[PATCH] drm/msm/mdp5: high precision vblank timestamp support
Rob Clark
robdclark at gmail.com
Mon Oct 26 17:03:24 PDT 2015
On Mon, Oct 26, 2015 at 5:54 AM, Archit Taneja <architt at codeaurora.org> wrote:
> MDP5 has line count and frame count registers for each interface. Enable
> these counters and use them to implement the get_vblank_timestamp drm
> driver op.
>
> The line counter starts with the value 1 at the beginning of the VSYNC
> pulse and ends with value VTOTAL at the end of VFP. This value is used
> to determine whether we're in blanking period or not, and an adjusted
> value of this counter is used to get vpos as expected by
> get_scanout_position. Since there is no way to calculate hpos, we always
> set it to 0.
What are the odds that mdp(n!=5) could support the same? If/when that
ever happens I could see making some of this helpers to duplicate a
bit less in mdpN backend.. but I guess also fine to cross that bridge
when we come to it. Other than that, lgtm, thanks
BR,
-R
> Signed-off-by: Archit Taneja <architt at codeaurora.org>
> ---
> drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c | 18 ++++
> drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c | 129 ++++++++++++++++++++++++++++
> drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h | 2 +
> 3 files changed, 149 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
> index c9e32b0..a019656 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
> @@ -293,6 +293,24 @@ static const struct drm_encoder_helper_funcs mdp5_encoder_helper_funcs = {
> .enable = mdp5_encoder_enable,
> };
>
> +int mdp5_encoder_get_linecount(struct drm_encoder *encoder)
> +{
> + struct mdp5_encoder *mdp5_encoder = to_mdp5_encoder(encoder);
> + struct mdp5_kms *mdp5_kms = get_kms(encoder);
> + int intf = mdp5_encoder->intf.num;
> +
> + return mdp5_read(mdp5_kms, REG_MDP5_INTF_LINE_COUNT(intf));
> +}
> +
> +u32 mdp5_encoder_get_framecount(struct drm_encoder *encoder)
> +{
> + struct mdp5_encoder *mdp5_encoder = to_mdp5_encoder(encoder);
> + struct mdp5_kms *mdp5_kms = get_kms(encoder);
> + int intf = mdp5_encoder->intf.num;
> +
> + return mdp5_read(mdp5_kms, REG_MDP5_INTF_FRAME_COUNT(intf));
> +}
> +
> int mdp5_encoder_set_split_display(struct drm_encoder *encoder,
> struct drm_encoder *slave_encoder)
> {
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
> index b532faa..e115318 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
> @@ -468,6 +468,127 @@ static int get_clk(struct platform_device *pdev, struct clk **clkp,
> return 0;
> }
>
> +static struct drm_encoder *get_encoder_from_crtc(struct drm_crtc *crtc)
> +{
> + struct drm_device *dev = crtc->dev;
> + struct drm_encoder *encoder;
> +
> + drm_for_each_encoder(encoder, dev)
> + if (encoder->crtc == crtc)
> + return encoder;
> +
> + return NULL;
> +}
> +
> +static int mdp5_get_scanoutpos(struct drm_device *dev, unsigned int pipe,
> + unsigned int flags, int *vpos, int *hpos,
> + ktime_t *stime, ktime_t *etime,
> + const struct drm_display_mode *mode)
> +{
> + struct msm_drm_private *priv = dev->dev_private;
> + struct drm_crtc *crtc;
> + struct drm_encoder *encoder;
> + int line, vsw, vbp, vactive_start, vactive_end, vfp_end;
> + int ret = 0;
> +
> + crtc = priv->crtcs[pipe];
> + if (!crtc) {
> + DRM_ERROR("Invalid crtc %d\n", pipe);
> + return 0;
> + }
> +
> + encoder = get_encoder_from_crtc(crtc);
> + if (!encoder) {
> + DRM_ERROR("no encoder found for crtc %d\n", pipe);
> + return 0;
> + }
> +
> + ret |= DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE;
> +
> + vsw = mode->crtc_vsync_end - mode->crtc_vsync_start;
> + vbp = mode->crtc_vtotal - mode->crtc_vsync_end;
> +
> + /*
> + * the line counter is 1 at the start of the VSYNC pulse and VTOTAL at
> + * the end of VFP. Translate the porch values relative to the line
> + * counter positions.
> + */
> +
> + vactive_start = vsw + vbp + 1;
> +
> + vactive_end = vactive_start + mode->crtc_vdisplay;
> +
> + /* last scan line before VSYNC */
> + vfp_end = mode->crtc_vtotal;
> +
> + if (stime)
> + *stime = ktime_get();
> +
> + line = mdp5_encoder_get_linecount(encoder);
> +
> + if (line < vactive_start) {
> + line -= vactive_start;
> + ret |= DRM_SCANOUTPOS_IN_VBLANK;
> + } else if (line > vactive_end) {
> + line = line - vfp_end - vactive_start;
> + ret |= DRM_SCANOUTPOS_IN_VBLANK;
> + } else {
> + line -= vactive_start;
> + }
> +
> + *vpos = line;
> + *hpos = 0;
> +
> + if (etime)
> + *etime = ktime_get();
> +
> + return ret;
> +}
> +
> +static int mdp5_get_vblank_timestamp(struct drm_device *dev, unsigned int pipe,
> + int *max_error,
> + struct timeval *vblank_time,
> + unsigned flags)
> +{
> + struct msm_drm_private *priv = dev->dev_private;
> + struct drm_crtc *crtc;
> +
> + if (pipe < 0 || pipe >= priv->num_crtcs) {
> + DRM_ERROR("Invalid crtc %d\n", pipe);
> + return -EINVAL;
> + }
> +
> + crtc = priv->crtcs[pipe];
> + if (!crtc) {
> + DRM_ERROR("Invalid crtc %d\n", pipe);
> + return -EINVAL;
> + }
> +
> + return drm_calc_vbltimestamp_from_scanoutpos(dev, pipe, max_error,
> + vblank_time, flags,
> + &crtc->mode);
> +}
> +
> +static u32 mdp5_get_vblank_counter(struct drm_device *dev, unsigned int pipe)
> +{
> + struct msm_drm_private *priv = dev->dev_private;
> + struct drm_crtc *crtc;
> + struct drm_encoder *encoder;
> +
> + if (pipe < 0 || pipe >= priv->num_crtcs)
> + return 0;
> +
> + crtc = priv->crtcs[pipe];
> + if (!crtc)
> + return 0;
> +
> + encoder = get_encoder_from_crtc(crtc);
> + if (!encoder)
> + return 0;
> +
> + return mdp5_encoder_get_framecount(encoder);
> +}
> +
> struct msm_kms *mdp5_kms_init(struct drm_device *dev)
> {
> struct platform_device *pdev = dev->platformdev;
> @@ -590,6 +711,8 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
> !config->hw->intf.base[i])
> continue;
> mdp5_write(mdp5_kms, REG_MDP5_INTF_TIMING_ENGINE_EN(i), 0);
> +
> + mdp5_write(mdp5_kms, REG_MDP5_INTF_FRAME_LINE_COUNT_EN(i), 0x3);
> }
> mdp5_disable(mdp5_kms);
> mdelay(16);
> @@ -635,6 +758,12 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
> dev->mode_config.max_width = config->hw->lm.max_width;
> dev->mode_config.max_height = config->hw->lm.max_height;
>
> + dev->driver->get_vblank_timestamp = mdp5_get_vblank_timestamp;
> + dev->driver->get_scanout_position = mdp5_get_scanoutpos;
> + dev->driver->get_vblank_counter = mdp5_get_vblank_counter;
> + dev->max_vblank_count = 0xffffffff;
> + dev->vblank_disable_immediate = true;
> +
> return kms;
>
> fail:
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
> index 84f65d4..00730ba 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
> @@ -222,6 +222,8 @@ struct drm_encoder *mdp5_encoder_init(struct drm_device *dev,
> struct mdp5_interface *intf, struct mdp5_ctl *ctl);
> int mdp5_encoder_set_split_display(struct drm_encoder *encoder,
> struct drm_encoder *slave_encoder);
> +int mdp5_encoder_get_linecount(struct drm_encoder *encoder);
> +u32 mdp5_encoder_get_framecount(struct drm_encoder *encoder);
>
> #ifdef CONFIG_DRM_MSM_DSI
> struct drm_encoder *mdp5_cmd_encoder_init(struct drm_device *dev,
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> hosted by The Linux Foundation
>
More information about the dri-devel
mailing list