[PATCH v3 10/10] scsi: ufs-mediatek: Support multiple VCC sources

[Stanley Chu <stanley.chu@xxxxxxxxxxxx>]

Support multiple VCC source in MediaTek UFS platforms.

Two options are provided and distinguished by specific
device tree attributes as below examples,

[Option 1: By numbering]
mediatek,ufs-vcc-by-num;
vcc-opt1-supply = <&mt6373_vbuck4_ufs>;
vcc-opt2-supply = <&mt6363_vemc>;

[Option 2: By UFS version]
mediatek,ufs-vcc-by-ver;
vcc-ufs3-supply = <&mt6373_vbuck4_ufs>;

Signed-off-by: Alice Chao <alice.chao@xxxxxxxxxxxx>
Signed-off-by: Peter Wang <peter.wang@xxxxxxxxxxxx>
Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
---
 drivers/ufs/host/ufs-mediatek.c | 46 +++++++++++++++++++++++++++++++++
 drivers/ufs/host/ufs-mediatek.h | 14 ++++++++++
 2 files changed, 60 insertions(+)

diff --git a/drivers/ufs/host/ufs-mediatek.c b/drivers/ufs/host/ufs-mediatek.c
index 2c1e55f8d7c6..a029ec2fc971 100755
--- a/drivers/ufs/host/ufs-mediatek.c
+++ b/drivers/ufs/host/ufs-mediatek.c
@@ -669,6 +669,50 @@ static u32 ufs_mtk_get_ufs_hci_version(struct ufs_hba *hba)
 	return hba->ufs_version;
 }
 
+#define MAX_VCC_NAME 30
+static int ufs_mtk_vreg_fix_vcc(struct ufs_hba *hba)
+{
+	struct ufs_vreg_info *info = &hba->vreg_info;
+	struct device_node *np = hba->dev->of_node;
+	struct device *dev = hba->dev;
+	char vcc_name[MAX_VCC_NAME];
+	struct arm_smccc_res res;
+	int err = 0;
+	int ver;
+
+	if (hba->vreg_info.vcc)
+		return 0;
+
+	if (of_property_read_bool(np, "mediatek,ufs-vcc-by-num")) {
+		ufs_mtk_get_vcc_num(res);
+		if (res.a1 > UFS_VCC_NONE && res.a1 < UFS_VCC_MAX)
+			snprintf(vcc_name, MAX_VCC_NAME, "vcc-opt%u", res.a1);
+		else
+			return -ENODEV;
+	} else if (of_property_read_bool(np, "mediatek,ufs-vcc-by-ver")) {
+		ver = (hba->dev_info.wspecversion & 0xF00) >> 8;
+		snprintf(vcc_name, MAX_VCC_NAME, "vcc-ufs%u", ver);
+	} else {
+		return 0;
+	}
+
+	err = ufshcd_populate_vreg(dev, vcc_name, &info->vcc);
+	if (err)
+		return err;
+
+	err = ufshcd_get_vreg(dev, info->vcc);
+	if (err)
+		return err;
+
+	err = regulator_enable(info->vcc->reg);
+	if (!err) {
+		info->vcc->enabled = true;
+		dev_info(dev, "%s: %s enabled\n", __func__, vcc_name);
+	}
+
+	return err;
+}
+
 /**
  * ufs_mtk_init - find other essential mmio bases
  * @hba: host controller instance
@@ -1179,6 +1223,8 @@ static int ufs_mtk_apply_dev_quirks(struct ufs_hba *hba)
 		ufs_mtk_setup_ref_clk_wait_us(hba,
 					      REFCLK_DEFAULT_WAIT_US);
 
+	ufs_mtk_vreg_fix_vcc(hba);
+
 	return 0;
 }
 
diff --git a/drivers/ufs/host/ufs-mediatek.h b/drivers/ufs/host/ufs-mediatek.h
index eb26306a719f..b72007ecba05 100755
--- a/drivers/ufs/host/ufs-mediatek.h
+++ b/drivers/ufs/host/ufs-mediatek.h
@@ -83,6 +83,7 @@ enum {
 #define UFS_MTK_SIP_DEVICE_RESET          BIT(1)
 #define UFS_MTK_SIP_CRYPTO_CTRL           BIT(2)
 #define UFS_MTK_SIP_REF_CLK_NOTIFICATION  BIT(3)
+#define UFS_MTK_SIP_GET_VCC_NUM           BIT(6)
 #define UFS_MTK_SIP_DEVICE_PWR_CTRL       BIT(7)
 
 /*
@@ -144,6 +145,16 @@ struct ufs_mtk_host {
 	u32 ip_ver;
 };
 
+/*
+ * Multi-VCC by Numbering
+ */
+enum ufs_mtk_vcc_num {
+	UFS_VCC_NONE = 0,
+	UFS_VCC_1,
+	UFS_VCC_2,
+	UFS_VCC_MAX
+};
+
 /*
  * SMC call wapper function
  */
@@ -200,6 +211,9 @@ struct ufs_mtk_host {
 #define ufs_mtk_device_reset_ctrl(high, res) \
 	ufs_mtk_smc(UFS_MTK_SIP_DEVICE_RESET, res, high)
 
+#define ufs_mtk_get_vcc_num(res) \
+	ufs_mtk_smc(UFS_MTK_SIP_GET_VCC_NUM, res)
+
 #define ufs_mtk_device_pwr_ctrl(on, ufs_ver, res) \
 	ufs_mtk_smc(UFS_MTK_SIP_DEVICE_PWR_CTRL, res, on, ufs_ver)
 
-- 
2.18.0