From 488edafb1120f715bebd80b6fe4089f83fb082b2 Mon Sep 17 00:00:00 2001
From: Stanley Chu <stanley.chu@mediatek.com>
Date: Mon, 1 Jun 2020 18:46:44 +0800
Subject: [PATCH] scsi: ufs-mediatek: Introduce low-power mode for device power
supply
Allow device power supply to enter low-power mode.
Link: https://lore.kernel.org/r/20200601104646.15436-4-stanley.chu@mediatek.com
Reviewed-by: Pengshun Zhao <pengshun.zhao@mediatek.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
drivers/scsi/ufs/ufs-mediatek.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 3c85f5e97dea8..5f41b7b7db8fc 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -12,6 +12,7 @@
#include <linux/of_address.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
#include <linux/soc/mediatek/mtk_sip_svc.h>
#include "ufshcd.h"
@@ -521,6 +522,19 @@ static int ufs_mtk_link_set_lpm(struct ufs_hba *hba)
return 0;
}
+static void ufs_mtk_vreg_set_lpm(struct ufs_hba *hba, bool lpm)
+{
+ if (!hba->vreg_info.vccq2)
+ return;
+
+ if (lpm & !hba->vreg_info.vcc->enabled)
+ regulator_set_mode(hba->vreg_info.vccq2->reg,
+ REGULATOR_MODE_IDLE);
+ else if (!lpm)
+ regulator_set_mode(hba->vreg_info.vccq2->reg,
+ REGULATOR_MODE_NORMAL);
+}
+
static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
{
int err;
@@ -537,6 +551,12 @@ static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
ufshcd_set_link_off(hba);
return -EAGAIN;
}
+ /*
+ * Make sure no error will be returned to prevent
+ * ufshcd_suspend() re-enabling regulators while vreg is still
+ * in low-power mode.
+ */
+ ufs_mtk_vreg_set_lpm(hba, true);
}
if (!ufshcd_is_link_active(hba))
@@ -554,6 +574,7 @@ static int ufs_mtk_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
phy_power_on(host->mphy);
if (ufshcd_is_link_hibern8(hba)) {
+ ufs_mtk_vreg_set_lpm(hba, false);
err = ufs_mtk_link_set_hpm(hba);
if (err) {
err = ufshcd_link_recovery(hba);
--
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