[PATCH][v2] drivers: usb: fsl: Workaround for USB erratum-A005275

[Nikhil Badola]

Incoming packets in high speed are randomly corrupted by h/w
resulting in multiple errors. This workaround makes FS as
default mode in all affected socs by disabling HS chirp
signalling.This errata does not affect FS and LS mode.

Forces all HS devices to connect in FS mode for all socs
affected by this erratum:
P3041 and P2041 rev 1.0 and 1.1
P5020 and P5010 rev 1.0 and 2.0
P5040, P1010 and T4240 rev 1.0

Signed-off-by: Ramneek Mehresh <ramneek.mehresh@xxxxxxxxxxxxx>
Signed-off-by: Nikhil Badola <nikhil.badola@xxxxxxxxxxxxx>
---
changes for v2: 
	- Changed PFSC bit writing hunk position
	- Changed ehci_has_fsl_hs_errata(e) definition hunk position

 drivers/usb/host/ehci-fsl.c      |  4 ++++
 drivers/usb/host/ehci-hub.c      |  7 +++++++
 drivers/usb/host/ehci.h          | 12 ++++++++++++
 drivers/usb/host/fsl-mph-dr-of.c |  4 ++++
 include/linux/fsl_devices.h      |  1 +
 5 files changed, 28 insertions(+)

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 202dafb..3b6eb21 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -278,6 +278,10 @@ static int ehci_fsl_usb_setup(struct ehci_hcd *ehci)
 		out_be32(non_ehci + FSL_SOC_USB_SNOOP2, 0x80000000 | SNOOP_SIZE_2GB);
 	}
 
+	/* Deal with USB erratum A-005275 */
+	if (pdata->has_fsl_erratum_a005275 == 1)
+		ehci->has_fsl_hs_errata = 1;
+
 	if ((pdata->operating_mode == FSL_USB2_DR_HOST) ||
 			(pdata->operating_mode == FSL_USB2_DR_OTG))
 		if (ehci_fsl_setup_phy(hcd, pdata->phy_mode, 0))
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 22abb68..086a711 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -1221,6 +1221,13 @@ int ehci_hub_control(
 				 */
 				ehci->reset_done [wIndex] = jiffies
 						+ msecs_to_jiffies (50);
+
+				/*
+				 * Force full-speed connect for FSL high-speed
+				 * erratum; disable HS Chirp by setting PFSC bit
+				 */
+				if (ehci_has_fsl_hs_errata(ehci))
+					temp |= (1 << PORTSC_FSL_PFSC);
 			}
 			ehci_writel(ehci, temp, status_reg);
 			break;
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index f700157..46f62e4 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -215,6 +215,7 @@ struct ehci_hcd {			/* one per controller */
 	/* SILICON QUIRKS */
 	unsigned		no_selective_suspend:1;
 	unsigned		has_fsl_port_bug:1; /* FreeScale */
+	unsigned		has_fsl_hs_errata:1;	/* Freescale HS quirk */
 	unsigned		big_endian_mmio:1;
 	unsigned		big_endian_desc:1;
 	unsigned		big_endian_capbase:1;
@@ -686,6 +687,17 @@ ehci_port_speed(struct ehci_hcd *ehci, unsigned int portsc)
 #define	ehci_has_fsl_portno_bug(e)		(0)
 #endif
 
+#define PORTSC_FSL_PFSC	24	/* Port Force Full-Speed Connect */
+
+#if defined(CONFIG_PPC_85xx)
+/* Some Freescale processors have an erratum (USB A-005275) in which
+ * incoming packets get corrupted in HS mode
+ */
+#define ehci_has_fsl_hs_errata(e)	((e)->has_fsl_hs_errata)
+#else
+#define ehci_has_fsl_hs_errata(e)	(0)
+#endif
+
 /*
  * While most USB host controllers implement their registers in
  * little-endian format, a minority (celleb companion chip) implement
diff --git a/drivers/usb/host/fsl-mph-dr-of.c b/drivers/usb/host/fsl-mph-dr-of.c
index 9f73141..534c4c5 100644
--- a/drivers/usb/host/fsl-mph-dr-of.c
+++ b/drivers/usb/host/fsl-mph-dr-of.c
@@ -221,6 +221,10 @@ static int fsl_usb2_mph_dr_of_probe(struct platform_device *ofdev)
 		pdata->has_fsl_erratum_a007792 = 1;
 	else
 		pdata->has_fsl_erratum_a007792 = 0;
+	if (of_get_property(np, "fsl,usb-erratum-a005275", NULL))
+		pdata->has_fsl_erratum_a005275 = 1;
+	else
+		pdata->has_fsl_erratum_a005275 = 0;
 
 	/*
 	 * Determine whether phy_clk_valid needs to be checked
diff --git a/include/linux/fsl_devices.h b/include/linux/fsl_devices.h
index cebdbbb..f291291 100644
--- a/include/linux/fsl_devices.h
+++ b/include/linux/fsl_devices.h
@@ -99,6 +99,7 @@ struct fsl_usb2_platform_data {
 	unsigned	suspended:1;
 	unsigned	already_suspended:1;
 	unsigned        has_fsl_erratum_a007792:1;
+	unsigned        has_fsl_erratum_a005275:1;
 	unsigned        check_phy_clk_valid:1;
 
 	/* register save area for suspend/resume */
-- 
2.1.0

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