[PATCH v2 7/7] scsi: ufs: exynos: gs101: put ufs device in reset on .suspend()

From: Peter Griffin
Date: Wed Mar 19 2025 - 11:35:59 EST


GPIO_OUT[0] is connected to the reset pin of embedded UFS device.
Before powering off the phy assert the reset signal.

This is added as a gs101 specific suspend hook so as not to
have any unintended consequences for other SoCs supported by
this driver.

Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
---
Changes since v1:
* Add a gs101 specific suspend hook (Bart)
* Drop asserting GPIO_OUT in .exit (Peter)
---
drivers/ufs/host/ufs-exynos.c | 10 ++++++++++
drivers/ufs/host/ufs-exynos.h | 1 +
2 files changed, 11 insertions(+)

diff --git a/drivers/ufs/host/ufs-exynos.c b/drivers/ufs/host/ufs-exynos.c
index 81a1f04411c0426d6fae931e75db5f4c8693daca..3e545af536e53e06b66c624ed0dc6dc7de13549f 100644
--- a/drivers/ufs/host/ufs-exynos.c
+++ b/drivers/ufs/host/ufs-exynos.c
@@ -1701,6 +1701,12 @@ static void exynos_ufs_hibern8_notify(struct ufs_hba *hba,
}
}

+static int gs101_ufs_suspend(struct exynos_ufs *ufs)
+{
+ hci_writel(ufs, 0 << 0, HCI_GPIO_OUT);
+ return 0;
+}
+
static int exynos_ufs_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op,
enum ufs_notify_change_status status)
{
@@ -1709,6 +1715,9 @@ static int exynos_ufs_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op,
if (status == PRE_CHANGE)
return 0;

+ if (ufs->drv_data->suspend)
+ ufs->drv_data->suspend(ufs);
+
if (!ufshcd_is_link_active(hba))
phy_power_off(ufs->phy);

@@ -2171,6 +2180,7 @@ static const struct exynos_ufs_drv_data gs101_ufs_drvs = {
.pre_link = gs101_ufs_pre_link,
.post_link = gs101_ufs_post_link,
.pre_pwr_change = gs101_ufs_pre_pwr_change,
+ .suspend = gs101_ufs_suspend,
};

static const struct of_device_id exynos_ufs_of_match[] = {
diff --git a/drivers/ufs/host/ufs-exynos.h b/drivers/ufs/host/ufs-exynos.h
index a345809af79dc528ad518d3572fe8be034341ee0..abe7e472759e94fef353e9a97bc9b55f6a0324c1 100644
--- a/drivers/ufs/host/ufs-exynos.h
+++ b/drivers/ufs/host/ufs-exynos.h
@@ -192,6 +192,7 @@ struct exynos_ufs_drv_data {
const struct ufs_pa_layer_attr *pwr);
int (*pre_hce_enable)(struct exynos_ufs *ufs);
int (*post_hce_enable)(struct exynos_ufs *ufs);
+ int (*suspend)(struct exynos_ufs *ufs);
};

struct ufs_phy_time_cfg {

--
2.49.0.rc1.451.g8f38331e32-goog