Re: [PATCH 1/3] phy: qcom-qusb2: Allow specifying default clock scheme

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Thu 14 Jan 11:47 CST 2021, AngeloGioacchino Del Regno wrote:

> The TCSR's PHY_CLK_SCHEME register is not available on all SoC
> models, but some may still use a differential reference clock.
> 
> In preparation for these SoCs, add a se_clk_scheme_default
> configuration entry and declare it to true for all currently
> supported SoCs (retaining the previous defaults.
> 
> This patch brings no functional changes.
> 

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
> ---
>  drivers/phy/qualcomm/phy-qcom-qusb2.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qusb2.c b/drivers/phy/qualcomm/phy-qcom-qusb2.c
> index 109792203baf..8fcfea2a8f1f 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qusb2.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qusb2.c
> @@ -245,6 +245,9 @@ struct qusb2_phy_cfg {
>  
>  	/* true if PHY has PLL_CORE_INPUT_OVERRIDE register to reset PLL */
>  	bool has_pll_override;
> +
> +	/* true if PHY default clk scheme is single-ended */
> +	bool se_clk_scheme_default;
>  };
>  
>  static const struct qusb2_phy_cfg msm8996_phy_cfg = {
> @@ -253,6 +256,7 @@ static const struct qusb2_phy_cfg msm8996_phy_cfg = {
>  	.regs		= msm8996_regs_layout,
>  
>  	.has_pll_test	= true,
> +	.se_clk_scheme_default = true,
>  	.disable_ctrl	= (CLAMP_N_EN | FREEZIO_N | POWER_DOWN),
>  	.mask_core_ready = PLL_LOCKED,
>  	.autoresume_en	 = BIT(3),
> @@ -266,6 +270,7 @@ static const struct qusb2_phy_cfg msm8998_phy_cfg = {
>  	.disable_ctrl   = POWER_DOWN,
>  	.mask_core_ready = CORE_READY_STATUS,
>  	.has_pll_override = true,
> +	.se_clk_scheme_default = true,
>  	.autoresume_en   = BIT(0),
>  	.update_tune1_with_efuse = true,
>  };
> @@ -279,6 +284,7 @@ static const struct qusb2_phy_cfg qusb2_v2_phy_cfg = {
>  			   POWER_DOWN),
>  	.mask_core_ready = CORE_READY_STATUS,
>  	.has_pll_override = true,
> +	.se_clk_scheme_default = true,
>  	.autoresume_en	  = BIT(0),
>  	.update_tune1_with_efuse = true,
>  };
> @@ -701,8 +707,13 @@ static int qusb2_phy_init(struct phy *phy)
>  	/* Required to get phy pll lock successfully */
>  	usleep_range(150, 160);
>  
> -	/* Default is single-ended clock on msm8996 */
> -	qphy->has_se_clk_scheme = true;
> +	/*
> +	 * Not all the SoCs have got a readable TCSR_PHY_CLK_SCHEME
> +	 * register in the TCSR so, if there's none, use the default
> +	 * value hardcoded in the configuration.
> +	 */
> +	qphy->has_se_clk_scheme = cfg->se_clk_scheme_default;
> +
>  	/*
>  	 * read TCSR_PHY_CLK_SCHEME register to check if single-ended
>  	 * clock scheme is selected. If yes, then disable differential
> -- 
> 2.29.2
>