drm/vc4: Add KMS support for Raspberry Pi.

This is enough for fbcon and bringing up X using
xf86-video-modesetting.  It doesn't support the 3D accelerator or
power management yet.

v2: Drop FB_HELPER select thanks to Archit's patches.  Do manual init
    ordering instead of using the .load hook.  Structure registration
    more like tegra's, but still using the typical "component" code.
    Drop no-op hooks for atomic_begin and mode_fixup() now that
    they're optional.  Drop sentinel in Makefile.  Fix minor style
    nits I noticed on another reread.

v3: Use the new bcm2835 clk driver to manage pixel/HSM clocks instead
    of having a fixed video mode.  Use exynos-style component driver
    matching instead of devicetree nodes to list the component driver
    instances.  Rename compatibility strings to say bcm2835, and
    distinguish pv0/1/2.  Clean up some h/vsync code, and add in
    interlaced mode setup.  Fix up probe/bind error paths.  Use
    bitops.h macros for vc4_regs.h

v4: Include i2c.h, allow building under COMPILE_TEST, drop msleep now
    that other bugs have been fixed, add timeouts to cpu_relax()
    loops, rename hpd-gpio to hpd-gpios.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 320 insertions, 0 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
new file mode 100644
index 0000000..cdd8b10
--- /dev/null
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -0,0 +1,320 @@
+/*
+ * Copyright (C) 2015 Broadcom
+ *
+ * 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.
+ */
+
+/**
+ * DOC: VC4 plane module
+ *
+ * Each DRM plane is a layer of pixels being scanned out by the HVS.
+ *
+ * At atomic modeset check time, we compute the HVS display element
+ * state that would be necessary for displaying the plane (giving us a
+ * chance to figure out if a plane configuration is invalid), then at
+ * atomic flush time the CRTC will ask us to write our element state
+ * into the region of the HVS that it has allocated for us.
+ */
+
+#include "vc4_drv.h"
+#include "vc4_regs.h"
+#include "drm_atomic_helper.h"
+#include "drm_fb_cma_helper.h"
+#include "drm_plane_helper.h"
+
+struct vc4_plane_state {
+	struct drm_plane_state base;
+	u32 *dlist;
+	u32 dlist_size; /* Number of dwords in allocated for the display list */
+	u32 dlist_count; /* Number of used dwords in the display list. */
+};
+
+static inline struct vc4_plane_state *
+to_vc4_plane_state(struct drm_plane_state *state)
+{
+	return (struct vc4_plane_state *)state;
+}
+
+static const struct hvs_format {
+	u32 drm; /* DRM_FORMAT_* */
+	u32 hvs; /* HVS_FORMAT_* */
+	u32 pixel_order;
+	bool has_alpha;
+} hvs_formats[] = {
+	{
+		.drm = DRM_FORMAT_XRGB8888, .hvs = HVS_PIXEL_FORMAT_RGBA8888,
+		.pixel_order = HVS_PIXEL_ORDER_ABGR, .has_alpha = false,
+	},
+	{
+		.drm = DRM_FORMAT_ARGB8888, .hvs = HVS_PIXEL_FORMAT_RGBA8888,
+		.pixel_order = HVS_PIXEL_ORDER_ABGR, .has_alpha = true,
+	},
+};
+
+static const struct hvs_format *vc4_get_hvs_format(u32 drm_format)
+{
+	unsigned i;
+
+	for (i = 0; i < ARRAY_SIZE(hvs_formats); i++) {
+		if (hvs_formats[i].drm == drm_format)
+			return &hvs_formats[i];
+	}
+
+	return NULL;
+}
+
+static bool plane_enabled(struct drm_plane_state *state)
+{
+	return state->fb && state->crtc;
+}
+
+struct drm_plane_state *vc4_plane_duplicate_state(struct drm_plane *plane)
+{
+	struct vc4_plane_state *vc4_state;
+
+	if (WARN_ON(!plane->state))
+		return NULL;
+
+	vc4_state = kmemdup(plane->state, sizeof(*vc4_state), GFP_KERNEL);
+	if (!vc4_state)
+		return NULL;
+
+	__drm_atomic_helper_plane_duplicate_state(plane, &vc4_state->base);
+
+	if (vc4_state->dlist) {
+		vc4_state->dlist = kmemdup(vc4_state->dlist,
+					   vc4_state->dlist_count * 4,
+					   GFP_KERNEL);
+		if (!vc4_state->dlist) {
+			kfree(vc4_state);
+			return NULL;
+		}
+		vc4_state->dlist_size = vc4_state->dlist_count;
+	}
+
+	return &vc4_state->base;
+}
+
+void vc4_plane_destroy_state(struct drm_plane *plane,
+			     struct drm_plane_state *state)
+{
+	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);
+
+	kfree(vc4_state->dlist);
+	__drm_atomic_helper_plane_destroy_state(plane, &vc4_state->base);
+	kfree(state);
+}
+
+/* Called during init to allocate the plane's atomic state. */
+void vc4_plane_reset(struct drm_plane *plane)
+{
+	struct vc4_plane_state *vc4_state;
+
+	WARN_ON(plane->state);
+
+	vc4_state = kzalloc(sizeof(*vc4_state), GFP_KERNEL);
+	if (!vc4_state)
+		return;
+
+	plane->state = &vc4_state->base;
+	vc4_state->base.plane = plane;
+}
+
+static void vc4_dlist_write(struct vc4_plane_state *vc4_state, u32 val)
+{
+	if (vc4_state->dlist_count == vc4_state->dlist_size) {
+		u32 new_size = max(4u, vc4_state->dlist_count * 2);
+		u32 *new_dlist = kmalloc(new_size * 4, GFP_KERNEL);
+
+		if (!new_dlist)
+			return;
+		memcpy(new_dlist, vc4_state->dlist, vc4_state->dlist_count * 4);
+
+		kfree(vc4_state->dlist);
+		vc4_state->dlist = new_dlist;
+		vc4_state->dlist_size = new_size;
+	}
+
+	vc4_state->dlist[vc4_state->dlist_count++] = val;
+}
+
+/* Writes out a full display list for an active plane to the plane's
+ * private dlist state.
+ */
+static int vc4_plane_mode_set(struct drm_plane *plane,
+			      struct drm_plane_state *state)
+{
+	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);
+	struct drm_framebuffer *fb = state->fb;
+	struct drm_gem_cma_object *bo = drm_fb_cma_get_gem_obj(fb, 0);
+	u32 ctl0_offset = vc4_state->dlist_count;
+	const struct hvs_format *format = vc4_get_hvs_format(fb->pixel_format);
+	uint32_t offset = fb->offsets[0];
+	int crtc_x = state->crtc_x;
+	int crtc_y = state->crtc_y;
+	int crtc_w = state->crtc_w;
+	int crtc_h = state->crtc_h;
+
+	if (crtc_x < 0) {
+		offset += drm_format_plane_cpp(fb->pixel_format, 0) * -crtc_x;
+		crtc_w += crtc_x;
+		crtc_x = 0;
+	}
+
+	if (crtc_y < 0) {
+		offset += fb->pitches[0] * -crtc_y;
+		crtc_h += crtc_y;
+		crtc_y = 0;
+	}
+
+	vc4_dlist_write(vc4_state,
+			SCALER_CTL0_VALID |
+			(format->pixel_order << SCALER_CTL0_ORDER_SHIFT) |
+			(format->hvs << SCALER_CTL0_PIXEL_FORMAT_SHIFT) |
+			SCALER_CTL0_UNITY);
+
+	/* Position Word 0: Image Positions and Alpha Value */
+	vc4_dlist_write(vc4_state,
+			VC4_SET_FIELD(0xff, SCALER_POS0_FIXED_ALPHA) |
+			VC4_SET_FIELD(crtc_x, SCALER_POS0_START_X) |
+			VC4_SET_FIELD(crtc_y, SCALER_POS0_START_Y));
+
+	/* Position Word 1: Scaled Image Dimensions.
+	 * Skipped due to SCALER_CTL0_UNITY scaling.
+	 */
+
+	/* Position Word 2: Source Image Size, Alpha Mode */
+	vc4_dlist_write(vc4_state,
+			VC4_SET_FIELD(format->has_alpha ?
+				      SCALER_POS2_ALPHA_MODE_PIPELINE :
+				      SCALER_POS2_ALPHA_MODE_FIXED,
+				      SCALER_POS2_ALPHA_MODE) |
+			VC4_SET_FIELD(crtc_w, SCALER_POS2_WIDTH) |
+			VC4_SET_FIELD(crtc_h, SCALER_POS2_HEIGHT));
+
+	/* Position Word 3: Context.  Written by the HVS. */
+	vc4_dlist_write(vc4_state, 0xc0c0c0c0);
+
+	/* Pointer Word 0: RGB / Y Pointer */
+	vc4_dlist_write(vc4_state, bo->paddr + offset);
+
+	/* Pointer Context Word 0: Written by the HVS */
+	vc4_dlist_write(vc4_state, 0xc0c0c0c0);
+
+	/* Pitch word 0: Pointer 0 Pitch */
+	vc4_dlist_write(vc4_state,
+			VC4_SET_FIELD(fb->pitches[0], SCALER_SRC_PITCH));
+
+	vc4_state->dlist[ctl0_offset] |=
+		VC4_SET_FIELD(vc4_state->dlist_count, SCALER_CTL0_SIZE);
+
+	return 0;
+}
+
+/* If a modeset involves changing the setup of a plane, the atomic
+ * infrastructure will call this to validate a proposed plane setup.
+ * However, if a plane isn't getting updated, this (and the
+ * corresponding vc4_plane_atomic_update) won't get called.  Thus, we
+ * compute the dlist here and have all active plane dlists get updated
+ * in the CRTC's flush.
+ */
+static int vc4_plane_atomic_check(struct drm_plane *plane,
+				  struct drm_plane_state *state)
+{
+	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);
+
+	vc4_state->dlist_count = 0;
+
+	if (plane_enabled(state))
+		return vc4_plane_mode_set(plane, state);
+	else
+		return 0;
+}
+
+static void vc4_plane_atomic_update(struct drm_plane *plane,
+				    struct drm_plane_state *old_state)
+{
+	/* No contents here.  Since we don't know where in the CRTC's
+	 * dlist we should be stored, our dlist is uploaded to the
+	 * hardware with vc4_plane_write_dlist() at CRTC atomic_flush
+	 * time.
+	 */
+}
+
+u32 vc4_plane_write_dlist(struct drm_plane *plane, u32 __iomem *dlist)
+{
+	struct vc4_plane_state *vc4_state = to_vc4_plane_state(plane->state);
+	int i;
+
+	/* Can't memcpy_toio() because it needs to be 32-bit writes. */
+	for (i = 0; i < vc4_state->dlist_count; i++)
+		writel(vc4_state->dlist[i], &dlist[i]);
+
+	return vc4_state->dlist_count;
+}
+
+u32 vc4_plane_dlist_size(struct drm_plane_state *state)
+{
+	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);
+
+	return vc4_state->dlist_count;
+}
+
+static const struct drm_plane_helper_funcs vc4_plane_helper_funcs = {
+	.prepare_fb = NULL,
+	.cleanup_fb = NULL,
+	.atomic_check = vc4_plane_atomic_check,
+	.atomic_update = vc4_plane_atomic_update,
+};
+
+static void vc4_plane_destroy(struct drm_plane *plane)
+{
+	drm_plane_helper_disable(plane);
+	drm_plane_cleanup(plane);
+}
+
+static const struct drm_plane_funcs vc4_plane_funcs = {
+	.update_plane = drm_atomic_helper_update_plane,
+	.disable_plane = drm_atomic_helper_disable_plane,
+	.destroy = vc4_plane_destroy,
+	.set_property = NULL,
+	.reset = vc4_plane_reset,
+	.atomic_duplicate_state = vc4_plane_duplicate_state,
+	.atomic_destroy_state = vc4_plane_destroy_state,
+};
+
+struct drm_plane *vc4_plane_init(struct drm_device *dev,
+				 enum drm_plane_type type)
+{
+	struct drm_plane *plane = NULL;
+	struct vc4_plane *vc4_plane;
+	u32 formats[ARRAY_SIZE(hvs_formats)];
+	int ret = 0;
+	unsigned i;
+
+	vc4_plane = devm_kzalloc(dev->dev, sizeof(*vc4_plane),
+				 GFP_KERNEL);
+	if (!vc4_plane) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(hvs_formats); i++)
+		formats[i] = hvs_formats[i].drm;
+	plane = &vc4_plane->base;
+	ret = drm_universal_plane_init(dev, plane, 0xff,
+				       &vc4_plane_funcs,
+				       formats, ARRAY_SIZE(formats),
+				       type);
+
+	drm_plane_helper_add(plane, &vc4_plane_helper_funcs);
+
+	return plane;
+fail:
+	if (plane)
+		vc4_plane_destroy(plane);
+
+	return ERR_PTR(ret);
+}