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From:   Jessica Zhang <quic_jesszhan@quicinc.com>
Date:   Fri, 19 May 2023 14:17:27 -0700
Subject: [PATCH v3 2/5] drm/msm/dsi: Adjust pclk rate for compression
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Message-ID: <20230405-add-dsc-support-v3-2-6e1d35a206b3@quicinc.com>
References: <20230405-add-dsc-support-v3-0-6e1d35a206b3@quicinc.com>
In-Reply-To: <20230405-add-dsc-support-v3-0-6e1d35a206b3@quicinc.com>
To:     Rob Clark <robdclark@gmail.com>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Marijn Suijten <marijn.suijten@somainline.org>
CC:     Konrad Dybcio <konrad.dybcio@linaro.org>,
        <linux-arm-msm@vger.kernel.org>, <dri-devel@lists.freedesktop.org>,
        <freedreno@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>,
        Jessica Zhang <quic_jesszhan@quicinc.com>
Precedence: bulk

Adjust the pclk rate to divide hdisplay by the compression ratio when DSC
is enabled.

Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
---
 drivers/gpu/drm/msm/dsi/dsi_host.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 18d38b90eb28..d04f8bbd707d 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -561,7 +561,18 @@ void dsi_link_clk_disable_v2(struct msm_dsi_host *msm_host)
 	clk_disable_unprepare(msm_host->byte_clk);
 }
 
-static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode, bool is_bonded_dsi)
+static unsigned long dsi_adjust_compressed_pclk(const struct drm_display_mode *mode,
+		const struct drm_dsc_config *dsc)
+{
+	int new_hdisplay = DIV_ROUND_UP(mode->hdisplay * drm_dsc_get_bpp_int(dsc),
+			dsc->bits_per_component * 3);
+
+	return (new_hdisplay + (mode->htotal - mode->hdisplay))
+			* mode->vtotal * drm_mode_vrefresh(mode);
+}
+
+static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode,
+		const struct drm_dsc_config *dsc, bool is_bonded_dsi)
 {
 	unsigned long pclk_rate;
 
@@ -576,6 +587,10 @@ static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode, bool
 	if (is_bonded_dsi)
 		pclk_rate /= 2;
 
+	/* If DSC is enabled, divide hdisplay by compression ratio */
+	if (dsc)
+		pclk_rate = dsi_adjust_compressed_pclk(mode, dsc);
+
 	return pclk_rate;
 }
 
@@ -585,7 +600,7 @@ unsigned long dsi_byte_clk_get_rate(struct mipi_dsi_host *host, bool is_bonded_d
 	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
 	u8 lanes = msm_host->lanes;
 	u32 bpp = dsi_get_bpp(msm_host->format);
-	unsigned long pclk_rate = dsi_get_pclk_rate(mode, is_bonded_dsi);
+	unsigned long pclk_rate = dsi_get_pclk_rate(mode, msm_host->dsc, is_bonded_dsi);
 	u64 pclk_bpp = (u64)pclk_rate * bpp;
 
 	if (lanes == 0) {
@@ -604,7 +619,7 @@ unsigned long dsi_byte_clk_get_rate(struct mipi_dsi_host *host, bool is_bonded_d
 
 static void dsi_calc_pclk(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
 {
-	msm_host->pixel_clk_rate = dsi_get_pclk_rate(msm_host->mode, is_bonded_dsi);
+	msm_host->pixel_clk_rate = dsi_get_pclk_rate(msm_host->mode, msm_host->dsc, is_bonded_dsi);
 	msm_host->byte_clk_rate = dsi_byte_clk_get_rate(&msm_host->base, is_bonded_dsi,
 							msm_host->mode);
 
@@ -634,7 +649,7 @@ int dsi_calc_clk_rate_v2(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
 
 	dsi_calc_pclk(msm_host, is_bonded_dsi);
 
-	pclk_bpp = (u64)dsi_get_pclk_rate(msm_host->mode, is_bonded_dsi) * bpp;
+	pclk_bpp = (u64)dsi_get_pclk_rate(msm_host->mode, msm_host->dsc, is_bonded_dsi) * bpp;
 	do_div(pclk_bpp, 8);
 	msm_host->src_clk_rate = pclk_bpp;
 

-- 
2.40.1