[PATCH v2 2/2 RESEND] scsi: ufs-mediatek: add device reset implementation

Stanley Chu
2019-12-16T03:49:16Z

Add device reset vops implementation in MediaTek UFS driver.

Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
---
drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++++++++++++++++++++
drivers/scsi/ufs/ufs-mediatek.h | 7 +++++++
2 files changed, 34 insertions(+)

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 83e28edc3ac5..6a3ec11b16db 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -6,10 +6,12 @@
* Peter Wang <peter.wang@mediatek.com>
*/

+#include <linux/arm-smccc.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
+#include <linux/soc/mediatek/mtk_sip_svc.h>

#include "ufshcd.h"
#include "ufshcd-pltfrm.h"
@@ -269,6 +271,30 @@ static int ufs_mtk_link_startup_notify(struct ufs_hba *hba,
return ret;
}

+static void ufs_mtk_device_reset(struct ufs_hba *hba)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_smc(MTK_SIP_UFS_CONTROL, UFS_MTK_SIP_DEVICE_RESET,
+ 0, 0, 0, 0, 0, 0, &res);
+ /*
+ * The reset signal is active low. UFS devices shall detect
+ * more than or equal to 1us of positive or negative RST_n
+ * pulse width.
+ *
+ * To be on safe side, keep the reset low for at least 10us.
+ */
+ usleep_range(10, 15);
+
+ arm_smccc_smc(MTK_SIP_UFS_CONTROL, UFS_MTK_SIP_DEVICE_RESET,
+ 1, 0, 0, 0, 0, 0, &res);
+
+ /* Some devices may need time to respond to rst_n */
+ usleep_range(10000, 15000);
+
+ dev_info(hba->dev, "device reset done\n");
+}
+
static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
{
struct ufs_mtk_host *host = ufshcd_get_variant(hba);
@@ -303,6 +329,7 @@ static struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
.pwr_change_notify = ufs_mtk_pwr_change_notify,
.suspend = ufs_mtk_suspend,
.resume = ufs_mtk_resume,
+ .device_reset = ufs_mtk_device_reset,
};

/**
diff --git a/drivers/scsi/ufs/ufs-mediatek.h b/drivers/scsi/ufs/ufs-mediatek.h
index 19f8c42fe06f..b03f601d3a9e 100644
--- a/drivers/scsi/ufs/ufs-mediatek.h
+++ b/drivers/scsi/ufs/ufs-mediatek.h
@@ -6,6 +6,8 @@
#ifndef _UFS_MEDIATEK_H
#define _UFS_MEDIATEK_H

+#include <linux/bitops.h>
+
/*
* Vendor specific pre-defined parameters
*/
@@ -29,6 +31,11 @@
#define VS_SAVEPOWERCONTROL 0xD0A6
#define VS_UNIPROPOWERDOWNCONTROL 0xD0A8

+/*
+ * SiP commands
+ */
+#define UFS_MTK_SIP_DEVICE_RESET BIT(1)
+
/*
* VS_DEBUGCLOCKENABLE
*/
--
2.18.0