linux/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c

153 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2014 Traphandler
* Copyright (C) 2014 Free Electrons
* Copyright (C) 2014 Atmel
*
* Author: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
* Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
*/
#include <linux/media-bus-format.h>
#include <linux/of_graph.h>
#include <drm/drm_encoder.h>
#include <drm/drm_of.h>
#include <drm/drm_bridge.h>
#include "atmel_hlcdc_dc.h"
struct atmel_hlcdc_rgb_output {
struct drm_encoder encoder;
int bus_fmt;
};
static const struct drm_encoder_funcs atmel_hlcdc_panel_encoder_funcs = {
.destroy = drm_encoder_cleanup,
};
static struct atmel_hlcdc_rgb_output *
atmel_hlcdc_encoder_to_rgb_output(struct drm_encoder *encoder)
{
return container_of(encoder, struct atmel_hlcdc_rgb_output, encoder);
}
int atmel_hlcdc_encoder_get_bus_fmt(struct drm_encoder *encoder)
{
struct atmel_hlcdc_rgb_output *output;
output = atmel_hlcdc_encoder_to_rgb_output(encoder);
return output->bus_fmt;
}
static int atmel_hlcdc_of_bus_fmt(const struct device_node *ep)
{
u32 bus_width;
int ret;
ret = of_property_read_u32(ep, "bus-width", &bus_width);
if (ret == -EINVAL)
return 0;
if (ret)
return ret;
switch (bus_width) {
case 12:
return MEDIA_BUS_FMT_RGB444_1X12;
case 16:
return MEDIA_BUS_FMT_RGB565_1X16;
case 18:
return MEDIA_BUS_FMT_RGB666_1X18;
case 24:
return MEDIA_BUS_FMT_RGB888_1X24;
default:
return -EINVAL;
}
}
static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint)
{
struct atmel_hlcdc_rgb_output *output;
struct device_node *ep;
struct drm_panel *panel;
struct drm_bridge *bridge;
int ret;
ep = of_graph_get_endpoint_by_regs(dev->dev->of_node, 0, endpoint);
if (!ep)
return -ENODEV;
ret = drm_of_find_panel_or_bridge(dev->dev->of_node, 0, endpoint,
&panel, &bridge);
if (ret) {
of_node_put(ep);
return ret;
}
output = devm_kzalloc(dev->dev, sizeof(*output), GFP_KERNEL);
if (!output) {
of_node_put(ep);
return -ENOMEM;
}
output->bus_fmt = atmel_hlcdc_of_bus_fmt(ep);
of_node_put(ep);
if (output->bus_fmt < 0) {
dev_err(dev->dev, "endpoint %d: invalid bus width\n", endpoint);
return -EINVAL;
}
ret = drm_encoder_init(dev, &output->encoder,
&atmel_hlcdc_panel_encoder_funcs,
DRM_MODE_ENCODER_NONE, NULL);
if (ret)
return ret;
output->encoder.possible_crtcs = 0x1;
if (panel) {
bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_Unknown);
if (IS_ERR(bridge))
return PTR_ERR(bridge);
}
if (bridge) {
ret = drm_bridge_attach(&output->encoder, bridge, NULL);
if (!ret)
return 0;
if (panel)
drm_panel_bridge_remove(bridge);
}
drm_encoder_cleanup(&output->encoder);
return ret;
}
int atmel_hlcdc_create_outputs(struct drm_device *dev)
{
int endpoint, ret = 0;
int attached = 0;
/*
* Always scan the first few endpoints even if we get -ENODEV,
* but keep going after that as long as we keep getting hits.
*/
for (endpoint = 0; !ret || endpoint < 4; endpoint++) {
ret = atmel_hlcdc_attach_endpoint(dev, endpoint);
if (ret == -ENODEV)
continue;
if (ret)
break;
attached++;
}
/* At least one device was successfully attached.*/
if (ret == -ENODEV && attached)
return 0;
return ret;
}