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-rw-r--r--drivers/gpu/drm/i915/i915_irq.c54
-rw-r--r--drivers/gpu/drm/i915/i915_reg.h9
-rw-r--r--drivers/gpu/drm/i915/intel_drv.h2
-rw-r--r--drivers/gpu/drm/i915/intel_dsi.c8
4 files changed, 73 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 6a07ef38fb47..0b7562135d1c 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -783,6 +783,57 @@ static u32 g4x_get_vblank_counter(struct drm_device *dev, unsigned int pipe)
return I915_READ(PIPE_FRMCOUNT_G4X(pipe));
}
+/*
+ * On certain encoders on certain platforms, pipe
+ * scanline register will not work to get the scanline,
+ * since the timings are driven from the PORT or issues
+ * with scanline register updates.
+ * This function will use Framestamp and current
+ * timestamp registers to calculate the scanline.
+ */
+static u32 __intel_get_crtc_scanline_from_timestamp(struct intel_crtc *crtc)
+{
+ struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+ struct drm_vblank_crtc *vblank =
+ &crtc->base.dev->vblank[drm_crtc_index(&crtc->base)];
+ const struct drm_display_mode *mode = &vblank->hwmode;
+ u32 vblank_start = mode->crtc_vblank_start;
+ u32 vtotal = mode->crtc_vtotal;
+ u32 htotal = mode->crtc_htotal;
+ u32 clock = mode->crtc_clock;
+ u32 scanline, scan_prev_time, scan_curr_time, scan_post_time;
+
+ /*
+ * To avoid the race condition where we might cross into the
+ * next vblank just between the PIPE_FRMTMSTMP and TIMESTAMP_CTR
+ * reads. We make sure we read PIPE_FRMTMSTMP and TIMESTAMP_CTR
+ * during the same frame.
+ */
+ do {
+ /*
+ * This field provides read back of the display
+ * pipe frame time stamp. The time stamp value
+ * is sampled at every start of vertical blank.
+ */
+ scan_prev_time = I915_READ_FW(PIPE_FRMTMSTMP(crtc->pipe));
+
+ /*
+ * The TIMESTAMP_CTR register has the current
+ * time stamp value.
+ */
+ scan_curr_time = I915_READ_FW(IVB_TIMESTAMP_CTR);
+
+ scan_post_time = I915_READ_FW(PIPE_FRMTMSTMP(crtc->pipe));
+ } while (scan_post_time != scan_prev_time);
+
+ scanline = div_u64(mul_u32_u32(scan_curr_time - scan_prev_time,
+ clock), 1000 * htotal);
+ scanline = min(scanline, vtotal - 1);
+ scanline = (scanline + vblank_start) % vtotal;
+
+ return scanline;
+}
+
/* I915_READ_FW, only for fast reads of display block, no need for forcewake etc. */
static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
{
@@ -799,6 +850,9 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
vblank = &crtc->base.dev->vblank[drm_crtc_index(&crtc->base)];
mode = &vblank->hwmode;
+ if (mode->private_flags & I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP)
+ return __intel_get_crtc_scanline_from_timestamp(crtc);
+
vtotal = mode->crtc_vtotal;
if (mode->flags & DRM_MODE_FLAG_INTERLACE)
vtotal /= 2;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 82f36dd0cd94..76fd8fda46d2 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8808,6 +8808,15 @@ enum skl_power_gate {
#define MIPIO_TXESC_CLK_DIV2 _MMIO(0x160008)
#define GLK_TX_ESC_CLK_DIV2_MASK 0x3FF
+/* Gen4+ Timestamp and Pipe Frame time stamp registers */
+#define GEN4_TIMESTAMP _MMIO(0x2358)
+#define ILK_TIMESTAMP_HI _MMIO(0x70070)
+#define IVB_TIMESTAMP_CTR _MMIO(0x44070)
+
+#define _PIPE_FRMTMSTMP_A 0x70048
+#define PIPE_FRMTMSTMP(pipe) \
+ _MMIO_PIPE2(pipe, _PIPE_FRMTMSTMP_A)
+
/* BXT MIPI clock controls */
#define BXT_MAX_VAR_OUTPUT_KHZ 39500
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 64358d2f2422..0cab667fff57 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -494,6 +494,8 @@ struct intel_crtc_scaler_state {
/* drm_mode->private_flags */
#define I915_MODE_FLAG_INHERITED 1
+/* Flag to get scanline using frame time stamps */
+#define I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP (1<<1)
struct intel_pipe_wm {
struct intel_wm_level wm[5];
diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index 578254ac799c..20a7b004ffd7 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -330,6 +330,10 @@ static bool intel_dsi_compute_config(struct intel_encoder *encoder,
adjusted_mode->flags = 0;
if (IS_GEN9_LP(dev_priv)) {
+ /* Enable Frame time stamp based scanline reporting */
+ adjusted_mode->private_flags |=
+ I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP;
+
/* Dual link goes to DSI transcoder A. */
if (intel_dsi->ports == BIT(PORT_C))
pipe_config->cpu_transcoder = TRANSCODER_DSI_C;
@@ -1102,6 +1106,10 @@ static void bxt_dsi_get_pipe_config(struct intel_encoder *encoder,
pixel_format_from_register_bits(fmt));
bpp = pipe_config->pipe_bpp;
+ /* Enable Frame time stamo based scanline reporting */
+ adjusted_mode->private_flags |=
+ I915_MODE_FLAG_GET_SCANLINE_FROM_TIMESTAMP;
+
/* In terms of pixels */
adjusted_mode->crtc_hdisplay =
I915_READ(BXT_MIPI_TRANS_HACTIVE(port));