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linux-stable/drivers/gpu/drm/bridge/parade-ps8622.c
Laurent Pinchart a25b988ff8 drm/bridge: Extend bridge API to disable connector creation 
Most bridge drivers create a DRM connector to model the connector at the
output of the bridge. This model is historical and has worked pretty
well so far, but causes several issues:

- It prevents supporting more complex display pipelines where DRM
connector operations are split over multiple components. For instance a
pipeline with a bridge connected to the DDC signals to read EDID data,
and another one connected to the HPD signal to detect connection and
disconnection, will not be possible to support through this model.

- It requires every bridge driver to implement similar connector
handling code, resulting in code duplication.

- It assumes that a bridge will either be wired to a connector or to
another bridge, but doesn't support bridges that can be used in both
positions very well (although there is some ad-hoc support for this in
the analogix_dp bridge driver).

In order to solve these issues, ownership of the connector should be
moved to the display controller driver (where it can be implemented
using helpers provided by the core).

Extend the bridge API to allow disabling connector creation in bridge
drivers as a first step towards the new model. The new flags argument to
the bridge .attach() operation allows instructing the bridge driver to
skip creating a connector. Unconditionally set the new flags argument to
0 for now to keep the existing behaviour, and modify all existing bridge
drivers to return an error when connector creation is not requested as
they don't support this feature yet.

The change is based on the following semantic patch, with manual review
and edits.

@ rule1 @
identifier funcs;
identifier fn;
@@
 struct drm_bridge_funcs funcs = {
 	...,
 	.attach = fn
 };

@ depends on rule1 @
identifier rule1.fn;
identifier bridge;
statement S, S1;
@@
 int fn(
 	struct drm_bridge *bridge
+	, enum drm_bridge_attach_flags flags
 )
 {
 	... when != S
+	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
+		DRM_ERROR("Fix bridge driver to make connector optional!");
+		return -EINVAL;
+	}
+
 	S1
 	...
 }

@ depends on rule1 @
identifier rule1.fn;
identifier bridge, flags;
expression E1, E2, E3;
@@
 int fn(
 	struct drm_bridge *bridge,
 	enum drm_bridge_attach_flags flags
 ) {
 <...
 drm_bridge_attach(E1, E2, E3
+	, flags
 )
 ...>
 }

@@
expression E1, E2, E3;
@@
 drm_bridge_attach(E1, E2, E3
+	, 0
 )

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-10-laurent.pinchart@ideasonboard.com
2020-02-26 13:31:23 +02:00

637 lines
15 KiB
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Parade PS8622 eDP/LVDS bridge driver
*
* Copyright (C) 2014 Google, Inc.
*/
#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pm.h>
#include <linux/regulator/consumer.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_crtc.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
/* Brightness scale on the Parade chip */
#define PS8622_MAX_BRIGHTNESS 0xff
/* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
#define PS8622_POWER_RISE_T1_MIN_US 10
#define PS8622_POWER_RISE_T1_MAX_US 10000
#define PS8622_RST_HIGH_T2_MIN_US 3000
#define PS8622_RST_HIGH_T2_MAX_US 30000
#define PS8622_PWMO_END_T12_MS 200
#define PS8622_POWER_FALL_T16_MAX_US 10000
#define PS8622_POWER_OFF_T17_MS 500
#if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
(PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
#error "T2.min + T1.max must be less than T2.max + T1.min"
#endif
struct ps8622_bridge {
struct drm_connector connector;
struct i2c_client *client;
struct drm_bridge bridge;
struct drm_panel *panel;
struct regulator *v12;
struct backlight_device *bl;
struct gpio_desc *gpio_slp;
struct gpio_desc *gpio_rst;
u32 max_lane_count;
u32 lane_count;
bool enabled;
};
static inline struct ps8622_bridge *
bridge_to_ps8622(struct drm_bridge *bridge)
{
return container_of(bridge, struct ps8622_bridge, bridge);
}
static inline struct ps8622_bridge *
connector_to_ps8622(struct drm_connector *connector)
{
return container_of(connector, struct ps8622_bridge, connector);
}
static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
{
int ret;
struct i2c_adapter *adap = client->adapter;
struct i2c_msg msg;
u8 data[] = {reg, val};
msg.addr = client->addr + page;
msg.flags = 0;
msg.len = sizeof(data);
msg.buf = data;
ret = i2c_transfer(adap, &msg, 1);
if (ret != 1)
pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
client->addr + page, reg, val, ret);
return !(ret == 1);
}
static int ps8622_send_config(struct ps8622_bridge *ps8622)
{
struct i2c_client *cl = ps8622->client;
int err = 0;
/* HPD low */
err = ps8622_set(cl, 0x02, 0xa1, 0x01);
if (err)
goto error;
/* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
err = ps8622_set(cl, 0x04, 0x14, 0x01);
if (err)
goto error;
/* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
err = ps8622_set(cl, 0x04, 0xe3, 0x20);
if (err)
goto error;
/* [7] RCO SS enable */
err = ps8622_set(cl, 0x04, 0xe2, 0x80);
if (err)
goto error;
/* RPHY Setting
* [3:2] CDR tune wait cycle before measure for fine tune
* b00: 1us b01: 0.5us b10:2us, b11: 4us
*/
err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
if (err)
goto error;
/* [3] RFD always on */
err = ps8622_set(cl, 0x04, 0x89, 0x08);
if (err)
goto error;
/* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
err = ps8622_set(cl, 0x04, 0x71, 0x2d);
if (err)
goto error;
/* 2.7G CDR settings: NOF=40LSB for HBR CDR setting */
err = ps8622_set(cl, 0x04, 0x7d, 0x07);
if (err)
goto error;
/* [1:0] Fmin=+4bands */
err = ps8622_set(cl, 0x04, 0x7b, 0x00);
if (err)
goto error;
/* [7:5] DCO_FTRNG=+-40% */
err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
if (err)
goto error;
/* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
err = ps8622_set(cl, 0x04, 0xc0, 0x12);
if (err)
goto error;
/* Gitune=-37% */
err = ps8622_set(cl, 0x04, 0xc1, 0x92);
if (err)
goto error;
/* Fbstep=100% */
err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
if (err)
goto error;
/* [7] LOS signal disable */
err = ps8622_set(cl, 0x04, 0x32, 0x80);
if (err)
goto error;
/* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
err = ps8622_set(cl, 0x04, 0x00, 0xb0);
if (err)
goto error;
/* [7:6] Right-bar GPIO output strength is 8mA */
err = ps8622_set(cl, 0x04, 0x15, 0x40);
if (err)
goto error;
/* EQ Training State Machine Setting, RCO calibration start */
err = ps8622_set(cl, 0x04, 0x54, 0x10);
if (err)
goto error;
/* Logic, needs more than 10 I2C command */
/* [4:0] MAX_LANE_COUNT set to max supported lanes */
err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count);
if (err)
goto error;
/* [4:0] LANE_COUNT_SET set to chosen lane count */
err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count);
if (err)
goto error;
err = ps8622_set(cl, 0x00, 0x52, 0x20);
if (err)
goto error;
/* HPD CP toggle enable */
err = ps8622_set(cl, 0x00, 0xf1, 0x03);
if (err)
goto error;
err = ps8622_set(cl, 0x00, 0x62, 0x41);
if (err)
goto error;
/* Counter number, add 1ms counter delay */
err = ps8622_set(cl, 0x00, 0xf6, 0x01);
if (err)
goto error;
/* [6]PWM function control by DPCD0040f[7], default is PWM block */
err = ps8622_set(cl, 0x00, 0x77, 0x06);
if (err)
goto error;
/* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
err = ps8622_set(cl, 0x00, 0x4c, 0x04);
if (err)
goto error;
/* DPCD00400='h00, Parade OUI ='h001cf8 */
err = ps8622_set(cl, 0x01, 0xc0, 0x00);
if (err)
goto error;
/* DPCD00401='h1c */
err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
if (err)
goto error;
/* DPCD00402='hf8 */
err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
if (err)
goto error;
/* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
err = ps8622_set(cl, 0x01, 0xc3, 0x44);
if (err)
goto error;
/* DPCD404 */
err = ps8622_set(cl, 0x01, 0xc4, 0x32);
if (err)
goto error;
/* DPCD405 */
err = ps8622_set(cl, 0x01, 0xc5, 0x53);
if (err)
goto error;
/* DPCD406 */
err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
if (err)
goto error;
/* DPCD407 */
err = ps8622_set(cl, 0x01, 0xc7, 0x56);
if (err)
goto error;
/* DPCD408 */
err = ps8622_set(cl, 0x01, 0xc8, 0x35);
if (err)
goto error;
/* DPCD40A, Initial Code major revision '01' */
err = ps8622_set(cl, 0x01, 0xca, 0x01);
if (err)
goto error;
/* DPCD40B, Initial Code minor revision '05' */
err = ps8622_set(cl, 0x01, 0xcb, 0x05);
if (err)
goto error;
if (ps8622->bl) {
/* DPCD720, internal PWM */
err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
if (err)
goto error;
/* FFh for 100% brightness, 0h for 0% brightness */
err = ps8622_set(cl, 0x01, 0xa7,
ps8622->bl->props.brightness);
if (err)
goto error;
} else {
/* DPCD720, external PWM */
err = ps8622_set(cl, 0x01, 0xa5, 0x80);
if (err)
goto error;
}
/* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
err = ps8622_set(cl, 0x01, 0xcc, 0x13);
if (err)
goto error;
/* Enable SSC set by register */
err = ps8622_set(cl, 0x02, 0xb1, 0x20);
if (err)
goto error;
/* Set SSC enabled and +/-1% central spreading */
err = ps8622_set(cl, 0x04, 0x10, 0x16);
if (err)
goto error;
/* Logic end */
/* MPU Clock source: LC => RCO */
err = ps8622_set(cl, 0x04, 0x59, 0x60);
if (err)
goto error;
/* LC -> RCO */
err = ps8622_set(cl, 0x04, 0x54, 0x14);
if (err)
goto error;
/* HPD high */
err = ps8622_set(cl, 0x02, 0xa1, 0x91);
error:
return err ? -EIO : 0;
}
static int ps8622_backlight_update(struct backlight_device *bl)
{
struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
int ret, brightness = bl->props.brightness;
if (bl->props.power != FB_BLANK_UNBLANK ||
bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
brightness = 0;
if (!ps8622->enabled)
return -EINVAL;
ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);
return ret;
}
static const struct backlight_ops ps8622_backlight_ops = {
.update_status = ps8622_backlight_update,
};
static void ps8622_pre_enable(struct drm_bridge *bridge)
{
struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
int ret;
if (ps8622->enabled)
return;
gpiod_set_value(ps8622->gpio_rst, 0);
if (ps8622->v12) {
ret = regulator_enable(ps8622->v12);
if (ret)
DRM_ERROR("fails to enable ps8622->v12");
}
if (drm_panel_prepare(ps8622->panel)) {
DRM_ERROR("failed to prepare panel\n");
return;
}
gpiod_set_value(ps8622->gpio_slp, 1);
/*
* T1 is the range of time that it takes for the power to rise after we
* enable the lcd/ps8622 fet. T2 is the range of time in which the
* data sheet specifies we should deassert the reset pin.
*
* If it takes T1.max for the power to rise, we need to wait atleast
* T2.min before deasserting the reset pin. If it takes T1.min for the
* power to rise, we need to wait at most T2.max before deasserting the
* reset pin.
*/
usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);
gpiod_set_value(ps8622->gpio_rst, 1);
/* wait 20ms after RST high */
usleep_range(20000, 30000);
ret = ps8622_send_config(ps8622);
if (ret) {
DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
return;
}
ps8622->enabled = true;
}
static void ps8622_enable(struct drm_bridge *bridge)
{
struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
if (drm_panel_enable(ps8622->panel)) {
DRM_ERROR("failed to enable panel\n");
return;
}
}
static void ps8622_disable(struct drm_bridge *bridge)
{
struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
if (drm_panel_disable(ps8622->panel)) {
DRM_ERROR("failed to disable panel\n");
return;
}
msleep(PS8622_PWMO_END_T12_MS);
}
static void ps8622_post_disable(struct drm_bridge *bridge)
{
struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
if (!ps8622->enabled)
return;
ps8622->enabled = false;
/*
* This doesn't matter if the regulators are turned off, but something
* else might keep them on. In that case, we want to assert the slp gpio
* to lower power.
*/
gpiod_set_value(ps8622->gpio_slp, 0);
if (drm_panel_unprepare(ps8622->panel)) {
DRM_ERROR("failed to unprepare panel\n");
return;
}
if (ps8622->v12)
regulator_disable(ps8622->v12);
/*
* Sleep for at least the amount of time that it takes the power rail to
* fall to prevent asserting the rst gpio from doing anything.
*/
usleep_range(PS8622_POWER_FALL_T16_MAX_US,
2 * PS8622_POWER_FALL_T16_MAX_US);
gpiod_set_value(ps8622->gpio_rst, 0);
msleep(PS8622_POWER_OFF_T17_MS);
}
static int ps8622_get_modes(struct drm_connector *connector)
{
struct ps8622_bridge *ps8622;
ps8622 = connector_to_ps8622(connector);
return drm_panel_get_modes(ps8622->panel, connector);
}
static const struct drm_connector_helper_funcs ps8622_connector_helper_funcs = {
.get_modes = ps8622_get_modes,
};
static const struct drm_connector_funcs ps8622_connector_funcs = {
.fill_modes = drm_helper_probe_single_connector_modes,
.destroy = drm_connector_cleanup,
.reset = drm_atomic_helper_connector_reset,
.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};
static int ps8622_attach(struct drm_bridge *bridge,
enum drm_bridge_attach_flags flags)
{
struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
int ret;
if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
DRM_ERROR("Fix bridge driver to make connector optional!");
return -EINVAL;
}
if (!bridge->encoder) {
DRM_ERROR("Parent encoder object not found");
return -ENODEV;
}
ps8622->connector.polled = DRM_CONNECTOR_POLL_HPD;
ret = drm_connector_init(bridge->dev, &ps8622->connector,
&ps8622_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
if (ret) {
DRM_ERROR("Failed to initialize connector with drm\n");
return ret;
}
drm_connector_helper_add(&ps8622->connector,
&ps8622_connector_helper_funcs);
drm_connector_register(&ps8622->connector);
drm_connector_attach_encoder(&ps8622->connector,
bridge->encoder);
if (ps8622->panel)
drm_panel_attach(ps8622->panel, &ps8622->connector);
drm_helper_hpd_irq_event(ps8622->connector.dev);
return ret;
}
static const struct drm_bridge_funcs ps8622_bridge_funcs = {
.pre_enable = ps8622_pre_enable,
.enable = ps8622_enable,
.disable = ps8622_disable,
.post_disable = ps8622_post_disable,
.attach = ps8622_attach,
};
static const struct of_device_id ps8622_devices[] = {
{.compatible = "parade,ps8622",},
{.compatible = "parade,ps8625",},
{}
};
MODULE_DEVICE_TABLE(of, ps8622_devices);
static int ps8622_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
struct ps8622_bridge *ps8622;
int ret;
ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
if (!ps8622)
return -ENOMEM;
ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &ps8622->panel, NULL);
if (ret)
return ret;
ps8622->client = client;
ps8622->v12 = devm_regulator_get(dev, "vdd12");
if (IS_ERR(ps8622->v12)) {
dev_info(dev, "no 1.2v regulator found for PS8622\n");
ps8622->v12 = NULL;
}
ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH);
if (IS_ERR(ps8622->gpio_slp)) {
ret = PTR_ERR(ps8622->gpio_slp);
dev_err(dev, "cannot get gpio_slp %d\n", ret);
return ret;
}
/*
* Assert the reset pin high to avoid the bridge being
* initialized prematurely
*/
ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(ps8622->gpio_rst)) {
ret = PTR_ERR(ps8622->gpio_rst);
dev_err(dev, "cannot get gpio_rst %d\n", ret);
return ret;
}
ps8622->max_lane_count = id->driver_data;
if (of_property_read_u32(dev->of_node, "lane-count",
&ps8622->lane_count)) {
ps8622->lane_count = ps8622->max_lane_count;
} else if (ps8622->lane_count > ps8622->max_lane_count) {
dev_info(dev, "lane-count property is too high,"
"using max_lane_count\n");
ps8622->lane_count = ps8622->max_lane_count;
}
if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
ps8622->bl = backlight_device_register("ps8622-backlight",
dev, ps8622, &ps8622_backlight_ops,
NULL);
if (IS_ERR(ps8622->bl)) {
DRM_ERROR("failed to register backlight\n");
ret = PTR_ERR(ps8622->bl);
ps8622->bl = NULL;
return ret;
}
ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
}
ps8622->bridge.funcs = &ps8622_bridge_funcs;
ps8622->bridge.of_node = dev->of_node;
drm_bridge_add(&ps8622->bridge);
i2c_set_clientdata(client, ps8622);
return 0;
}
static int ps8622_remove(struct i2c_client *client)
{
struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);
backlight_device_unregister(ps8622->bl);
drm_bridge_remove(&ps8622->bridge);
return 0;
}
static const struct i2c_device_id ps8622_i2c_table[] = {
/* Device type, max_lane_count */
{"ps8622", 1},
{"ps8625", 2},
{},
};
MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);
static struct i2c_driver ps8622_driver = {
.id_table = ps8622_i2c_table,
.probe = ps8622_probe,
.remove = ps8622_remove,
.driver = {
.name = "ps8622",
.of_match_table = ps8622_devices,
},
};
module_i2c_driver(ps8622_driver);
MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
MODULE_LICENSE("GPL v2");
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