imx-drm: imx-drm-core: Fix circular locking dependency

[mirror_ubuntu-artful-kernel.git] / drivers / staging / imx-drm / imx-drm-core.c

/*
 * 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                                     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 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);
}

static int imx_drm_driver_unload(struct drm_device *drm)
{
        struct imx_drm_device *imxdrm = drm->dev_private;

        imx_drm_device_put();

        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_pins(struct drm_crtc *crtc, u32 encoder_type,
                u32 interface_pix_fmt, int hsync_pin, int vsync_pin)
{
        struct imx_drm_device *imxdrm = crtc->dev->dev_private;
        struct imx_drm_crtc *imx_crtc;
        struct imx_drm_crtc_helper_funcs *helper;

        list_for_each_entry(imx_crtc, &imxdrm->crtc_list, list)
                if (imx_crtc->crtc == crtc)
                        goto found;

        return -EINVAL;
found:
        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,
                                hsync_pin, vsync_pin);
        return 0;
}
EXPORT_SYMBOL_GPL(imx_drm_crtc_panel_format_pins);

int imx_drm_crtc_panel_format(struct drm_crtc *crtc, u32 encoder_type,
                u32 interface_pix_fmt)
{
        return imx_drm_crtc_panel_format_pins(crtc, encoder_type,
                                              interface_pix_fmt, 2, 3);
}
EXPORT_SYMBOL_GPL(imx_drm_crtc_panel_format);

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,
        .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;

        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;
                }
        }

        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);

        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;

        if (!imx_drm_device_get())
                ret = -EINVAL;

        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;
        int ret;

        mutex_lock(&imxdrm->mutex);

        if (imxdrm->drm->open_count) {
                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;

        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->drm->open_count) {
                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) {
                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;
}
EXPORT_SYMBOL_GPL(imx_drm_encoder_add_possible_crtcs);

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;

        list_for_each_entry(imx_crtc, &imxdrm->crtc_list, list) {
                if (imx_crtc->crtc == crtc)
                        goto found;
                i++;
        }

        return -EINVAL;
found:
        return i;
}
EXPORT_SYMBOL_GPL(imx_drm_encoder_get_mux_id);

/*
 * 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->drm->open_count) {
                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 const 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,
        .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_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         = 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");