From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Date: Wed, 18 Jan 2023 10:16:50 +0200

Subject: [PATCH] drm/bridge: lt9611: fix clock calculation

References: bsc#1012628

Patch-mainline: 6.2.3

Git-commit: 2576eb26494eb0509dd9ceb0cd27771a7a5e3674

[ Upstream commit 2576eb26494eb0509dd9ceb0cd27771a7a5e3674 ]

Instead of having several fixed values for the pcr register, calculate

it before programming. This allows the bridge to support most of the

display modes.

Fixes: 23278bf54afe ("drm/bridge: Introduce LT9611 DSI to HDMI bridge")

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

Link: https://patchwork.freedesktop.org/patch/msgid/20230118081658.2198520-6-dmitry.baryshkov@linaro.org

Signed-off-by: Sasha Levin <sashal@kernel.org>

Signed-off-by: Jiri Slaby <jslaby@suse.cz>

---

 drivers/gpu/drm/bridge/lontium-lt9611.c | 32 +++++++++++--------------

 1 file changed, 14 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c

index f377052a..e2799a0d 100644

--- a/drivers/gpu/drm/bridge/lontium-lt9611.c

+++ b/drivers/gpu/drm/bridge/lontium-lt9611.c

@@ -192,8 +192,9 @@ static void lt9611_mipi_video_setup(struct lt9611 *lt9611,

 	regmap_write(lt9611->regmap, 0x831b, (u8)(hsync_porch % 256));

 }

-static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mode *mode)

+static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mode *mode, unsigned int postdiv)

 {

+	unsigned int pcr_m = mode->clock * 5 * postdiv / 27000;

 	const struct reg_sequence reg_cfg[] = {

 		{ 0x830b, 0x01 },

 		{ 0x830c, 0x10 },

@@ -236,24 +237,14 @@ static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mod

 	else

 		regmap_multi_reg_write(lt9611->regmap, reg_cfg, ARRAY_SIZE(reg_cfg));

-	switch (mode->hdisplay) {

-	case 640:

-		regmap_write(lt9611->regmap, 0x8326, 0x14);

-		break;

-	case 1920:

-		regmap_write(lt9611->regmap, 0x8326, 0x37);

-		break;

-	case 3840:

-		regmap_write(lt9611->regmap, 0x8326, 0x37);

-		break;

-	}

+	regmap_write(lt9611->regmap, 0x8326, pcr_m);

 	/* pcr rst */

 	regmap_write(lt9611->regmap, 0x8011, 0x5a);

 	regmap_write(lt9611->regmap, 0x8011, 0xfa);

 }

-static int lt9611_pll_setup(struct lt9611 *lt9611, const struct drm_display_mode *mode)

+static int lt9611_pll_setup(struct lt9611 *lt9611, const struct drm_display_mode *mode, unsigned int *postdiv)

 {

 	unsigned int pclk = mode->clock;

 	const struct reg_sequence reg_cfg[] = {

@@ -271,12 +262,16 @@ static int lt9611_pll_setup(struct lt9611 *lt9611, const struct drm_display_mode

 	regmap_multi_reg_write(lt9611->regmap, reg_cfg, ARRAY_SIZE(reg_cfg));

-	if (pclk > 150000)

+	if (pclk > 150000) {

 		regmap_write(lt9611->regmap, 0x812d, 0x88);

-	else if (pclk > 70000)

+		*postdiv = 1;

+	} else if (pclk > 70000) {

 		regmap_write(lt9611->regmap, 0x812d, 0x99);

-	else

+		*postdiv = 2;

+	} else {

 		regmap_write(lt9611->regmap, 0x812d, 0xaa);

+		*postdiv = 4;

+	}

 	/*

 	 * first divide pclk by 2 first

@@ -895,14 +890,15 @@ static void lt9611_bridge_mode_set(struct drm_bridge *bridge,

 {

 	struct lt9611 *lt9611 = bridge_to_lt9611(bridge);

 	struct hdmi_avi_infoframe avi_frame;

+	unsigned int postdiv;

 	int ret;

 	lt9611_bridge_pre_enable(bridge);

 	lt9611_mipi_input_digital(lt9611, mode);

-	lt9611_pll_setup(lt9611, mode);

+	lt9611_pll_setup(lt9611, mode, &postdiv);

 	lt9611_mipi_video_setup(lt9611, mode);

-	lt9611_pcr_setup(lt9611, mode);

+	lt9611_pcr_setup(lt9611, mode, postdiv);

 	ret = drm_hdmi_avi_infoframe_from_display_mode(&avi_frame,

 						       &lt9611->connector,

-- 

2.35.3