Re: [PATCH v2 3/4] drm/msm/dsi/phy: Do not overwite PHY_CMN_CLK_CFG1 when choosing bitclk source

From: Dmitry Baryshkov
Date: Mon Feb 03 2025 - 12:41:02 EST


On Mon, Feb 03, 2025 at 06:29:20PM +0100, Krzysztof Kozlowski wrote:
> 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.
>
> Fixes: 1ef7c99d145c ("drm/msm/dsi: add support for 7nm DSI PHY/PLL")
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c | 3 +--
> 1 file changed, 1 insertion(+), 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 e26f53f7cde8f0f6419a633f5d39784dc2e5bb98..926fd8e3330b2cdfc69d1e0e5d3930abae77b7d8 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
> @@ -616,7 +616,6 @@ 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);
> @@ -635,7 +634,7 @@ 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, GENMASK(3, 2), data << 2);

The mask is not defined, still.

>
> return 0;
> }
>
> --
> 2.43.0
>

--
With best wishes
Dmitry