[PATCH v1 4/4] scsi: ufs-mediatek: configure and enable clk-gating

[Stanley Chu]

Enable clk-gating with customized delayed timer value in
MediaTek Chipsets.

Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
---
 drivers/scsi/ufs/ufs-mediatek.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 71e2e0e4ea11..282ad06ec846 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -205,6 +205,9 @@ static int ufs_mtk_init(struct ufs_hba *hba)
 	/* Enable runtime autosuspend */
 	hba->caps |= UFSHCD_CAP_RPM_AUTOSUSPEND;
 
+	/* Enable clock-gating */
+	hba->caps |= UFSHCD_CAP_CLK_GATING;
+
 	/*
 	 * ufshcd_vops_init() is invoked after
 	 * ufshcd_setup_clock(true) in ufshcd_hba_init() thus
@@ -293,6 +296,23 @@ static int ufs_mtk_pre_link(struct ufs_hba *hba)
 	return ret;
 }
 
+static void ufs_mtk_setup_clk_gating(struct ufs_hba *hba)
+{
+	unsigned long flags;
+	u32 ah_ms;
+
+	if (ufshcd_is_clkgating_allowed(hba)) {
+		if (ufshcd_is_auto_hibern8_supported(hba) && hba->ahit)
+			ah_ms = FIELD_GET(UFSHCI_AHIBERN8_TIMER_MASK,
+					  hba->ahit);
+		else
+			ah_ms = 10;
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		hba->clk_gating.delay_ms = ah_ms + 5;
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	}
+}
+
 static int ufs_mtk_post_link(struct ufs_hba *hba)
 {
 	/* disable device LCC */
@@ -308,6 +328,8 @@ static int ufs_mtk_post_link(struct ufs_hba *hba)
 			FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3));
 	}
 
+	ufs_mtk_setup_clk_gating(hba);
+
 	return 0;
 }
 
-- 
2.18.0