[RFC PATCH 2/4] usb: dwc3: core: add gfladj_refclk_lpm_sel quirk

[Alexander Stein]

This selects the SOF/ITP counter be running on ref_clk. As documented
U2_FREECLK_EXISTS has to be set to 0 as well.

Signed-off-by: Alexander Stein <alexander.stein at ew.tq-group.com>
---
 drivers/usb/dwc3/core.c | 8 +++++++-
 drivers/usb/dwc3/core.h | 2 ++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index cb8742f2a4b0..e000f3898a6a 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -403,6 +403,10 @@ static void dwc3_ref_clk_period(struct dwc3 *dwc)
 	reg |= FIELD_PREP(DWC3_GFLADJ_REFCLK_FLADJ_MASK, fladj)
 	    |  FIELD_PREP(DWC3_GFLADJ_240MHZDECR, decr >> 1)
 	    |  FIELD_PREP(DWC3_GFLADJ_240MHZDECR_PLS1, decr & 1);
+
+	if (dwc->gfladj_refclk_lpm_sel)
+		reg |=  DWC3_GFLADJ_REFCLK_LPM_SEL;
+
 	dwc3_writel(dwc->regs, DWC3_GFLADJ, reg);
 }
 
@@ -784,7 +788,7 @@ static int dwc3_phy_setup(struct dwc3 *dwc)
 	else
 		reg |= DWC3_GUSB2PHYCFG_ENBLSLPM;
 
-	if (dwc->dis_u2_freeclk_exists_quirk)
+	if (dwc->dis_u2_freeclk_exists_quirk || dwc->gfladj_refclk_lpm_sel)
 		reg &= ~DWC3_GUSB2PHYCFG_U2_FREECLK_EXISTS;
 
 	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
@@ -1519,6 +1523,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 				"snps,dis-tx-ipgap-linecheck-quirk");
 	dwc->parkmode_disable_ss_quirk = device_property_read_bool(dev,
 				"snps,parkmode-disable-ss-quirk");
+	dwc->gfladj_refclk_lpm_sel = device_property_read_bool(dev,
+				"snps,gfladj-refclk-lpm-sel-quirk");
 
 	dwc->tx_de_emphasis_quirk = device_property_read_bool(dev,
 				"snps,tx_de_emphasis_quirk");
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 722808d8c0af..92ce2743ccc8 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -391,6 +391,7 @@
 #define DWC3_GFLADJ_30MHZ_SDBND_SEL		BIT(7)
 #define DWC3_GFLADJ_30MHZ_MASK			0x3f
 #define DWC3_GFLADJ_REFCLK_FLADJ_MASK		GENMASK(21, 8)
+#define DWC3_GFLADJ_REFCLK_LPM_SEL		BIT(23)
 #define DWC3_GFLADJ_240MHZDECR			GENMASK(30, 24)
 #define DWC3_GFLADJ_240MHZDECR_PLS1		BIT(31)
 
@@ -1310,6 +1311,7 @@ struct dwc3 {
 	unsigned		dis_del_phy_power_chg_quirk:1;
 	unsigned		dis_tx_ipgap_linecheck_quirk:1;
 	unsigned		parkmode_disable_ss_quirk:1;
+	unsigned		gfladj_refclk_lpm_sel:1;
 
 	unsigned		tx_de_emphasis_quirk:1;
 	unsigned		tx_de_emphasis:2;
-- 
2.25.1