[RFC v2 2/5] video: panel: Add DPI panel support
Philipp Zabel
p.zabel at pengutronix.de
Fri Nov 30 01:26:51 PST 2012
Hi Laurent,
Am Donnerstag, den 22.11.2012, 22:45 +0100 schrieb Laurent Pinchart:
> From: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> drivers/video/display/Kconfig | 13 +++
> drivers/video/display/Makefile | 1 +
> drivers/video/display/panel-dpi.c | 147 +++++++++++++++++++++++++++++++++++++
> include/video/panel-dpi.h | 24 ++++++
> 4 files changed, 185 insertions(+), 0 deletions(-)
> create mode 100644 drivers/video/display/panel-dpi.c
> create mode 100644 include/video/panel-dpi.h
>
> diff --git a/drivers/video/display/Kconfig b/drivers/video/display/Kconfig
> index 1d533e7..0f9b990 100644
> --- a/drivers/video/display/Kconfig
> +++ b/drivers/video/display/Kconfig
> @@ -2,3 +2,16 @@ menuconfig DISPLAY_CORE
> tristate "Display Core"
> ---help---
> Support common display framework for graphics devices.
> +
> +if DISPLAY_CORE
> +
> +config DISPLAY_PANEL_DPI
> + tristate "DPI (Parallel) Display Panels"
> + ---help---
> + Support for simple digital (parallel) pixel interface panels. Those
> + panels receive pixel data through a parallel bus and have no control
> + bus.
I have tried this driver together with the imx parallel-display with the
added patch below for device tree support.
> + If you are in doubt, say N.
> +
> +endif # DISPLAY_CORE
> diff --git a/drivers/video/display/Makefile b/drivers/video/display/Makefile
> index bd93496..47978d4 100644
> --- a/drivers/video/display/Makefile
> +++ b/drivers/video/display/Makefile
> @@ -1 +1,2 @@
> obj-$(CONFIG_DISPLAY_CORE) += display-core.o
> +obj-$(CONFIG_DISPLAY_PANEL_DPI) += panel-dpi.o
> diff --git a/drivers/video/display/panel-dpi.c b/drivers/video/display/panel-dpi.c
> new file mode 100644
> index 0000000..c56197a
> --- /dev/null
> +++ b/drivers/video/display/panel-dpi.c
> @@ -0,0 +1,147 @@
> +/*
> + * DPI Display Panel
> + *
> + * Copyright (C) 2012 Renesas Solutions Corp.
> + *
> + * Contacts: Laurent Pinchart <laurent.pinchart at ideasonboard.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/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#include <video/display.h>
> +#include <video/panel-dpi.h>
> +
> +struct panel_dpi {
> + struct display_entity entity;
> + const struct panel_dpi_platform_data *pdata;
> +};
> +
> +#define to_panel_dpi(p) container_of(p, struct panel_dpi, entity)
> +
> +static const struct display_entity_interface_params panel_dpi_params = {
> + .type = DISPLAY_ENTITY_INTERFACE_DPI,
> +};
> +
> +static int panel_dpi_set_state(struct display_entity *entity,
> + enum display_entity_state state)
> +{
> + switch (state) {
> + case DISPLAY_ENTITY_STATE_OFF:
> + case DISPLAY_ENTITY_STATE_STANDBY:
> + display_entity_set_stream(entity->source,
> + DISPLAY_ENTITY_STREAM_STOPPED);
> + break;
> +
> + case DISPLAY_ENTITY_STATE_ON:
> + display_entity_set_stream(entity->source,
> + DISPLAY_ENTITY_STREAM_CONTINUOUS);
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static int panel_dpi_get_modes(struct display_entity *entity,
> + const struct videomode **modes)
> +{
> + struct panel_dpi *panel = to_panel_dpi(entity);
> +
> + *modes = panel->pdata->mode;
> + return 1;
> +}
> +
> +static int panel_dpi_get_size(struct display_entity *entity,
> + unsigned int *width, unsigned int *height)
> +{
> + struct panel_dpi *panel = to_panel_dpi(entity);
> +
> + *width = panel->pdata->width;
> + *height = panel->pdata->height;
> + return 0;
> +}
> +
> +static int panel_dpi_get_params(struct display_entity *entity,
> + struct display_entity_interface_params *params)
> +{
> + *params = panel_dpi_params;
> + return 0;
> +}
> +
> +static const struct display_entity_control_ops panel_dpi_control_ops = {
> + .set_state = panel_dpi_set_state,
> + .get_modes = panel_dpi_get_modes,
> + .get_size = panel_dpi_get_size,
> + .get_params = panel_dpi_get_params,
> +};
> +
> +static void panel_dpi_release(struct display_entity *entity)
> +{
> + struct panel_dpi *panel = to_panel_dpi(entity);
> +
> + kfree(panel);
> +}
> +
> +static int panel_dpi_remove(struct platform_device *pdev)
> +{
> + struct panel_dpi *panel = platform_get_drvdata(pdev);
> +
> + platform_set_drvdata(pdev, NULL);
> + display_entity_unregister(&panel->entity);
> +
> + return 0;
> +}
> +
> +static int __devinit panel_dpi_probe(struct platform_device *pdev)
> +{
> + const struct panel_dpi_platform_data *pdata = pdev->dev.platform_data;
> + struct panel_dpi *panel;
> + int ret;
> +
> + if (pdata == NULL)
> + return -ENODEV;
> +
> + panel = kzalloc(sizeof(*panel), GFP_KERNEL);
> + if (panel == NULL)
> + return -ENOMEM;
> +
> + panel->pdata = pdata;
> + panel->entity.dev = &pdev->dev;
> + panel->entity.release = panel_dpi_release;
I don't understand this. Shouldn't the panel be allocated with
devm_kzalloc and display_entity_register make sure that this driver
cannot be unbound instead?
What if we call in sequence on this device's entity:
display_entity_get(entity);
display_entity_release(entity); /* here struct panel_dpi gets freed */
display_entity_get(entity);
display_entity_release(entity);
> + panel->entity.ops.ctrl = &panel_dpi_control_ops;
> +
> + ret = display_entity_register(&panel->entity);
> + if (ret < 0) {
> + kfree(panel);
> + return ret;
> + }
> +
> + platform_set_drvdata(pdev, panel);
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops panel_dpi_dev_pm_ops = {
> +};
> +
> +static struct platform_driver panel_dpi_driver = {
> + .probe = panel_dpi_probe,
> + .remove = panel_dpi_remove,
> + .driver = {
> + .name = "panel_dpi",
> + .owner = THIS_MODULE,
> + .pm = &panel_dpi_dev_pm_ops,
> + },
> +};
> +
> +module_platform_driver(panel_dpi_driver);
> +
> +MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart at ideasonboard.com>");
> +MODULE_DESCRIPTION("DPI Display Panel");
> +MODULE_LICENSE("GPL");
> diff --git a/include/video/panel-dpi.h b/include/video/panel-dpi.h
> new file mode 100644
> index 0000000..0547b4a
> --- /dev/null
> +++ b/include/video/panel-dpi.h
> @@ -0,0 +1,24 @@
> +/*
> + * DPI Display Panel
> + *
> + * Copyright (C) 2012 Renesas Solutions Corp.
> + *
> + * Contacts: Laurent Pinchart <laurent.pinchart at ideasonboard.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.
> + */
> +
> +#ifndef __PANEL_DPI_H__
> +#define __PANEL_DPI_H__
> +
> +#include <linux/videomode.h>
> +
> +struct panel_dpi_platform_data {
> + unsigned long width; /* Panel width in mm */
> + unsigned long height; /* Panel height in mm */
> + const struct videomode *mode;
> +};
> +
> +#endif /* __PANEL_DPI_H__ */
From: Philipp Zabel <p.zabel at pengutronix.de>
Date: Thu, 29 Nov 2012 19:18:30 +0100
Subject: [PATCH] video: panel: Add device tree support to the DPI panel
driver
Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
---
drivers/video/display/panel-dpi.c | 56 ++++++++++++++++++++++++++++++++++---
1 file changed, 52 insertions(+), 4 deletions(-)
diff --git a/drivers/video/display/panel-dpi.c b/drivers/video/display/panel-dpi.c
index c56197a..5a7dd8e 100644
--- a/drivers/video/display/panel-dpi.c
+++ b/drivers/video/display/panel-dpi.c
@@ -14,6 +14,8 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_videomode.h>
#include <video/display.h>
#include <video/panel-dpi.h>
@@ -98,20 +100,60 @@ static int panel_dpi_remove(struct platform_device *pdev)
return 0;
}
-static int __devinit panel_dpi_probe(struct platform_device *pdev)
+static int __devinit panel_dpi_parse_dt(struct device *dev,
+ struct panel_dpi *panel)
{
- const struct panel_dpi_platform_data *pdata = pdev->dev.platform_data;
- struct panel_dpi *panel;
+ struct device_node *np = dev->of_node;
+ struct panel_dpi_platform_data *pdata;
+ struct videomode *vm;
+ u32 width, height;
int ret;
+ if (!np)
+ return -ENODEV;
+
+ pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
if (pdata == NULL)
+ return -ENOMEM;
+
+ vm = devm_kzalloc(dev, sizeof(*vm), GFP_KERNEL);
+ if (vm == NULL)
+ return -ENOMEM;
+
+ ret = of_get_videomode(np, vm, 0);
+ if (ret < 0)
return -ENODEV;
+ of_property_read_u32(np, "width", &width);
+ of_property_read_u32(np, "height", &height);
+
+ pdata->mode = vm;
+ pdata->width = width;
+ pdata->height = height;
+ panel->pdata = pdata;
+
+ return 0;
+}
+
+static int __devinit panel_dpi_probe(struct platform_device *pdev)
+{
+ const struct panel_dpi_platform_data *pdata = pdev->dev.platform_data;
+ struct panel_dpi *panel;
+ int ret;
+
panel = kzalloc(sizeof(*panel), GFP_KERNEL);
if (panel == NULL)
return -ENOMEM;
- panel->pdata = pdata;
+ if (pdata) {
+ panel->pdata = pdata;
+ } else {
+ ret = panel_dpi_parse_dt(&pdev->dev, panel);
+ if (ret < 0) {
+ kfree(panel);
+ return ret;
+ }
+ }
panel->entity.dev = &pdev->dev;
panel->entity.release = panel_dpi_release;
panel->entity.ops.ctrl = &panel_dpi_control_ops;
@@ -130,11 +172,17 @@ static int __devinit panel_dpi_probe(struct platform_device *pdev)
static const struct dev_pm_ops panel_dpi_dev_pm_ops = {
};
+static const struct of_device_id panel_dpi_dt_ids[] = {
+ { .compatible = "dpi-panel", },
+ { }
+};
+
static struct platform_driver panel_dpi_driver = {
.probe = panel_dpi_probe,
.remove = panel_dpi_remove,
.driver = {
.name = "panel_dpi",
+ .of_match_table = panel_dpi_dt_ids,
.owner = THIS_MODULE,
.pm = &panel_dpi_dev_pm_ops,
},
--
1.7.10.4
regards
Philipp
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