scsi: ufs: Add DeepSleep feature
DeepSleep is a UFS v3.1 feature that achieves the lowest power consumption
of the device, apart from power off.
In DeepSleep mode, no commands are accepted, and the only way to exit is
using a hardware reset or power cycle.
This patch assumes that if a power cycle was an option, then power off
would be preferable, so only exit via a hardware reset is supported.
Drivers that wish to support DeepSleep need to set a new capability flag
UFSHCD_CAP_DEEPSLEEP and provide a hardware reset via the existing
->device_reset() callback.
It is assumed that UFS devices with wspecversion >= 0x310 support
DeepSleep.
[mkp: dropped sysfs ABI doc due to conflicts]
Link: https://lore.kernel.org/r/20201103141403.2142-2-adrian.hunter@intel.com
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Can Guo <cang@codeaurora.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2309253..ee083b9 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -163,6 +163,11 @@ struct ufs_pm_lvl_states ufs_pm_lvl_states[] = {
{UFS_SLEEP_PWR_MODE, UIC_LINK_HIBERN8_STATE},
{UFS_POWERDOWN_PWR_MODE, UIC_LINK_HIBERN8_STATE},
{UFS_POWERDOWN_PWR_MODE, UIC_LINK_OFF_STATE},
+ /*
+ * For DeepSleep, the link is first put in hibern8 and then off.
+ * Leaving the link in hibern8 is not supported.
+ */
+ {UFS_DEEPSLEEP_PWR_MODE, UIC_LINK_OFF_STATE},
};
static inline enum ufs_dev_pwr_mode
@@ -8297,7 +8302,8 @@ static int ufshcd_link_state_transition(struct ufs_hba *hba,
}
/*
* If autobkops is enabled, link can't be turned off because
- * turning off the link would also turn off the device.
+ * turning off the link would also turn off the device, except in the
+ * case of DeepSleep where the device is expected to remain powered.
*/
else if ((req_link_state == UIC_LINK_OFF_STATE) &&
(!check_for_bkops || !hba->auto_bkops_enabled)) {
@@ -8307,6 +8313,9 @@ static int ufshcd_link_state_transition(struct ufs_hba *hba,
* put the link in low power mode is to send the DME end point
* to device and then send the DME reset command to local
* unipro. But putting the link in hibern8 is much faster.
+ *
+ * Note also that putting the link in Hibern8 is a requirement
+ * for entering DeepSleep.
*/
ret = ufshcd_uic_hibern8_enter(hba);
if (ret) {
@@ -8439,6 +8448,7 @@ static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
{
int ret = 0;
+ int check_for_bkops;
enum ufs_pm_level pm_lvl;
enum ufs_dev_pwr_mode req_dev_pwr_mode;
enum uic_link_state req_link_state;
@@ -8524,7 +8534,13 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
}
flush_work(&hba->eeh_work);
- ret = ufshcd_link_state_transition(hba, req_link_state, 1);
+
+ /*
+ * In the case of DeepSleep, the device is expected to remain powered
+ * with the link off, so do not check for bkops.
+ */
+ check_for_bkops = !ufshcd_is_ufs_dev_deepsleep(hba);
+ ret = ufshcd_link_state_transition(hba, req_link_state, check_for_bkops);
if (ret)
goto set_dev_active;
@@ -8565,11 +8581,25 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
if (hba->clk_scaling.is_allowed)
ufshcd_resume_clkscaling(hba);
ufshcd_vreg_set_hpm(hba);
+ /*
+ * Device hardware reset is required to exit DeepSleep. Also, for
+ * DeepSleep, the link is off so host reset and restore will be done
+ * further below.
+ */
+ if (ufshcd_is_ufs_dev_deepsleep(hba)) {
+ ufshcd_vops_device_reset(hba);
+ WARN_ON(!ufshcd_is_link_off(hba));
+ }
if (ufshcd_is_link_hibern8(hba) && !ufshcd_uic_hibern8_exit(hba))
ufshcd_set_link_active(hba);
else if (ufshcd_is_link_off(hba))
ufshcd_host_reset_and_restore(hba);
set_dev_active:
+ /* Can also get here needing to exit DeepSleep */
+ if (ufshcd_is_ufs_dev_deepsleep(hba)) {
+ ufshcd_vops_device_reset(hba);
+ ufshcd_host_reset_and_restore(hba);
+ }
if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
ufshcd_disable_auto_bkops(hba);
enable_gating:
@@ -8631,6 +8661,9 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
if (ret)
goto disable_vreg;
+ /* 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));
+
if (ufshcd_is_link_hibern8(hba)) {
ret = ufshcd_uic_hibern8_exit(hba);
if (!ret) {
@@ -8644,6 +8677,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
/*
* A full initialization of the host and the device is
* required since the link was put to off during suspend.
+ * Note, in the case of DeepSleep, the device will exit
+ * DeepSleep due to device reset.
*/
ret = ufshcd_reset_and_restore(hba);
/*