staging: drm/imx: Add i.MX drm core support

This patch adds the i.MX glue stuff between i.MX and drm.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6 files changed, 1084 insertions, 0 deletions

diff --git a/drivers/staging/imx-drm/Kconfig b/drivers/staging/imx-drm/Kconfig
new file mode 100644
index 000000000000..2ef867b6f7c2
--- /dev/null
+++ b/drivers/staging/imx-drm/Kconfig
@@ -0,0 +1,17 @@
+config DRM_IMX
+	tristate "DRM Support for Freescale i.MX"
+	select DRM_KMS_HELPER
+	select DRM_GEM_CMA_HELPER
+	select DRM_KMS_CMA_HELPER
+	depends on DRM && ARCH_MXC
+	help
+	  enable i.MX graphics support
+
+config DRM_IMX_FB_HELPER
+	tristate "provide legacy framebuffer /dev/fb0"
+	select DRM_KMS_CMA_HELPER
+	depends on DRM_IMX
+	help
+	  The DRM framework can provide a legacy /dev/fb0 framebuffer
+	  for your device. This is necessary to get a framebuffer console
+	  and also for appplications using the legacy framebuffer API
diff --git a/drivers/staging/imx-drm/Makefile b/drivers/staging/imx-drm/Makefile
new file mode 100644
index 000000000000..ff825f72a0f8
--- /dev/null
+++ b/drivers/staging/imx-drm/Makefile
@@ -0,0 +1,6 @@
+
+imxdrm-objs := imx-drm-core.o imx-fb.o
+
+obj-$(CONFIG_DRM_IMX) += imxdrm.o
+
+obj-$(CONFIG_DRM_IMX_FB_HELPER) += imx-fbdev.o
diff --git a/drivers/staging/imx-drm/imx-drm-core.c b/drivers/staging/imx-drm/imx-drm-core.c
new file mode 100644
index 000000000000..225e83507ce3
--- /dev/null
+++ b/drivers/staging/imx-drm/imx-drm-core.c
@@ -0,0 +1,882 @@
+/*
+ * Freescale i.MX drm driver
+ *
+ * Copyright (C) 2011 Sascha Hauer, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <drm/drmP.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <linux/fb.h>
+#include <linux/module.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+
+#include "imx-drm.h"
+
+#define MAX_CRTC	4
+
+struct crtc_cookie {
+	void *cookie;
+	int id;
+	struct list_head list;
+};
+
+struct imx_drm_device {
+	struct drm_device			*drm;
+	struct device				*dev;
+	struct list_head			crtc_list;
+	struct list_head			encoder_list;
+	struct list_head			connector_list;
+	struct mutex				mutex;
+	int					references;
+	int					pipes;
+	struct drm_fbdev_cma			*fbhelper;
+};
+
+struct imx_drm_crtc {
+	struct drm_crtc				*crtc;
+	struct list_head			list;
+	struct imx_drm_device			*imxdrm;
+	int					pipe;
+	struct imx_drm_crtc_helper_funcs	imx_drm_helper_funcs;
+	struct module				*owner;
+	struct crtc_cookie			cookie;
+};
+
+struct imx_drm_encoder {
+	struct drm_encoder			*encoder;
+	struct list_head			list;
+	struct module				*owner;
+	struct list_head			possible_crtcs;
+};
+
+struct imx_drm_connector {
+	struct drm_connector			*connector;
+	struct list_head			list;
+	struct module				*owner;
+};
+
+static int imx_drm_driver_firstopen(struct drm_device *drm)
+{
+	if (!imx_drm_device_get())
+		return -EINVAL;
+
+	return 0;
+}
+
+static void imx_drm_driver_lastclose(struct drm_device *drm)
+{
+	struct imx_drm_device *imxdrm = drm->dev_private;
+
+	if (imxdrm->fbhelper)
+		drm_fbdev_cma_restore_mode(imxdrm->fbhelper);
+
+	imx_drm_device_put();
+}
+
+static int imx_drm_driver_unload(struct drm_device *drm)
+{
+	struct imx_drm_device *imxdrm = drm->dev_private;
+
+	drm_mode_config_cleanup(imxdrm->drm);
+	drm_kms_helper_poll_fini(imxdrm->drm);
+
+	return 0;
+}
+
+/*
+ * We don't care at all for crtc numbers, but the core expects the
+ * crtcs to be numbered
+ */
+static struct imx_drm_crtc *imx_drm_crtc_by_num(struct imx_drm_device *imxdrm,
+		int num)
+{
+	struct imx_drm_crtc *imx_drm_crtc;
+
+	list_for_each_entry(imx_drm_crtc, &imxdrm->crtc_list, list)
+		if (imx_drm_crtc->pipe == num)
+			return imx_drm_crtc;
+	return NULL;
+}
+
+int imx_drm_crtc_panel_format(struct drm_crtc *crtc, u32 encoder_type,
+		u32 interface_pix_fmt)
+{
+	struct imx_drm_device *imxdrm = crtc->dev->dev_private;
+	struct imx_drm_crtc *imx_crtc;
+	struct imx_drm_crtc_helper_funcs *helper;
+
+	mutex_lock(&imxdrm->mutex);
+
+	list_for_each_entry(imx_crtc, &imxdrm->crtc_list, list)
+		if (imx_crtc->crtc == crtc)
+			goto found;
+
+	mutex_unlock(&imxdrm->mutex);
+
+	return -EINVAL;
+found:
+	mutex_unlock(&imxdrm->mutex);
+
+	helper = &imx_crtc->imx_drm_helper_funcs;
+	if (helper->set_interface_pix_fmt)
+		return helper->set_interface_pix_fmt(crtc,
+				encoder_type, interface_pix_fmt);
+	return 0;
+}
+
+int imx_drm_crtc_vblank_get(struct imx_drm_crtc *imx_drm_crtc)
+{
+	return drm_vblank_get(imx_drm_crtc->imxdrm->drm, imx_drm_crtc->pipe);
+}
+EXPORT_SYMBOL_GPL(imx_drm_crtc_vblank_get);
+
+void imx_drm_crtc_vblank_put(struct imx_drm_crtc *imx_drm_crtc)
+{
+	drm_vblank_put(imx_drm_crtc->imxdrm->drm, imx_drm_crtc->pipe);
+}
+EXPORT_SYMBOL_GPL(imx_drm_crtc_vblank_put);
+
+void imx_drm_handle_vblank(struct imx_drm_crtc *imx_drm_crtc)
+{
+	drm_handle_vblank(imx_drm_crtc->imxdrm->drm, imx_drm_crtc->pipe);
+}
+EXPORT_SYMBOL_GPL(imx_drm_handle_vblank);
+
+static int imx_drm_enable_vblank(struct drm_device *drm, int crtc)
+{
+	struct imx_drm_device *imxdrm = drm->dev_private;
+	struct imx_drm_crtc *imx_drm_crtc;
+	int ret;
+
+	imx_drm_crtc = imx_drm_crtc_by_num(imxdrm, crtc);
+	if (!imx_drm_crtc)
+		return -EINVAL;
+
+	if (!imx_drm_crtc->imx_drm_helper_funcs.enable_vblank)
+		return -ENOSYS;
+
+	ret = imx_drm_crtc->imx_drm_helper_funcs.enable_vblank(
+			imx_drm_crtc->crtc);
+
+	return ret;
+}
+
+static void imx_drm_disable_vblank(struct drm_device *drm, int crtc)
+{
+	struct imx_drm_device *imxdrm = drm->dev_private;
+	struct imx_drm_crtc *imx_drm_crtc;
+
+	imx_drm_crtc = imx_drm_crtc_by_num(imxdrm, crtc);
+	if (!imx_drm_crtc)
+		return;
+
+	if (!imx_drm_crtc->imx_drm_helper_funcs.disable_vblank)
+		return;
+
+	imx_drm_crtc->imx_drm_helper_funcs.disable_vblank(imx_drm_crtc->crtc);
+}
+
+static const struct file_operations imx_drm_driver_fops = {
+	.owner = THIS_MODULE,
+	.open = drm_open,
+	.release = drm_release,
+	.unlocked_ioctl = drm_ioctl,
+	.mmap = drm_gem_cma_mmap,
+	.poll = drm_poll,
+	.fasync = drm_fasync,
+	.read = drm_read,
+	.llseek = noop_llseek,
+};
+
+static struct imx_drm_device *imx_drm_device;
+
+static struct imx_drm_device *__imx_drm_device(void)
+{
+	return imx_drm_device;
+}
+
+struct drm_device *imx_drm_device_get(void)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	struct imx_drm_encoder *enc;
+	struct imx_drm_connector *con;
+	struct imx_drm_crtc *crtc;
+
+	mutex_lock(&imxdrm->mutex);
+
+	list_for_each_entry(enc, &imxdrm->encoder_list, list) {
+		if (!try_module_get(enc->owner)) {
+			dev_err(imxdrm->dev, "could not get module %s\n",
+					module_name(enc->owner));
+			goto unwind_enc;
+		}
+	}
+
+	list_for_each_entry(con, &imxdrm->connector_list, list) {
+		if (!try_module_get(con->owner)) {
+			dev_err(imxdrm->dev, "could not get module %s\n",
+					module_name(con->owner));
+			goto unwind_con;
+		}
+	}
+
+	list_for_each_entry(crtc, &imxdrm->crtc_list, list) {
+		if (!try_module_get(crtc->owner)) {
+			dev_err(imxdrm->dev, "could not get module %s\n",
+					module_name(crtc->owner));
+			goto unwind_crtc;
+		}
+	}
+
+	imxdrm->references++;
+
+	mutex_unlock(&imxdrm->mutex);
+
+	return imxdrm->drm;
+
+unwind_crtc:
+	list_for_each_entry_continue_reverse(crtc, &imxdrm->crtc_list, list)
+		module_put(crtc->owner);
+unwind_con:
+	list_for_each_entry_continue_reverse(con, &imxdrm->connector_list, list)
+		module_put(con->owner);
+unwind_enc:
+	list_for_each_entry_continue_reverse(enc, &imxdrm->encoder_list, list)
+		module_put(enc->owner);
+
+	mutex_unlock(&imxdrm->mutex);
+
+	return NULL;
+
+}
+EXPORT_SYMBOL_GPL(imx_drm_device_get);
+
+void imx_drm_device_put(void)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	struct imx_drm_encoder *enc;
+	struct imx_drm_connector *con;
+	struct imx_drm_crtc *crtc;
+
+	mutex_lock(&imxdrm->mutex);
+
+	list_for_each_entry(crtc, &imxdrm->crtc_list, list)
+		module_put(crtc->owner);
+
+	list_for_each_entry(con, &imxdrm->connector_list, list)
+		module_put(con->owner);
+
+	list_for_each_entry(enc, &imxdrm->encoder_list, list)
+		module_put(enc->owner);
+
+	imxdrm->references--;
+
+	mutex_unlock(&imxdrm->mutex);
+}
+EXPORT_SYMBOL_GPL(imx_drm_device_put);
+
+static int drm_mode_group_reinit(struct drm_device *dev)
+{
+	struct drm_mode_group *group = &dev->primary->mode_group;
+	uint32_t *id_list = group->id_list;
+	int ret;
+
+	ret = drm_mode_group_init_legacy_group(dev, group);
+	if (ret < 0)
+		return ret;
+
+	kfree(id_list);
+	return 0;
+}
+
+/*
+ * register an encoder to the drm core
+ */
+static int imx_drm_encoder_register(struct imx_drm_encoder *imx_drm_encoder)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+
+	INIT_LIST_HEAD(&imx_drm_encoder->possible_crtcs);
+
+	drm_encoder_init(imxdrm->drm, imx_drm_encoder->encoder,
+			imx_drm_encoder->encoder->funcs,
+			imx_drm_encoder->encoder->encoder_type);
+
+	drm_mode_group_reinit(imxdrm->drm);
+
+	return 0;
+}
+
+/*
+ * unregister an encoder from the drm core
+ */
+static void imx_drm_encoder_unregister(struct imx_drm_encoder
+		*imx_drm_encoder)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+
+	drm_encoder_cleanup(imx_drm_encoder->encoder);
+
+	drm_mode_group_reinit(imxdrm->drm);
+}
+
+/*
+ * register a connector to the drm core
+ */
+static int imx_drm_connector_register(
+		struct imx_drm_connector *imx_drm_connector)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+
+	drm_connector_init(imxdrm->drm, imx_drm_connector->connector,
+			imx_drm_connector->connector->funcs,
+			imx_drm_connector->connector->connector_type);
+	drm_mode_group_reinit(imxdrm->drm);
+
+	return drm_sysfs_connector_add(imx_drm_connector->connector);
+}
+
+/*
+ * unregister a connector from the drm core
+ */
+static void imx_drm_connector_unregister(
+		struct imx_drm_connector *imx_drm_connector)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+
+	drm_sysfs_connector_remove(imx_drm_connector->connector);
+	drm_connector_cleanup(imx_drm_connector->connector);
+
+	drm_mode_group_reinit(imxdrm->drm);
+}
+
+/*
+ * register a crtc to the drm core
+ */
+static int imx_drm_crtc_register(struct imx_drm_crtc *imx_drm_crtc)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	int ret;
+
+	drm_crtc_init(imxdrm->drm, imx_drm_crtc->crtc,
+			imx_drm_crtc->imx_drm_helper_funcs.crtc_funcs);
+	ret = drm_mode_crtc_set_gamma_size(imx_drm_crtc->crtc, 256);
+	if (ret)
+		return ret;
+
+	drm_crtc_helper_add(imx_drm_crtc->crtc,
+			imx_drm_crtc->imx_drm_helper_funcs.crtc_helper_funcs);
+
+	drm_mode_group_reinit(imxdrm->drm);
+
+	return 0;
+}
+
+/*
+ * Called by the CRTC driver when all CRTCs are registered. This
+ * puts all the pieces together and initializes the driver.
+ * Once this is called no more CRTCs can be registered since
+ * the drm core has hardcoded the number of crtcs in several
+ * places.
+ */
+static int imx_drm_driver_load(struct drm_device *drm, unsigned long flags)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	int ret;
+
+	imxdrm->drm = drm;
+
+	drm->dev_private = imxdrm;
+
+	/*
+	 * enable drm irq mode.
+	 * - with irq_enabled = 1, we can use the vblank feature.
+	 *
+	 * P.S. note that we wouldn't use drm irq handler but
+	 *      just specific driver own one instead because
+	 *      drm framework supports only one irq handler and
+	 *      drivers can well take care of their interrupts
+	 */
+	drm->irq_enabled = 1;
+
+	drm_mode_config_init(drm);
+	imx_drm_mode_config_init(drm);
+
+	mutex_lock(&imxdrm->mutex);
+
+	drm_kms_helper_poll_init(imxdrm->drm);
+
+	/* setup the grouping for the legacy output */
+	ret = drm_mode_group_init_legacy_group(imxdrm->drm,
+			&imxdrm->drm->primary->mode_group);
+	if (ret)
+		goto err_init;
+
+	ret = drm_vblank_init(imxdrm->drm, MAX_CRTC);
+	if (ret)
+		goto err_init;
+
+	/*
+	 * with vblank_disable_allowed = 1, vblank interrupt will be disabled
+	 * by drm timer once a current process gives up ownership of
+	 * vblank event.(after drm_vblank_put function is called)
+	 */
+	imxdrm->drm->vblank_disable_allowed = 1;
+
+	ret = 0;
+
+err_init:
+	mutex_unlock(&imxdrm->mutex);
+
+	return ret;
+}
+
+static void imx_drm_update_possible_crtcs(void)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	struct imx_drm_crtc *imx_drm_crtc;
+	struct imx_drm_encoder *enc;
+	struct crtc_cookie *cookie;
+
+	list_for_each_entry(enc, &imxdrm->encoder_list, list) {
+		u32 possible_crtcs = 0;
+
+		list_for_each_entry(cookie, &enc->possible_crtcs, list) {
+			list_for_each_entry(imx_drm_crtc, &imxdrm->crtc_list, list) {
+				if (imx_drm_crtc->cookie.cookie == cookie->cookie &&
+						imx_drm_crtc->cookie.id == cookie->id) {
+					possible_crtcs |= 1 << imx_drm_crtc->pipe;
+				}
+			}
+		}
+		enc->encoder->possible_crtcs = possible_crtcs;
+		enc->encoder->possible_clones = possible_crtcs;
+	}
+}
+
+/*
+ * imx_drm_add_crtc - add a new crtc
+ *
+ * The return value if !NULL is a cookie for the caller to pass to
+ * imx_drm_remove_crtc later.
+ */
+int imx_drm_add_crtc(struct drm_crtc *crtc,
+		struct imx_drm_crtc **new_crtc,
+		const struct imx_drm_crtc_helper_funcs *imx_drm_helper_funcs,
+		struct module *owner, void *cookie, int id)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	struct imx_drm_crtc *imx_drm_crtc;
+	const struct drm_crtc_funcs *crtc_funcs;
+	int ret;
+
+	mutex_lock(&imxdrm->mutex);
+
+	if (imxdrm->references) {
+		ret = -EBUSY;
+		goto err_busy;
+	}
+
+	imx_drm_crtc = kzalloc(sizeof(*imx_drm_crtc), GFP_KERNEL);
+	if (!imx_drm_crtc) {
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	imx_drm_crtc->imx_drm_helper_funcs = *imx_drm_helper_funcs;
+	imx_drm_crtc->pipe = imxdrm->pipes++;
+	imx_drm_crtc->cookie.cookie = cookie;
+	imx_drm_crtc->cookie.id = id;
+
+	crtc_funcs = imx_drm_helper_funcs->crtc_funcs;
+
+	imx_drm_crtc->crtc = crtc;
+	imx_drm_crtc->imxdrm = imxdrm;
+
+	imx_drm_crtc->owner = owner;
+
+	list_add_tail(&imx_drm_crtc->list, &imxdrm->crtc_list);
+
+	*new_crtc = imx_drm_crtc;
+
+	ret = imx_drm_crtc_register(imx_drm_crtc);
+	if (ret)
+		goto err_register;
+
+	imx_drm_update_possible_crtcs();
+
+	mutex_unlock(&imxdrm->mutex);
+
+	return 0;
+
+err_register:
+	kfree(imx_drm_crtc);
+err_alloc:
+err_busy:
+	mutex_unlock(&imxdrm->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(imx_drm_add_crtc);
+
+/*
+ * imx_drm_remove_crtc - remove a crtc
+ */
+int imx_drm_remove_crtc(struct imx_drm_crtc *imx_drm_crtc)
+{
+	struct imx_drm_device *imxdrm = imx_drm_crtc->imxdrm;
+
+	mutex_lock(&imxdrm->mutex);
+
+	drm_crtc_cleanup(imx_drm_crtc->crtc);
+
+	list_del(&imx_drm_crtc->list);
+
+	drm_mode_group_reinit(imxdrm->drm);
+
+	mutex_unlock(&imxdrm->mutex);
+
+	kfree(imx_drm_crtc);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(imx_drm_remove_crtc);
+
+/*
+ * imx_drm_add_encoder - add a new encoder
+ */
+int imx_drm_add_encoder(struct drm_encoder *encoder,
+		struct imx_drm_encoder **newenc, struct module *owner)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	struct imx_drm_encoder *imx_drm_encoder;
+	int ret;
+
+	mutex_lock(&imxdrm->mutex);
+
+	if (imxdrm->references) {
+		ret = -EBUSY;
+		goto err_busy;
+	}
+
+	imx_drm_encoder = kzalloc(sizeof(*imx_drm_encoder), GFP_KERNEL);
+	if (!imx_drm_encoder) {
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	imx_drm_encoder->encoder = encoder;
+	imx_drm_encoder->owner = owner;
+
+	ret = imx_drm_encoder_register(imx_drm_encoder);
+	if (ret) {
+		kfree(imx_drm_encoder);
+		ret = -ENOMEM;
+		goto err_register;
+	}
+
+	list_add_tail(&imx_drm_encoder->list, &imxdrm->encoder_list);
+
+	*newenc = imx_drm_encoder;
+
+	mutex_unlock(&imxdrm->mutex);
+
+	return 0;
+
+err_register:
+	kfree(imx_drm_encoder);
+err_alloc:
+err_busy:
+	mutex_unlock(&imxdrm->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(imx_drm_add_encoder);
+
+int imx_drm_encoder_add_possible_crtcs(
+		struct imx_drm_encoder *imx_drm_encoder,
+		struct device_node *np)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	struct of_phandle_args args;
+	struct crtc_cookie *c;
+	int ret = 0;
+	int i;
+
+	if (!list_empty(&imx_drm_encoder->possible_crtcs))
+		return -EBUSY;
+
+	for (i = 0; !ret; i++) {
+		ret = of_parse_phandle_with_args(np, "crtcs",
+				"#crtc-cells", i, &args);
+		if (ret < 0)
+			break;
+
+		c = kzalloc(sizeof(*c), GFP_KERNEL);
+		if (!c) {
+			of_node_put(args.np);
+			return -ENOMEM;
+		}
+
+		c->cookie = args.np;
+		c->id = args.args_count > 0 ? args.args[0] : 0;
+
+		of_node_put(args.np);
+
+		mutex_lock(&imxdrm->mutex);
+
+		list_add_tail(&c->list, &imx_drm_encoder->possible_crtcs);
+
+		mutex_unlock(&imxdrm->mutex);
+	}
+
+	imx_drm_update_possible_crtcs();
+
+	return 0;
+}
+
+int imx_drm_encoder_get_mux_id(struct imx_drm_encoder *imx_drm_encoder,
+		struct drm_crtc *crtc)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	struct imx_drm_crtc *imx_crtc;
+	int i = 0;
+
+	mutex_lock(&imxdrm->mutex);
+
+	list_for_each_entry(imx_crtc, &imxdrm->crtc_list, list) {
+		if (imx_crtc->crtc == crtc)
+			goto found;
+		i++;
+	}
+
+	mutex_unlock(&imxdrm->mutex);
+
+	return -EINVAL;
+found:
+	mutex_unlock(&imxdrm->mutex);
+
+	return i;
+}
+
+/*
+ * imx_drm_remove_encoder - remove an encoder
+ */
+int imx_drm_remove_encoder(struct imx_drm_encoder *imx_drm_encoder)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	struct crtc_cookie *c, *tmp;
+
+	mutex_lock(&imxdrm->mutex);
+
+	imx_drm_encoder_unregister(imx_drm_encoder);
+
+	list_del(&imx_drm_encoder->list);
+
+	list_for_each_entry_safe(c, tmp, &imx_drm_encoder->possible_crtcs,
+			list)
+		kfree(c);
+
+	mutex_unlock(&imxdrm->mutex);
+
+	kfree(imx_drm_encoder);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(imx_drm_remove_encoder);
+
+/*
+ * imx_drm_add_connector - add a connector
+ */
+int imx_drm_add_connector(struct drm_connector *connector,
+		struct imx_drm_connector **new_con,
+		struct module *owner)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+	struct imx_drm_connector *imx_drm_connector;
+	int ret;
+
+	mutex_lock(&imxdrm->mutex);
+
+	if (imxdrm->references) {
+		ret = -EBUSY;
+		goto err_busy;
+	}
+
+	imx_drm_connector = kzalloc(sizeof(*imx_drm_connector), GFP_KERNEL);
+	if (!imx_drm_connector) {
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	imx_drm_connector->connector = connector;
+	imx_drm_connector->owner = owner;
+
+	ret = imx_drm_connector_register(imx_drm_connector);
+	if (ret)
+		goto err_register;
+
+	list_add_tail(&imx_drm_connector->list, &imxdrm->connector_list);
+
+	*new_con = imx_drm_connector;
+
+	mutex_unlock(&imxdrm->mutex);
+
+	return 0;
+
+err_register:
+	kfree(imx_drm_connector);
+err_alloc:
+err_busy:
+	mutex_unlock(&imxdrm->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(imx_drm_add_connector);
+
+void imx_drm_fb_helper_set(struct drm_fbdev_cma *fbdev_helper)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+
+	imxdrm->fbhelper = fbdev_helper;
+}
+EXPORT_SYMBOL_GPL(imx_drm_fb_helper_set);
+
+/*
+ * imx_drm_remove_connector - remove a connector
+ */
+int imx_drm_remove_connector(struct imx_drm_connector *imx_drm_connector)
+{
+	struct imx_drm_device *imxdrm = __imx_drm_device();
+
+	mutex_lock(&imxdrm->mutex);
+
+	imx_drm_connector_unregister(imx_drm_connector);
+
+	list_del(&imx_drm_connector->list);
+
+	mutex_unlock(&imxdrm->mutex);
+
+	kfree(imx_drm_connector);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(imx_drm_remove_connector);
+
+static struct drm_ioctl_desc imx_drm_ioctls[] = {
+	/* none so far */
+};
+
+static struct drm_driver imx_drm_driver = {
+	.driver_features	= DRIVER_MODESET | DRIVER_GEM,
+	.load			= imx_drm_driver_load,
+	.unload			= imx_drm_driver_unload,
+	.firstopen		= imx_drm_driver_firstopen,
+	.lastclose		= imx_drm_driver_lastclose,
+	.gem_free_object	= drm_gem_cma_free_object,
+	.gem_vm_ops		= &drm_gem_cma_vm_ops,
+	.dumb_create		= drm_gem_cma_dumb_create,
+	.dumb_map_offset	= drm_gem_cma_dumb_map_offset,
+	.dumb_destroy		= drm_gem_cma_dumb_destroy,
+
+	.get_vblank_counter	= drm_vblank_count,
+	.enable_vblank		= imx_drm_enable_vblank,
+	.disable_vblank		= imx_drm_disable_vblank,
+	.ioctls			= imx_drm_ioctls,
+	.num_ioctls		= ARRAY_SIZE(imx_drm_ioctls),
+	.fops			= &imx_drm_driver_fops,
+	.name			= "imx-drm",
+	.desc			= "i.MX DRM graphics",
+	.date			= "20120507",
+	.major			= 1,
+	.minor			= 0,
+	.patchlevel		= 0,
+};
+
+static int imx_drm_platform_probe(struct platform_device *pdev)
+{
+	imx_drm_device->dev = &pdev->dev;
+
+	return drm_platform_init(&imx_drm_driver, pdev);
+}
+
+static int imx_drm_platform_remove(struct platform_device *pdev)
+{
+	drm_platform_exit(&imx_drm_driver, pdev);
+
+	return 0;
+}
+
+static struct platform_driver imx_drm_pdrv = {
+	.probe		= imx_drm_platform_probe,
+	.remove		= __devexit_p(imx_drm_platform_remove),
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "imx-drm",
+	},
+};
+
+static struct platform_device *imx_drm_pdev;
+
+static int __init imx_drm_init(void)
+{
+	int ret;
+
+	imx_drm_device = kzalloc(sizeof(*imx_drm_device), GFP_KERNEL);
+	if (!imx_drm_device)
+		return -ENOMEM;
+
+	mutex_init(&imx_drm_device->mutex);
+	INIT_LIST_HEAD(&imx_drm_device->crtc_list);
+	INIT_LIST_HEAD(&imx_drm_device->connector_list);
+	INIT_LIST_HEAD(&imx_drm_device->encoder_list);
+
+	imx_drm_pdev = platform_device_register_simple("imx-drm", -1, NULL, 0);
+	if (!imx_drm_pdev) {
+		ret = -EINVAL;
+		goto err_pdev;
+	}
+
+	imx_drm_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32),
+
+	ret = platform_driver_register(&imx_drm_pdrv);
+	if (ret)
+		goto err_pdrv;
+
+	return 0;
+
+err_pdrv:
+	platform_device_unregister(imx_drm_pdev);
+err_pdev:
+	kfree(imx_drm_device);
+
+	return ret;
+}
+
+static void __exit imx_drm_exit(void)
+{
+	platform_device_unregister(imx_drm_pdev);
+	platform_driver_unregister(&imx_drm_pdrv);
+
+	kfree(imx_drm_device);
+}
+
+module_init(imx_drm_init);
+module_exit(imx_drm_exit);
+
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
+MODULE_DESCRIPTION("i.MX drm driver core");
+MODULE_LICENSE("GPL");
diff --git a/drivers/staging/imx-drm/imx-drm.h b/drivers/staging/imx-drm/imx-drm.h
new file mode 100644
index 000000000000..ae28a490c445
--- /dev/null
+++ b/drivers/staging/imx-drm/imx-drm.h
@@ -0,0 +1,58 @@
+#ifndef _IMX_DRM_H_
+#define _IMX_DRM_H_
+
+struct imx_drm_crtc;
+struct drm_fbdev_cma;
+
+struct imx_drm_crtc_helper_funcs {
+	int (*enable_vblank)(struct drm_crtc *crtc);
+	void (*disable_vblank)(struct drm_crtc *crtc);
+	int (*set_interface_pix_fmt)(struct drm_crtc *crtc, u32 encoder_type,
+			u32 pix_fmt);
+	const struct drm_crtc_helper_funcs *crtc_helper_funcs;
+	const struct drm_crtc_funcs *crtc_funcs;
+};
+
+int imx_drm_add_crtc(struct drm_crtc *crtc,
+		struct imx_drm_crtc **new_crtc,
+		const struct imx_drm_crtc_helper_funcs *imx_helper_funcs,
+		struct module *owner, void *cookie, int id);
+int imx_drm_remove_crtc(struct imx_drm_crtc *);
+int imx_drm_init_drm(struct platform_device *pdev,
+		int preferred_bpp);
+int imx_drm_exit_drm(void);
+
+int imx_drm_crtc_vblank_get(struct imx_drm_crtc *imx_drm_crtc);
+void imx_drm_crtc_vblank_put(struct imx_drm_crtc *imx_drm_crtc);
+void imx_drm_handle_vblank(struct imx_drm_crtc *imx_drm_crtc);
+
+struct imx_drm_encoder;
+int imx_drm_add_encoder(struct drm_encoder *encoder,
+		struct imx_drm_encoder **new_enc,
+		struct module *owner);
+int imx_drm_remove_encoder(struct imx_drm_encoder *);
+
+struct imx_drm_connector;
+int imx_drm_add_connector(struct drm_connector *connector,
+		struct imx_drm_connector **new_con,
+		struct module *owner);
+int imx_drm_remove_connector(struct imx_drm_connector *);
+
+void imx_drm_mode_config_init(struct drm_device *drm);
+
+struct drm_gem_cma_object *imx_drm_fb_get_obj(struct drm_framebuffer *fb);
+
+struct drm_device *imx_drm_device_get(void);
+void imx_drm_device_put(void);
+int imx_drm_crtc_panel_format(struct drm_crtc *crtc, u32 encoder_type,
+		u32 interface_pix_fmt);
+void imx_drm_fb_helper_set(struct drm_fbdev_cma *fbdev_helper);
+
+struct device_node;
+
+int imx_drm_encoder_get_mux_id(struct imx_drm_encoder *imx_drm_encoder,
+		struct drm_crtc *crtc);
+int imx_drm_encoder_add_possible_crtcs(struct imx_drm_encoder *imx_drm_encoder,
+		struct device_node *np);
+
+#endif /* _IMX_DRM_H_ */
diff --git a/drivers/staging/imx-drm/imx-fb.c b/drivers/staging/imx-drm/imx-fb.c
new file mode 100644
index 000000000000..03a7b4e14f67
--- /dev/null
+++ b/drivers/staging/imx-drm/imx-fb.c
@@ -0,0 +1,47 @@
+/*
+ * i.MX drm driver
+ *
+ * Copyright (C) 2012 Sascha Hauer, Pengutronix
+ *
+ * Based on Samsung Exynos code
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/module.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+
+#include "imx-drm.h"
+
+static struct drm_mode_config_funcs imx_drm_mode_config_funcs = {
+	.fb_create = drm_fb_cma_create,
+};
+
+void imx_drm_mode_config_init(struct drm_device *dev)
+{
+	dev->mode_config.min_width = 64;
+	dev->mode_config.min_height = 64;
+
+	/*
+	 * set max width and height as default value(4096x4096).
+	 * this value would be used to check framebuffer size limitation
+	 * at drm_mode_addfb().
+	 */
+	dev->mode_config.max_width = 4096;
+	dev->mode_config.max_height = 4096;
+
+	dev->mode_config.funcs = &imx_drm_mode_config_funcs;
+}
diff --git a/drivers/staging/imx-drm/imx-fbdev.c b/drivers/staging/imx-drm/imx-fbdev.c
new file mode 100644
index 000000000000..8331739c3d08
--- /dev/null
+++ b/drivers/staging/imx-drm/imx-fbdev.c
@@ -0,0 +1,74 @@
+/*
+ * i.MX drm driver
+ *
+ * Copyright (C) 2012 Sascha Hauer, Pengutronix
+ *
+ * Based on Samsung Exynos code
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/module.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+
+#include "imx-drm.h"
+
+#define MAX_CONNECTOR		4
+#define PREFERRED_BPP		16
+
+static struct drm_fbdev_cma *fbdev_cma;
+
+static int legacyfb_depth = 16;
+
+module_param(legacyfb_depth, int, 0444);
+
+static int __init imx_fb_helper_init(void)
+{
+	struct drm_device *drm = imx_drm_device_get();
+
+	if (!drm)
+		return -EINVAL;
+
+	if (legacyfb_depth != 16 && legacyfb_depth != 32) {
+		pr_warn("i.MX legacyfb: invalid legacyfb_depth setting. defaulting to 16bpp\n");
+		legacyfb_depth = 16;
+	}
+
+	fbdev_cma = drm_fbdev_cma_init(drm, legacyfb_depth,
+			drm->mode_config.num_crtc, MAX_CONNECTOR);
+
+	if (IS_ERR(fbdev_cma)) {
+		imx_drm_device_put();
+		return PTR_ERR(fbdev_cma);
+	}
+
+	imx_drm_fb_helper_set(fbdev_cma);
+
+	return 0;
+}
+
+static void __exit imx_fb_helper_exit(void)
+{
+	imx_drm_fb_helper_set(NULL);
+	drm_fbdev_cma_fini(fbdev_cma);
+	imx_drm_device_put();
+}
+
+late_initcall(imx_fb_helper_init);
+module_exit(imx_fb_helper_exit);
+
+MODULE_DESCRIPTION("Freescale i.MX legacy fb driver");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_LICENSE("GPL");