[PATCH v2 07/16] usb: dwc3: add lpm erratum support

[Huang Rui <ray.huang@amd.com>]

When parameter DWC_USB3_LPM_ERRATA_ENABLE is enabled in Andvanced Configuration
of coreConsultant, it supports of xHCI BESL Errata Dated 10/19/2011 is enabled
in host mode. In device mode it adds the capability to send NYET response based
on the BESL value received in the LPM token.

This patch add an entry that soc platform is able to define the lpm capacity
with their own device tree or bus glue layer.

Suggested-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
---
 drivers/usb/dwc3/core.c          |  2 ++
 drivers/usb/dwc3/core.h          | 24 +++++++++++++++---------
 drivers/usb/dwc3/dwc3-pci.c      |  1 +
 drivers/usb/dwc3/gadget.c        |  7 +++++++
 drivers/usb/dwc3/platform_data.h |  1 +
 5 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 819e501..25db533 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -708,11 +708,13 @@ static int dwc3_probe(struct platform_device *pdev)
 
 	if (node) {
 		dwc->maximum_speed = of_usb_get_maximum_speed(node);
+		dwc->has_lpm_erratum = of_property_read_bool(node, "snps,has-lpm-erratum");
 
 		dwc->needs_fifo_resize = of_property_read_bool(node, "tx-fifo-resize");
 		dwc->dr_mode = of_usb_get_dr_mode(node);
 	} else if (pdata) {
 		dwc->maximum_speed = pdata->maximum_speed;
+		dwc->has_lpm_erratum = pdata->has_lpm_erratum;
 
 		dwc->needs_fifo_resize = pdata->tx_fifo_resize;
 		dwc->dr_mode = pdata->dr_mode;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index cfe0d57..d58479e 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -246,16 +246,19 @@
 #define DWC3_DCTL_TRGTULST_SS_INACT	(DWC3_DCTL_TRGTULST(6))
 
 /* These apply for core versions 1.94a and later */
-#define DWC3_DCTL_KEEP_CONNECT	(1 << 19)
-#define DWC3_DCTL_L1_HIBER_EN	(1 << 18)
-#define DWC3_DCTL_CRS		(1 << 17)
-#define DWC3_DCTL_CSS		(1 << 16)
+#define DWC3_DCTL_LPM_ERRATA_MASK	DWC3_DCTL_LPM_ERRATA(0xf)
+#define DWC3_DCTL_LPM_ERRATA(n)		((n) << 20)
 
-#define DWC3_DCTL_INITU2ENA	(1 << 12)
-#define DWC3_DCTL_ACCEPTU2ENA	(1 << 11)
-#define DWC3_DCTL_INITU1ENA	(1 << 10)
-#define DWC3_DCTL_ACCEPTU1ENA	(1 << 9)
-#define DWC3_DCTL_TSTCTRL_MASK	(0xf << 1)
+#define DWC3_DCTL_KEEP_CONNECT		(1 << 19)
+#define DWC3_DCTL_L1_HIBER_EN		(1 << 18)
+#define DWC3_DCTL_CRS			(1 << 17)
+#define DWC3_DCTL_CSS			(1 << 16)
+
+#define DWC3_DCTL_INITU2ENA		(1 << 12)
+#define DWC3_DCTL_ACCEPTU2ENA		(1 << 11)
+#define DWC3_DCTL_INITU1ENA		(1 << 10)
+#define DWC3_DCTL_ACCEPTU1ENA		(1 << 9)
+#define DWC3_DCTL_TSTCTRL_MASK		(0xf << 1)
 
 #define DWC3_DCTL_ULSTCHNGREQ_MASK	(0x0f << 5)
 #define DWC3_DCTL_ULSTCHNGREQ(n) (((n) << 5) & DWC3_DCTL_ULSTCHNGREQ_MASK)
@@ -665,6 +668,8 @@ struct dwc3_scratchpad_array {
  * @ep0_bounced: true when we used bounce buffer
  * @ep0_expect_in: true when we expect a DATA IN transfer
  * @has_hibernation: true when dwc3 was configured with Hibernation
+ * @has_lpm_erratum: true when core was configured with LPM Erratum. Note that
+ *			there's now way for software to detect this in runtime.
  * @is_selfpowered: true when we are selfpowered
  * @is_fpga: true when we are using the FPGA board
  * @needs_fifo_resize: not all users might want fifo resizing, flag it
@@ -771,6 +776,7 @@ struct dwc3 {
 	unsigned		ep0_bounced:1;
 	unsigned		ep0_expect_in:1;
 	unsigned		has_hibernation:1;
+	unsigned		has_lpm_erratum:1;
 	unsigned		is_selfpowered:1;
 	unsigned		is_fpga:1;
 	unsigned		needs_fifo_resize:1;
diff --git a/drivers/usb/dwc3/dwc3-pci.c b/drivers/usb/dwc3/dwc3-pci.c
index a89db6c..bbe946c 100644
--- a/drivers/usb/dwc3/dwc3-pci.c
+++ b/drivers/usb/dwc3/dwc3-pci.c
@@ -148,6 +148,7 @@ static int dwc3_pci_probe(struct pci_dev *pci,
 
 	if (pci->vendor == PCI_VENDOR_ID_AMD && pci->device ==
 			PCI_DEVICE_ID_AMD_NL) {
+		dwc3_pdata.has_lpm_erratum = true;
 		dwc3_pdata.quirks |= DWC3_QUIRK_AMD_NL;
 	}
 
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 1f2a719..33bfc70 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1581,6 +1581,13 @@ static int dwc3_gadget_start(struct usb_gadget *g,
 	}
 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
 
+	if (dwc->has_lpm_erratum) {
+		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+		/* REVISIT should this be configurable ? */
+		reg |= DWC3_DCTL_LPM_ERRATA(0xf);
+		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+	}
+
 	dwc->start_config_issued = false;
 
 	/* Start with SuperSpeed Default */
diff --git a/drivers/usb/dwc3/platform_data.h b/drivers/usb/dwc3/platform_data.h
index 9c5f074..098ab04 100644
--- a/drivers/usb/dwc3/platform_data.h
+++ b/drivers/usb/dwc3/platform_data.h
@@ -25,6 +25,7 @@ struct dwc3_platform_data {
 	enum usb_dr_mode dr_mode;
 	bool tx_fifo_resize;
 
+	unsigned has_lpm_erratum:1;
 	u32     quirks;
 
 #define DWC3_QUIRK_AMD_NL		(1 << 0)
-- 
1.9.1