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scsi: ufs: core: Allow host driver to disable wb toggling during clock scaling

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Mediatek UFS does not want to toggle write booster during clock scaling.
Permit host driver to disable wb toggling during clock scaling.

Introduce a flag UFSHCD_CAP_WB_WITH_CLK_SCALING to decouple WB and clock
scaling.  UFSHCD_CAP_WB_WITH_CLK_SCALING is only valid when
UFSHCD_CAP_CLK_SCALING is set. Just like UFSHCD_CAP_HIBERN8_WITH_CLK_GATING
is valid only when UFSHCD_CAP_CLK_GATING set.

Set UFSHCD_CAP_WB_WITH_CLK_SCALING for qcom to compatible legacy design at
the same time.

Link: https://lore.kernel.org/r/20220804025422.18803-1-peter.wang@mediatek.com
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Peter Wang 2022-08-04 10:54:22 +08:00 committed by Martin K. Petersen
parent 0f85e74756
commit 87bd05016a
4 changed files with 19 additions and 5 deletions
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3
drivers/ufs/core/ufs-sysfs.c
View file

@ -225,7 +225,8 @@ static ssize_t wb_on_store(struct device *dev, struct device_attribute *attr,
unsigned int wb_enable;
ssize_t res;
if (!ufshcd_is_wb_allowed(hba) || ufshcd_is_clkscaling_supported(hba)) {
if (!ufshcd_is_wb_allowed(hba) || (ufshcd_is_clkscaling_supported(hba)
&& ufshcd_enable_wb_if_scaling_up(hba))) {
/*
* If the platform supports UFSHCD_CAP_CLK_SCALING, turn WB
* on/off will be done while clock scaling up/down.

8
drivers/ufs/core/ufshcd.c
View file

@ -1299,9 +1299,11 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
}
/* Enable Write Booster if we have scaled up else disable it */
downgrade_write(&hba->clk_scaling_lock);
is_writelock = false;
ufshcd_wb_toggle(hba, scale_up);
if (ufshcd_enable_wb_if_scaling_up(hba)) {
downgrade_write(&hba->clk_scaling_lock);
is_writelock = false;
ufshcd_wb_toggle(hba, scale_up);
}
out_unprepare:
ufshcd_clock_scaling_unprepare(hba, is_writelock);

2
drivers/ufs/host/ufs-qcom.c
View file

@ -846,7 +846,7 @@ static void ufs_qcom_set_caps(struct ufs_hba *hba)
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
hba->caps |= UFSHCD_CAP_CLK_GATING | UFSHCD_CAP_HIBERN8_WITH_CLK_GATING;
hba->caps |= UFSHCD_CAP_CLK_SCALING;
hba->caps |= UFSHCD_CAP_CLK_SCALING | UFSHCD_CAP_WB_WITH_CLK_SCALING;
hba->caps |= UFSHCD_CAP_AUTO_BKOPS_SUSPEND;
hba->caps |= UFSHCD_CAP_WB_EN;
hba->caps |= UFSHCD_CAP_CRYPTO;

11
include/ufs/ufshcd.h
View file

@ -664,6 +664,12 @@ enum ufshcd_caps {
* notification if it is supported by the UFS device.
*/
UFSHCD_CAP_TEMP_NOTIF = 1 << 11,
/*
* Enable WriteBooster when scaling up the clock and disable
* WriteBooster when scaling the clock down.
*/
UFSHCD_CAP_WB_WITH_CLK_SCALING = 1 << 12,
};
struct ufs_hba_variant_params {
@ -1021,6 +1027,11 @@ static inline bool ufshcd_is_wb_allowed(struct ufs_hba *hba)
return hba->caps & UFSHCD_CAP_WB_EN;
}
static inline bool ufshcd_enable_wb_if_scaling_up(struct ufs_hba *hba)
{
return hba->caps & UFSHCD_CAP_WB_WITH_CLK_SCALING;
}
#define ufshcd_writel(hba, val, reg) \
writel((val), (hba)->mmio_base + (reg))
#define ufshcd_readl(hba, reg) \