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Date:   Mon, 28 Aug 2023 13:08:49 +0530
From:   Manivannan Sadhasivam <mani@kernel.org>
To:     Nitin Rawat <quic_nitirawa@quicinc.com>
Cc:     agross@kernel.org, andersson@kernel.org, konrad.dybcio@linaro.org,
        jejb@linux.ibm.com, martin.petersen@oracle.com,
        quic_cang@quicinc.com, quic_nguyenb@quicinc.com,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org,
        Naveen Kumar Goud Arepalli <quic_narepall@quicinc.com>
Subject: Re: [PATCH V5 1/6] scsi: ufs: qcom: Update offset for
 core_clk_1us_cycles
Message-ID: <20230828073849.GB5148@thinkpad>
References: <20230823154413.23788-1-quic_nitirawa@quicinc.com>
 <20230823154413.23788-2-quic_nitirawa@quicinc.com>
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In-Reply-To: <20230823154413.23788-2-quic_nitirawa@quicinc.com>
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On Wed, Aug 23, 2023 at 09:14:08PM +0530, Nitin Rawat wrote:
> This Patch updates offset for core_clk_1us_cycles in DME_VS_CORE_CLK_CTRL

Please do not use "This patch" in commit message. Just reword it in imperative
form.

> register. Offset for core_clk_1us_cycles is changed from Qualcomm UFS
> Controller V4.0.0 onwards.
> 
> Co-developed-by: Naveen Kumar Goud Arepalli <quic_narepall@quicinc.com>
> Signed-off-by: Naveen Kumar Goud Arepalli <quic_narepall@quicinc.com>
> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
> ---
>  drivers/ufs/host/ufs-qcom.c | 19 ++++++++++++++-----
>  drivers/ufs/host/ufs-qcom.h |  2 ++
>  2 files changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
> index f88febb23123..1108b0cd43b3 100644
> --- a/drivers/ufs/host/ufs-qcom.c
> +++ b/drivers/ufs/host/ufs-qcom.c
> @@ -1297,12 +1297,21 @@ static void ufs_qcom_exit(struct ufs_hba *hba)
>  }
> 
>  static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
> -						       u32 clk_cycles)
> +						       u32 clk_1us_cycles)

How about "cycles_in_1us", since this value specifies "Number of clk cycles in
1us"?

>  {
> -	int err;
> +	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> +	u32 mask = DME_VS_CORE_CLK_CTRL_MAX_CORE_CLK_1US_CYCLES_MASK;
>  	u32 core_clk_ctrl_reg;
> +	u32 offset = 0;
> +	int err;
> +
> +	/* Bit mask and offset changed on UFS host controller V4.0.0 onwards */

This is not offset value, but rather shift. Still, if you use bitfield macros
as I suggested below, you could get rid of this variable.

> +	if (host->hw_ver.major >= 4) {
> +		mask = MAX_CORE_CLK_1US_CYCLES_MASK_V4;
> +		offset = MAX_CORE_CLK_1US_CYCLES_OFFSET_V4;
> +	}
> 
> -	if (clk_cycles > DME_VS_CORE_CLK_CTRL_MAX_CORE_CLK_1US_CYCLES_MASK)
> +	if (clk_1us_cycles > mask)
>  		return -EINVAL;

	if (!FIELD_FIT(mask, cycles_in_1us))
		return -ERANGE;

> 
>  	err = ufshcd_dme_get(hba,
> @@ -1311,8 +1320,8 @@ static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
>  	if (err)
>  		return err;
> 
> -	core_clk_ctrl_reg &= ~DME_VS_CORE_CLK_CTRL_MAX_CORE_CLK_1US_CYCLES_MASK;
> -	core_clk_ctrl_reg |= clk_cycles;
> +	core_clk_ctrl_reg &= ~(mask << offset);
> +	core_clk_ctrl_reg |= clk_1us_cycles << offset;
> 

	core_clk_ctrl_reg &= ~mask;
	core_clk_ctrl_reg |= FIELD_PREP(mask, cycles_in_1us);

>  	/* Clear CORE_CLK_DIV_EN */
>  	core_clk_ctrl_reg &= ~DME_VS_CORE_CLK_CTRL_CORE_CLK_DIV_EN_BIT;
> diff --git a/drivers/ufs/host/ufs-qcom.h b/drivers/ufs/host/ufs-qcom.h
> index d6f8e74bd538..a829296e11bb 100644
> --- a/drivers/ufs/host/ufs-qcom.h
> +++ b/drivers/ufs/host/ufs-qcom.h
> @@ -129,6 +129,8 @@ enum {
>  #define PA_VS_CONFIG_REG1	0x9000
>  #define DME_VS_CORE_CLK_CTRL	0xD002
>  /* bit and mask definitions for DME_VS_CORE_CLK_CTRL attribute */

> +#define MAX_CORE_CLK_1US_CYCLES_MASK_V4		0xFFF

#define MAX_CORE_CLK_1US_CYCLES_MASK_V4				GENMASK(27, 16)
#define DME_VS_CORE_CLK_CTRL_MAX_CORE_CLK_1US_CYCLES_MASK	GENMASK(7, 0)

- Mani

> +#define MAX_CORE_CLK_1US_CYCLES_OFFSET_V4	0x10
>  #define DME_VS_CORE_CLK_CTRL_CORE_CLK_DIV_EN_BIT		BIT(8)
>  #define DME_VS_CORE_CLK_CTRL_MAX_CORE_CLK_1US_CYCLES_MASK	0xFF
> 
> --
> 2.17.1
> 

-- 
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