phy: qcom-qmp-combo: drop power-down delay config

The power-down delay was included in the first version of the QMP driver
as an optional delay after powering on the PHY (using
POWER_DOWN_CONTROL) and just before starting it. Later changes modified
this sequence by powering on before initialising the PHY, but the
optional delay stayed where it was (i.e. before starting the PHY).

The vendor driver does not use a delay before starting the PHY and this
is likely not needed on any platform unless there is a corresponding
delay in the vendor kernel init sequence tables (i.e. in devicetree).

Let's keep the delay for now, but drop the redundant delay period
configuration while increasing the unnecessarily low timer slack
somewhat.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20221012081241.18273-13-johan+linaro@kernel.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/qualcomm/phy-qcom-qmp-combo.c

@@ -63,8 +63,6 @@
 #define CLAMP_EN				BIT(0) /* enables i/o clamp_n */
 
 #define PHY_INIT_COMPLETE_TIMEOUT		10000
-#define POWER_DOWN_DELAY_US_MIN			10
-#define POWER_DOWN_DELAY_US_MAX			11
 
 struct qmp_phy_init_tbl {
 	unsigned int offset;
@@ -860,9 +858,6 @@ struct qmp_phy_cfg {
 
 	/* true, if PHY needs delay after POWER_DOWN */
 	bool has_pwrdn_delay;
-	/* power_down delay in usec */
-	int pwrdn_delay_min;
-	int pwrdn_delay_max;
 
 	/* Offset from PCS to PCS_USB region */
 	unsigned int pcs_usb_offset;
@@ -1031,8 +1026,6 @@ static const struct qmp_phy_cfg sc7180_usb3phy_cfg = {
 	.phy_status		= PHYSTATUS,
 
 	.has_pwrdn_delay	= true,
-	.pwrdn_delay_min	= POWER_DOWN_DELAY_US_MIN,
-	.pwrdn_delay_max	= POWER_DOWN_DELAY_US_MAX,
 };
 
 static const struct qmp_phy_cfg sc7180_dpphy_cfg = {
@@ -1102,8 +1095,6 @@ static const struct qmp_phy_cfg sdm845_usb3phy_cfg = {
 	.phy_status		= PHYSTATUS,
 
 	.has_pwrdn_delay	= true,
-	.pwrdn_delay_min	= POWER_DOWN_DELAY_US_MIN,
-	.pwrdn_delay_max	= POWER_DOWN_DELAY_US_MAX,
 };
 
 static const struct qmp_phy_combo_cfg sdm845_usb3dpphy_cfg = {
@@ -1138,10 +1129,7 @@ static const struct qmp_phy_cfg sm8150_usb3phy_cfg = {
 	.pwrdn_ctrl		= SW_PWRDN,
 	.phy_status		= PHYSTATUS,
 
-
 	.has_pwrdn_delay	= true,
-	.pwrdn_delay_min	= POWER_DOWN_DELAY_US_MIN,
-	.pwrdn_delay_max	= POWER_DOWN_DELAY_US_MAX,
 };
 
 static const struct qmp_phy_cfg sc8180x_dpphy_cfg = {
@@ -1282,8 +1270,6 @@ static const struct qmp_phy_cfg sm8250_usb3phy_cfg = {
 	.phy_status		= PHYSTATUS,
 
 	.has_pwrdn_delay	= true,
-	.pwrdn_delay_min	= POWER_DOWN_DELAY_US_MIN,
-	.pwrdn_delay_max	= POWER_DOWN_DELAY_US_MAX,
 };
 
 static const struct qmp_phy_cfg sm8250_dpphy_cfg = {
@@ -2064,7 +2050,7 @@ static int qmp_combo_power_on(struct phy *phy)
 		qmp_combo_configure(pcs, cfg->pcs_tbl, cfg->pcs_tbl_num);
 
 	if (cfg->has_pwrdn_delay)
-		usleep_range(cfg->pwrdn_delay_min, cfg->pwrdn_delay_max);
+		usleep_range(10, 20);
 
 	if (cfg->type != PHY_TYPE_DP) {
 		/* Pull PHY out of reset state */