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

Message ID 20090923185244.GC18755@oksana.dev.rtsoft.ru (mailing list archive)
State Superseded
Delegated to: Kumar Gala
Headers show

Commit Message

Anton Vorontsov Sept. 23, 2009, 6:52 p.m. UTC
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@ru.mvista.com>
---
 drivers/usb/host/ehci-fsl.c |   88 +++++++++++++++++++++++++++++++++++++++---
 1 files changed, 81 insertions(+), 7 deletions(-)

Comments

Scott Wood Sept. 25, 2009, 2:30 a.m. UTC | #1
On Wed, Sep 23, 2009 at 10:52:44PM +0400, Anton Vorontsov wrote:
+#ifdef CONFIG_SUSPEND
+struct ehci_fsl {
+       struct ehci_hcd ehci;
+
+       /* Saved USB PHY settings, need to restore after deep sleep. */
+       u32 usb_ctrl;
+};

This doesn't seem like the right place to define this... what if we later
need something else that isn't for suspend?  And you could get rid of
EHCI_FSL_PRIV_SIZE.

> +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;

We'll also need to do this if we support suspend to disk...  is there any
good way for the driver to determine that that's what's being done?  Or
more generally, for the platform to communicate to the drivers which ones
are going to lose state without one-off hacks like fsl_deep_sleep().

> +	/* 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);

Instead of mdelay, can we somehow hold off any USB operations for a
while?

-Scott
diff mbox

Patch

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@mvista.com> using code provided
  * by Hunter Wu.
+ * Power Management support by Dave Liu <daveliu@freescale.com> and
+ * Jerry Huang <Chang-Ming.Huang@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,
 	},
 };