drm/arm: Add support for Mali Display Processors

Add support for the new family of Display Processors from ARM Ltd.
This commit adds basic support for Mali DP500, DP550 and DP650
parts, with only the display engine being supported at the moment.

Cc: David Brown <David.Brown@arm.com>
Cc: Brian Starkey <Brian.Starkey@arm.com>

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 216 insertions, 0 deletions

diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
new file mode 100644
index 000000000000..08e6a71f5d05
--- /dev/null
+++ b/drivers/gpu/drm/arm/malidp_crtc.c
@@ -0,0 +1,216 @@
+/*
+ * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
+ * Author: Liviu Dudau <Liviu.Dudau@arm.com>
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms
+ * of such GNU licence.
+ *
+ * ARM Mali DP500/DP550/DP650 driver (crtc operations)
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <linux/clk.h>
+#include <video/videomode.h>
+
+#include "malidp_drv.h"
+#include "malidp_hw.h"
+
+static bool malidp_crtc_mode_fixup(struct drm_crtc *crtc,
+				   const struct drm_display_mode *mode,
+				   struct drm_display_mode *adjusted_mode)
+{
+	struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
+	struct malidp_hw_device *hwdev = malidp->dev;
+
+	/*
+	 * check that the hardware can drive the required clock rate,
+	 * but skip the check if the clock is meant to be disabled (req_rate = 0)
+	 */
+	long rate, req_rate = mode->crtc_clock * 1000;
+
+	if (req_rate) {
+		rate = clk_round_rate(hwdev->mclk, req_rate);
+		if (rate < req_rate) {
+			DRM_DEBUG_DRIVER("mclk clock unable to reach %d kHz\n",
+					 mode->crtc_clock);
+			return false;
+		}
+
+		rate = clk_round_rate(hwdev->pxlclk, req_rate);
+		if (rate != req_rate) {
+			DRM_DEBUG_DRIVER("pxlclk doesn't support %ld Hz\n",
+					 req_rate);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static void malidp_crtc_enable(struct drm_crtc *crtc)
+{
+	struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
+	struct malidp_hw_device *hwdev = malidp->dev;
+	struct videomode vm;
+
+	drm_display_mode_to_videomode(&crtc->state->adjusted_mode, &vm);
+
+	clk_prepare_enable(hwdev->pxlclk);
+
+	/* mclk needs to be set to the same or higher rate than pxlclk */
+	clk_set_rate(hwdev->mclk, crtc->state->adjusted_mode.crtc_clock * 1000);
+	clk_set_rate(hwdev->pxlclk, crtc->state->adjusted_mode.crtc_clock * 1000);
+
+	hwdev->modeset(hwdev, &vm);
+	hwdev->leave_config_mode(hwdev);
+	drm_crtc_vblank_on(crtc);
+}
+
+static void malidp_crtc_disable(struct drm_crtc *crtc)
+{
+	struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
+	struct malidp_hw_device *hwdev = malidp->dev;
+
+	drm_crtc_vblank_off(crtc);
+	hwdev->enter_config_mode(hwdev);
+	clk_disable_unprepare(hwdev->pxlclk);
+}
+
+static int malidp_crtc_atomic_check(struct drm_crtc *crtc,
+				    struct drm_crtc_state *state)
+{
+	struct malidp_drm *malidp = crtc_to_malidp_device(crtc);
+	struct malidp_hw_device *hwdev = malidp->dev;
+	struct drm_plane *plane;
+	const struct drm_plane_state *pstate;
+	u32 rot_mem_free, rot_mem_usable;
+	int rotated_planes = 0;
+
+	/*
+	 * check if there is enough rotation memory available for planes
+	 * that need 90° and 270° rotation. Each plane has set its required
+	 * memory size in the ->plane_check() callback, here we only make
+	 * sure that the sums are less that the total usable memory.
+	 *
+	 * The rotation memory allocation algorithm (for each plane):
+	 *  a. If no more rotated planes exist, all remaining rotate
+	 *     memory in the bank is available for use by the plane.
+	 *  b. If other rotated planes exist, and plane's layer ID is
+	 *     DE_VIDEO1, it can use all the memory from first bank if
+	 *     secondary rotation memory bank is available, otherwise it can
+	 *     use up to half the bank's memory.
+	 *  c. If other rotated planes exist, and plane's layer ID is not
+	 *     DE_VIDEO1, it can use half of the available memory
+	 *
+	 * Note: this algorithm assumes that the order in which the planes are
+	 * checked always has DE_VIDEO1 plane first in the list if it is
+	 * rotated. Because that is how we create the planes in the first
+	 * place, under current DRM version things work, but if ever the order
+	 * in which drm_atomic_crtc_state_for_each_plane() iterates over planes
+	 * changes, we need to pre-sort the planes before validation.
+	 */
+
+	/* first count the number of rotated planes */
+	drm_atomic_crtc_state_for_each_plane_state(plane, pstate, state) {
+		if (pstate->rotation & MALIDP_ROTATED_MASK)
+			rotated_planes++;
+	}
+
+	rot_mem_free = hwdev->rotation_memory[0];
+	/*
+	 * if we have more than 1 plane using rotation memory, use the second
+	 * block of rotation memory as well
+	 */
+	if (rotated_planes > 1)
+		rot_mem_free += hwdev->rotation_memory[1];
+
+	/* now validate the rotation memory requirements */
+	drm_atomic_crtc_state_for_each_plane_state(plane, pstate, state) {
+		struct malidp_plane *mp = to_malidp_plane(plane);
+		struct malidp_plane_state *ms = to_malidp_plane_state(pstate);
+
+		if (pstate->rotation & MALIDP_ROTATED_MASK) {
+			/* process current plane */
+			rotated_planes--;
+
+			if (!rotated_planes) {
+				/* no more rotated planes, we can use what's left */
+				rot_mem_usable = rot_mem_free;
+			} else {
+				if ((mp->layer->id != DE_VIDEO1) ||
+				    (hwdev->rotation_memory[1] == 0))
+					rot_mem_usable = rot_mem_free / 2;
+				else
+					rot_mem_usable = hwdev->rotation_memory[0];
+			}
+
+			rot_mem_free -= rot_mem_usable;
+
+			if (ms->rotmem_size > rot_mem_usable)
+				return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static const struct drm_crtc_helper_funcs malidp_crtc_helper_funcs = {
+	.mode_fixup = malidp_crtc_mode_fixup,
+	.enable = malidp_crtc_enable,
+	.disable = malidp_crtc_disable,
+	.atomic_check = malidp_crtc_atomic_check,
+};
+
+static const struct drm_crtc_funcs malidp_crtc_funcs = {
+	.destroy = drm_crtc_cleanup,
+	.set_config = drm_atomic_helper_set_config,
+	.page_flip = drm_atomic_helper_page_flip,
+	.reset = drm_atomic_helper_crtc_reset,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
+int malidp_crtc_init(struct drm_device *drm)
+{
+	struct malidp_drm *malidp = drm->dev_private;
+	struct drm_plane *primary = NULL, *plane;
+	int ret;
+
+	ret = malidp_de_planes_init(drm);
+	if (ret < 0) {
+		DRM_ERROR("Failed to initialise planes\n");
+		return ret;
+	}
+
+	drm_for_each_plane(plane, drm) {
+		if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
+			primary = plane;
+			break;
+		}
+	}
+
+	if (!primary) {
+		DRM_ERROR("no primary plane found\n");
+		ret = -EINVAL;
+		goto crtc_cleanup_planes;
+	}
+
+	ret = drm_crtc_init_with_planes(drm, &malidp->crtc, primary, NULL,
+					&malidp_crtc_funcs, NULL);
+
+	if (!ret) {
+		drm_crtc_helper_add(&malidp->crtc, &malidp_crtc_helper_funcs);
+		return 0;
+	}
+
+crtc_cleanup_planes:
+	malidp_de_planes_destroy(drm);
+
+	return ret;
+}