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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
*/
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <drm/drm_bridge.h>
#include <drm/drm_edid.h>
struct display_connector {
struct drm_bridge bridge;
struct gpio_desc *hpd_gpio;
int hpd_irq;
struct regulator *dp_pwr;
};
static inline struct display_connector *
to_display_connector(struct drm_bridge *bridge)
{
return container_of(bridge, struct display_connector, bridge);
}
static int display_connector_attach(struct drm_bridge *bridge,
enum drm_bridge_attach_flags flags)
{
return flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR ? 0 : -EINVAL;
}
static enum drm_connector_status
display_connector_detect(struct drm_bridge *bridge)
{
struct display_connector *conn = to_display_connector(bridge);
if (conn->hpd_gpio) {
if (gpiod_get_value_cansleep(conn->hpd_gpio))
return connector_status_connected;
else
return connector_status_disconnected;
}
if (conn->bridge.ddc && drm_probe_ddc(conn->bridge.ddc))
return connector_status_connected;
switch (conn->bridge.type) {
case DRM_MODE_CONNECTOR_DVIA:
case DRM_MODE_CONNECTOR_DVID:
case DRM_MODE_CONNECTOR_DVII:
case DRM_MODE_CONNECTOR_HDMIA:
case DRM_MODE_CONNECTOR_HDMIB:
/*
* For DVI and HDMI connectors a DDC probe failure indicates
* that no cable is connected.
*/
return connector_status_disconnected;
case DRM_MODE_CONNECTOR_Composite:
case DRM_MODE_CONNECTOR_SVIDEO:
case DRM_MODE_CONNECTOR_VGA:
default:
/*
* Composite and S-Video connectors have no other detection
* mean than the HPD GPIO. For VGA connectors, even if we have
* an I2C bus, we can't assume that the cable is disconnected
* if drm_probe_ddc fails, as some cables don't wire the DDC
* pins.
*/
return connector_status_unknown;
}
}
static struct edid *display_connector_get_edid(struct drm_bridge *bridge,
struct drm_connector *connector)
{
struct display_connector *conn = to_display_connector(bridge);
return drm_get_edid(connector, conn->bridge.ddc);
}
static const struct drm_bridge_funcs display_connector_bridge_funcs = {
.attach = display_connector_attach,
.detect = display_connector_detect,
.get_edid = display_connector_get_edid,
};
static irqreturn_t display_connector_hpd_irq(int irq, void *arg)
{
struct display_connector *conn = arg;
struct drm_bridge *bridge = &conn->bridge;
drm_bridge_hpd_notify(bridge, display_connector_detect(bridge));
return IRQ_HANDLED;
}
static int display_connector_probe(struct platform_device *pdev)
{
struct display_connector *conn;
unsigned int type;
const char *label = NULL;
int ret;
conn = devm_kzalloc(&pdev->dev, sizeof(*conn), GFP_KERNEL);
if (!conn)
return -ENOMEM;
platform_set_drvdata(pdev, conn);
type = (uintptr_t)of_device_get_match_data(&pdev->dev);
/* Get the exact connector type. */
switch (type) {
case DRM_MODE_CONNECTOR_DVII: {
bool analog, digital;
analog = of_property_read_bool(pdev->dev.of_node, "analog");
digital = of_property_read_bool(pdev->dev.of_node, "digital");
if (analog && !digital) {
conn->bridge.type = DRM_MODE_CONNECTOR_DVIA;
} else if (!analog && digital) {
conn->bridge.type = DRM_MODE_CONNECTOR_DVID;
} else if (analog && digital) {
conn->bridge.type = DRM_MODE_CONNECTOR_DVII;
} else {
dev_err(&pdev->dev, "DVI connector with no type\n");
return -EINVAL;
}
break;
}
case DRM_MODE_CONNECTOR_HDMIA: {
const char *hdmi_type;
ret = of_property_read_string(pdev->dev.of_node, "type",
&hdmi_type);
if (ret < 0) {
dev_err(&pdev->dev, "HDMI connector with no type\n");
return -EINVAL;
}
if (!strcmp(hdmi_type, "a") || !strcmp(hdmi_type, "c") ||
!strcmp(hdmi_type, "d") || !strcmp(hdmi_type, "e")) {
conn->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
} else if (!strcmp(hdmi_type, "b")) {
conn->bridge.type = DRM_MODE_CONNECTOR_HDMIB;
} else {
dev_err(&pdev->dev,
"Unsupported HDMI connector type '%s'\n",
hdmi_type);
return -EINVAL;
}
break;
}
default:
conn->bridge.type = type;
break;
}
/* All the supported connector types support interlaced modes. */
conn->bridge.interlace_allowed = true;
/* Get the optional connector label. */
of_property_read_string(pdev->dev.of_node, "label", &label);
/*
* Get the HPD GPIO for DVI, HDMI and DP connectors. If the GPIO can provide
* edge interrupts, register an interrupt handler.
*/
if (type == DRM_MODE_CONNECTOR_DVII ||
type == DRM_MODE_CONNECTOR_HDMIA ||
type == DRM_MODE_CONNECTOR_DisplayPort) {
conn->hpd_gpio = devm_gpiod_get_optional(&pdev->dev, "hpd",
GPIOD_IN);
if (IS_ERR(conn->hpd_gpio)) {
if (PTR_ERR(conn->hpd_gpio) != -EPROBE_DEFER)
dev_err(&pdev->dev,
"Unable to retrieve HPD GPIO\n");
return PTR_ERR(conn->hpd_gpio);
}
conn->hpd_irq = gpiod_to_irq(conn->hpd_gpio);
} else {
conn->hpd_irq = -EINVAL;
}
if (conn->hpd_irq >= 0) {
ret = devm_request_threaded_irq(&pdev->dev, conn->hpd_irq,
NULL, display_connector_hpd_irq,
IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING |
IRQF_ONESHOT,
"HPD", conn);
if (ret) {
dev_info(&pdev->dev,
"Failed to request HPD edge interrupt, falling back to polling\n");
conn->hpd_irq = -EINVAL;
}
}
/* Retrieve the DDC I2C adapter for DVI, HDMI and VGA connectors. */
if (type == DRM_MODE_CONNECTOR_DVII ||
type == DRM_MODE_CONNECTOR_HDMIA ||
type == DRM_MODE_CONNECTOR_VGA) {
struct device_node *phandle;
phandle = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
if (phandle) {
conn->bridge.ddc = of_get_i2c_adapter_by_node(phandle);
of_node_put(phandle);
if (!conn->bridge.ddc)
return -EPROBE_DEFER;
} else {
dev_dbg(&pdev->dev,
"No I2C bus specified, disabling EDID readout\n");
}
}
/* Get the DP PWR for DP connector. */
if (type == DRM_MODE_CONNECTOR_DisplayPort) {
int ret;
conn->dp_pwr = devm_regulator_get_optional(&pdev->dev, "dp-pwr");
if (IS_ERR(conn->dp_pwr)) {
ret = PTR_ERR(conn->dp_pwr);
switch (ret) {
case -ENODEV:
conn->dp_pwr = NULL;
break;
case -EPROBE_DEFER:
return -EPROBE_DEFER;
default:
dev_err(&pdev->dev, "failed to get DP PWR regulator: %d\n", ret);
return ret;
}
}
if (conn->dp_pwr) {
ret = regulator_enable(conn->dp_pwr);
if (ret) {
dev_err(&pdev->dev, "failed to enable DP PWR regulator: %d\n", ret);
return ret;
}
}
}
conn->bridge.funcs = &display_connector_bridge_funcs;
conn->bridge.of_node = pdev->dev.of_node;
if (conn->bridge.ddc)
conn->bridge.ops |= DRM_BRIDGE_OP_EDID
| DRM_BRIDGE_OP_DETECT;
if (conn->hpd_gpio)
conn->bridge.ops |= DRM_BRIDGE_OP_DETECT;
if (conn->hpd_irq >= 0)
conn->bridge.ops |= DRM_BRIDGE_OP_HPD;
dev_dbg(&pdev->dev,
"Found %s display connector '%s' %s DDC bus and %s HPD GPIO (ops 0x%x)\n",
drm_get_connector_type_name(conn->bridge.type),
label ? label : "<unlabelled>",
conn->bridge.ddc ? "with" : "without",
conn->hpd_gpio ? "with" : "without",
conn->bridge.ops);
drm_bridge_add(&conn->bridge);
return 0;
}
static int display_connector_remove(struct platform_device *pdev)
{
struct display_connector *conn = platform_get_drvdata(pdev);
if (conn->dp_pwr)
regulator_disable(conn->dp_pwr);
drm_bridge_remove(&conn->bridge);
if (!IS_ERR(conn->bridge.ddc))
i2c_put_adapter(conn->bridge.ddc);
return 0;
}
static const struct of_device_id display_connector_match[] = {
{
.compatible = "composite-video-connector",
.data = (void *)DRM_MODE_CONNECTOR_Composite,
}, {
.compatible = "dvi-connector",
.data = (void *)DRM_MODE_CONNECTOR_DVII,
}, {
.compatible = "hdmi-connector",
.data = (void *)DRM_MODE_CONNECTOR_HDMIA,
}, {
.compatible = "svideo-connector",
.data = (void *)DRM_MODE_CONNECTOR_SVIDEO,
}, {
.compatible = "vga-connector",
.data = (void *)DRM_MODE_CONNECTOR_VGA,
}, {
.compatible = "dp-connector",
.data = (void *)DRM_MODE_CONNECTOR_DisplayPort,
},
{},
};
MODULE_DEVICE_TABLE(of, display_connector_match);
static struct platform_driver display_connector_driver = {
.probe = display_connector_probe,
.remove = display_connector_remove,
.driver = {
.name = "display-connector",
.of_match_table = display_connector_match,
},
};
module_platform_driver(display_connector_driver);
MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_DESCRIPTION("Display connector driver");
MODULE_LICENSE("GPL");
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