DRM: Armada: Add Armada DRM driver

This patch adds support for the pair of LCD controllers on the Marvell
Armada 510 SoCs.  This driver supports:
- multiple contiguous scanout buffers for video and graphics
- shm backed cacheable buffer objects for X pixmaps for Vivante GPU
  acceleration
- dual lcd0 and lcd1 crt operation
- video overlay on each LCD crt via DRM planes
- page flipping of the main scanout buffers
- DRM prime for buffer export/import

This driver is trivial to extend to other Armada SoCs.

Included in this commit is the core driver with no output support; output
support is platform and encoder driver dependent.

Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/gpu/drm/armada/armada_fb.c

@@ -0,0 +1,170 @@
+/*
+ * Copyright (C) 2012 Russell King
+ *
+ * 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 <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_helper.h>
+#include "armada_drm.h"
+#include "armada_fb.h"
+#include "armada_gem.h"
+#include "armada_hw.h"
+
+static void armada_fb_destroy(struct drm_framebuffer *fb)
+{
+	struct armada_framebuffer *dfb = drm_fb_to_armada_fb(fb);
+
+	drm_framebuffer_cleanup(&dfb->fb);
+	drm_gem_object_unreference_unlocked(&dfb->obj->obj);
+	kfree(dfb);
+}
+
+static int armada_fb_create_handle(struct drm_framebuffer *fb,
+	struct drm_file *dfile, unsigned int *handle)
+{
+	struct armada_framebuffer *dfb = drm_fb_to_armada_fb(fb);
+	return drm_gem_handle_create(dfile, &dfb->obj->obj, handle);
+}
+
+static const struct drm_framebuffer_funcs armada_fb_funcs = {
+	.destroy	= armada_fb_destroy,
+	.create_handle	= armada_fb_create_handle,
+};
+
+struct armada_framebuffer *armada_framebuffer_create(struct drm_device *dev,
+	struct drm_mode_fb_cmd2 *mode, struct armada_gem_object *obj)
+{
+	struct armada_framebuffer *dfb;
+	uint8_t format, config;
+	int ret;
+
+	switch (mode->pixel_format) {
+#define FMT(drm, fmt, mod)		\
+	case DRM_FORMAT_##drm:		\
+		format = CFG_##fmt;	\
+		config = mod;		\
+		break
+	FMT(RGB565,	565,		CFG_SWAPRB);
+	FMT(BGR565,	565,		0);
+	FMT(ARGB1555,	1555,		CFG_SWAPRB);
+	FMT(ABGR1555,	1555,		0);
+	FMT(RGB888,	888PACK,	CFG_SWAPRB);
+	FMT(BGR888,	888PACK,	0);
+	FMT(XRGB8888,	X888,		CFG_SWAPRB);
+	FMT(XBGR8888,	X888,		0);
+	FMT(ARGB8888,	8888,		CFG_SWAPRB);
+	FMT(ABGR8888,	8888,		0);
+	FMT(YUYV,	422PACK,	CFG_YUV2RGB | CFG_SWAPYU | CFG_SWAPUV);
+	FMT(UYVY,	422PACK,	CFG_YUV2RGB);
+	FMT(VYUY,	422PACK,	CFG_YUV2RGB | CFG_SWAPUV);
+	FMT(YVYU,	422PACK,	CFG_YUV2RGB | CFG_SWAPYU);
+	FMT(YUV422,	422,		CFG_YUV2RGB);
+	FMT(YVU422,	422,		CFG_YUV2RGB | CFG_SWAPUV);
+	FMT(YUV420,	420,		CFG_YUV2RGB);
+	FMT(YVU420,	420,		CFG_YUV2RGB | CFG_SWAPUV);
+	FMT(C8,		PSEUDO8,	0);
+#undef FMT
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+
+	dfb = kzalloc(sizeof(*dfb), GFP_KERNEL);
+	if (!dfb) {
+		DRM_ERROR("failed to allocate Armada fb object\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	dfb->fmt = format;
+	dfb->mod = config;
+	dfb->obj = obj;
+
+	drm_helper_mode_fill_fb_struct(&dfb->fb, mode);
+
+	ret = drm_framebuffer_init(dev, &dfb->fb, &armada_fb_funcs);
+	if (ret) {
+		kfree(dfb);
+		return ERR_PTR(ret);
+	}
+
+	/*
+	 * Take a reference on our object as we're successful - the
+	 * caller already holds a reference, which keeps us safe for
+	 * the above call, but the caller will drop their reference
+	 * to it.  Hence we need to take our own reference.
+	 */
+	drm_gem_object_reference(&obj->obj);
+
+	return dfb;
+}
+
+static struct drm_framebuffer *armada_fb_create(struct drm_device *dev,
+	struct drm_file *dfile, struct drm_mode_fb_cmd2 *mode)
+{
+	struct armada_gem_object *obj;
+	struct armada_framebuffer *dfb;
+	int ret;
+
+	DRM_DEBUG_DRIVER("w%u h%u pf%08x f%u p%u,%u,%u\n",
+		mode->width, mode->height, mode->pixel_format,
+		mode->flags, mode->pitches[0], mode->pitches[1],
+		mode->pitches[2]);
+
+	/* We can only handle a single plane at the moment */
+	if (drm_format_num_planes(mode->pixel_format) > 1 &&
+	    (mode->handles[0] != mode->handles[1] ||
+	     mode->handles[0] != mode->handles[2])) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	obj = armada_gem_object_lookup(dev, dfile, mode->handles[0]);
+	if (!obj) {
+		ret = -ENOENT;
+		goto err;
+	}
+
+	if (obj->obj.import_attach && !obj->sgt) {
+		ret = armada_gem_map_import(obj);
+		if (ret)
+			goto err_unref;
+	}
+
+	/* Framebuffer objects must have a valid device address for scanout */
+	if (obj->dev_addr == DMA_ERROR_CODE) {
+		ret = -EINVAL;
+		goto err_unref;
+	}
+
+	dfb = armada_framebuffer_create(dev, mode, obj);
+	if (IS_ERR(dfb)) {
+		ret = PTR_ERR(dfb);
+		goto err;
+	}
+
+	drm_gem_object_unreference_unlocked(&obj->obj);
+
+	return &dfb->fb;
+
+ err_unref:
+	drm_gem_object_unreference_unlocked(&obj->obj);
+ err:
+	DRM_ERROR("failed to initialize framebuffer: %d\n", ret);
+	return ERR_PTR(ret);
+}
+
+static void armada_output_poll_changed(struct drm_device *dev)
+{
+	struct armada_private *priv = dev->dev_private;
+	struct drm_fb_helper *fbh = priv->fbdev;
+
+	if (fbh)
+		drm_fb_helper_hotplug_event(fbh);
+}
+
+const struct drm_mode_config_funcs armada_drm_mode_config_funcs = {
+	.fb_create		= armada_fb_create,
+	.output_poll_changed	= armada_output_poll_changed,
+};