Files
android_kernel_xiaomi_sm8450/drivers/gpu/drm/omapdrm/displays/panel-dpi.c
Laurent Pinchart 31cd7afa30 drm/omap: panels: Don't modify fixed timings
Panels drivers store their timings in a device data structure field that
is initialized at probe time, either from hardcoded values or from
firmware-supplied values. Those timings are then reported through the
.get_timings() operation to construct the panel display mode.

The panel timings are further modified by the .set_timings() operation,
which is called with the timings retrieved by .get_timings(), and
mangled by .check_timings(). The latter potentially adjusts the pixel
clock only.

Conceptually, modifying the panel timings is wrong, as the timings are
an intrinsic property of the panel and should thus be fixed.
Furthermore, modifying them this way at runtime can result in display
modes reported to userspace varying between calls, which is also wrong.

There's no actual need to store the mangled pixel clock value in the
timings. Don't modify the panel timings in the .set_timings() operation,
just forward it to the previous device in the display pipeline.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2018-09-03 16:13:30 +03:00

230 lines
5.2 KiB
C

/*
* Generic MIPI DPI Panel Driver
*
* Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
* Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>
#include <linux/backlight.h>
#include <video/of_display_timing.h>
#include "../dss/omapdss.h"
struct panel_drv_data {
struct omap_dss_device dssdev;
struct videomode vm;
struct backlight_device *backlight;
struct gpio_desc *enable_gpio;
struct regulator *vcc_supply;
};
#define to_panel_data(p) container_of(p, struct panel_drv_data, dssdev)
static int panel_dpi_connect(struct omap_dss_device *src,
struct omap_dss_device *dst)
{
return 0;
}
static void panel_dpi_disconnect(struct omap_dss_device *src,
struct omap_dss_device *dst)
{
}
static int panel_dpi_enable(struct omap_dss_device *dssdev)
{
struct panel_drv_data *ddata = to_panel_data(dssdev);
struct omap_dss_device *src = dssdev->src;
int r;
if (!omapdss_device_is_connected(dssdev))
return -ENODEV;
if (omapdss_device_is_enabled(dssdev))
return 0;
r = src->ops->enable(src);
if (r)
return r;
r = regulator_enable(ddata->vcc_supply);
if (r) {
src->ops->disable(src);
return r;
}
gpiod_set_value_cansleep(ddata->enable_gpio, 1);
backlight_enable(ddata->backlight);
dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
return 0;
}
static void panel_dpi_disable(struct omap_dss_device *dssdev)
{
struct panel_drv_data *ddata = to_panel_data(dssdev);
struct omap_dss_device *src = dssdev->src;
if (!omapdss_device_is_enabled(dssdev))
return;
backlight_disable(ddata->backlight);
gpiod_set_value_cansleep(ddata->enable_gpio, 0);
regulator_disable(ddata->vcc_supply);
src->ops->disable(src);
dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
}
static void panel_dpi_set_timings(struct omap_dss_device *dssdev,
const struct videomode *vm)
{
struct omap_dss_device *src = dssdev->src;
src->ops->set_timings(src, vm);
}
static void panel_dpi_get_timings(struct omap_dss_device *dssdev,
struct videomode *vm)
{
struct panel_drv_data *ddata = to_panel_data(dssdev);
*vm = ddata->vm;
}
static const struct omap_dss_device_ops panel_dpi_ops = {
.connect = panel_dpi_connect,
.disconnect = panel_dpi_disconnect,
.enable = panel_dpi_enable,
.disable = panel_dpi_disable,
.set_timings = panel_dpi_set_timings,
.get_timings = panel_dpi_get_timings,
};
static int panel_dpi_probe_of(struct platform_device *pdev)
{
struct panel_drv_data *ddata = platform_get_drvdata(pdev);
struct device_node *node = pdev->dev.of_node;
int r;
struct display_timing timing;
struct gpio_desc *gpio;
gpio = devm_gpiod_get_optional(&pdev->dev, "enable", GPIOD_OUT_LOW);
if (IS_ERR(gpio))
return PTR_ERR(gpio);
ddata->enable_gpio = gpio;
/*
* Many different panels are supported by this driver and there are
* probably very different needs for their reset pins in regards to
* timing and order relative to the enable gpio. So for now it's just
* ensured that the reset line isn't active.
*/
gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
if (IS_ERR(gpio))
return PTR_ERR(gpio);
ddata->vcc_supply = devm_regulator_get(&pdev->dev, "vcc");
if (IS_ERR(ddata->vcc_supply))
return PTR_ERR(ddata->vcc_supply);
ddata->backlight = devm_of_find_backlight(&pdev->dev);
if (IS_ERR(ddata->backlight))
return PTR_ERR(ddata->backlight);
r = of_get_display_timing(node, "panel-timing", &timing);
if (r) {
dev_err(&pdev->dev, "failed to get video timing\n");
return r;
}
videomode_from_timing(&timing, &ddata->vm);
return 0;
}
static int panel_dpi_probe(struct platform_device *pdev)
{
struct panel_drv_data *ddata;
struct omap_dss_device *dssdev;
int r;
ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
if (ddata == NULL)
return -ENOMEM;
platform_set_drvdata(pdev, ddata);
r = panel_dpi_probe_of(pdev);
if (r)
return r;
dssdev = &ddata->dssdev;
dssdev->dev = &pdev->dev;
dssdev->ops = &panel_dpi_ops;
dssdev->type = OMAP_DISPLAY_TYPE_DPI;
dssdev->owner = THIS_MODULE;
dssdev->of_ports = BIT(0);
omapdss_display_init(dssdev);
omapdss_device_register(dssdev);
return 0;
}
static int __exit panel_dpi_remove(struct platform_device *pdev)
{
struct panel_drv_data *ddata = platform_get_drvdata(pdev);
struct omap_dss_device *dssdev = &ddata->dssdev;
omapdss_device_unregister(dssdev);
panel_dpi_disable(dssdev);
return 0;
}
static const struct of_device_id panel_dpi_of_match[] = {
{ .compatible = "omapdss,panel-dpi", },
{},
};
MODULE_DEVICE_TABLE(of, panel_dpi_of_match);
static struct platform_driver panel_dpi_driver = {
.probe = panel_dpi_probe,
.remove = __exit_p(panel_dpi_remove),
.driver = {
.name = "panel-dpi",
.of_match_table = panel_dpi_of_match,
.suppress_bind_attrs = true,
},
};
module_platform_driver(panel_dpi_driver);
MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
MODULE_DESCRIPTION("Generic MIPI DPI Panel Driver");
MODULE_LICENSE("GPL");