This patchset introduces a set of helper function for implementing the KMS
framebuffer layer for drivers which use the drm gem CMA helper function.

Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>

---
Note: This patch depends on Sascha's "DRM: add drm gem CMA helper" patch

Changes since v2:
        * Adapt to changes in the GEM CMA helper
        * Add basic buffer size checking in drm_fb_cma_create
Changes since v1:
        * Some spelling fixes
        * Add missing kfree in drm_fb_cma_alloc error path
        * Add multi-plane support
---
 drivers/gpu/drm/Kconfig             |   10 +
 drivers/gpu/drm/Makefile            |    1 +
 drivers/gpu/drm/drm_fb_cma_helper.c |  393 +++++++++++++++++++++++++++++++++++
 include/drm/drm_fb_cma_helper.h     |   27 +++
 4 files changed, 431 insertions(+)
 create mode 100644 drivers/gpu/drm/drm_fb_cma_helper.c
 create mode 100644 include/drm/drm_fb_cma_helper.h

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 41bbd95..e511c9a 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -41,6 +41,16 @@ config DRM_GEM_CMA_HELPER
        help
          Choose this if you need the GEM CMA helper functions

+config DRM_KMS_CMA_HELPER
+       tristate
+       select DRM_GEM_CMA_HELPER
+       select DRM_KMS_HELPER
+       select FB_SYS_FILLRECT
+       select FB_SYS_COPYAREA
+       select FB_SYS_IMAGEBLIT
+       help
+         Choose this if you need the KMS cma helper functions
+
 config DRM_TDFX
        tristate "3dfx Banshee/Voodoo3+"
        depends on DRM && PCI
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 6e9e948..5dcb1a5 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -18,6 +18,7 @@ drm-$(CONFIG_COMPAT) += drm_ioc32.o
 drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o

 drm_kms_helper-y := drm_fb_helper.o drm_crtc_helper.o drm_dp_i2c_helper.o
+drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o

 obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o

diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c 
b/drivers/gpu/drm/drm_fb_cma_helper.c
new file mode 100644
index 0000000..9042233
--- /dev/null
+++ b/drivers/gpu/drm/drm_fb_cma_helper.c
@@ -0,0 +1,393 @@
+/*
+ * drm kms/fb cma (contiguous memory allocator) helper functions
+ *
+ * Copyright (C) 2012 Analog Device Inc.
+ *   Author: Lars-Peter Clausen <lars at metafoo.de>
+ *
+ * Based on udl_fbdev.c
+ *  Copyright (C) 2012 Red Hat
+ *
+ * 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 <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <linux/module.h>
+
+struct drm_fb_cma {
+       struct drm_framebuffer          fb;
+       struct drm_gem_cma_object       *obj[4];
+};
+
+struct drm_fbdev_cma {
+       struct drm_fb_helper    fb_helper;
+       struct drm_fb_cma       *fb;
+};
+
+static inline struct drm_fbdev_cma *to_fbdev_cma(struct drm_fb_helper *helper)
+{
+       return container_of(helper, struct drm_fbdev_cma, fb_helper);
+}
+
+static inline struct drm_fb_cma *to_fb_cma(struct drm_framebuffer *fb)
+{
+       return container_of(fb, struct drm_fb_cma, fb);
+}
+
+static void drm_fb_cma_destroy(struct drm_framebuffer *fb)
+{
+       struct drm_fb_cma *fb_cma = to_fb_cma(fb);
+       int i;
+
+       for (i = 0; i < 4; i++) {
+               if (fb_cma->obj[i])
+                       
drm_gem_object_unreference_unlocked(&fb_cma->obj[i]->base);
+       }
+
+       drm_framebuffer_cleanup(fb);
+       kfree(fb_cma);
+}
+
+static int drm_fb_cma_create_handle(struct drm_framebuffer *fb,
+       struct drm_file *file_priv, unsigned int *handle)
+{
+       struct drm_fb_cma *fb_cma = to_fb_cma(fb);
+
+       return drm_gem_handle_create(file_priv,
+                       &fb_cma->obj[0]->base, handle);
+}
+
+static struct drm_framebuffer_funcs drm_fb_cma_funcs = {
+       .destroy        = drm_fb_cma_destroy,
+       .create_handle  = drm_fb_cma_create_handle,
+};
+
+static struct drm_fb_cma *drm_fb_cma_alloc(struct drm_device *dev,
+       struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_cma_object **obj,
+       unsigned int num_planes)
+{
+       struct drm_fb_cma *fb_cma;
+       int ret;
+       int i;
+
+       fb_cma = kzalloc(sizeof(*fb_cma), GFP_KERNEL);
+       if (!fb_cma)
+               return ERR_PTR(-ENOMEM);
+
+       ret = drm_framebuffer_init(dev, &fb_cma->fb, &drm_fb_cma_funcs);
+       if (ret) {
+               dev_err(dev->dev, "Failed to initalize framebuffer: %d\n", ret);
+               kfree(fb_cma);
+               return ERR_PTR(ret);
+       }
+
+       drm_helper_mode_fill_fb_struct(&fb_cma->fb, mode_cmd);
+
+       for (i = 0; i < num_planes; i++)
+               fb_cma->obj[i] = obj[i];
+
+       return fb_cma;
+}
+
+/**
+ * drm_fb_cma_create() - (struct drm_mode_config_funcs *)->fb_create callback 
function
+ *
+ * If your hardware has special alignment or pitch requirements these should be
+ * checked before calling this function.
+ */
+struct drm_framebuffer *drm_fb_cma_create(struct drm_device *dev,
+       struct drm_file *file_priv, struct drm_mode_fb_cmd2 *mode_cmd)
+{
+       struct drm_fb_cma *fb_cma;
+       struct drm_gem_cma_object *objs[4];
+       struct drm_gem_object *obj;
+       int ret;
+       int i;
+
+       for (i = 0; i < drm_format_num_planes(mode_cmd->pixel_format); i++) {
+               obj = drm_gem_object_lookup(dev, file_priv, 
mode_cmd->handles[i]);
+               if (!obj) {
+                       dev_err(dev->dev, "Failed to lookup GEM object\n");
+                       ret = -ENXIO;
+                       goto err_gem_object_unreference;
+               }
+
+               if (obj->size < mode_cmd->height * mode_cmd->pitches[i]) {
+                       drm_gem_object_unreference_unlocked(obj);
+                       ret = -EINVAL;
+                       goto err_gem_object_unreference;
+               }
+               objs[i] = to_drm_gem_cma_obj(obj);
+       }
+
+       fb_cma = drm_fb_cma_alloc(dev, mode_cmd, objs, i);
+       if (IS_ERR(fb_cma)) {
+               ret = PTR_ERR(fb_cma);
+               goto err_gem_object_unreference;
+       }
+
+       return &fb_cma->fb;
+
+err_gem_object_unreference:
+       for (i--; i >= 0; i--)
+               drm_gem_object_unreference_unlocked(&objs[i]->base);
+       return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_fb_cma_create);
+
+/**
+ * drm_fb_cma_get_gem_obj() - Get CMA GEM object for framebuffer
+ * @fb: The framebuffer
+ * @plane: Which plane
+ *
+ * Return the CMA GEM object for given framebuffer.
+ *
+ * This function will usually be called from the CRTC callback functions.
+ */
+struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
+       unsigned int plane)
+{
+       struct drm_fb_cma *fb_cma = to_fb_cma(fb);
+
+       if (plane >= 4)
+               return NULL;
+
+       return fb_cma->obj[plane];
+}
+EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);
+
+static struct fb_ops drm_fbdev_cma_ops = {
+       .owner          = THIS_MODULE,
+       .fb_fillrect    = sys_fillrect,
+       .fb_copyarea    = sys_copyarea,
+       .fb_imageblit   = sys_imageblit,
+       .fb_check_var   = drm_fb_helper_check_var,
+       .fb_set_par     = drm_fb_helper_set_par,
+       .fb_blank       = drm_fb_helper_blank,
+       .fb_pan_display = drm_fb_helper_pan_display,
+       .fb_setcmap     = drm_fb_helper_setcmap,
+};
+
+static int drm_fbdev_cma_create(struct drm_fb_helper *helper,
+       struct drm_fb_helper_surface_size *sizes)
+{
+       struct drm_fbdev_cma *fbdev_cma = to_fbdev_cma(helper);
+       struct drm_mode_fb_cmd2 mode_cmd = { 0 };
+       struct drm_device *dev = helper->dev;
+       struct drm_gem_cma_object *obj;
+       struct drm_framebuffer *fb;
+       unsigned int bytes_per_pixel;
+       unsigned long offset;
+       struct fb_info *fbi;
+       size_t size;
+       int ret;
+
+       DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d\n",
+                       sizes->surface_width, sizes->surface_height,
+                       sizes->surface_bpp);
+
+       bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
+
+       mode_cmd.width = sizes->surface_width;
+       mode_cmd.height = sizes->surface_height;
+       mode_cmd.pitches[0] = sizes->surface_width * bytes_per_pixel;
+       mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
+               sizes->surface_depth);
+
+       size = mode_cmd.pitches[0] * mode_cmd.height;
+       obj = drm_gem_cma_create(dev, size);
+       if (!obj)
+               return -ENOMEM;
+
+       fbi = framebuffer_alloc(0, dev->dev);
+       if (!fbi) {
+               dev_err(dev->dev, "Failed to allocate framebuffer info.\n");
+               ret = -ENOMEM;
+               goto err_drm_gem_cma_free_object;
+       }
+
+       fbdev_cma->fb = drm_fb_cma_alloc(dev, &mode_cmd, &obj, 1);
+       if (IS_ERR(fbdev_cma->fb)) {
+               dev_err(dev->dev, "Failed to allocate DRM framebuffer.\n");
+               ret = PTR_ERR(fbdev_cma->fb);
+               goto err_framebuffer_release;
+       }
+
+       fb = &fbdev_cma->fb->fb;
+       helper->fb = fb;
+       helper->fbdev = fbi;
+
+       fbi->par = helper;
+       fbi->flags = FBINFO_FLAG_DEFAULT;
+       fbi->fbops = &drm_fbdev_cma_ops;
+
+       ret = fb_alloc_cmap(&fbi->cmap, 256, 0);
+       if (ret) {
+               dev_err(dev->dev, "Failed to allocate color map.\n");
+               goto err_drm_fb_cma_destroy;
+       }
+
+       drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
+       drm_fb_helper_fill_var(fbi, helper, fb->width, fb->height);
+
+       offset = fbi->var.xoffset * bytes_per_pixel;
+       offset += fbi->var.yoffset * fb->pitches[0];
+
+       dev->mode_config.fb_base = (resource_size_t)obj->paddr;
+       fbi->screen_base = obj->vaddr + offset;
+       fbi->fix.smem_start = (unsigned long)(obj->paddr + offset);
+       fbi->screen_size = size;
+       fbi->fix.smem_len = size;
+
+       return 0;
+
+err_drm_fb_cma_destroy:
+       drm_fb_cma_destroy(fb);
+err_framebuffer_release:
+       framebuffer_release(fbi);
+err_drm_gem_cma_free_object:
+       drm_gem_cma_free_object(&obj->base);
+       return ret;
+}
+
+static int drm_fbdev_cma_probe(struct drm_fb_helper *helper,
+       struct drm_fb_helper_surface_size *sizes)
+{
+       int ret = 0;
+
+       if (!helper->fb) {
+               ret = drm_fbdev_cma_create(helper, sizes);
+               if (ret < 0)
+                       return ret;
+               ret = 1;
+       }
+
+       return ret;
+}
+
+static struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
+       .fb_probe = drm_fbdev_cma_probe,
+};
+
+/**
+ * drm_fbdev_cma_init() - Allocate and initializes a drm_fbdev_cma struct
+ * @dev: DRM device
+ * @preferred_bpp: Preferred bits per pixel for the device
+ * @num_crtc: Number of CRTCs
+ * @max_conn_count: Maximum number of connectors
+ *
+ * Returns a newly allocated drm_fbdev_cma struct or a ERR_PTR.
+ */
+struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
+       unsigned int preferred_bpp, unsigned int num_crtc,
+       unsigned int max_conn_count)
+{
+       struct drm_fbdev_cma *fbdev_cma;
+       struct drm_fb_helper *helper;
+       int ret;
+
+       fbdev_cma = kzalloc(sizeof(*fbdev_cma), GFP_KERNEL);
+       if (!fbdev_cma) {
+               dev_err(dev->dev, "Failed to allocate drm fbdev.\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       fbdev_cma->fb_helper.funcs = &drm_fb_cma_helper_funcs;
+       helper = &fbdev_cma->fb_helper;
+
+       ret = drm_fb_helper_init(dev, helper, num_crtc, max_conn_count);
+       if (ret < 0) {
+               dev_err(dev->dev, "Failed to initialize drm fb helper.\n");
+               goto err_free;
+       }
+
+       ret = drm_fb_helper_single_add_all_connectors(helper);
+       if (ret < 0) {
+               dev_err(dev->dev, "Failed to add connectors.\n");
+               goto err_drm_fb_helper_fini;
+
+       }
+
+       ret = drm_fb_helper_initial_config(helper, preferred_bpp);
+       if (ret < 0) {
+               dev_err(dev->dev, "Failed to set inital hw configuration.\n");
+               goto err_drm_fb_helper_fini;
+       }
+
+       return fbdev_cma;
+
+err_drm_fb_helper_fini:
+       drm_fb_helper_fini(helper);
+err_free:
+       kfree(fbdev_cma);
+
+       return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_fbdev_cma_init);
+
+/**
+ * drm_fbdev_cma_fini() - Free drm_fbdev_cma struct
+ * @fbdev_cma: The drm_fbdev_cma struct
+ */
+void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma)
+{
+       if (fbdev_cma->fb_helper.fbdev) {
+               struct fb_info *info;
+               int ret;
+
+               info = fbdev_cma->fb_helper.fbdev;
+               ret = unregister_framebuffer(info);
+               if (ret < 0)
+                       DRM_DEBUG_KMS("failed unregister_framebuffer()\n");
+
+               if (info->cmap.len)
+                       fb_dealloc_cmap(&info->cmap);
+
+               framebuffer_release(info);
+       }
+
+       if (fbdev_cma->fb)
+               drm_fb_cma_destroy(&fbdev_cma->fb->fb);
+
+       drm_fb_helper_fini(&fbdev_cma->fb_helper);
+       kfree(fbdev_cma);
+}
+EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
+
+/**
+ * drm_fbdev_cma_restore_mode() - Restores initial framebuffer mode
+ * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
+ *
+ * This function is usually called from the DRM drivers lastclose callback.
+ */
+void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)
+{
+       if (fbdev_cma)
+               drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper);
+}
+EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);
+
+/**
+ * drm_fbdev_cma_hotplug_event() - Poll for hotpulug events
+ * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
+ *
+ * This function is usually called from the DRM drivers output_poll_changed
+ * callback.
+ */
+void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma)
+{
+       if (fbdev_cma)
+               drm_fb_helper_hotplug_event(&fbdev_cma->fb_helper);
+}
+EXPORT_SYMBOL_GPL(drm_fbdev_cma_hotplug_event);
diff --git a/include/drm/drm_fb_cma_helper.h b/include/drm/drm_fb_cma_helper.h
new file mode 100644
index 0000000..76c7098
--- /dev/null
+++ b/include/drm/drm_fb_cma_helper.h
@@ -0,0 +1,27 @@
+#ifndef __DRM_FB_CMA_HELPER_H__
+#define __DRM_FB_CMA_HELPER_H__
+
+struct drm_fbdev_cma;
+struct drm_gem_cma_object;
+
+struct drm_framebuffer;
+struct drm_device;
+struct drm_file;
+struct drm_mode_fb_cmd2;
+
+struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
+       unsigned int preferred_bpp, unsigned int num_crtc,
+       unsigned int max_conn_count);
+void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma);
+
+void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma);
+void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma);
+
+struct drm_framebuffer *drm_fb_cma_create(struct drm_device *dev,
+       struct drm_file *file_priv, struct drm_mode_fb_cmd2 *mode_cmd);
+
+struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
+       unsigned int plane);
+
+#endif
+
-- 
1.7.10

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