// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2015-2016 Free Electrons
* Copyright (C) 2015-2016 NextThing Co
*
* Maxime Ripard <[email protected]>
*/
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/platform_device.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_edid.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
struct simple_bridge_info {
const struct drm_bridge_timings *timings;
unsigned int connector_type;
};
struct simple_bridge {
struct drm_bridge bridge;
struct drm_connector connector;
const struct simple_bridge_info *info;
struct drm_bridge *next_bridge;
struct regulator *vdd;
struct gpio_desc *enable;
};
static inline struct simple_bridge *
drm_bridge_to_simple_bridge(struct drm_bridge *bridge)
{
return container_of(bridge, struct simple_bridge, bridge);
}
static inline struct simple_bridge *
drm_connector_to_simple_bridge(struct drm_connector *connector)
{
return container_of(connector, struct simple_bridge, connector);
}
static int simple_bridge_get_modes(struct drm_connector *connector)
{
struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector);
const struct drm_edid *drm_edid;
int ret;
if (sbridge->next_bridge->ops & DRM_BRIDGE_OP_EDID) {
drm_edid = drm_bridge_edid_read(sbridge->next_bridge, connector);
if (!drm_edid)
DRM_INFO("EDID read failed. Fallback to standard modes\n");
} else {
drm_edid = NULL;
}
drm_edid_connector_update(connector, drm_edid);
if (!drm_edid) {
/*
* In case we cannot retrieve the EDIDs (missing or broken DDC
* bus from the next bridge), fallback on the XGA standards and
* prefer a mode pretty much anyone can handle.
*/
ret = drm_add_modes_noedid(connector, 1920, 1200);
drm_set_preferred_mode(connector, 1024, 768);
return ret;
}
ret = drm_edid_connector_add_modes(connector);
drm_edid_free(drm_edid);
return ret;
}
static const struct drm_connector_helper_funcs simple_bridge_con_helper_funcs = {
.get_modes = simple_bridge_get_modes,
};
static enum drm_connector_status
simple_bridge_connector_detect(struct drm_connector *connector, bool force)
{
struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector);
return drm_bridge_detect(sbridge->next_bridge);
}
static const struct drm_connector_funcs simple_bridge_con_funcs = {
.detect = simple_bridge_connector_detect,
.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 simple_bridge_attach(struct drm_bridge *bridge,
enum drm_bridge_attach_flags flags)
{
struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
int ret;
ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge,
DRM_BRIDGE_ATTACH_NO_CONNECTOR);
if (ret < 0)
return ret;
if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
return 0;
drm_connector_helper_add(&sbridge->connector,
&simple_bridge_con_helper_funcs);
ret = drm_connector_init_with_ddc(bridge->dev, &sbridge->connector,
&simple_bridge_con_funcs,
sbridge->info->connector_type,
sbridge->next_bridge->ddc);
if (ret) {
DRM_ERROR("Failed to initialize connector\n");
return ret;
}
drm_connector_attach_encoder(&sbridge->connector, bridge->encoder);
return 0;
}
static void simple_bridge_enable(struct drm_bridge *bridge)
{
struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
int ret;
if (sbridge->vdd) {
ret = regulator_enable(sbridge->vdd);
if (ret)
DRM_ERROR("Failed to enable vdd regulator: %d\n", ret);
}
gpiod_set_value_cansleep(sbridge->enable, 1);
}
static void simple_bridge_disable(struct drm_bridge *bridge)
{
struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
gpiod_set_value_cansleep(sbridge->enable, 0);
if (sbridge->vdd)
regulator_disable(sbridge->vdd);
}
static const struct drm_bridge_funcs simple_bridge_bridge_funcs = {
.attach = simple_bridge_attach,
.enable = simple_bridge_enable,
.disable = simple_bridge_disable,
};
static int simple_bridge_probe(struct platform_device *pdev)
{
struct simple_bridge *sbridge;
struct device_node *remote;
sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL);
if (!sbridge)
return -ENOMEM;
sbridge->info = of_device_get_match_data(&pdev->dev);
/* Get the next bridge in the pipeline. */
remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
if (!remote)
return -EINVAL;
sbridge->next_bridge = of_drm_find_bridge(remote);
of_node_put(remote);
if (!sbridge->next_bridge) {
dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");
return -EPROBE_DEFER;
}
/* Get the regulator and GPIO resources. */
sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
if (IS_ERR(sbridge->vdd)) {
int ret = PTR_ERR(sbridge->vdd);
if (ret == -EPROBE_DEFER)
return -EPROBE_DEFER;
sbridge->vdd = NULL;
dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret);
}
sbridge->enable = devm_gpiod_get_optional(&pdev->dev, "enable",
GPIOD_OUT_LOW);
if (IS_ERR(sbridge->enable))
return dev_err_probe(&pdev->dev, PTR_ERR(sbridge->enable),
"Unable to retrieve enable GPIO\n");
/* Register the bridge. */
sbridge->bridge.funcs = &simple_bridge_bridge_funcs;
sbridge->bridge.of_node = pdev->dev.of_node;
sbridge->bridge.timings = sbridge->info->timings;
return devm_drm_bridge_add(&pdev->dev, &sbridge->bridge);
}
/*
* We assume the ADV7123 DAC is the "default" for historical reasons
* Information taken from the ADV7123 datasheet, revision D.
* NOTE: the ADV7123EP seems to have other timings and need a new timings
* set if used.
*/
static const struct drm_bridge_timings default_bridge_timings = {
/* Timing specifications, datasheet page 7 */
.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
.setup_time_ps = 500,
.hold_time_ps = 1500,
};
/*
* Information taken from the THS8134, THS8134A, THS8134B datasheet named
* "SLVS205D", dated May 1990, revised March 2000.
*/
static const struct drm_bridge_timings ti_ths8134_bridge_timings = {
/* From timing diagram, datasheet page 9 */
.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
/* From datasheet, page 12 */
.setup_time_ps = 3000,
/* I guess this means latched input */
.hold_time_ps = 0,
};
/*
* Information taken from the THS8135 datasheet named "SLAS343B", dated
* May 2001, revised April 2013.
*/
static const struct drm_bridge_timings ti_ths8135_bridge_timings = {
/* From timing diagram, datasheet page 14 */
.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
/* From datasheet, page 16 */
.setup_time_ps = 2000,
.hold_time_ps = 500,
};
static const struct of_device_id simple_bridge_match[] = {
{
.compatible = "dumb-vga-dac",
.data = &(const struct simple_bridge_info) {
.connector_type = DRM_MODE_CONNECTOR_VGA,
},
}, {
.compatible = "adi,adv7123",
.data = &(const struct simple_bridge_info) {
.timings = &default_bridge_timings,
.connector_type = DRM_MODE_CONNECTOR_VGA,
},
}, {
.compatible = "ti,opa362",
.data = &(const struct simple_bridge_info) {
.connector_type = DRM_MODE_CONNECTOR_Composite,
},
}, {
.compatible = "ti,ths8135",
.data = &(const struct simple_bridge_info) {
.timings = &ti_ths8135_bridge_timings,
.connector_type = DRM_MODE_CONNECTOR_VGA,
},
}, {
.compatible = "ti,ths8134",
.data = &(const struct simple_bridge_info) {
.timings = &ti_ths8134_bridge_timings,
.connector_type = DRM_MODE_CONNECTOR_VGA,
},
},
{},
};
MODULE_DEVICE_TABLE(of, simple_bridge_match);
static struct platform_driver simple_bridge_driver = {
.probe = simple_bridge_probe,
.driver = {
.name = "simple-bridge",
.of_match_table = simple_bridge_match,
},
};
module_platform_driver(simple_bridge_driver);
MODULE_AUTHOR("Maxime Ripard <[email protected]>");
MODULE_DESCRIPTION("Simple DRM bridge driver");
MODULE_LICENSE("GPL");
Codebase Browser
linux