diff options
Diffstat (limited to 'drivers/gpu/drm/bridge/display-connector.c')
| -rw-r--r-- | drivers/gpu/drm/bridge/display-connector.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/drivers/gpu/drm/bridge/display-connector.c b/drivers/gpu/drm/bridge/display-connector.c new file mode 100644 index 000000000000..4d278573cdb9 --- /dev/null +++ b/drivers/gpu/drm/bridge/display-connector.c @@ -0,0 +1,295 @@ +// 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 <drm/drm_bridge.h> +#include <drm/drm_edid.h> + +struct display_connector { + struct drm_bridge bridge; + + struct gpio_desc *hpd_gpio; + int hpd_irq; +}; + +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; + 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 and HDMI connectors. If the GPIO can provide + * edge interrupts, register an interrupt handler. + */ + if (type == DRM_MODE_CONNECTOR_DVII || + type == DRM_MODE_CONNECTOR_HDMIA) { + 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"); + } + } + + 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); + + 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, + }, + {}, +}; +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"); |