Hi Boris,
I can't speak for the HW-specific details, but the writeback part
looks pretty good (and familiar ;-) to me. There certainly seems to be
some scope for code-sharing there, but I think it's fine not to do it
yet.
I've a further query below about the handling of CRTC events.
On Fri, Jun 02, 2017 at 10:32:10AM +0200, Boris Brezillon wrote:
The TXP block is providing writeback support. Add a driver to expose this
feature.
Supporting this engine requires reworking the CRTC because it's not using
the usual 'HVS -> PV -> VC4 Encoder' scheme. Instead, the TXP block is
directly connected to HVS FIFO2, and the PV is completely bypassed.
In order to make things work, we have to detect when the TXP is enabled,
avoid enabling the PV when this is the case, and generate fake VBLANK
events when the TXP is done writing the frame back to memory.
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
---
[snip]
diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c
new file mode 100644
index 000000000000..1886e031bef3
--- /dev/null
+++ b/drivers/gpu/drm/vc4/vc4_txp.c
@@ -0,0 +1,509 @@
+/*
+ * Copyright © 2017 Broadcom
+ *
+ * Author: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_writeback.h>
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/of_graph.h>
+#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
+
+#include "vc4_drv.h"
+#include "vc4_regs.h"
+
+/* Base address of the output. Raster formats must be 4-byte aligned,
+ * T and LT must be 16-byte aligned or maybe utile-aligned (docs are
+ * inconsistent, but probably utile).
+ */
+#define TXP_DST_PTR 0x00
+
+/* Pitch in bytes for raster images, 16-byte aligned. For tiled, it's
+ * the width in tiles.
+ */
+#define TXP_DST_PITCH 0x04
+/* For T-tiled imgaes, DST_PITCH should be the number of tiles wide,
+ * shifted up.
+ */
+# define TXP_T_TILE_WIDTH_SHIFT 7
+/* For LT-tiled images, DST_PITCH should be the number of utiles wide,
+ * shifted up.
+ */
+# define TXP_LT_TILE_WIDTH_SHIFT 4
+
+/* Pre-rotation width/height of the image. Must match HVS config.
+ *
+ * If TFORMAT and 32-bit, limit is 1920 for 32-bit and 3840 to 16-bit
+ * and width/height must be tile or utile-aligned as appropriate. If
+ * transposing (rotating), width is limited to 1920.
+ *
+ * Height is limited to various numbers between 4088 and 4095. I'd
+ * just use 4088 to be safe.
+ */
+#define TXP_DIM 0x08
+# define TXP_HEIGHT_SHIFT 16
+# define TXP_HEIGHT_MASK GENMASK(31, 16)
+# define TXP_WIDTH_SHIFT 0
+# define TXP_WIDTH_MASK GENMASK(15, 0)
+
+#define TXP_DST_CTRL 0x0c
+/* These bits are set to 0x54 */
+#define TXP_PILOT_SHIFT 24
+#define TXP_PILOT_MASK GENMASK(31, 24)
+/* Bits 22-23 are set to 0x01 */
+#define TXP_VERSION_SHIFT 22
+#define TXP_VERSION_MASK GENMASK(23, 22)
+
+/* Powers down the internal memory. */
+# define TXP_POWERDOWN BIT(21)
+
+/* Enables storing the alpha component in 8888/4444, instead of
+ * filling with ~ALPHA_INVERT.
+ */
+# define TXP_ALPHA_ENABLE BIT(20)
+
+/* 4 bits, each enables stores for a channel in each set of 4 bytes.
+ * Set to 0xf for normal operation.
+ */
+# define TXP_BYTE_ENABLE_SHIFT 16
+# define TXP_BYTE_ENABLE_MASK GENMASK(19, 16)
+
+/* Debug: Generate VSTART again at EOF. */
+# define TXP_VSTART_AT_EOF BIT(15)
+
+/* Debug: Terminate the current frame immediately. Stops AXI
+ * writes.
+ */
+# define TXP_ABORT BIT(14)
+
+# define TXP_DITHER BIT(13)
+
+/* Inverts alpha if TXP_ALPHA_ENABLE, chooses fill value for
+ * !TXP_ALPHA_ENABLE.
+ */
+# define TXP_ALPHA_INVERT BIT(12)
+
+/* Note: I've listed the channels here in high bit (in byte 3/2/1) to
+ * low bit (in byte 0) order.
+ */
+# define TXP_FORMAT_SHIFT 8
+# define TXP_FORMAT_MASK GENMASK(11, 8)
+# define TXP_FORMAT_ABGR4444 0
+# define TXP_FORMAT_ARGB4444 1
+# define TXP_FORMAT_BGRA4444 2
+# define TXP_FORMAT_RGBA4444 3
+# define TXP_FORMAT_BGR565 6
+# define TXP_FORMAT_RGB565 7
+/* 888s are non-rotated, raster-only */
+# define TXP_FORMAT_BGR888 8
+# define TXP_FORMAT_RGB888 9
+# define TXP_FORMAT_ABGR8888 12
+# define TXP_FORMAT_ARGB8888 13
+# define TXP_FORMAT_BGRA8888 14
+# define TXP_FORMAT_RGBA8888 15
+
+/* If TFORMAT is set, generates LT instead of T format. */
+# define TXP_LINEAR_UTILE BIT(7)
+
+/* Rotate output by 90 degrees. */
+# define TXP_TRANSPOSE BIT(6)
+
+/* Generate a tiled format for V3D. */
+# define TXP_TFORMAT BIT(5)
+
+/* Generates some undefined test mode output. */
+# define TXP_TEST_MODE BIT(4)
+
+/* Request odd field from HVS. */
+# define TXP_FIELD BIT(3)
+
+/* Raise interrupt when idle. */
+# define TXP_EI BIT(2)
+
+/* Set when generating a frame, clears when idle. */
+# define TXP_BUSY BIT(1)
+
+/* Starts a frame. Self-clearing. */
+# define TXP_GO BIT(0)
+
+/* Number of lines received and committed to memory. */
+#define TXP_PROGRESS 0x10
+
+#define TXP_READ(offset) readl(txp->regs + (offset))
+#define TXP_WRITE(offset, val) writel(val, txp->regs + (offset))
+
+struct vc4_txp {
+ struct platform_device *pdev;
+
+ struct drm_writeback_connector connector;
+
+ void __iomem *regs;
+};
+
+static inline struct vc4_txp *connector_to_vc4_txp(struct drm_connector *conn)
+{
+ return container_of(conn, struct vc4_txp, connector.base);
+}
+
+#define TXP_REG(reg) { reg, #reg }
+static const struct {
+ u32 reg;
+ const char *name;
+} txp_regs[] = {
+ TXP_REG(TXP_DST_PTR),
+ TXP_REG(TXP_DST_PITCH),
+ TXP_REG(TXP_DIM),
+ TXP_REG(TXP_DST_CTRL),
+ TXP_REG(TXP_PROGRESS),
+};
+
+#ifdef CONFIG_DEBUG_FS
+int vc4_txp_debugfs_regs(struct seq_file *m, void *unused)
+{
+ struct drm_info_node *node = (struct drm_info_node *)m->private;
+ struct drm_device *dev = node->minor->dev;
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
+ struct vc4_txp *txp = vc4->txp;
+ int i;
+
+ if (!txp)
+ return 0;
+
+ for (i = 0; i < ARRAY_SIZE(txp_regs); i++) {
+ seq_printf(m, "%s (0x%04x): 0x%08x\n",
+ txp_regs[i].name, txp_regs[i].reg,
+ TXP_READ(txp_regs[i].reg));
+ }
+
+ return 0;
+}
+#endif
+
+static int vc4_txp_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
+vc4_txp_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;
+}
+
+static const u32 vc4_txp_formats[] = {
+ DRM_FORMAT_RGB888,
+ DRM_FORMAT_BGR888,
+ DRM_FORMAT_XRGB8888,
+ DRM_FORMAT_XBGR8888,
+ DRM_FORMAT_ARGB8888,
+ DRM_FORMAT_ABGR8888,
+ DRM_FORMAT_RGBX8888,
+ DRM_FORMAT_BGRX8888,
+ DRM_FORMAT_RGBA8888,
+ DRM_FORMAT_BGRA8888,
+};
+
+static int
+vc4_txp_connector_atomic_check(struct drm_connector *connector,
+ struct drm_connector_state *conn_state)
+{
+ struct drm_crtc_state *crtc_state;
+ struct drm_gem_cma_object *gem;
+ struct drm_framebuffer *fb;
+ int i;
+
+ if (!conn_state->crtc)
+ return 0;
+
+ if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
+ return 0;
+
+ crtc_state = drm_atomic_get_crtc_state(conn_state->state,
+ conn_state->crtc);
+ fb = conn_state->writeback_job->fb;
+ 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;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(vc4_txp_formats); i++) {
+ if (fb->format->format == vc4_txp_formats[i])
+ break;
+ }
+
+ if (i == ARRAY_SIZE(vc4_txp_formats))
+ return -EINVAL;
+
+ gem = drm_fb_cma_get_gem_obj(fb, 0);
+
+ /* Pitch must be aligned on 16 bytes. */
+ if (fb->pitches[0] & GENMASK(3, 0))
+ return -EINVAL;
+
+ return 0;
+}
+
+void vc4_txp_atomic_commit(struct drm_device *dev,
+ struct drm_atomic_state *old_state)
+{
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
+ struct vc4_txp *txp = vc4->txp;
+ struct drm_connector_state *conn_state = txp->connector.base.state;
+ struct drm_display_mode *mode;
+ struct drm_gem_cma_object *gem;
+ struct drm_framebuffer *fb;
+ u32 ctrl = TXP_GO | TXP_EI;
+
+ /* Writeback connector is disabled, nothing to do. */
+ if (!conn_state->crtc)
+ return;
+
+ /* Writeback connector is enabled, but has no FB assigned to it. Fake a
+ * vblank event to complete ->flip_done.
+ */
+ if (!conn_state->writeback_job || !conn_state->writeback_job->fb) {
+ vc4_crtc_eof_event(conn_state->crtc);
I'm not sure about hiding away the one-shot thing like this. If the
CRTC remains "active" from the API point of view, I'd expect it to be
able to keep generating VBLANK events.
I don't know how to do if, but if there were some notion of
"auto-disabling" CRTCs then this quirk would go away, and you'd also
be able to enforce that the CRTC can't be enabled without a writeback
framebuffer.
I'm also not sure how (if?) this works today with a CRTC driving a DSI
command-mode panel. Does the CRTC keep generating VBLANKs even when
there are no updates?
+ return;
+ }
+
+ fb = conn_state->writeback_job->fb;
+
+ switch (fb->format->format) {
+ case DRM_FORMAT_ARGB8888:
+ ctrl |= TXP_ALPHA_ENABLE;
+ case DRM_FORMAT_XRGB8888:
+ ctrl |= VC4_SET_FIELD(TXP_FORMAT_ARGB8888, TXP_FORMAT) |
+ VC4_SET_FIELD(0xf, TXP_BYTE_ENABLE);
+ break;
+
+ case DRM_FORMAT_ABGR8888:
+ ctrl |= TXP_ALPHA_ENABLE;
+ case DRM_FORMAT_XBGR8888:
+ ctrl |= VC4_SET_FIELD(TXP_FORMAT_ABGR8888, TXP_FORMAT) |
+ VC4_SET_FIELD(0xf, TXP_BYTE_ENABLE);
+ break;
+
+ case DRM_FORMAT_RGBA8888:
+ ctrl |= TXP_ALPHA_ENABLE;
+ case DRM_FORMAT_RGBX8888:
+ ctrl |= VC4_SET_FIELD(TXP_FORMAT_RGBA8888, TXP_FORMAT) |
+ VC4_SET_FIELD(0xf, TXP_BYTE_ENABLE);
+ break;
+
+ case DRM_FORMAT_BGRA8888:
+ ctrl |= TXP_ALPHA_ENABLE;
+ case DRM_FORMAT_BGRX8888:
+ ctrl |= VC4_SET_FIELD(TXP_FORMAT_BGRA8888, TXP_FORMAT) |
+ VC4_SET_FIELD(0xf, TXP_BYTE_ENABLE);
+ break;
+
+ case DRM_FORMAT_BGR888:
+ ctrl |= VC4_SET_FIELD(TXP_FORMAT_BGR888, TXP_FORMAT) |
+ VC4_SET_FIELD(0xf, TXP_BYTE_ENABLE);
+ break;
+
+ case DRM_FORMAT_RGB888:
+ ctrl |= VC4_SET_FIELD(TXP_FORMAT_RGB888, TXP_FORMAT) |
+ VC4_SET_FIELD(0xf, TXP_BYTE_ENABLE);
+ break;
+ default:
+ WARN_ON(1);
+ return;
+ }
+
+ if (!(ctrl & TXP_ALPHA_ENABLE))
+ ctrl |= TXP_ALPHA_INVERT;
+
+ mode = &conn_state->crtc->state->adjusted_mode;
+ gem = drm_fb_cma_get_gem_obj(fb, 0);
+ TXP_WRITE(TXP_DST_PTR, gem->paddr + fb->offsets[0]);
+ TXP_WRITE(TXP_DST_PITCH, fb->pitches[0]);
+ TXP_WRITE(TXP_DIM,
+ VC4_SET_FIELD(mode->hdisplay, TXP_WIDTH) |
+ VC4_SET_FIELD(mode->vdisplay, TXP_HEIGHT));
+
+ TXP_WRITE(TXP_DST_CTRL, ctrl);
+
+ drm_writeback_queue_job(&txp->connector, conn_state->writeback_job);
+ conn_state->writeback_job = NULL;
+}
+
+bool vc4_is_txp_encoder(struct drm_device *dev, struct drm_encoder *encoder)
+{
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
+
+ return encoder == &vc4->txp->connector.encoder;
+}
+
+static const struct drm_connector_helper_funcs vc4_txp_connector_helper_funcs = {
+ .get_modes = vc4_txp_connector_get_modes,
+ .mode_valid = vc4_txp_connector_mode_valid,
+ .atomic_check = vc4_txp_connector_atomic_check,
huh. This hook didn't exist when I did Mali-DP. I wonder if we should
switch Mali-DP to it too. Do you know if the semantics are any
different from the encoder atomic_check?
Cheers,
-Brian
+};
+
+static enum drm_connector_status
+vc4_txp_connector_detect(struct drm_connector *connector, bool force)
+{
+ return connector_status_disconnected;
+}
+
+static void vc4_txp_connector_destroy(struct drm_connector *connector)
+{
+ drm_connector_unregister(connector);
+ drm_connector_cleanup(connector);
+}
+
+static const struct drm_connector_funcs vc4_txp_connector_funcs = {
+ .dpms = drm_atomic_helper_connector_dpms,
+ .detect = vc4_txp_connector_detect,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .set_property = drm_atomic_helper_connector_set_property,
+ .destroy = vc4_txp_connector_destroy,
+ .reset = drm_atomic_helper_connector_reset,
+ .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static const struct drm_encoder_funcs vc4_txp_encoder_funcs = {
+ .destroy = drm_encoder_cleanup,
+};
+
+static irqreturn_t vc4_txp_interrupt(int irq, void *data)
+{
+ struct vc4_txp *txp = data;
+ struct drm_crtc *crtc = txp->connector.base.state->crtc;
+
+ TXP_WRITE(TXP_DST_CTRL, 0);
+ vc4_crtc_eof_event(crtc);
+ drm_writeback_signal_completion(&txp->connector, 0);
+
+ return IRQ_HANDLED;
+}
+
+static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct drm_device *drm = dev_get_drvdata(master);
+ struct vc4_dev *vc4 = to_vc4_dev(drm);
+ struct vc4_txp *txp;
+ int ret, irq;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ txp = devm_kzalloc(dev, sizeof(*txp), GFP_KERNEL);
+ if (!txp)
+ return -ENOMEM;
+
+ txp->pdev = pdev;
+
+ txp->regs = vc4_ioremap_regs(pdev, 0);
+ if (IS_ERR(txp->regs))
+ return PTR_ERR(txp->regs);
+
+ drm_connector_helper_add(&txp->connector.base,
+ &vc4_txp_connector_helper_funcs);
+ ret = drm_writeback_connector_init(drm, &txp->connector,
+ &vc4_txp_connector_funcs,
+ NULL,
+ vc4_txp_formats,
+ ARRAY_SIZE(vc4_txp_formats));
+ if (ret)
+ return ret;
+
+ ret = devm_request_irq(dev, irq, vc4_txp_interrupt, 0,
+ dev_name(dev), txp);
+ if (ret)
+ return ret;
+
+ dev_set_drvdata(dev, txp);
+ vc4->txp = txp;
+
+ return 0;
+}
+
+static void vc4_txp_unbind(struct device *dev, struct device *master,
+ void *data)
+{
+ struct drm_device *drm = dev_get_drvdata(master);
+ struct vc4_dev *vc4 = to_vc4_dev(drm);
+ struct vc4_txp *txp = dev_get_drvdata(dev);
+
+ vc4_txp_connector_destroy(&txp->connector.base);
+
+ vc4->txp = NULL;
+}
+
+static const struct component_ops vc4_txp_ops = {
+ .bind = vc4_txp_bind,
+ .unbind = vc4_txp_unbind,
+};
+
+static int vc4_txp_dev_probe(struct platform_device *pdev)
+{
+ return component_add(&pdev->dev, &vc4_txp_ops);
+}
+
+static int vc4_txp_dev_remove(struct platform_device *pdev)
+{
+ component_del(&pdev->dev, &vc4_txp_ops);
+ return 0;
+}
+
+static const struct of_device_id vc4_txp_dt_match[] = {
+ { .compatible = "brcm,bcm2835-txp" },
+ { /* sentinel */ },
+};
+
+struct platform_driver vc4_txp_driver = {
+ .probe = vc4_txp_dev_probe,
+ .remove = vc4_txp_dev_remove,
+ .driver = {
+ .name = "vc4_txp",
+ .of_match_table = vc4_txp_dt_match,
+ },
+};
--
2.7.4
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