scsi: ufs-mediatek: Keep VCC always-on for specific devices

For some devices which need extra delay after VCC power down, VCC shall be
kept always-on in some MediaTek UFS platforms to ensure the stability of
such devices because the extra delay may not be enough in those platforms.

Link: https://lore.kernel.org/r/20201207054955.24366-3-stanley.chu@mediatek.com
Reviewed-by: Andy Teng <andy.teng@mediatek.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 3522458..80618af 100644 (file)
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -70,6 +70,13 @@ static bool ufs_mtk_is_va09_supported(struct ufs_hba *hba)
        return !!(host->caps & UFS_MTK_CAP_VA09_PWR_CTRL);
 }
 
+static bool ufs_mtk_is_broken_vcc(struct ufs_hba *hba)
+{
+       struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+
+       return !!(host->caps & UFS_MTK_CAP_BROKEN_VCC);
+}
+
 static void ufs_mtk_cfg_unipro_cg(struct ufs_hba *hba, bool enable)
 {
        u32 tmp;
@@ -514,6 +521,9 @@ static void ufs_mtk_init_host_caps(struct ufs_hba *hba)
        if (of_property_read_bool(np, "mediatek,ufs-disable-ah8"))
                host->caps |= UFS_MTK_CAP_DISABLE_AH8;
 
+       if (of_property_read_bool(np, "mediatek,ufs-broken-vcc"))
+               host->caps |= UFS_MTK_CAP_BROKEN_VCC;
+
        dev_info(hba->dev, "caps: 0x%x", host->caps);
 }
 
@@ -1003,6 +1013,17 @@ static int ufs_mtk_apply_dev_quirks(struct ufs_hba *hba)
 static void ufs_mtk_fixup_dev_quirks(struct ufs_hba *hba)
 {
        ufshcd_fixup_dev_quirks(hba, ufs_mtk_dev_fixups);
+
+       if (ufs_mtk_is_broken_vcc(hba) && hba->vreg_info.vcc &&
+           (hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM)) {
+               hba->vreg_info.vcc->always_on = true;
+               /*
+                * VCC will be kept always-on thus we don't
+                * need any delay during regulator operations
+                */
+               hba->dev_quirks &= ~(UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM |
+                       UFS_DEVICE_QUIRK_DELAY_AFTER_LPM);
+       }
 }
 
 static void ufs_mtk_event_notify(struct ufs_hba *hba,

diff --git a/drivers/scsi/ufs/ufs-mediatek.h b/drivers/scsi/ufs/ufs-mediatek.h
index 93d3509..3f0d3bb 100644 (file)
--- a/drivers/scsi/ufs/ufs-mediatek.h
+++ b/drivers/scsi/ufs/ufs-mediatek.h
@@ -81,6 +81,7 @@ enum ufs_mtk_host_caps {
        UFS_MTK_CAP_BOOST_CRYPT_ENGINE         = 1 << 0,
        UFS_MTK_CAP_VA09_PWR_CTRL              = 1 << 1,
        UFS_MTK_CAP_DISABLE_AH8                = 1 << 2,
+       UFS_MTK_CAP_BROKEN_VCC                 = 1 << 3,
 };
 
 struct ufs_mtk_crypt_cfg {