[RFC v2 0/5] Common Display Framework

@@ -2442,6 +2442,7 @@ source "drivers/video/omap/Kconfig"
 source "drivers/video/omap2/Kconfig"
 source "drivers/video/exynos/Kconfig"
 source "drivers/video/backlight/Kconfig"
+source "drivers/video/display/Kconfig"
 
 if VT
 	source "drivers/video/console/Kconfig"

@@ -14,6 +14,7 @@ fb-objs                           := $(fb-y)
 obj-$(CONFIG_VT)		  += console/
 obj-$(CONFIG_LOGO)		  += logo/
 obj-y				  += backlight/
+obj-y				  += display/
 
 obj-$(CONFIG_EXYNOS_VIDEO)     += exynos/
 

@@ -0,0 +1,4 @@
+menuconfig DISPLAY_CORE
+	tristate "Display Core"
+	---help---
+	  Support common display framework for graphics devices.

@@ -0,0 +1 @@
+obj-$(CONFIG_DISPLAY_CORE) += display-core.o

@@ -0,0 +1,362 @@
+/*
+ * Display Core
+ *
+ * Copyright (C) 2012 Renesas Solutions Corp.
+ *
+ * Contacts: Laurent Pinchart <laurent.pinchart@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/export.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/videomode.h>
+
+#include <video/display.h>
+
+static LIST_HEAD(display_entity_list);
+static LIST_HEAD(display_entity_notifiers);
+static DEFINE_MUTEX(display_entity_mutex);
+
+/* -----------------------------------------------------------------------------
+ * Control operations
+ */
+
+/**
+ * display_entity_set_state - Set the display entity operation state
+ * @entity: The display entity
+ * @state: Display entity operation state
+ *
+ * See &enum display_entity_state for information regarding the entity states.
+ *
+ * Return 0 on success or a negative error code otherwise.
+ */
+int display_entity_set_state(struct display_entity *entity,
+			     enum display_entity_state state)
+{
+	int ret;
+
+	if (entity->state = state)
+		return 0;
+
+	if (!entity->ops.ctrl || !entity->ops.ctrl->set_state)
+		return 0;
+
+	ret = entity->ops.ctrl->set_state(entity, state);
+	if (ret < 0)
+		return ret;
+
+	entity->state = state;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(display_entity_set_state);
+
+/**
+ * display_entity_update - Update the display
+ * @entity: The display entity
+ *
+ * Make the display entity ready to receive pixel data and start frame transfer.
+ * This operation can only be called if the display entity is in STANDBY or ON
+ * state.
+ *
+ * The display entity will call the upstream entity in the video chain to start
+ * the video stream.
+ *
+ * Return 0 on success or a negative error code otherwise.
+ */
+int display_entity_update(struct display_entity *entity)
+{
+	if (!entity->ops.ctrl || !entity->ops.ctrl->update)
+		return 0;
+
+	return entity->ops.ctrl->update(entity);
+}
+EXPORT_SYMBOL_GPL(display_entity_update);
+
+/**
+ * display_entity_get_modes - Get video modes supported by the display entity
+ * @entity The display entity
+ * @modes: Pointer to an array of modes
+ *
+ * Fill the modes argument with a pointer to an array of video modes. The array
+ * is owned by the display entity.
+ *
+ * Return the number of supported modes on success (including 0 if no mode is
+ * supported) or a negative error code otherwise.
+ */
+int display_entity_get_modes(struct display_entity *entity,
+			     const struct videomode **modes)
+{
+	if (!entity->ops.ctrl || !entity->ops.ctrl->get_modes)
+		return 0;
+
+	return entity->ops.ctrl->get_modes(entity, modes);
+}
+EXPORT_SYMBOL_GPL(display_entity_get_modes);
+
+/**
+ * display_entity_get_size - Get display entity physical size
+ * @entity: The display entity
+ * @width: Physical width in millimeters
+ * @height: Physical height in millimeters
+ *
+ * When applicable, for instance for display panels, retrieve the display
+ * physical size in millimeters.
+ *
+ * Return 0 on success or a negative error code otherwise.
+ */
+int display_entity_get_size(struct display_entity *entity,
+			    unsigned int *width, unsigned int *height)
+{
+	if (!entity->ops.ctrl || !entity->ops.ctrl->get_size)
+		return -EOPNOTSUPP;
+
+	return entity->ops.ctrl->get_size(entity, width, height);
+}
+EXPORT_SYMBOL_GPL(display_entity_get_size);
+
+/**
+ * display_entity_get_params - Get display entity interface parameters
+ * @entity: The display entity
+ * @params: Pointer to interface parameters
+ *
+ * Fill the parameters structure pointed to by the params argument with display
+ * entity interface parameters.
+ *
+ * Return 0 on success or a negative error code otherwise.
+ */
+int display_entity_get_params(struct display_entity *entity,
+			      struct display_entity_interface_params *params)
+{
+	if (!entity->ops.ctrl || !entity->ops.ctrl->get_modes)
+		return -EOPNOTSUPP;
+
+	return entity->ops.ctrl->get_params(entity, params);
+}
+EXPORT_SYMBOL_GPL(display_entity_get_params);
+
+/* -----------------------------------------------------------------------------
+ * Video operations
+ */
+
+/**
+ * display_entity_set_stream - Control the video stream state
+ * @entity: The display entity
+ * @state: Display video stream state
+ *
+ * Control the video stream state at the entity video output.
+ *
+ * See &enum display_entity_stream_state for information regarding the stream
+ * states.
+ *
+ * Return 0 on success or a negative error code otherwise.
+ */
+int display_entity_set_stream(struct display_entity *entity,
+			      enum display_entity_stream_state state)
+{
+	if (!entity->ops.video || !entity->ops.video->set_stream)
+		return 0;
+
+	return entity->ops.video->set_stream(entity, state);
+}
+EXPORT_SYMBOL_GPL(display_entity_set_stream);
+
+/* -----------------------------------------------------------------------------
+ * Connections
+ */
+
+/**
+ * display_entity_connect - Connect two entities through a video stream
+ * @source: The video stream source
+ * @sink: The video stream sink
+ *
+ * Set the sink entity source field to the source entity.
+ */
+
+/**
+ * display_entity_disconnect - Disconnect two previously connected entities
+ * @source: The video stream source
+ * @sink: The video stream sink
+ *
+ * Break a connection between two previously connected entities. The source
+ * entity source field is reset to NULL.
+ */
+
+/* -----------------------------------------------------------------------------
+ * Registration and notification
+ */
+
+static void display_entity_release(struct kref *ref)
+{
+	struct display_entity *entity +		container_of(ref, struct display_entity, ref);
+
+	if (entity->release)
+		entity->release(entity);
+}
+
+/**
+ * display_entity_get - get a reference to a display entity
+ * @display_entity: the display entity
+ *
+ * Return the display entity pointer.
+ */
+struct display_entity *display_entity_get(struct display_entity *entity)
+{
+	if (entity = NULL)
+		return NULL;
+
+	kref_get(&entity->ref);
+	return entity;
+}
+EXPORT_SYMBOL_GPL(display_entity_get);
+
+/**
+ * display_entity_put - release a reference to a display entity
+ * @display_entity: the display entity
+ *
+ * Releasing the last reference to a display entity releases the display entity
+ * itself.
+ */
+void display_entity_put(struct display_entity *entity)
+{
+	kref_put(&entity->ref, display_entity_release);
+}
+EXPORT_SYMBOL_GPL(display_entity_put);
+
+static int display_entity_notifier_match(struct display_entity *entity,
+				struct display_entity_notifier *notifier)
+{
+	return notifier->dev = NULL || notifier->dev = entity->dev;
+}
+
+/**
+ * display_entity_register_notifier - register a display entity notifier
+ * @notifier: display entity notifier structure we want to register
+ *
+ * Display entity notifiers are called to notify drivers of display
+ * entity-related events for matching display_entitys.
+ *
+ * Notifiers and display_entitys are matched through the device they correspond
+ * to. If the notifier dev field is equal to the display entity dev field the
+ * notifier will be called when an event is reported. Notifiers with a NULL dev
+ * field act as catch-all and will be called for all display_entitys.
+ *
+ * Supported events are
+ *
+ * - DISPLAY_ENTITY_NOTIFIER_CONNECT reports display entity connection and is
+ *   sent at display entity or notifier registration time
+ * - DISPLAY_ENTITY_NOTIFIER_DISCONNECT reports display entity disconnection and
+ *   is sent at display entity unregistration time
+ *
+ * Registering a notifier sends DISPLAY_ENTITY_NOTIFIER_CONNECT events for all
+ * previously registered display_entitys that match the notifiers.
+ *
+ * Return 0 on success.
+ */
+int display_entity_register_notifier(struct display_entity_notifier *notifier)
+{
+	struct display_entity *entity;
+
+	mutex_lock(&display_entity_mutex);
+	list_add_tail(&notifier->list, &display_entity_notifiers);
+
+	list_for_each_entry(entity, &display_entity_list, list) {
+		if (!display_entity_notifier_match(entity, notifier))
+			continue;
+
+		if (notifier->notify(notifier, entity,
+				     DISPLAY_ENTITY_NOTIFIER_CONNECT))
+			break;
+	}
+	mutex_unlock(&display_entity_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(display_entity_register_notifier);
+
+/**
+ * display_entity_unregister_notifier - unregister a display entity notifier
+ * @notifier: display entity notifier to be unregistered
+ *
+ * Unregistration guarantees that the notifier will never be called upon return
+ * of this function.
+ */
+void display_entity_unregister_notifier(struct display_entity_notifier *notifier)
+{
+	mutex_lock(&display_entity_mutex);
+	list_del(&notifier->list);
+	mutex_unlock(&display_entity_mutex);
+}
+EXPORT_SYMBOL_GPL(display_entity_unregister_notifier);
+
+/**
+ * display_entity_register - register a display entity
+ * @display_entity: display entity to be registered
+ *
+ * Register the display entity and send the DISPLAY_ENTITY_NOTIFIER_CONNECT
+ * event to all matching registered notifiers.
+ *
+ * Return 0 on success.
+ */
+int __must_check __display_entity_register(struct display_entity *entity,
+					   struct module *owner)
+{
+	struct display_entity_notifier *notifier;
+
+	kref_init(&entity->ref);
+	entity->owner = owner;
+	entity->state = DISPLAY_ENTITY_STATE_OFF;
+
+	mutex_lock(&display_entity_mutex);
+	list_add(&entity->list, &display_entity_list);
+
+	list_for_each_entry(notifier, &display_entity_notifiers, list) {
+		if (!display_entity_notifier_match(entity, notifier))
+			continue;
+
+		if (notifier->notify(notifier, entity,
+				     DISPLAY_ENTITY_NOTIFIER_CONNECT))
+			break;
+	}
+	mutex_unlock(&display_entity_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__display_entity_register);
+
+/**
+ * display_entity_unregister - unregister a display entity
+ * @display_entity: display entity to be unregistered
+ *
+ * Unregister the display entity and send the DISPLAY_ENTITY_NOTIFIER_DISCONNECT
+ * event to all matching registered notifiers.
+ */
+void display_entity_unregister(struct display_entity *entity)
+{
+	struct display_entity_notifier *notifier;
+
+	mutex_lock(&display_entity_mutex);
+	list_for_each_entry(notifier, &display_entity_notifiers, list) {
+		if (!display_entity_notifier_match(entity, notifier))
+			continue;
+
+		notifier->notify(notifier, entity,
+				 DISPLAY_ENTITY_NOTIFIER_DISCONNECT);
+	}
+
+	list_del(&entity->list);
+	mutex_unlock(&display_entity_mutex);
+
+	display_entity_put(entity);
+}
+EXPORT_SYMBOL_GPL(display_entity_unregister);
+
+MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
+MODULE_DESCRIPTION("Display Core");
+MODULE_LICENSE("GPL");

@@ -0,0 +1,150 @@
+/*
+ * Display Core
+ *
+ * Copyright (C) 2012 Renesas Solutions Corp.
+ *
+ * Contacts: Laurent Pinchart <laurent.pinchart@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 __DISPLAY_H__
+#define __DISPLAY_H__
+
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/module.h>
+
+/* -----------------------------------------------------------------------------
+ * Display Entity
+ */
+
+struct display_entity;
+struct videomode;
+
+#define DISPLAY_ENTITY_NOTIFIER_CONNECT		1
+#define DISPLAY_ENTITY_NOTIFIER_DISCONNECT	2
+
+struct display_entity_notifier {
+	int (*notify)(struct display_entity_notifier *, struct display_entity *,
+		      int);
+	struct device *dev;
+	struct list_head list;
+};
+
+/**
+ * enum display_entity_state - State of a display entity
+ * @DISPLAY_ENTITY_STATE_OFF: The entity is turned off completely, possibly
+ *	including its power supplies. Communication with a display entity in
+ *	that state is not possible.
+ * @DISPLAY_ENTITY_STATE_STANDBY: The entity is in a low-power state. Full
+ *	communication with the display entity is supported, including pixel data
+ *	transfer, but the output is kept blanked.
+ * @DISPLAY_ENTITY_STATE_ON: The entity is fully operational.
+ */
+enum display_entity_state {
+	DISPLAY_ENTITY_STATE_OFF,
+	DISPLAY_ENTITY_STATE_STANDBY,
+	DISPLAY_ENTITY_STATE_ON,
+};
+
+/**
+ * enum display_entity_stream_state - State of a video stream
+ * @DISPLAY_ENTITY_STREAM_STOPPED: The video stream is stopped, no frames are
+ *	transferred.
+ * @DISPLAY_ENTITY_STREAM_SINGLE_SHOT: The video stream has been started for
+ *      single shot operation. The source entity will transfer a single frame
+ *      and then stop.
+ * @DISPLAY_ENTITY_STREAM_CONTINUOUS: The video stream is running, frames are
+ *	transferred continuously by the source entity.
+ */
+enum display_entity_stream_state {
+	DISPLAY_ENTITY_STREAM_STOPPED,
+	DISPLAY_ENTITY_STREAM_SINGLE_SHOT,
+	DISPLAY_ENTITY_STREAM_CONTINUOUS,
+};
+
+enum display_entity_interface_type {
+	DISPLAY_ENTITY_INTERFACE_DPI,
+};
+
+struct display_entity_interface_params {
+	enum display_entity_interface_type type;
+};
+
+struct display_entity_control_ops {
+	int (*set_state)(struct display_entity *ent,
+			 enum display_entity_state state);
+	int (*update)(struct display_entity *ent);
+	int (*get_modes)(struct display_entity *ent,
+			 const struct videomode **modes);
+	int (*get_params)(struct display_entity *ent,
+			  struct display_entity_interface_params *params);
+	int (*get_size)(struct display_entity *ent,
+			unsigned int *width, unsigned int *height);
+};
+
+struct display_entity_video_ops {
+	int (*set_stream)(struct display_entity *ent,
+			  enum display_entity_stream_state state);
+};
+
+struct display_entity {
+	struct list_head list;
+	struct device *dev;
+	struct module *owner;
+	struct kref ref;
+
+	struct display_entity *source;
+
+	struct {
+		const struct display_entity_control_ops *ctrl;
+		const struct display_entity_video_ops *video;
+	} ops;
+
+	void(*release)(struct display_entity *ent);
+
+	enum display_entity_state state;
+};
+
+int display_entity_set_state(struct display_entity *entity,
+			     enum display_entity_state state);
+int display_entity_update(struct display_entity *entity);
+int display_entity_get_modes(struct display_entity *entity,
+			     const struct videomode **modes);
+int display_entity_get_params(struct display_entity *entity,
+			      struct display_entity_interface_params *params);
+int display_entity_get_size(struct display_entity *entity,
+			    unsigned int *width, unsigned int *height);
+
+int display_entity_set_stream(struct display_entity *entity,
+			      enum display_entity_stream_state state);
+
+static inline void display_entity_connect(struct display_entity *source,
+					  struct display_entity *sink)
+{
+	sink->source = source;
+}
+
+static inline void display_entity_disconnect(struct display_entity *source,
+					     struct display_entity *sink)
+{
+	sink->source = NULL;
+}
+
+struct display_entity *display_entity_get(struct display_entity *entity);
+void display_entity_put(struct display_entity *entity);
+
+int __must_check __display_entity_register(struct display_entity *entity,
+					   struct module *owner);
+void display_entity_unregister(struct display_entity *entity);
+
+int display_entity_register_notifier(struct display_entity_notifier *notifier);
+void display_entity_unregister_notifier(struct display_entity_notifier *notifier);
+
+#define display_entity_register(display_entity) \
+	__display_entity_register(display_entity, THIS_MODULE)
+
+#endif /* __DISPLAY_H__ */

@@ -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

@@ -1 +1,2 @@
 obj-$(CONFIG_DISPLAY_CORE) += display-core.o
+obj-$(CONFIG_DISPLAY_PANEL_DPI) += panel-dpi.o

@@ -0,0 +1,147 @@
+/*
+ * DPI Display Panel
+ *
+ * Copyright (C) 2012 Renesas Solutions Corp.
+ *
+ * Contacts: Laurent Pinchart <laurent.pinchart@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;
+	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@ideasonboard.com>");
+MODULE_DESCRIPTION("DPI Display Panel");
+MODULE_LICENSE("GPL");

@@ -0,0 +1,24 @@
+/*
+ * DPI Display Panel
+ *
+ * Copyright (C) 2012 Renesas Solutions Corp.
+ *
+ * Contacts: Laurent Pinchart <laurent.pinchart@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__ */

@@ -5,6 +5,10 @@ menuconfig DISPLAY_CORE
 
 if DISPLAY_CORE
 
+config DISPLAY_MIPI_DBI
+	tristate
+	default n
+
 config DISPLAY_PANEL_DPI
 	tristate "DPI (Parallel) Display Panels"
 	---help---

@@ -1,2 +1,3 @@
 obj-$(CONFIG_DISPLAY_CORE) += display-core.o
+obj-$(CONFIG_DISPLAY_MIPI_DBI) += mipi-dbi-bus.o
 obj-$(CONFIG_DISPLAY_PANEL_DPI) += panel-dpi.o

@@ -0,0 +1,228 @@
+/*
+ * MIPI DBI Bus
+ *
+ * Copyright (C) 2012 Renesas Solutions Corp.
+ *
+ * Contacts: Laurent Pinchart <laurent.pinchart@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/device.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+
+#include <video/mipi-dbi-bus.h>
+
+/* -----------------------------------------------------------------------------
+ * Bus operations
+ */
+
+int mipi_dbi_set_data_width(struct mipi_dbi_device *dev, unsigned int width)
+{
+	if (width != 8 && width != 16)
+		return -EINVAL;
+
+	dev->data_width = width;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mipi_dbi_set_data_width);
+
+int mipi_dbi_write_command(struct mipi_dbi_device *dev, u16 cmd)
+{
+	return dev->bus->ops->write_command(dev->bus, dev, cmd);
+}
+EXPORT_SYMBOL_GPL(mipi_dbi_write_command);
+
+int mipi_dbi_write_data(struct mipi_dbi_device *dev, const u8 *data,
+			size_t len)
+{
+	return dev->bus->ops->write_data(dev->bus, dev, data, len);
+}
+EXPORT_SYMBOL_GPL(mipi_dbi_write_data);
+
+int mipi_dbi_read_data(struct mipi_dbi_device *dev, u8 *data, size_t len)
+{
+	return dev->bus->ops->read_data(dev->bus, dev, data, len);
+}
+EXPORT_SYMBOL_GPL(mipi_dbi_read_data);
+
+/* -----------------------------------------------------------------------------
+ * Bus type
+ */
+
+static const struct mipi_dbi_device_id *
+mipi_dbi_match_id(const struct mipi_dbi_device_id *id,
+		  struct mipi_dbi_device *dev)
+{
+	while (id->name[0]) {
+		if (strcmp(dev->name, id->name) = 0) {
+			dev->id_entry = id;
+			return id;
+		}
+		id++;
+	}
+	return NULL;
+}
+
+static int mipi_dbi_match(struct device *_dev, struct device_driver *_drv)
+{
+	struct mipi_dbi_device *dev = to_mipi_dbi_device(_dev);
+	struct mipi_dbi_driver *drv = to_mipi_dbi_driver(_drv);
+
+	if (drv->id_table)
+		return mipi_dbi_match_id(drv->id_table, dev) != NULL;
+
+	return (strcmp(dev->name, _drv->name) = 0);
+}
+
+static ssize_t modalias_show(struct device *_dev, struct device_attribute *a,
+			     char *buf)
+{
+	struct mipi_dbi_device *dev = to_mipi_dbi_device(_dev);
+	int len = snprintf(buf, PAGE_SIZE, MIPI_DBI_MODULE_PREFIX "%s\n",
+			   dev->name);
+
+	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
+}
+
+static struct device_attribute mipi_dbi_dev_attrs[] = {
+	__ATTR_RO(modalias),
+	__ATTR_NULL,
+};
+
+static int mipi_dbi_uevent(struct device *_dev, struct kobj_uevent_env *env)
+{
+	struct mipi_dbi_device *dev = to_mipi_dbi_device(_dev);
+
+	add_uevent_var(env, "MODALIAS=%s%s", MIPI_DBI_MODULE_PREFIX,
+		       dev->name);
+	return 0;
+}
+
+static const struct dev_pm_ops mipi_dbi_dev_pm_ops = {
+	.runtime_suspend = pm_generic_runtime_suspend,
+	.runtime_resume = pm_generic_runtime_resume,
+	.runtime_idle = pm_generic_runtime_idle,
+	.suspend = pm_generic_suspend,
+	.resume = pm_generic_resume,
+	.freeze = pm_generic_freeze,
+	.thaw = pm_generic_thaw,
+	.poweroff = pm_generic_poweroff,
+	.restore = pm_generic_restore,
+};
+
+static struct bus_type mipi_dbi_bus_type = {
+	.name		= "mipi-dbi",
+	.dev_attrs	= mipi_dbi_dev_attrs,
+	.match		= mipi_dbi_match,
+	.uevent		= mipi_dbi_uevent,
+	.pm		= &mipi_dbi_dev_pm_ops,
+};
+
+/* -----------------------------------------------------------------------------
+ * Device and driver (un)registration
+ */
+
+/**
+ * mipi_dbi_device_register - register a DBI device
+ * @dev: DBI device we're registering
+ */
+int mipi_dbi_device_register(struct mipi_dbi_device *dev,
+			      struct mipi_dbi_bus *bus)
+{
+	device_initialize(&dev->dev);
+
+	dev->bus = bus;
+	dev->dev.bus = &mipi_dbi_bus_type;
+	dev->dev.parent = bus->dev;
+
+	if (dev->id != -1)
+		dev_set_name(&dev->dev, "%s.%d", dev->name,  dev->id);
+	else
+		dev_set_name(&dev->dev, "%s", dev->name);
+
+	return device_add(&dev->dev);
+}
+EXPORT_SYMBOL_GPL(mipi_dbi_device_register);
+
+/**
+ * mipi_dbi_device_unregister - unregister a DBI device
+ * @dev: DBI device we're unregistering
+ */
+void mipi_dbi_device_unregister(struct mipi_dbi_device *dev)
+{
+	device_del(&dev->dev);
+	put_device(&dev->dev);
+}
+EXPORT_SYMBOL_GPL(mipi_dbi_device_unregister);
+
+static int mipi_dbi_drv_probe(struct device *_dev)
+{
+	struct mipi_dbi_driver *drv = to_mipi_dbi_driver(_dev->driver);
+	struct mipi_dbi_device *dev = to_mipi_dbi_device(_dev);
+
+	return drv->probe(dev);
+}
+
+static int mipi_dbi_drv_remove(struct device *_dev)
+{
+	struct mipi_dbi_driver *drv = to_mipi_dbi_driver(_dev->driver);
+	struct mipi_dbi_device *dev = to_mipi_dbi_device(_dev);
+
+	return drv->remove(dev);
+}
+
+/**
+ * mipi_dbi_driver_register - register a driver for DBI devices
+ * @drv: DBI driver structure
+ */
+int mipi_dbi_driver_register(struct mipi_dbi_driver *drv)
+{
+	drv->driver.bus = &mipi_dbi_bus_type;
+	if (drv->probe)
+		drv->driver.probe = mipi_dbi_drv_probe;
+	if (drv->remove)
+		drv->driver.remove = mipi_dbi_drv_remove;
+
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(mipi_dbi_driver_register);
+
+/**
+ * mipi_dbi_driver_unregister - unregister a driver for DBI devices
+ * @drv: DBI driver structure
+ */
+void mipi_dbi_driver_unregister(struct mipi_dbi_driver *drv)
+{
+	driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(mipi_dbi_driver_unregister);
+
+/* -----------------------------------------------------------------------------
+ * Init/exit
+ */
+
+static int __init mipi_dbi_init(void)
+{
+	return bus_register(&mipi_dbi_bus_type);
+}
+
+static void __exit mipi_dbi_exit(void)
+{
+	bus_unregister(&mipi_dbi_bus_type);
+}
+
+module_init(mipi_dbi_init);
+module_exit(mipi_dbi_exit)
+
+MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
+MODULE_DESCRIPTION("MIPI DBI Bus");
+MODULE_LICENSE("GPL");