Re: [RFC v2 2/5] video: panel: Add DPI panel support
Hi Laurent,
Am Donnerstag, den 22.11.2012, 22:45 +0100 schrieb Laurent Pinchart:
From: Laurent Pinchart laurent.pinchart+rene...@ideasonboard.com
Signed-off-by: Laurent Pinchart laurent.pinch...@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 000..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.pinch...@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 ==
Re: [RFC v2 2/5] video: panel: Add DPI panel support
Hi,
On 2012-11-22 23:45, Laurent Pinchart wrote:
+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;
+ 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,
+ },
+};
I'm not sure of how the free/release works. The release func is called
when the ref count drops to zero. But... The object in question, the
panel_dpi struct which contains the display entity, is not only about
data, it's also about code located in this module.
So I don't see anything preventing from unloading this module, while
some other component is holding a ref for the display entity. While its
holding the ref, it's valid to call ops in the display entity, but the
code for the ops in this module is already unloaded.
I don't really know how the kref can be used properly in this use case...
Tomi
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Description: OpenPGP digital signature
[RFC v2 2/5] video: panel: Add DPI panel support
From: Laurent Pinchart laurent.pinchart+rene...@ideasonboard.com
Signed-off-by: Laurent Pinchart laurent.pinch...@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.
+
+ 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 000..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.pinch...@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 =
