(cl, 0x04, 0x89, 0x08);
140 /* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
141 err = ps8622_set(cl, 0x04, 0x71, 0x2d);
145 /* 2.7G CDR settings: NOF=40LSB for HBR CDR setting */
146 err = ps8622_set(cl, 0x04, 0x7d, 0x07);
150 /* [1:0] Fmin=+4bands */
151 err = ps8622_set(cl, 0x04, 0x7b, 0x00);
155 /* [7:5] DCO_FTRNG=+-40% */
156 err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
160 /* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
161 err = ps8622_set(cl, 0x04, 0xc0, 0x12);
166 err = ps8622_set(cl, 0x04, 0xc1, 0x92);
171 err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
175 /* [7] LOS signal disable */
176 err = ps8622_set(cl, 0x04, 0x32, 0x80);
180 /* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
181 err = ps8622_set(cl, 0x04, 0x00, 0xb0);
185 /* [7:6] Right-bar GPIO output strength is 8mA */
186 err = ps8622_set(cl, 0x04, 0x15, 0x40);
190 /* EQ Training State Machine Setting, RCO calibration start */
191 err = ps8622_set(cl, 0x04, 0x54, 0x10);
195 /* Logic, needs more than 10 I2C command */
196 /* [4:0] MAX_LANE_COUNT set to max supported lanes */
197 err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count);
201 /* [4:0] LANE_COUNT_SET set to chosen lane count */
202 err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count);
206 err = ps8622_set(cl, 0x00, 0x52, 0x20);
210 /* HPD CP toggle enable */
211 err = ps8622_set(cl, 0x00, 0xf1, 0x03);
215 err = ps8622_set(cl, 0x00, 0x62, 0x41);
219 /* Counter number, add 1ms counter delay */
220 err = ps8622_set(cl, 0x00, 0xf6, 0x01);
224 /* [6]PWM function control by DPCD0040f[7], default is PWM block */
225 err = ps8622_set(cl, 0x00, 0x77, 0x06);
229 /* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
230 err = ps8622_set(cl, 0x00, 0x4c, 0x04);
234 /* DPCD00400='h00, Parade OUI ='h001cf8 */
235 err = ps8622_set(cl, 0x01, 0xc0, 0x00);
240 err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
245 err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
249 /* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
250 err = ps8622_set(cl, 0x01, 0xc3, 0x44);
255 err = ps8622_set(cl, 0x01, 0xc4, 0x32);
260 err = ps8622_set(cl, 0x01, 0xc5, 0x53);
265 err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
270 err = ps8622_set(cl, 0x01, 0xc7, 0x56);
275 err = ps8622_set(cl, 0x01, 0xc8, 0x35);
279 /* DPCD40A, Initial Code major revision '01' */
280 err = ps8622_set(cl, 0x01, 0xca, 0x01);
284 /* DPCD40B, Initial Code minor revision '05' */
285 err = ps8622_set(cl, 0x01, 0xcb, 0x05);
291 /* DPCD720, internal PWM */
292 err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
296 /* FFh for 100% brightness, 0h for 0% brightness */
297 err = ps8622_set(cl, 0x01, 0xa7,
298 ps8622->bl->props.brightness);
302 /* DPCD720, external PWM */
303 err = ps8622_set(cl, 0x01, 0xa5, 0x80);
308 /* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
309 err = ps8622_set(cl, 0x01, 0xcc, 0x13);
313 /* Enable SSC set by register */
314 err = ps8622_set(cl, 0x02, 0xb1, 0x20);
318 /* Set SSC enabled and +/-1% central spreading */
319 err = ps8622_set(cl, 0x04, 0x10, 0x16);
324 /* MPU Clock source: LC => RCO */
325 err = ps8622_set(cl, 0x04, 0x59, 0x60);
330 err = ps8622_set(cl, 0x04, 0x54, 0x14);
335 err = ps8622_set(cl, 0x02, 0xa1, 0x91);
338 return err ? -EIO : 0;
341 static int ps8622_backlight_update(struct backlight_device *bl)
343 struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
344 int ret, brightness = bl->props.brightness;
346 if (bl->props.power != FB_BLANK_UNBLANK ||
347 bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
350 if (!ps8622->enabled)
353 ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);
358 static const struct backlight_ops ps8622_backlight_ops = {
359 .update_status = ps8622_backlight_update,
362 static void ps8622_pre_enable(struct drm_bridge *bridge)
364 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
370 gpiod_set_value(ps8622->gpio_rst, 0);
373 ret = regulator_enable(ps8622->v12);
375 DRM_ERROR("fails to enable ps8622->v12");
378 if (drm_panel_prepare(ps8622->panel)) {
379 DRM_ERROR("failed to prepare panel\n");
383 gpiod_set_value(ps8622->gpio_slp, 1);
386 * T1 is the range of time that it takes for the power to rise after we
387 * enable the lcd/ps8622 fet. T2 is the range of time in which the
388 * data sheet specifies we should deassert the reset pin.
390 * If it takes T1.max for the power to rise, we need to wait atleast
391 * T2.min before deasserting the reset pin. If it takes T1.min for the
392 * power to rise, we need to wait at most T2.max before deasserting the
395 usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
396 PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);
398 gpiod_set_value(ps8622->gpio_rst, 1);
400 /* wait 20ms after RST high */
401 usleep_range(20000, 30000);
403 ret = ps8622_send_config(ps8622);
405 DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
409 ps8622->enabled = true;
412 static void ps8622_enable(struct drm_bridge *bridge)
414 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
416 if (drm_panel_enable(ps8622->panel)) {
417 DRM_ERROR("failed to enable panel\n");
422 static void ps8622_disable(struct drm_bridge *bridge)
424 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
426 if (drm_panel_disable(ps8622->panel)) {
427 DRM_ERROR("failed to disable panel\n");
430 msleep(PS8622_PWMO_END_T12_MS);
433 static void ps8622_post_disable(struct drm_bridge *bridge)
435 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
437 if (!ps8622->enabled)
440 ps8622->enabled = false;
443 * This doesn't matter if the regulators are turned off, but something
444 * else might keep them on. In that case, we want to assert the slp gpio
447 gpiod_set_value(ps8622->gpio_slp, 0);
449 if (drm_panel_unprepare(ps8622->panel)) {
450 DRM_ERROR("failed to unprepare panel\n");
455 regulator_disable(ps8622->v12);
458 * Sleep for at least the amount of time that it takes the power rail to
459 * fall to prevent asserting the rst gpio from doing anything.
461 usleep_range(PS8622_POWER_FALL_T16_MAX_US,
462 2 * PS8622_POWER_FALL_T16_MAX_US);
463 gpiod_set_value(ps8622->gpio_rst, 0);
465 msleep(PS8622_POWER_OFF_T17_MS);
468 static int ps8622_get_modes(struct drm_connector *connector)
470 struct ps8622_bridge *ps8622;
472 ps8622 = connector_to_ps8622(connector);
474 return drm_panel_get_modes(ps8622->panel);
477 static struct drm_encoder *ps8622_best_encoder(struct drm_connector *connector)
479 struct ps8622_bridge *ps8622;
481 ps8622 = connector_to_ps8622(connector);
483 return ps8622->bridge.encoder;
486 static const struct drm_connector_helper_funcs ps8622_connector_helper_funcs = {
487 .get_modes = ps8622_get_modes,
488 .best_encoder = ps8622_best_encoder,
491 static enum drm_connector_status ps8622_detect(struct drm_connector *connector,
494 return connector_status_connected;
497 static void ps8622_connector_destroy(struct drm_connector *connector)
499 drm_connector_cleanup(connector);
502 static const struct drm_connector_funcs ps8622_connector_funcs = {
503 .dpms = drm_atomic_helper_connector_dpms,
504 .fill_modes = drm_helper_probe_single_connector_modes,
505 .detect = ps8622_detect,
506 .destroy = ps8622_connector_destroy,
507 .reset = drm_atomic_helper_connector_reset,
508 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
509 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
512 static int ps8622_attach(struct drm_bridge *bridge)
514 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
517 if (!bridge->encoder) {
518 DRM_ERROR("Parent encoder object not found");
522 ps8622->connector.polled = DRM_CONNECTOR_POLL_HPD;
523 ret = drm_connector_init(bridge->dev, &ps8622->connector,
524 &ps8622_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
526 DRM_ERROR("Failed to initialize connector with drm\n");
529 drm_connector_helper_add(&ps8622->connector,
530 &ps8622_connector_helper_funcs);
531 drm_connector_register(&ps8622->connector);
532 drm_mode_connector_attach_encoder(&ps8622->connector,
536 drm_panel_attach(ps8622->panel, &ps8622->connector);
538 drm_helper_hpd_irq_event(ps8622->connector.dev);
543 static const struct drm_bridge_funcs ps8622_bridge_funcs = {
544 .pre_enable = ps8622_pre_enable,
545 .enable = ps8622_enable,
546 .disable = ps8622_disable,
547 .post_disable = ps8622_post_disable,
548 .attach = ps8622_attach,
551 static const struct of_device_id ps8622_devices[] = {
552 {.compatible = "parade,ps8622",},
553 {.compatible = "parade,ps8625",},
556 MODULE_DEVICE_TABLE(of, ps8622_devices);
558 static int ps8622_probe(struct i2c_client *client,
559 const struct i2c_device_id *id)
561 struct device *dev = &client->dev;
562 struct device_node *endpoint, *panel_node;
563 struct ps8622_bridge *ps8622;
566 ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
570 endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
572 panel_node = of_graph_get_remote_port_parent(endpoint);
574 ps8622->panel = of_drm_find_panel(panel_node);
575 of_node_put(panel_node);
577 return -EPROBE_DEFER;
581 ps8622->client = client;
583 ps8622->v12 = devm_regulator_get(dev, "vdd12");
584 if (IS_ERR(ps8622->v12)) {
585 dev_info(dev, "no 1.2v regulator found for PS8622\n");
589 ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH);
590 if (IS_ERR(ps8622->gpio_slp)) {
591 ret = PTR_ERR(ps8622->gpio_slp);
592 dev_err(dev, "cannot get gpio_slp %d\n", ret);
597 * Assert the reset pin high to avoid the bridge being
598 * initialized prematurely
600 ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
601 if (IS_ERR(ps8622->gpio_rst)) {
602 ret = PTR_ERR(ps8622->gpio_rst);
603 dev_err(dev, "cannot get gpio_rst %d\n", ret);
607 ps8622->max_lane_count = id->driver_data;
609 if (of_property_read_u32(dev->of_node, "lane-count",
610 &ps8622->lane_count)) {
611 ps8622->lane_count = ps8622->max_lane_count;
612 } else if (ps8622->lane_count > ps8622->max_lane_count) {
613 dev_info(dev, "lane-count property is too high,"
614 "using max_lane_count\n");
615 ps8622->lane_count = ps8622->max_lane_count;
618 if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
619 ps8622->bl = backlight_device_register("ps8622-backlight",
620 dev, ps8622, &ps8622_backlight_ops,
622 if (IS_ERR(ps8622->bl)) {
623 DRM_ERROR("failed to register backlight\n");
624 ret = PTR_ERR(ps8622->bl);
628 ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
629 ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
632 ps8622->bridge.funcs = &ps8622_bridge_funcs;
633 ps8622->bridge.of_node = dev->of_node;
634 ret = drm_bridge_add(&ps8622->bridge);
636 DRM_ERROR("Failed to add bridge\n");
640 i2c_set_clientdata(client, ps8622);
645 static int ps8622_remove(struct i2c_client *client)
647 struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);
650 backlight_device_unregister(ps8622->bl);
652 drm_bridge_remove(&ps8622->bridge);
657 static const struct i2c_device_id ps8622_i2c_table[] = {
658 /* Device type, max_lane_count */
663 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);
665 static struct i2c_driver ps8622_driver = {
666 .id_table = ps8622_i2c_table,
667 .probe = ps8622_probe,
668 .remove = ps8622_remove,
671 .owner = THIS_MODULE,
672 .of_match_table = ps8622_devices,
675 module_i2c_driver(ps8622_driver);
678 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
679 MODULE_LICENSE("GPL v2");