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References: <20200117035108.19699-1-stanley.chu@mediatek.com> <20200117035108.19699-4-stanley.chu@mediatek.com>
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From:   Alim Akhtar <alim.akhtar@gmail.com>
Date:   Sun, 19 Jan 2020 19:57:47 +0530
Message-ID: <CAGOxZ51V6XmAuu4ki_X7kEkCoUHZguM1=peEHSktsuu1obyDFw@mail.gmail.com>
Subject: Re: [PATCH v1 3/3] scsi: ufs-mediatek: enable low-power mode for
 hibern8 state
To:     Stanley Chu <stanley.chu@mediatek.com>
Cc:     linux-scsi@vger.kernel.org,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Avri Altman <avri.altman@wdc.com>,
        Alim Akhtar <alim.akhtar@samsung.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Bean Huo (beanhuo)" <beanhuo@micron.com>, asutoshd@codeaurora.org,
        Can Guo <cang@codeaurora.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Bart Van Assche <bvanassche@acm.org>,
        linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        open list <linux-kernel@vger.kernel.org>,
        Kuohong Wang <kuohong.wang@mediatek.com>,
        peter.wang@mediatek.com, chun-hung.wu@mediatek.com,
        andy.teng@mediatek.com
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Sender: linux-kernel-owner@vger.kernel.org
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On Fri, Jan 17, 2020 at 9:44 AM Stanley Chu <stanley.chu@mediatek.com> wrote:
>
> In MediaTek Chipsets, UniPro link and ufshci can enter proprietary
> low-power mode while link is in hibern8 state.
>
> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
> ---
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>

>  drivers/scsi/ufs/ufs-mediatek.c | 53 +++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
> index d5194d0c4ef5..f32f3f34f6d0 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -382,11 +382,60 @@ static void ufs_mtk_device_reset(struct ufs_hba *hba)
>         dev_info(hba->dev, "device reset done\n");
>  }
>
> +static int ufs_mtk_link_set_hpm(struct ufs_hba *hba)
> +{
> +       int err;
> +
> +       err = ufshcd_hba_enable(hba);
> +       if (err)
> +               return err;
> +
> +       err = ufshcd_dme_set(hba,
> +                            UIC_ARG_MIB_SEL(VS_UNIPROPOWERDOWNCONTROL, 0),
> +                            0);
> +       if (err)
> +               return err;
> +
> +       err = ufshcd_uic_hibern8_exit(hba);
> +       if (!err)
> +               ufshcd_set_link_active(hba);
> +       else
> +               return err;
> +
> +       err = ufshcd_make_hba_operational(hba);
> +       if (err)
> +               return err;
> +
> +       return 0;
> +}
> +
> +static int ufs_mtk_link_set_lpm(struct ufs_hba *hba)
> +{
> +       int err;
> +
> +       err = ufshcd_dme_set(hba,
> +                            UIC_ARG_MIB_SEL(VS_UNIPROPOWERDOWNCONTROL, 0),
> +                            1);
> +       if (err) {
> +               /* Resume UniPro state for following error recovery */
> +               ufshcd_dme_set(hba,
> +                              UIC_ARG_MIB_SEL(VS_UNIPROPOWERDOWNCONTROL, 0),
> +                              0);
> +               return err;
> +       }
> +
> +       return 0;
> +}
> +
>  static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  {
> +       int err;
>         struct ufs_mtk_host *host = ufshcd_get_variant(hba);
>
>         if (ufshcd_is_link_hibern8(hba)) {
> +               err = ufs_mtk_link_set_lpm(hba);
> +               if (err)
> +                       return -EAGAIN;
>                 phy_power_off(host->mphy);
>                 ufs_mtk_setup_ref_clk(hba, false);
>         }
> @@ -397,10 +446,14 @@ static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  static int ufs_mtk_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  {
>         struct ufs_mtk_host *host = ufshcd_get_variant(hba);
> +       int err;
>
>         if (ufshcd_is_link_hibern8(hba)) {
>                 ufs_mtk_setup_ref_clk(hba, true);
>                 phy_power_on(host->mphy);
> +               err = ufs_mtk_link_set_hpm(hba);
> +               if (err)
> +                       return err;
>         }
>
>         return 0;
> --
> 2.18.0


-- 
Regards,
Alim