On 2020-12-22 02:41, Bjorn Andersson wrote:
On Mon 21 Dec 01:51 CST 2020, Ziqi Chen wrote:As per specs, e.g, JESD220E chapter 7.2, while powering off/on the ufs device, RST_N signal and REF_CLK signal should be between VSS(Ground) and VCCQ/VCCQ2. To flexibly control device reset line, re-name the function ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_ vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new parameter "bool down" is used to separate device reset line pulling down from pulling up. Cc: Kiwoong Kim <kwmad.kim@xxxxxxxxxxx> Cc: Stanley Chu <stanley.chu@xxxxxxxxxxxx> Signed-off-by: Ziqi Chen <ziqichen@xxxxxxxxxxxxxx> --- drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++----------------- drivers/scsi/ufs/ufs-qcom.c | 22 ++++++++++-----------drivers/scsi/ufs/ufshcd.c | 43 ++++++++++++++++++++++++++++++-----------drivers/scsi/ufs/ufshcd.h | 10 +++++----- 4 files changed, 56 insertions(+), 46 deletions(-)diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.cindex 80618af..bff2c42 100644 --- a/drivers/scsi/ufs/ufs-mediatek.c +++ b/drivers/scsi/ufs/ufs-mediatek.c@@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct ufs_hba *hba,return ret; } -static int ufs_mtk_device_reset(struct ufs_hba *hba)+static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down){ struct arm_smccc_res res; - ufs_mtk_device_reset_ctrl(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); - - ufs_mtk_device_reset_ctrl(1, res); - - /* Some devices may need time to respond to rst_n */ - usleep_range(10000, 15000); + if (down) { + ufs_mtk_device_reset_ctrl(0, res); + } else { + ufs_mtk_device_reset_ctrl(1, res); - dev_info(hba->dev, "device reset done\n"); + /* Some devices may need time to respond to rst_n */ + usleep_range(10000, 15000); + } return 0; }@@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {.suspend = ufs_mtk_suspend, .resume = ufs_mtk_resume, .dbg_register_dump = ufs_mtk_dbg_register_dump, - .device_reset = ufs_mtk_device_reset, + .toggle_device_reset = ufs_mtk_toggle_device_reset, .event_notify = ufs_mtk_event_notify, }; diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c index 2206b1e..c2ccaa5 100644 --- a/drivers/scsi/ufs/ufs-qcom.c +++ b/drivers/scsi/ufs/ufs-qcom.c@@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)} /** - * ufs_qcom_device_reset() - toggle the (optional) device reset line+ * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset line* @hba: per-adapter instance + * @down: pull down or pull up device reset line * * Toggles the (optional) reset line to reset the attached device. */ -static int ufs_qcom_device_reset(struct ufs_hba *hba)+static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down){ struct ufs_qcom_host *host = ufshcd_get_variant(hba);@@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba)if (!host->device_reset) return -EOPNOTSUPP; - /*- * 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); - usleep_range(10, 15); - - gpiod_set_value_cansleep(host->device_reset, 0); - usleep_range(10, 15); + if (down) { + gpiod_set_value_cansleep(host->device_reset, 1); + } else { + gpiod_set_value_cansleep(host->device_reset, 0); + usleep_range(10, 15);The comment above describes that the reset pulse should be 10uS, so the only reason I can see for the sleep here would be for devices to come back up after the reset pulse - i.e. what Mediatek believes needs 10-15mS. As such, I would like you to move this sleep out to the caller and then turns this snippet into just: gpiod_set_value_cansleep(host->device_reset, down);I don't see a problem using Mediatek's reasoning and sleep values in thecommon case.
Understood. It would better to move this sleep (10-15ms)out to the caller and
simplify this function.
+ } return 0; }@@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {.suspend = ufs_qcom_suspend, .resume = ufs_qcom_resume, .dbg_register_dump = ufs_qcom_dump_dbg_regs, - .device_reset = ufs_qcom_device_reset, + .toggle_device_reset = ufs_qcom_toggle_device_reset, .config_scaling_param = ufs_qcom_config_scaling_param, .program_key = ufs_qcom_ice_program_key, }; diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index e221add..2ee905f 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c@@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba){ int err; - err = ufshcd_vops_device_reset(hba); + err = ufshcd_vops_toggle_device_reset(hba, true); + if (err) { + dev_err(hba->dev, "device reset pulling down failure: %d\n", err);"asserting device reset failed"
Agree, thanks.
+ return; + } + + /* + * The reset signal is active low. The UFS device + * shall detect reset pulses of 1us, sleep for at + * least 10us to be on the safe side. + */ + usleep_range(10, 15); + + err = ufshcd_vops_toggle_device_reset(hba, false); if (!err) { ufshcd_set_ufs_dev_active(hba);@@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)hba->wb_enabled = false; hba->wb_buf_flush_enabled = false; } + dev_info(hba->dev, "device reset done\n");Please use dev_dbg(), as this is only interesting to us when we're actually debugging UFS related issues.
Agree, thanks.
+ } else { + dev_err(hba->dev, "device reset pulling up failure: %d\n", err);"deasserting device reset failed"
Agree, thanks.
} + if (err != -EOPNOTSUPP) ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err); }@@ -8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)if (ret) goto set_dev_active; - ufshcd_vreg_set_lpm(hba); - disable_clks: /** Call vendor specific suspend callback. As these callbacks may access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)*/ ufshcd_disable_irq(hba); + if (ufshcd_is_link_off(hba)) + ufshcd_vops_toggle_device_reset(hba, true); + ufshcd_setup_clocks(hba, false); if (ufshcd_is_clkgating_allowed(hba)) {@@ -8711,6 +8729,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)hba->clk_gating.state); } + ufshcd_vreg_set_lpm(hba); + /* Put the host controller in low power mode if possible */ ufshcd_hba_vreg_set_lpm(hba); goto out;@@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)old_link_state = hba->uic_link_state; ufshcd_hba_vreg_set_hpm(hba); + + ret = ufshcd_vreg_set_hpm(hba); + if (ret) + goto out; + /* Make sure clocks are enabled before accessing controller */ ret = ufshcd_setup_clocks(hba, true); if (ret) - goto out; + goto disable_vreg; /* enable the host irq as host controller would be active soon */ ufshcd_enable_irq(hba); - ret = ufshcd_vreg_set_hpm(hba); - if (ret) - goto disable_irq_and_vops_clks; - /** Call vendor specific resume callback. As these callbacks may access* vendor specific host controller register space call them when the@@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)*/ ret = ufshcd_vops_resume(hba, pm_op); if (ret) - goto disable_vreg; + goto disable_irq_and_vops_clks;/* For DeepSleep, the only supported option is to have the link off */ WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)ufshcd_link_state_transition(hba, old_link_state, 0); vendor_suspend: ufshcd_vops_suspend(hba, pm_op); -disable_vreg: - ufshcd_vreg_set_lpm(hba); disable_irq_and_vops_clks: ufshcd_disable_irq(hba); if (hba->clk_scaling.is_allowed)@@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)trace_ufshcd_clk_gating(dev_name(hba->dev), hba->clk_gating.state); } +disable_vreg: + ufshcd_vreg_set_lpm(hba); out: hba->pm_op_in_progress = 0; if (ret) diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 9bb5f0e..dccc3eb 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info { * @resume: called during host controller PM callback * @dbg_register_dump: used to dump controller debug information * @phy_initialization: used to initialize phys - * @device_reset: called to issue a reset pulse on the UFS device+ * @toggle_device_reset: called to change logic level of reset gpio on the UFS device* @program_key: program or evict an inline encryption key * @event_notify: called to notify important events */ @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops { int (*resume)(struct ufs_hba *, enum ufs_pm_op); void (*dbg_register_dump)(struct ufs_hba *hba); int (*phy_initialization)(struct ufs_hba *); - int (*device_reset)(struct ufs_hba *hba); + int (*toggle_device_reset)(struct ufs_hba *hba, bool down);I don't think "toggle" adds any value to the understanding of what this function is expected to do, so I would prefer that you just keep it "device_reset". I also would prefer that you replace "down" with "asserted" - as this avoids questions about active high/low etc from the API. Thanks, Bjorn
Agree, thanks. Best Regards, Ziqi
void (*config_scaling_param)(struct ufs_hba *hba, struct devfreq_dev_profile *profile, void *data);@@ -1216,10 +1216,10 @@ static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)hba->vops->dbg_register_dump(hba); } -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)+static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba, bool down){ - if (hba->vops && hba->vops->device_reset) - return hba->vops->device_reset(hba); + if (hba->vops && hba->vops->toggle_device_reset) + return hba->vops->toggle_device_reset(hba, down); return -EOPNOTSUPP; } --The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,a Linux Foundation Collaborative Project
