linux-kernel - [PATCH v4 3/4] drm/msm/dsi/phy: Do not overwite PHY_CMN_CLK

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Message-Id: <20250217-drm-msm-phy-pll-cfg-reg-v4-3-106b0d1df51e@linaro.org>
Date: Mon, 17 Feb 2025 12:53:16 +0100
From: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To: Rob Clark <robdclark@...il.com>, 
 Abhinav Kumar <quic_abhinavk@...cinc.com>, 
 Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, Sean Paul <sean@...rly.run>, 
 Marijn Suijten <marijn.suijten@...ainline.org>, 
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
 Jonathan Marek <jonathan@...ek.ca>
Cc: linux-arm-msm@...r.kernel.org, dri-devel@...ts.freedesktop.org, 
 freedreno@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
 Rob Clark <robdclark@...omium.org>, 
 Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
Subject: [PATCH v4 3/4] drm/msm/dsi/phy: Do not overwite PHY_CMN_CLK_CFG1
 when choosing bitclk source

PHY_CMN_CLK_CFG1 register has four fields being used in the driver: DSI
clock divider, source of bitclk and two for enabling the DSI PHY PLL
clocks.

dsi_7nm_set_usecase() sets only the source of bitclk, so should leave
all other bits untouched.  Use newly introduced
dsi_pll_cmn_clk_cfg1_update() to update respective bits without
overwriting the rest.

While shuffling the code, define and use PHY_CMN_CLK_CFG1 bitfields to
make the code more readable and obvious.

Fixes: 1ef7c99d145c ("drm/msm/dsi: add support for 7nm DSI PHY/PLL")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@...cinc.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
---

Changes in v3:
1. Define bitfields (move here parts from patch #4)
---
 drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c             | 4 ++--
 drivers/gpu/drm/msm/registers/display/dsi_phy_7nm.xml | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
index 388017db45d802c4ef1299296f932c4182512aae..798168180c1ab6c96ec2384f854302720cb27932 100644
--- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
+++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
@@ -617,7 +617,6 @@ static int dsi_7nm_pll_restore_state(struct msm_dsi_phy *phy)
 static int dsi_7nm_set_usecase(struct msm_dsi_phy *phy)
 {
 	struct dsi_pll_7nm *pll_7nm = to_pll_7nm(phy->vco_hw);
-	void __iomem *base = phy->base;
 	u32 data = 0x0;	/* internal PLL */
 
 	DBG("DSI PLL%d", pll_7nm->phy->id);
@@ -636,7 +635,8 @@ static int dsi_7nm_set_usecase(struct msm_dsi_phy *phy)
 	}
 
 	/* set PLL src */
-	writel(data << 2, base + REG_DSI_7nm_PHY_CMN_CLK_CFG1);
+	dsi_pll_cmn_clk_cfg1_update(pll_7nm, DSI_7nm_PHY_CMN_CLK_CFG1_BITCLK_SEL__MASK,
+				    DSI_7nm_PHY_CMN_CLK_CFG1_BITCLK_SEL(data));
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/msm/registers/display/dsi_phy_7nm.xml b/drivers/gpu/drm/msm/registers/display/dsi_phy_7nm.xml
index cfaf78c028b1325682889a5c2d8fffd0268122cf..35f7f40e405b7dd9687725eae754522a7136725e 100644
--- a/drivers/gpu/drm/msm/registers/display/dsi_phy_7nm.xml
+++ b/drivers/gpu/drm/msm/registers/display/dsi_phy_7nm.xml
@@ -16,6 +16,7 @@ xsi:schemaLocation="https://gitlab.freedesktop.org/freedreno/ rules-fd.xsd">
 	<reg32 offset="0x00014" name="CLK_CFG1">
 		<bitfield name="CLK_EN" pos="5" type="boolean"/>
 		<bitfield name="CLK_EN_SEL" pos="4" type="boolean"/>
+		<bitfield name="BITCLK_SEL" low="2" high="3" type="uint"/>
 	</reg32>
 	<reg32 offset="0x00018" name="GLBL_CTRL"/>
 	<reg32 offset="0x0001c" name="RBUF_CTRL"/>

-- 
2.43.0