Hi,
>
> 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, refactor the function
> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> vops_device_reset(sturct ufs_hba *hba, bool asserted). The
> new parameter "bool asserted" is used to separate device reset
> line pulling down from pulling up.
Sorry for my late response.
Please allow few more days to consult internally about this.
>
> Cc: Kiwoong Kim <kwmad.kim@xxxxxxxxxxx>
> Cc: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
> Signed-off-by: Ziqi Chen <ziqichen@xxxxxxxxxxxxxx>
> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> +static int ufs_qcom_device_reset(struct ufs_hba *hba, bool asserted)
> {
> struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>
> @@ -1417,15 +1418,20 @@ 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);
> + if (asserted) {
> + gpiod_set_value_cansleep(host->device_reset, 1);
>
> - gpiod_set_value_cansleep(host->device_reset, 0);
> - usleep_range(10, 15);
> + /*
> + * The UFS device shall detect reset pulses of 1us, sleep for 10us to
> + * be on the safe side.
> + */
> + usleep_range(10, 15);
> + } else {
> + gpiod_set_value_cansleep(host->device_reset, 0);
> +
> + /* Some devices may need time to respond to rst_n */
> + usleep_range(10, 15);
Since sleep the same on assert/de-assert can move it outside the if-else clause?
> + }
>
> return 0;
> }
All the below changes, in suspend/resume, deserves some references in your commit log,
And probably a separate patch.
Thanks,
Avri
> @@ -8686,8 +8696,6 @@ 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 +8711,9 @@ 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_device_reset(hba, true);
> +
> ufshcd_setup_clocks(hba, false);
>
> if (ufshcd_is_clkgating_allowed(hba)) {
> @@ -8711,6 +8722,8 @@ 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 +8791,19 @@ 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 +8811,7 @@ 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 +8878,6 @@ 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 +8888,8 @@ 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..d5fbaba 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
> + * @device_reset: called to assert or deassert device reset line
> * @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 (*device_reset)(struct ufs_hba *hba, bool asserted);
> 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_device_reset(struct ufs_hba *hba, bool
> asserted)
> {
> if (hba->vops && hba->vops->device_reset)
> - return hba->vops->device_reset(hba);
> + return hba->vops->device_reset(hba, asserted);
>
> return -EOPNOTSUPP;
> }
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
> Forum,
> a Linux Foundation Collaborative Project
