linux-kernel - [PATCH v5 11/11] scsi: ufs-mediatek: Disable unused VCCQx power rails

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Date:   Thu, 16 Jun 2022 13:37:25 +0800
From:   Stanley Chu <stanley.chu@...iatek.com>
To:     <linux-scsi@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <martin.petersen@...cle.com>, <avri.altman@....com>,
        <alim.akhtar@...sung.com>, <jejb@...ux.ibm.com>,
        <bvanassche@....org>
CC:     <peter.wang@...iatek.com>, <chun-hung.wu@...iatek.com>,
        <alice.chao@...iatek.com>, <powen.kao@...iatek.com>,
        <mason.zhang@...iatek.com>, <qilin.tan@...iatek.com>,
        <lin.gui@...iatek.com>, <eddie.huang@...iatek.com>,
        <tun-yu.yu@...iatek.com>, <cc.chou@...iatek.com>,
        <chaotian.jing@...iatek.com>, <jiajie.hao@...iatek.com>,
        <stanley.chu@...iatek.com>
Subject: [PATCH v5 11/11] scsi: ufs-mediatek: Disable unused VCCQx power rails

Some MediaTek UFS platforms support different VCCQx power rails,
for example, both 1.2v and 1.8v VCCQx, in a single kernel image.

To optimize the system power consumption, provide a way to disable
and release the unused power rail during the device probing.

Signed-off-by: Stanley Chu <stanley.chu@...iatek.com>
---
 drivers/ufs/host/ufs-mediatek.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/ufs/host/ufs-mediatek.c b/drivers/ufs/host/ufs-mediatek.c
index 34e51c094366..bfe04a4d1dce 100755
--- a/drivers/ufs/host/ufs-mediatek.c
+++ b/drivers/ufs/host/ufs-mediatek.c
@@ -712,6 +712,29 @@ static int ufs_mtk_vreg_fix_vcc(struct ufs_hba *hba)
 	return err;
 }
 
+static void ufs_mtk_vreg_fix_vccqx(struct ufs_hba *hba)
+{
+	struct ufs_vreg_info *info = &hba->vreg_info;
+	struct ufs_vreg **vreg_on, **vreg_off;
+
+	if (hba->dev_info.wspecversion >= 0x0300) {
+		vreg_on = &info->vccq;
+		vreg_off = &info->vccq2;
+	} else {
+		vreg_on = &info->vccq2;
+		vreg_off = &info->vccq;
+	}
+
+	if (*vreg_on)
+		(*vreg_on)->always_on = true;
+
+	if (*vreg_off) {
+		regulator_disable((*vreg_off)->reg);
+		devm_kfree(hba->dev, (*vreg_off)->name);
+		devm_kfree(hba->dev, *vreg_off);
+	}
+}
+
 /**
  * ufs_mtk_init - find other essential mmio bases
  * @hba: host controller instance
@@ -1241,6 +1264,7 @@ static void ufs_mtk_fixup_dev_quirks(struct ufs_hba *hba)
 	}
 
 	ufs_mtk_vreg_fix_vcc(hba);
+	ufs_mtk_vreg_fix_vccqx(hba);
 }
 
 static void ufs_mtk_event_notify(struct ufs_hba *hba,
-- 
2.18.0