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Subject: Re: [PATCH V2 2/3] scsi: ufs: add a vops to configure VCC voltage
 level
To:     Nitin Rawat <nitirawa@codeaurora.org>, cang@codeaurora.org,
        stummala@codeaurora.org, vbadigan@codeaurora.org,
        alim.akhtar@samsung.com, avri.altman@wdc.com, jejb@linux.ibm.com,
        martin.petersen@oracle.com, stanley.chu@mediatek.com,
        beanhuo@micron.com, bjorn.andersson@linaro.org,
        adrian.hunter@intel.com, bvanassche@acm.org
Cc:     linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
References: <1616363857-26760-1-git-send-email-nitirawa@codeaurora.org>
 <1616363857-26760-3-git-send-email-nitirawa@codeaurora.org>
From:   "Asutosh Das (asd)" <asutoshd@codeaurora.org>
Message-ID: <80f681a6-165f-0610-dfea-6b66ce4abddc@codeaurora.org>
Date:   Wed, 31 Mar 2021 11:00:07 -0700
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On 3/21/2021 2:57 PM, Nitin Rawat wrote:
> Add a vops to configure VCC voltage VCC voltage level
> for platform supporting both ufs2.x and ufs 3.x devices.
> 
> Suggested-by: Stanley Chu <stanley.chu@mediatek.com>
> Suggested-by: Asutosh Das <asutoshd@codeaurora.org>
> Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> Signed-off-by: Nitin Rawat <nitirawa@codeaurora.org>
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
> ---
>   drivers/scsi/ufs/ufshcd.c |  4 ++++
>   drivers/scsi/ufs/ufshcd.h | 10 ++++++++++
>   2 files changed, 14 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 633ca8e..5bfe987 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -7763,6 +7763,10 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
>   		goto out;
> 
>   	ufshcd_clear_ua_wluns(hba);
> +	if (ufshcd_vops_setup_vcc_regulators(hba))
This would be invoked even for platforms that don't support both 2.x and 
3.x and don't need to set the voltages in the driver.
I guess platforms that support both 2.x and 3.x and can't set the 
regulator voltages from dts due to different voltage requirements of 2.x 
and 3.x, should request the driver to set the voltages. And the driver 
may do so after determining the device version.

> +		dev_err(hba->dev,
> +			"%s: Failed to set the VCC regulator values, continue with 2.7v\n",
> +			__func__);
> 
>   	/* Initialize devfreq after UFS device is detected */
>   	if (ufshcd_is_clkscaling_supported(hba)) {
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 0db796a..8f0945d 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -324,6 +324,7 @@ struct ufs_pwr_mode_info {
>    * @device_reset: called to issue a reset pulse on the UFS device
>    * @program_key: program or evict an inline encryption key
>    * @event_notify: called to notify important events
> + * @setup_vcc_regulators : update vcc regulator level
>    */
>   struct ufs_hba_variant_ops {
>   	const char *name;
> @@ -360,6 +361,7 @@ struct ufs_hba_variant_ops {
>   			       const union ufs_crypto_cfg_entry *cfg, int slot);
>   	void	(*event_notify)(struct ufs_hba *hba,
>   				enum ufs_event_type evt, void *data);
> +	int    (*setup_vcc_regulators)(struct ufs_hba *hba);
>   };
> 
>   /* clock gating state  */
> @@ -1269,6 +1271,14 @@ static inline void ufshcd_vops_config_scaling_param(struct ufs_hba *hba,
>   		hba->vops->config_scaling_param(hba, profile, data);
>   }
> 
> +static inline int ufshcd_vops_setup_vcc_regulators(struct ufs_hba *hba)
> +{
> +	if (hba->vops && hba->vops->setup_vcc_regulators)
> +		return hba->vops->setup_vcc_regulators(hba);
> +
> +	return 0;
> +}
> +
>   extern struct ufs_pm_lvl_states ufs_pm_lvl_states[];
> 
>   /*
> --
> 2.7.4
> 


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