DRM: add DRM Driver for Samsung SoC EXYNOS4210.

This patch is a DRM Driver for Samsung SoC Exynos4210 and now enables
only FIMD yet but we will add HDMI support also in the future.

this patch is based on git repository below:
git://people.freedesktop.org/~airlied/linux.git
branch name: drm-next
commit-id: 88ef4e3f4f616462b78a7838eb3ffc3818d30f67

you can refer to our working repository below:
http://git.infradead.org/users/kmpark/linux-2.6-samsung
branch name: samsung-drm

We tried to re-use lowlevel codes of the FIMD driver(s3c-fb.c
based on Linux framebuffer) but couldn't so because lowlevel codes
of s3c-fb.c are included internally and so FIMD module of this driver has
its own lowlevel codes.

We used GEM framework for buffer management and DMA APIs(dma_alloc_*)
for buffer allocation so we can allocate physically continuous memory
for DMA through it and also we could use CMA later if CMA is applied to
mainline.

Refer to this link for CMA(Continuous Memory Allocator):
http://lkml.org/lkml/2011/7/20/45

this driver supports only physically continuous memory(non-iommu).

Links to previous versions of the patchset:
v1: < https://lwn.net/Articles/454380/ >
v2: < http://www.spinics.net/lists/kernel/msg1224275.html >
v3: < http://www.spinics.net/lists/dri-devel/msg13755.html >
v4: < http://permalink.gmane.org/gmane.comp.video.dri.devel/60439 >
v5: < http://comments.gmane.org/gmane.comp.video.dri.devel/60802 >

Changelog v2:
DRM: add DRM_IOCTL_SAMSUNG_GEM_MMAP ioctl command.

    this feature maps user address space to physical memory region
    once user application requests DRM_IOCTL_SAMSUNG_GEM_MMAP ioctl.

DRM: code clean and add exception codes.

Changelog v3:
DRM: Support multiple irq.

    FIMD and HDMI have their own irq handler but DRM Framework can regiter
    only one irq handler this patch supports mutiple irq for Samsung SoC.

DRM: Consider modularization.

    each DRM, FIMD could be built as a module.

DRM: Have indenpendent crtc object.

    crtc isn't specific to SoC Platform so this patch gets a crtc
    to be used as common object.
    created crtc could be attached to any encoder object.

DRM: code clean and add exception codes.

Changelog v4:
DRM: remove is_defult from samsung_fb.

    is_default isn't used for default framebuffer.

DRM: code refactoring to fimd module.
    this patch is be considered with multiple display objects and
    would use its own request_irq() to register a irq handler instead of
    drm framework's one.

DRM: remove find_samsung_drm_gem_object()

DRM: move kernel private data structures and definitions to driver folder.

    samsung_drm.h would contain only public information for userspace
    ioctl interface.

DRM: code refactoring to gem modules.
    buffer module isn't dependent of gem module anymore.

DRM: fixed security issue.

DRM: remove encoder porinter from specific connector.

    samsung connector doesn't need to have generic encoder.

DRM: code clean and add exception codes.

Changelog v5:
DRM: updated fimd(display controller) driver.
    added various pixel formats, color key and pixel blending features.

DRM: removed end_buf_off from samsung_drm_overlay structure.
    this variable isn't used and end buffer address would be
    calculated by each sub driver.

DRM: use generic function for mmap_offset.
    replaced samsung_drm_gem_create_mmap_offset() and
    samsung_drm_free_mmap_offset() with generic ones applied
    to mainline recentrly.

DRM: removed unnecessary codes and added exception codes.

DRM: added comments and code clean.

Changelog v6:
DRM: added default config options.

DRM: added padding for 64-bit align.

DRM: changed prefix 'samsung' to 'exynos'

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 415 insertions, 0 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
new file mode 100644
index 00000000000..a8e7a88906e
--- /dev/null
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -0,0 +1,415 @@
+/* exynos_drm_gem.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ * Author: Inki Dae <inki.dae@samsung.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "drmP.h"
+#include "drm.h"
+
+#include <drm/exynos_drm.h>
+
+#include "exynos_drm_drv.h"
+#include "exynos_drm_gem.h"
+#include "exynos_drm_buf.h"
+
+static unsigned int convert_to_vm_err_msg(int msg)
+{
+	unsigned int out_msg;
+
+	switch (msg) {
+	case 0:
+	case -ERESTARTSYS:
+	case -EINTR:
+		out_msg = VM_FAULT_NOPAGE;
+		break;
+
+	case -ENOMEM:
+		out_msg = VM_FAULT_OOM;
+		break;
+
+	default:
+		out_msg = VM_FAULT_SIGBUS;
+		break;
+	}
+
+	return out_msg;
+}
+
+static unsigned int get_gem_mmap_offset(struct drm_gem_object *obj)
+{
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	return (unsigned int)obj->map_list.hash.key << PAGE_SHIFT;
+}
+
+struct exynos_drm_gem_obj *exynos_drm_gem_create(struct drm_file *file_priv,
+		struct drm_device *dev, unsigned int size,
+		unsigned int *handle)
+{
+	struct exynos_drm_gem_obj *exynos_gem_obj;
+	struct exynos_drm_buf_entry *entry;
+	struct drm_gem_object *obj;
+	int ret;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	size = roundup(size, PAGE_SIZE);
+
+	exynos_gem_obj = kzalloc(sizeof(*exynos_gem_obj), GFP_KERNEL);
+	if (!exynos_gem_obj) {
+		DRM_ERROR("failed to allocate exynos gem object.\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* allocate the new buffer object and memory region. */
+	entry = exynos_drm_buf_create(dev, size);
+	if (!entry) {
+		kfree(exynos_gem_obj);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	exynos_gem_obj->entry = entry;
+
+	obj = &exynos_gem_obj->base;
+
+	ret = drm_gem_object_init(dev, obj, size);
+	if (ret < 0) {
+		DRM_ERROR("failed to initailize gem object.\n");
+		goto err_obj_init;
+	}
+
+	DRM_DEBUG_KMS("created file object = 0x%x\n", (unsigned int)obj->filp);
+
+	ret = drm_gem_create_mmap_offset(obj);
+	if (ret < 0) {
+		DRM_ERROR("failed to allocate mmap offset.\n");
+		goto err_create_mmap_offset;
+	}
+
+	/*
+	 * allocate a id of idr table where the obj is registered
+	 * and handle has the id what user can see.
+	 */
+	ret = drm_gem_handle_create(file_priv, obj, handle);
+	if (ret)
+		goto err_handle_create;
+
+	DRM_DEBUG_KMS("gem handle = 0x%x\n", *handle);
+
+	/* drop reference from allocate - handle holds it now. */
+	drm_gem_object_unreference_unlocked(obj);
+
+	return exynos_gem_obj;
+
+err_handle_create:
+	drm_gem_free_mmap_offset(obj);
+
+err_create_mmap_offset:
+	drm_gem_object_release(obj);
+
+err_obj_init:
+	exynos_drm_buf_destroy(dev, exynos_gem_obj->entry);
+
+	kfree(exynos_gem_obj);
+
+	return ERR_PTR(ret);
+}
+
+int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
+		struct drm_file *file_priv)
+{
+	struct drm_exynos_gem_create *args = data;
+	struct exynos_drm_gem_obj *exynos_gem_obj;
+
+	DRM_DEBUG_KMS("%s : size = 0x%x\n", __FILE__, args->size);
+
+	exynos_gem_obj = exynos_drm_gem_create(file_priv, dev, args->size,
+			&args->handle);
+	if (IS_ERR(exynos_gem_obj))
+		return PTR_ERR(exynos_gem_obj);
+
+	return 0;
+}
+
+int exynos_drm_gem_map_offset_ioctl(struct drm_device *dev, void *data,
+		struct drm_file *file_priv)
+{
+	struct drm_exynos_gem_map_off *args = data;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	DRM_DEBUG_KMS("handle = 0x%x, offset = 0x%lx\n",
+			args->handle, (unsigned long)args->offset);
+
+	if (!(dev->driver->driver_features & DRIVER_GEM)) {
+		DRM_ERROR("does not support GEM.\n");
+		return -ENODEV;
+	}
+
+	return exynos_drm_gem_dumb_map_offset(file_priv, dev, args->handle,
+			&args->offset);
+}
+
+static int exynos_drm_gem_mmap_buffer(struct file *filp,
+		struct vm_area_struct *vma)
+{
+	struct drm_gem_object *obj = filp->private_data;
+	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
+	struct exynos_drm_buf_entry *entry;
+	unsigned long pfn, vm_size;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	vma->vm_flags |= (VM_IO | VM_RESERVED);
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	vma->vm_file = filp;
+
+	vm_size = vma->vm_end - vma->vm_start;
+	/*
+	 * a entry contains information to physically continuous memory
+	 * allocated by user request or at framebuffer creation.
+	 */
+	entry = exynos_gem_obj->entry;
+
+	/* check if user-requested size is valid. */
+	if (vm_size > entry->size)
+		return -EINVAL;
+
+	/*
+	 * get page frame number to physical memory to be mapped
+	 * to user space.
+	 */
+	pfn = exynos_gem_obj->entry->paddr >> PAGE_SHIFT;
+
+	DRM_DEBUG_KMS("pfn = 0x%lx\n", pfn);
+
+	if (remap_pfn_range(vma, vma->vm_start, pfn, vm_size,
+				vma->vm_page_prot)) {
+		DRM_ERROR("failed to remap pfn range.\n");
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+static const struct file_operations exynos_drm_gem_fops = {
+	.mmap = exynos_drm_gem_mmap_buffer,
+};
+
+int exynos_drm_gem_mmap_ioctl(struct drm_device *dev, void *data,
+		struct drm_file *file_priv)
+{
+	struct drm_exynos_gem_mmap *args = data;
+	struct drm_gem_object *obj;
+	unsigned int addr;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	if (!(dev->driver->driver_features & DRIVER_GEM)) {
+		DRM_ERROR("does not support GEM.\n");
+		return -ENODEV;
+	}
+
+	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
+	if (!obj) {
+		DRM_ERROR("failed to lookup gem object.\n");
+		return -EINVAL;
+	}
+
+	obj->filp->f_op = &exynos_drm_gem_fops;
+	obj->filp->private_data = obj;
+
+	down_write(&current->mm->mmap_sem);
+	addr = do_mmap(obj->filp, 0, args->size,
+			PROT_READ | PROT_WRITE, MAP_SHARED, 0);
+	up_write(&current->mm->mmap_sem);
+
+	drm_gem_object_unreference_unlocked(obj);
+
+	if (IS_ERR((void *)addr))
+		return PTR_ERR((void *)addr);
+
+	args->mapped = addr;
+
+	DRM_DEBUG_KMS("mapped = 0x%lx\n", (unsigned long)args->mapped);
+
+	return 0;
+}
+
+int exynos_drm_gem_init_object(struct drm_gem_object *obj)
+{
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	return 0;
+}
+
+void exynos_drm_gem_free_object(struct drm_gem_object *gem_obj)
+{
+	struct exynos_drm_gem_obj *exynos_gem_obj;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	DRM_DEBUG_KMS("handle count = %d\n",
+			atomic_read(&gem_obj->handle_count));
+
+	if (gem_obj->map_list.map)
+		drm_gem_free_mmap_offset(gem_obj);
+
+	/* release file pointer to gem object. */
+	drm_gem_object_release(gem_obj);
+
+	exynos_gem_obj = to_exynos_gem_obj(gem_obj);
+
+	exynos_drm_buf_destroy(gem_obj->dev, exynos_gem_obj->entry);
+
+	kfree(exynos_gem_obj);
+}
+
+int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
+		struct drm_device *dev, struct drm_mode_create_dumb *args)
+{
+	struct exynos_drm_gem_obj *exynos_gem_obj;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/*
+	 * alocate memory to be used for framebuffer.
+	 * - this callback would be called by user application
+	 *	with DRM_IOCTL_MODE_CREATE_DUMB command.
+	 */
+
+	args->pitch = args->width * args->bpp >> 3;
+	args->size = args->pitch * args->height;
+
+	exynos_gem_obj = exynos_drm_gem_create(file_priv, dev, args->size,
+							&args->handle);
+	if (IS_ERR(exynos_gem_obj))
+		return PTR_ERR(exynos_gem_obj);
+
+	return 0;
+}
+
+int exynos_drm_gem_dumb_map_offset(struct drm_file *file_priv,
+		struct drm_device *dev, uint32_t handle, uint64_t *offset)
+{
+	struct exynos_drm_gem_obj *exynos_gem_obj;
+	struct drm_gem_object *obj;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	mutex_lock(&dev->struct_mutex);
+
+	/*
+	 * get offset of memory allocated for drm framebuffer.
+	 * - this callback would be called by user application
+	 *	with DRM_IOCTL_MODE_MAP_DUMB command.
+	 */
+
+	obj = drm_gem_object_lookup(dev, file_priv, handle);
+	if (!obj) {
+		DRM_ERROR("failed to lookup gem object.\n");
+		mutex_unlock(&dev->struct_mutex);
+		return -EINVAL;
+	}
+
+	exynos_gem_obj = to_exynos_gem_obj(obj);
+
+	*offset = get_gem_mmap_offset(&exynos_gem_obj->base);
+
+	drm_gem_object_unreference(obj);
+
+	DRM_DEBUG_KMS("offset = 0x%lx\n", (unsigned long)*offset);
+
+	mutex_unlock(&dev->struct_mutex);
+
+	return 0;
+}
+
+int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct drm_gem_object *obj = vma->vm_private_data;
+	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
+	struct drm_device *dev = obj->dev;
+	unsigned long pfn;
+	pgoff_t page_offset;
+	int ret;
+
+	page_offset = ((unsigned long)vmf->virtual_address -
+			vma->vm_start) >> PAGE_SHIFT;
+
+	mutex_lock(&dev->struct_mutex);
+
+	pfn = (exynos_gem_obj->entry->paddr >> PAGE_SHIFT) + page_offset;
+
+	ret = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address, pfn);
+
+	mutex_unlock(&dev->struct_mutex);
+
+	return convert_to_vm_err_msg(ret);
+}
+
+int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	int ret;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/* set vm_area_struct. */
+	ret = drm_gem_mmap(filp, vma);
+	if (ret < 0) {
+		DRM_ERROR("failed to mmap.\n");
+		return ret;
+	}
+
+	vma->vm_flags &= ~VM_PFNMAP;
+	vma->vm_flags |= VM_MIXEDMAP;
+
+	return ret;
+}
+
+
+int exynos_drm_gem_dumb_destroy(struct drm_file *file_priv,
+		struct drm_device *dev, unsigned int handle)
+{
+	int ret;
+
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/*
+	 * obj->refcount and obj->handle_count are decreased and
+	 * if both them are 0 then exynos_drm_gem_free_object()
+	 * would be called by callback to release resources.
+	 */
+	ret = drm_gem_handle_delete(file_priv, handle);
+	if (ret < 0) {
+		DRM_ERROR("failed to delete drm_gem_handle.\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
+MODULE_DESCRIPTION("Samsung SoC DRM GEM Module");
+MODULE_LICENSE("GPL");