From b61d0414136853fc38898829cde837ce5d691a9a Mon Sep 17 00:00:00 2001 From: Ziqi Chen Date: Fri, 8 Jan 2021 18:56:25 +0800 Subject: [PATCH] scsi: ufs-qcom: Fix ufs RST_n spec violation According to the spec (JESD220E chapter 7.2), while powering off/on the ufs device, RST_n signal should be between VSS(Ground) and VCCQ/VCCQ2. Link: https://lore.kernel.org/r/1610103385-45755-3-git-send-email-ziqichen@codeaurora.org Acked-by: Avri Altman Signed-off-by: Ziqi Chen Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufs-qcom.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c index 2206b1e..f97d7b0 100644 --- a/drivers/scsi/ufs/ufs-qcom.c +++ b/drivers/scsi/ufs/ufs-qcom.c @@ -568,6 +568,17 @@ out: return err; } +static void ufs_qcom_device_reset_ctrl(struct ufs_hba *hba, bool asserted) +{ + struct ufs_qcom_host *host = ufshcd_get_variant(hba); + + /* reset gpio is optional */ + if (!host->device_reset) + return; + + gpiod_set_value_cansleep(host->device_reset, asserted); +} + static int ufs_qcom_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) { struct ufs_qcom_host *host = ufshcd_get_variant(hba); @@ -582,6 +593,9 @@ static int ufs_qcom_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) ufs_qcom_disable_lane_clks(host); phy_power_off(phy); + /* reset the connected UFS device during power down */ + ufs_qcom_device_reset_ctrl(hba, true); + } else if (!ufs_qcom_is_link_active(hba)) { ufs_qcom_disable_lane_clks(host); } @@ -1421,10 +1435,10 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba) * The UFS device shall detect reset pulses of 1us, sleep for 10us to * be on the safe side. */ - gpiod_set_value_cansleep(host->device_reset, 1); + ufs_qcom_device_reset_ctrl(hba, true); usleep_range(10, 15); - gpiod_set_value_cansleep(host->device_reset, 0); + ufs_qcom_device_reset_ctrl(hba, false); usleep_range(10, 15); return 0; -- 2.7.4