usb: ohci-at91: Forcibly suspend ports while USB suspend

The usb controller does not manage correctly the suspend mode for
the ehci. In echi mode, there is no way to suspend without any
device connected to it. This is why this specific control is added
to fix this issue. Since the suspend mode works in ohci mode, this
specific control works by suspend the usb controller in ohci mode.

This specific control is by setting the SUSPEND_A/B/C fields of
SFR_OHCIICR(OHCI Interrupt Configuration Register) in the SFR
while the OHCI USB suspend.

This set operation must be done before the USB clock disabled,
clear operation after the USB clock enabled.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ohci-at91.c

@@ -21,8 +21,11 @@
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
+#include <soc/at91/atmel-sfr.h>
 
 #include "ohci.h"
 
@@ -51,6 +54,7 @@ struct ohci_at91_priv {
 	struct clk *hclk;
 	bool clocked;
 	bool wakeup;		/* Saved wake-up state for resume */
+	struct regmap *sfr_regmap;
 };
 /* interface and function clocks; sometimes also an AHB clock */
 
@@ -134,6 +138,17 @@ static void at91_stop_hc(struct platform_device *pdev)
 
 static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
 
+struct regmap *at91_dt_syscon_sfr(void)
+{
+	struct regmap *regmap;
+
+	regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr");
+	if (IS_ERR(regmap))
+		regmap = NULL;
+
+	return regmap;
+}
+
 /* configure so an HC device and id are always provided */
 /* always called with process context; sleeping is OK */
 
@@ -197,6 +212,10 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver,
 		goto err;
 	}
 
+	ohci_at91->sfr_regmap = at91_dt_syscon_sfr();
+	if (!ohci_at91->sfr_regmap)
+		dev_warn(dev, "failed to find sfr node\n");
+
 	board = hcd->self.controller->platform_data;
 	ohci = hcd_to_ohci(hcd);
 	ohci->num_ports = board->ports;
@@ -282,13 +301,36 @@ static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
 	return length;
 }
 
+static int ohci_at91_port_suspend(struct regmap *regmap, u8 set)
+{
+	u32 regval;
+	int ret;
+
+	if (!regmap)
+		return 0;
+
+	ret = regmap_read(regmap, AT91_SFR_OHCIICR, &regval);
+	if (ret)
+		return ret;
+
+	if (set)
+		regval |= AT91_OHCIICR_USB_SUSPEND;
+	else
+		regval &= ~AT91_OHCIICR_USB_SUSPEND;
+
+	regmap_write(regmap, AT91_SFR_OHCIICR, regval);
+
+	return 0;
+}
+
 /*
  * Look at the control requests to the root hub and see if we need to override.
  */
 static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 				 u16 wIndex, char *buf, u16 wLength)
 {
 	struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
+	struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 	struct usb_hub_descriptor *desc;
 	int ret = -EINVAL;
 	u32 *data = (u32 *)buf;
@@ -301,14 +343,24 @@ static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
 	switch (typeReq) {
 	case SetPortFeature:
-		if (wValue == USB_PORT_FEAT_POWER) {
+		switch (wValue) {
+		case USB_PORT_FEAT_POWER:
 			dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
 			if (valid_port(wIndex)) {
 				ohci_at91_usb_set_power(pdata, wIndex, 1);
 				ret = 0;
 			}
 
 			goto out;
+
+		case USB_PORT_FEAT_SUSPEND:
+			dev_dbg(hcd->self.controller, "SetPortFeat: SUSPEND\n");
+			if (valid_port(wIndex)) {
+				ohci_at91_port_suspend(ohci_at91->sfr_regmap,
+						       1);
+				return 0;
+			}
+			break;
 		}
 		break;
 
@@ -342,6 +394,16 @@ static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 				ohci_at91_usb_set_power(pdata, wIndex, 0);
 				return 0;
 			}
+			break;
+
+		case USB_PORT_FEAT_SUSPEND:
+			dev_dbg(hcd->self.controller, "ClearPortFeature: SUSPEND\n");
+			if (valid_port(wIndex)) {
+				ohci_at91_port_suspend(ohci_at91->sfr_regmap,
+						       0);
+				return 0;
+			}
+			break;
 		}
 		break;
 	}
@@ -599,6 +661,8 @@ ohci_hcd_at91_drv_suspend(struct device *dev)
 	if (ohci_at91->wakeup)
 		enable_irq_wake(hcd->irq);
 
+	ohci_at91_port_suspend(ohci_at91->sfr_regmap, 1);
+
 	ret = ohci_suspend(hcd, ohci_at91->wakeup);
 	if (ret) {
 		if (ohci_at91->wakeup)
@@ -638,6 +702,9 @@ ohci_hcd_at91_drv_resume(struct device *dev)
 	at91_start_clock(ohci_at91);
 
 	ohci_resume(hcd, false);
+
+	ohci_at91_port_suspend(ohci_at91->sfr_regmap, 0);
+
 	return 0;
 }
 

include/soc/at91/atmel-sfr.h

@@ -13,6 +13,20 @@
 #ifndef _LINUX_MFD_SYSCON_ATMEL_SFR_H
 #define _LINUX_MFD_SYSCON_ATMEL_SFR_H
 
+#define AT91_SFR_DDRCFG		0x04	/* DDR Configuration Register */
+/* 0x08 ~ 0x0c: Reserved */
+#define AT91_SFR_OHCIICR	0x10	/* OHCI INT Configuration Register */
+#define AT91_SFR_OHCIISR	0x14	/* OHCI INT Status Register */
 #define AT91_SFR_I2SCLKSEL	0x90	/* I2SC Register */
 
+/* Field definitions */
+#define AT91_OHCIICR_SUSPEND_A	BIT(8)
+#define AT91_OHCIICR_SUSPEND_B	BIT(9)
+#define AT91_OHCIICR_SUSPEND_C	BIT(10)
+
+#define AT91_OHCIICR_USB_SUSPEND	(AT91_OHCIICR_SUSPEND_A | \
+					 AT91_OHCIICR_SUSPEND_B | \
+					 AT91_OHCIICR_SUSPEND_C)
+
+
 #endif /* _LINUX_MFD_SYSCON_ATMEL_SFR_H */