[RFC PATCH 11/11] drm: mali-dp: Add writeback connector

From: Brian Starkey
Date: Tue Oct 11 2016 - 10:55:42 EST


Mali-DP has a memory writeback engine which can be used to write the
composition result to a memory buffer.
Expose this functionality as a DRM writeback connector on supported
hardware.

Signed-off-by: Brian Starkey <brian.starkey@xxxxxxx>
---
drivers/gpu/drm/arm/Makefile | 1 +
drivers/gpu/drm/arm/malidp_crtc.c | 10 ++
drivers/gpu/drm/arm/malidp_drv.c | 25 +++-
drivers/gpu/drm/arm/malidp_drv.h | 5 +
drivers/gpu/drm/arm/malidp_mw.c | 268 +++++++++++++++++++++++++++++++++++++
5 files changed, 305 insertions(+), 4 deletions(-)
create mode 100644 drivers/gpu/drm/arm/malidp_mw.c

diff --git a/drivers/gpu/drm/arm/Makefile b/drivers/gpu/drm/arm/Makefile
index bb8b158..3bf31d1 100644
--- a/drivers/gpu/drm/arm/Makefile
+++ b/drivers/gpu/drm/arm/Makefile
@@ -1,4 +1,5 @@
hdlcd-y := hdlcd_drv.o hdlcd_crtc.o
obj-$(CONFIG_DRM_HDLCD) += hdlcd.o
mali-dp-y := malidp_drv.o malidp_hw.o malidp_planes.o malidp_crtc.o
+mali-dp-y += malidp_mw.o
obj-$(CONFIG_DRM_MALI_DISPLAY) += mali-dp.o
diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
index 08e6a71..98ddcea 100644
--- a/drivers/gpu/drm/arm/malidp_crtc.c
+++ b/drivers/gpu/drm/arm/malidp_crtc.c
@@ -68,6 +68,16 @@ static void malidp_crtc_enable(struct drm_crtc *crtc)
clk_set_rate(hwdev->pxlclk, crtc->state->adjusted_mode.crtc_clock * 1000);

hwdev->modeset(hwdev, &vm);
+ /*
+ * We should always disable the memory write when leaving config mode,
+ * otherwise the hardware will start writing right away - possibly with
+ * a stale config, and definitely before we've had a chance to configure
+ * the planes.
+ * If the memory write needs to be enabled, that will get taken care
+ * of later during the atomic commit
+ */
+ if (hwdev->disable_memwrite)
+ hwdev->disable_memwrite(hwdev);
hwdev->leave_config_mode(hwdev);
drm_crtc_vblank_on(crtc);
}
diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index 62a29f6..e20266e 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -91,7 +91,16 @@ static void malidp_atomic_commit_tail(struct drm_atomic_state *state)
struct drm_device *drm = state->dev;

drm_atomic_helper_commit_modeset_disables(drm, state);
+
drm_atomic_helper_commit_modeset_enables(drm, state);
+
+ /*
+ * The order here is important. We must configure memory-write after
+ * the CRTC is already enabled, so that its configuration update is
+ * gated on the next CVAL.
+ */
+ malidp_mw_atomic_commit(drm, state);
+
drm_atomic_helper_commit_planes(drm, state,
DRM_PLANE_COMMIT_ACTIVE_ONLY);

@@ -148,12 +157,20 @@ static int malidp_init(struct drm_device *drm)
drm->mode_config.helper_private = &malidp_mode_config_helpers;

ret = malidp_crtc_init(drm);
- if (ret) {
- drm_mode_config_cleanup(drm);
- return ret;
- }
+ if (ret)
+ goto crtc_fail;
+
+ ret = malidp_mw_connector_init(drm);
+ if (ret)
+ goto mw_fail;

return 0;
+
+mw_fail:
+ malidp_de_planes_destroy(drm);
+crtc_fail:
+ drm_mode_config_cleanup(drm);
+ return ret;
}

static void malidp_fini(struct drm_device *drm)
diff --git a/drivers/gpu/drm/arm/malidp_drv.h b/drivers/gpu/drm/arm/malidp_drv.h
index 9fc8a2e..905c104 100644
--- a/drivers/gpu/drm/arm/malidp_drv.h
+++ b/drivers/gpu/drm/arm/malidp_drv.h
@@ -22,6 +22,8 @@ struct malidp_drm {
struct drm_fbdev_cma *fbdev;
struct list_head event_list;
struct drm_crtc crtc;
+ struct drm_encoder mw_encoder;
+ struct drm_connector mw_connector;
wait_queue_head_t wq;
atomic_t config_valid;
};
@@ -50,6 +52,9 @@ struct malidp_plane_state {
int malidp_de_planes_init(struct drm_device *drm);
void malidp_de_planes_destroy(struct drm_device *drm);
int malidp_crtc_init(struct drm_device *drm);
+int malidp_mw_connector_init(struct drm_device *drm);
+void malidp_mw_atomic_commit(struct drm_device *drm,
+ struct drm_atomic_state *old_state);

/* often used combination of rotational bits */
#define MALIDP_ROTATED_MASK (DRM_ROTATE_90 | DRM_ROTATE_270)
diff --git a/drivers/gpu/drm/arm/malidp_mw.c b/drivers/gpu/drm/arm/malidp_mw.c
new file mode 100644
index 0000000..72df3fd
--- /dev/null
+++ b/drivers/gpu/drm/arm/malidp_mw.c
@@ -0,0 +1,268 @@
+/*
+ * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
+ * Author: Brian Starkey <brian.starkey@xxxxxxx>
+ *
+ * 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 DP Writeback connector implementation
+ */
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+
+#include "malidp_drv.h"
+#include "malidp_hw.h"
+
+#define mw_conn_to_malidp_device(x) container_of(x, struct malidp_drm, mw_connector)
+#define to_mw_state(_state) (struct malidp_mw_connector_state *)(_state)
+
+struct malidp_mw_connector_state {
+ struct drm_connector_state base;
+ dma_addr_t addrs[2];
+ s32 pitches[2];
+ u8 format;
+ u8 n_planes;
+ u8 crtc_active:1;
+};
+
+static int malidp_mw_connector_get_modes(struct drm_connector *connector)
+{
+ struct drm_device *dev = connector->dev;
+
+ return drm_add_modes_noedid(connector, dev->mode_config.max_width,
+ dev->mode_config.max_height);
+}
+
+static enum drm_mode_status
+malidp_mw_connector_mode_valid(struct drm_connector *connector,
+ struct drm_display_mode *mode)
+{
+ struct drm_device *dev = connector->dev;
+ struct drm_mode_config *mode_config = &dev->mode_config;
+ int w = mode->hdisplay, h = mode->vdisplay;
+
+ if ((w < mode_config->min_width) || (w > mode_config->max_width))
+ return MODE_BAD_HVALUE;
+
+ if ((h < mode_config->min_height) || (h > mode_config->max_height))
+ return MODE_BAD_VVALUE;
+
+ return MODE_OK;
+}
+
+const struct drm_connector_helper_funcs malidp_mw_connector_helper_funcs = {
+ .get_modes = malidp_mw_connector_get_modes,
+ .mode_valid = malidp_mw_connector_mode_valid,
+};
+
+static enum drm_connector_status
+malidp_mw_connector_detect(struct drm_connector *connector, bool force)
+{
+ return connector_status_connected;
+}
+
+static void malidp_mw_connector_destroy(struct drm_connector *connector)
+{
+ drm_connector_cleanup(connector);
+}
+
+static struct drm_connector_state *
+malidp_mw_connector_duplicate_state(struct drm_connector *connector)
+{
+ struct malidp_mw_connector_state *mw_state, *old_state;
+
+ if (WARN_ON(!connector->state))
+ return NULL;
+
+ mw_state = kmalloc(sizeof(*mw_state), GFP_KERNEL);
+ if (!mw_state)
+ return NULL;
+
+ old_state = (struct malidp_mw_connector_state *)connector->state;
+ memcpy(mw_state, old_state, sizeof(*mw_state));
+ /*
+ * This duplicates a little memcpy, but it ensures we still do the
+ * right thing if drm_connector_state changes
+ */
+ __drm_atomic_helper_connector_duplicate_state(connector, &mw_state->base);
+
+ return &mw_state->base;
+}
+
+static void malidp_mw_connector_destroy_state(struct drm_connector *connector,
+ struct drm_connector_state *state)
+{
+ struct malidp_mw_connector_state *mw_state =
+ (struct malidp_mw_connector_state *)state;
+
+ __drm_atomic_helper_connector_destroy_state(&mw_state->base);
+ kfree(mw_state);
+}
+
+static const struct drm_connector_funcs malidp_mw_connector_funcs = {
+ .dpms = drm_atomic_helper_connector_dpms,
+ .reset = drm_atomic_helper_connector_reset,
+ .detect = malidp_mw_connector_detect,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .destroy = malidp_mw_connector_destroy,
+ .atomic_duplicate_state = malidp_mw_connector_duplicate_state,
+ .atomic_destroy_state = malidp_mw_connector_destroy_state,
+};
+
+static int
+malidp_mw_encoder_atomic_check(struct drm_encoder *encoder,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state)
+{
+ struct drm_connector *conn = conn_state->connector;
+ struct drm_framebuffer *fb = conn_state->fb;
+ struct malidp_drm *malidp = mw_conn_to_malidp_device(conn);
+ struct malidp_mw_connector_state *mw_state;
+ int i, n_planes;
+
+ mw_state = (struct malidp_mw_connector_state *)conn_state;
+ mw_state->crtc_active = crtc_state->active;
+
+ if (!conn_state->fb)
+ return 0;
+
+ if ((fb->width != crtc_state->mode.hdisplay) ||
+ (fb->height != crtc_state->mode.vdisplay)) {
+ DRM_DEBUG_KMS("Invalid framebuffer size %ux%u\n",
+ fb->width, fb->height);
+ return -EINVAL;
+ }
+
+ mw_state->format =
+ malidp_hw_get_format_id(&malidp->dev->map, SE_MEMWRITE,
+ fb->pixel_format);
+ if (mw_state->format == MALIDP_INVALID_FORMAT_ID) {
+ char *format_name = drm_get_format_name(fb->pixel_format);
+ DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
+ kfree(format_name);
+ return -EINVAL;
+ }
+
+ n_planes = drm_format_num_planes(fb->pixel_format);
+ for (i = 0; i < n_planes; i++) {
+ struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, i);
+ if (!malidp_hw_pitch_valid(malidp->dev, fb->pitches[i])) {
+ DRM_DEBUG_KMS("Invalid pitch %u for plane %d\n",
+ fb->pitches[i], i);
+ return -EINVAL;
+ }
+ mw_state->pitches[i] = fb->pitches[i];
+ mw_state->addrs[i] = obj->paddr + fb->offsets[i];
+ }
+ mw_state->n_planes = n_planes;
+
+ return 0;
+}
+
+static const struct drm_encoder_helper_funcs malidp_mw_encoder_helper_funcs = {
+ .atomic_check = malidp_mw_encoder_atomic_check,
+};
+
+static void malidp_mw_encoder_destroy(struct drm_encoder *encoder)
+{
+ drm_encoder_cleanup(encoder);
+}
+
+static const struct drm_encoder_funcs malidp_mw_encoder_funcs = {
+ .destroy = malidp_mw_encoder_destroy,
+};
+
+int malidp_mw_connector_init(struct drm_device *drm)
+{
+ struct malidp_drm *malidp = drm->dev_private;
+ const struct malidp_hw_regmap *map = &malidp->dev->map;
+ u32 *formats;
+ int ret, n, i;
+
+ if (!malidp->dev->enable_memwrite)
+ return 0;
+
+ ret = drm_mode_create_writeback_connector_properties(drm);
+ if (ret)
+ return ret;
+
+ drm_encoder_helper_add(&malidp->mw_encoder, &malidp_mw_encoder_helper_funcs);
+ malidp->mw_encoder.possible_crtcs = 1 << drm_crtc_index(&malidp->crtc);
+ ret = drm_encoder_init(drm, &malidp->mw_encoder, &malidp_mw_encoder_funcs,
+ DRM_MODE_ENCODER_VIRTUAL, NULL);
+ if (ret)
+ return ret;
+
+ drm_connector_helper_add(&malidp->mw_connector,
+ &malidp_mw_connector_helper_funcs);
+ malidp->mw_connector.interlace_allowed = 0;
+ ret = drm_connector_init(drm, &malidp->mw_connector,
+ &malidp_mw_connector_funcs,
+ DRM_MODE_CONNECTOR_WRITEBACK);
+ if (ret)
+ goto err_encoder;
+
+ ret = drm_mode_connector_attach_encoder(&malidp->mw_connector,
+ &malidp->mw_encoder);
+ if (ret)
+ goto err_connector;
+
+ formats = kcalloc(map->n_pixel_formats, sizeof(*formats), GFP_KERNEL);
+ if (!formats)
+ goto err_connector;
+
+ for (n = 0, i = 0; i < map->n_pixel_formats; i++) {
+ if (map->pixel_formats[i].layer & SE_MEMWRITE)
+ formats[n++] = map->pixel_formats[i].format;
+ }
+
+ ret = drm_mode_connector_set_writeback_formats(&malidp->mw_connector,
+ formats, n);
+ kfree(formats);
+ if (ret)
+ goto err_connector;
+
+ return 0;
+
+err_connector:
+ drm_connector_cleanup(&malidp->mw_connector);
+err_encoder:
+ drm_encoder_cleanup(&malidp->mw_encoder);
+ return ret;
+}
+
+void malidp_mw_atomic_commit(struct drm_device *drm,
+ struct drm_atomic_state *old_state)
+{
+ struct malidp_mw_connector_state *mw_state;
+ struct malidp_drm *malidp = drm->dev_private;
+ struct malidp_hw_device *hwdev = malidp->dev;
+ struct drm_connector *mw_conn = &malidp->mw_connector;
+ struct drm_framebuffer *fb;
+
+ mw_state = to_mw_state(mw_conn->state);
+ if (!mw_state || !mw_state->crtc_active)
+ return;
+
+ if (!mw_state->base.fb) {
+ struct malidp_mw_connector_state *old_mw_state;
+ old_mw_state = to_mw_state(drm_atomic_get_existing_connector_state(old_state,
+ mw_conn));
+ if (old_mw_state && old_mw_state->base.fb)
+ hwdev->disable_memwrite(hwdev);
+
+ return;
+ }
+
+ fb = mw_state->base.fb;
+ hwdev->enable_memwrite(hwdev, mw_state->addrs, mw_state->pitches,
+ mw_state->n_planes, fb->width, fb->height,
+ mw_state->format);
+}
--
1.7.9.5