Re: [PATCH v3 6/6] scsi: ufs: configure the attribute for power mode

[Subhash Jadavani <subhashj@codeaurora.org>]

On 8/26/2013 8:11 PM, Seungwon Jeon wrote:
> UIC attributes can be set with using DME_SET command for
> power mode change. For configuration the link capability
> attributes are used, which is updated after successful
> link startup.
>
> Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
> Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
> ---
>   drivers/scsi/ufs/ufshcd.c |   66 +++++++++++++++++++++++++++++++++++++++++++++
>   drivers/scsi/ufs/unipro.h |   21 ++++++++++++++
>   2 files changed, 87 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index c67118d..2ae845c 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1598,6 +1598,70 @@ out:
>   }
>   
>   /**
> + * ufshcd_config_max_pwr_mode - Set & Change power mode with
> + *	maximum capability attribute information.
> + * @hba: per adapter instance
> + *
> + * Returns 0 on success, non-zero value on failure
> + */
> +static int ufshcd_config_max_pwr_mode(struct ufs_hba *hba)
> +{
> +	enum {RX = 0, TX = 1};
> +	u32 lanes[] = {1, 1};
> +	u32 gear[] = {1, 1};
> +	u8 pwr[] = {FASTAUTO_MODE, FASTAUTO_MODE};
> +	int ret;
> +
> +	/* Get the connected lane count */
> +	ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDRXDATALANES), &lanes[RX]);
> +	ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDTXDATALANES), &lanes[TX]);
> +
> +	/*
> +	 * First, get the maximum gears of HS speed.
> +	 * If a zero value, it means there is no HSGEAR capability.
> +	 * Then, get the maximum gears of PWM speed.
> +	 */
> +	ufshcd_dme_get(hba, UIC_ARG_MIB(PA_MAXRXHSGEAR), &gear[RX]);
> +	if (!gear[RX]) {
> +		ufshcd_dme_get(hba, UIC_ARG_MIB(PA_MAXRXPWMGEAR), &gear[RX]);
> +		pwr[RX] = SLOWAUTO_MODE;
> +	}
As per UniPro specification, PA_MaxRxHsGear valid values are 0 (NO, HS), 
1 (HS_Gear1), 2 (HS_Gear2) & 3 (HS_Gear3). But UFS device specification 
(v1.1) only mandates to support Gear-1 and Gear-2 is optional. Gear-3 is 
no where mentioned in the specifcation so it means unsupported gear. So 
i guess after reading PA_MaxRxHsGear attribute, we have to ensure that 
we only set the Gear-1 or Gear-2 as mandated by UFS 1.1 spec.

Also, for PA_MaxRxPWMGear both UniPro and UFS device specification 
support the gear-1 to gear-7. so i guess we should have some safely 
check to ensure that gear is not 0 or greater than 7.

> +
> +	ufshcd_dme_peer_get(hba, UIC_ARG_MIB(PA_MAXRXHSGEAR), &gear[TX]);
> +	if (!gear[TX]) {
> +		ufshcd_dme_peer_get(hba, UIC_ARG_MIB(PA_MAXRXPWMGEAR),
> +				    &gear[TX]);
> +		pwr[TX] = SLOWAUTO_MODE;
> +	}
> +
> +	/*
> +	 * Configure attributes for power mode change with below.
> +	 * - PA_RXGEAR, PA_ACTIVERXDATALANES, PA_RXTERMINATION,
> +	 * - PA_TXGEAR, PA_ACTIVETXDATALANES, PA_TXTERMINATION,
> +	 * - PA_HSSERIES
> +	 */
> +	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXGEAR), gear[RX]);
> +	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_ACTIVERXDATALANES), lanes[RX]);
> +	if (pwr[RX] == FASTAUTO_MODE)
> +		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXTERMINATION), TRUE);
> +
> +	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXGEAR), gear[TX]);
> +	ufshcd_dme_set(hba, UIC_ARG_MIB(PA_ACTIVETXDATALANES), lanes[TX]);
> +	if (pwr[TX] == FASTAUTO_MODE)
> +		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXTERMINATION), TRUE);
> +
> +	if (pwr[RX] == FASTAUTO_MODE || pwr[TX] == FASTAUTO_MODE)
> +		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_HSSERIES), PA_HS_MODE_B);
> +
> +	ret = ufshcd_uic_change_pwr_mode(hba, pwr[RX] << 4 | pwr[TX]);
> +	if (ret)
> +		dev_err(hba->dev,
> +			"pwr_mode: power mode change failed %d\n", ret);
I guess it would be helpful to print the powermode, Gear, Lanes & Rate 
information after error. Also, i guess the gear change is one time 
operation, won't it be useful to print this information so we know what 
is the host-device configuration?

> +
> +	return ret;
> +}
> +
> +/**
>    * ufshcd_complete_dev_init() - checks device readiness
>    * hba: per-adapter instance
>    *
> @@ -2942,6 +3006,8 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
>   	if (ret)
>   		goto out;
>   
> +	ufshcd_config_max_pwr_mode(hba);
> +
>   	ret = ufshcd_verify_dev_init(hba);
>   	if (ret)
>   		goto out;
> diff --git a/drivers/scsi/ufs/unipro.h b/drivers/scsi/ufs/unipro.h
> index 3a710eb..0bb8041 100644
> --- a/drivers/scsi/ufs/unipro.h
> +++ b/drivers/scsi/ufs/unipro.h
> @@ -72,6 +72,21 @@
>   #define PA_STALLNOCONFIGTIME	0x15A3
>   #define PA_SAVECONFIGTIME	0x15A4
>   
> +/* PA power modes */
> +enum {
> +	FAST_MODE	= 1,
> +	SLOW_MODE	= 2,
> +	FASTAUTO_MODE	= 4,
> +	SLOWAUTO_MODE	= 5,
> +	UNCHANGED	= 7,
> +};
> +
> +/* PA TX/RX Frequency Series */
> +enum {
> +	PA_HS_MODE_A	= 1,
> +	PA_HS_MODE_B	= 2,
> +};
> +
>   /*
>    * Data Link Layer Attributes
>    */
> @@ -127,4 +142,10 @@
>   #define T_TC0TXMAXSDUSIZE	0x4060
>   #define T_TC1TXMAXSDUSIZE	0x4061
>   
> +/* Boolean attribute values */
> +enum {
> +	FALSE = 0,
> +	TRUE,
> +};
> +
>   #endif /* _UNIPRO_H_ */