[PATCH 3/3] USB: ehci-fsl: Add power management support (resume after deep sleep)

[Anton Vorontsov]

EHCI FSL controller preserve its state during sleep mode, so nothing
fancy needs to be done.

Though, during 'deep sleep' mode (as found in MPC831x CPUs) the
controller turns off and needs to be reinitialized upon resume.

This patch adds support for resuming after deep sleep. Based on Dave
Liu and Jerry Huang's work.

Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
---
 drivers/usb/host/ehci-fsl.c |   88 +++++++++++++++++++++++++++++++++++++++---
 1 files changed, 81 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 593a7e7..4454f1e 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -1,5 +1,6 @@
 /*
- * Copyright (c) 2005 MontaVista Software
+ * Copyright 2005-2009 MontaVista Software, Inc.
+ * Copyright 2008      Freescale Semiconductor, Inc.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -17,17 +18,18 @@
  *
  * Ported to 834x by Randy Vinson <rvinson at mvista.com> using code provided
  * by Hunter Wu.
+ * Power Management support by Dave Liu <daveliu at freescale.com> and
+ * Jerry Huang <Chang-Ming.Huang at freescale.com>.
  */
 
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/fsl_devices.h>
 
 #include "ehci-fsl.h"
 
-/* FIXME: Power Management is un-ported so temporarily disable it */
-#undef CONFIG_PM
-
-
 /* configure so an HC device and id are always provided */
 /* always called with process context; sleeping is OK */
 
@@ -285,10 +287,81 @@ static int ehci_fsl_setup(struct usb_hcd *hcd)
 	return retval;
 }
 
+#ifdef CONFIG_SUSPEND
+struct ehci_fsl {
+	struct ehci_hcd	ehci;
+
+	/* Saved USB PHY settings, need to restore after deep sleep. */
+	u32 usb_ctrl;
+};
+
+static struct ehci_fsl *hcd_to_ehci_fsl(struct usb_hcd *hcd)
+{
+	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+
+	return container_of(ehci, struct ehci_fsl, ehci);
+}
+
+static int ehci_fsl_drv_suspend(struct device *dev)
+{
+	struct usb_hcd *hcd = dev_get_drvdata(dev);
+	struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
+	void __iomem *non_ehci = hcd->regs;
+
+	if (!fsl_deep_sleep())
+		return 0;
+
+	ehci_fsl->usb_ctrl = in_be32(non_ehci + FSL_SOC_USB_CTRL);
+	return 0;
+}
+
+static int ehci_fsl_drv_resume(struct device *dev)
+{
+	struct usb_hcd *hcd = dev_get_drvdata(dev);
+	struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
+	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+	void __iomem *non_ehci = hcd->regs;
+	int port_nm;
+
+	if (!fsl_deep_sleep())
+		return 0;
+
+	/* Restore USB PHY settings and enable the controller. */
+	out_be32(non_ehci + FSL_SOC_USB_CTRL, ehci_fsl->usb_ctrl);
+
+	ehci_reset(ehci);
+	ehci_fsl_reinit(ehci);
+
+	/* Power up ports (avoids devices disconnect). */
+	port_nm = HCS_N_PORTS(ehci->hcs_params);
+	while (port_nm--) {
+		u32 port_sc;
+
+		port_sc = ehci_readl(ehci, &ehci->regs->port_status[port_nm]);
+		port_sc |= PORT_POWER;
+		ehci_writel(ehci, port_sc, &ehci->regs->port_status[port_nm]);
+	}
+	mdelay(30);
+
+	return 0;
+}
+
+static struct dev_pm_ops ehci_fsl_pm_ops = {
+	.suspend = ehci_fsl_drv_suspend,
+	.resume = ehci_fsl_drv_resume,
+};
+
+#define EHCI_FSL_PRIV_SIZE	sizeof(struct ehci_fsl)
+#define EHCI_FSL_PM_OPS		(&ehci_fsl_pm_ops)
+#else
+#define EHCI_FSL_PRIV_SIZE	sizeof(struct ehci_hcd)
+#define EHCI_FSL_PM_OPS		NULL
+#endif /* CONFIG_SUSPEND */
+
 static const struct hc_driver ehci_fsl_hc_driver = {
 	.description = hcd_name,
 	.product_desc = "Freescale On-Chip EHCI Host Controller",
-	.hcd_priv_size = sizeof(struct ehci_hcd),
+	.hcd_priv_size = EHCI_FSL_PRIV_SIZE,
 
 	/*
 	 * generic hardware linkage
@@ -355,6 +428,7 @@ static struct platform_driver ehci_fsl_driver = {
 	.remove = ehci_fsl_drv_remove,
 	.shutdown = usb_hcd_platform_shutdown,
 	.driver = {
-		   .name = "fsl-ehci",
+		.name = "fsl-ehci",
+		.pm = EHCI_FSL_PM_OPS,
 	},
 };
-- 
1.6.3.3