[PATCH v1 1/2] scsi: ufs: Put hba into LPM during clk gating

Asutosh Das
2020-10-26T23:30:45Z

From: Can Guo <cang@codeaurora.org>

During clock gating, after clocks are disabled,
put hba into LPM to save more power.

Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
---
drivers/scsi/ufs/ufshcd.c | 7 +++++--
drivers/scsi/ufs/ufshcd.h | 13 +++++++++++++
2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 47c544d..55ca8c6 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1548,6 +1548,7 @@ static void ufshcd_ungate_work(struct work_struct *work)
}

spin_unlock_irqrestore(hba->host->host_lock, flags);
+ ufshcd_hba_vreg_set_hpm(hba);
ufshcd_setup_clocks(hba, true);

ufshcd_enable_irq(hba);
@@ -1713,6 +1714,8 @@ static void ufshcd_gate_work(struct work_struct *work)
/* If link is active, device ref_clk can't be switched off */
__ufshcd_setup_clocks(hba, false, true);

+ /* Put the host controller in low power mode if possible */
+ ufshcd_hba_vreg_set_lpm(hba);
/*
* In case you are here to cancel this work the gating state
* would be marked as REQ_CLKS_ON. In this case keep the state
@@ -8405,13 +8408,13 @@ static int ufshcd_vreg_set_hpm(struct ufs_hba *hba)

static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba)
{
- if (ufshcd_is_link_off(hba))
+ if (ufshcd_is_link_off(hba) || ufshcd_can_aggressive_pc(hba))
ufshcd_setup_hba_vreg(hba, false);
}

static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
{
- if (ufshcd_is_link_off(hba))
+ if (ufshcd_is_link_off(hba) || ufshcd_can_aggressive_pc(hba))
ufshcd_setup_hba_vreg(hba, true);
}

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 47eb143..0fbb735 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -592,6 +592,13 @@ enum ufshcd_caps {
* inline crypto engine, if it is present
*/
UFSHCD_CAP_CRYPTO = 1 << 8,
+
+ /*
+ * This capability allows the controller regulators to be put into
+ * lpm mode aggressively during clock gating.
+ * This would increase power savings.
+ */
+ UFSHCD_CAP_AGGR_POWER_COLLAPSE = 1 << 9,
};

struct ufs_hba_variant_params {
@@ -829,6 +836,12 @@ return true;
#endif
}

+static inline bool ufshcd_can_aggressive_pc(struct ufs_hba *hba)
+{
+ return !!(ufshcd_is_link_hibern8(hba) &&
+ (hba->caps & UFSHCD_CAP_AGGR_POWER_COLLAPSE));
+}
+
static inline bool ufshcd_is_auto_hibern8_supported(struct ufs_hba *hba)
{
return (hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT) &&
--
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