[PATCH 4/4] scsi: ufs-mediatek: Add host reset mechanism

Stanley Chu
2020-09-08T06:51:01Z

Add host reset mechanism to try to recover host-side errors
during recovery flow.

Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
---
drivers/scsi/ufs/ufs-mediatek.c | 48 +++++++++++++++++++++++++++++++--
drivers/scsi/ufs/ufs-mediatek.h | 3 +++
2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index feba74a72309..1a9133ac6efb 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -13,6 +13,7 @@
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
#include <linux/soc/mediatek/mtk_sip_svc.h>

#include "ufshcd.h"
@@ -91,16 +92,57 @@ static void ufs_mtk_crypto_enable(struct ufs_hba *hba)
}
}

+static void ufs_mtk_host_reset(struct ufs_hba *hba)
+{
+ struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+
+ reset_control_assert(host->hci_reset);
+ reset_control_assert(host->crypto_reset);
+ reset_control_assert(host->unipro_reset);
+
+ usleep_range(100, 110);
+
+ reset_control_deassert(host->unipro_reset);
+ reset_control_deassert(host->crypto_reset);
+ reset_control_deassert(host->hci_reset);
+}
+
+static void ufs_mtk_init_reset_control(struct ufs_hba *hba,
+ struct reset_control **rc,
+ char *str)
+{
+ *rc = devm_reset_control_get(hba->dev, str);
+ if (IS_ERR(*rc)) {
+ dev_info(hba->dev, "Failed to get reset control %s: %d\n",
+ str, PTR_ERR(*rc));
+ *rc = NULL;
+ }
+}
+
+static void ufs_mtk_init_reset(struct ufs_hba *hba)
+{
+ struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+
+ ufs_mtk_init_reset_control(hba, &host->hci_reset,
+ "hci_rst");
+ ufs_mtk_init_reset_control(hba, &host->unipro_reset,
+ "unipro_rst");
+ ufs_mtk_init_reset_control(hba, &host->crypto_reset,
+ "crypto_rst");
+}
+
static int ufs_mtk_hce_enable_notify(struct ufs_hba *hba,
enum ufs_notify_change_status status)
{
struct ufs_mtk_host *host = ufshcd_get_variant(hba);

if (status == PRE_CHANGE) {
- if (host->unipro_lpm)
+ if (host->unipro_lpm) {
hba->vps->hba_enable_delay_us = 0;
- else
+ } else {
hba->vps->hba_enable_delay_us = 600;
+ ufs_mtk_host_reset(hba);
+ }

if (hba->caps & UFSHCD_CAP_CRYPTO)
ufs_mtk_crypto_enable(hba);
@@ -335,6 +377,8 @@ static int ufs_mtk_init(struct ufs_hba *hba)
if (err)
goto out_variant_clear;

+ ufs_mtk_init_reset(hba);
+
/* Enable runtime autosuspend */
hba->caps |= UFSHCD_CAP_RPM_AUTOSUSPEND;

diff --git a/drivers/scsi/ufs/ufs-mediatek.h b/drivers/scsi/ufs/ufs-mediatek.h
index 87657376d27a..5c32d5f52759 100644
--- a/drivers/scsi/ufs/ufs-mediatek.h
+++ b/drivers/scsi/ufs/ufs-mediatek.h
@@ -92,6 +92,9 @@ enum {
struct ufs_mtk_host {
struct ufs_hba *hba;
struct phy *mphy;
+ struct reset_control *hci_reset;
+ struct reset_control *unipro_reset;
+ struct reset_control *crypto_reset;
bool mphy_powered_on;
bool unipro_lpm;
bool ref_clk_enabled;
--
2.18.0