drivers/usb/host/ohci-s3c2410.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-1.0+
 /*
  * OHCI HCD (Host Controller Driver) for USB.
  *
  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
  * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
  * (C) Copyright 2002 Hewlett-Packard Company
  *
  * USB Bus Glue for Samsung S3C2410
  *
  * Written by Christopher Hoover <ch@hpl.hp.com>
  * Based on fragments of previous driver by Russell King et al.
  *
  * Modified for S3C2410 from ohci-sa1111.c, ohci-omap.c and ohci-lh7a40.c
  *	by Ben Dooks, <ben@simtec.co.uk>
  *	Copyright (C) 2004 Simtec Electronics
  *
  * Thanks to basprog@mail.ru for updates to newer kernels
  *
  * This file is licenced under the GPL.
 */

 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/usb-ohci-s3c2410.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>

 #include "ohci.h"


 #define valid_port(idx) ((idx) == 1 || (idx) == 2)

 /* clock device associated with the hcd */


 #define DRIVER_DESC "OHCI S3C2410 driver"

 static struct clk *clk;
 static struct clk *usb_clk;

 static struct hc_driver __read_mostly ohci_s3c2410_hc_driver;

 /* forward definitions */

 static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc);

 /* conversion functions */

 static struct s3c2410_hcd_info *to_s3c2410_info(struct usb_hcd *hcd)
 {
 	return dev_get_platdata(hcd->self.controller);
 }

 static void s3c2410_start_hc(struct platform_device *dev, struct usb_hcd *hcd)
 {
 	struct s3c2410_hcd_info *info = dev_get_platdata(&dev->dev);

 	dev_dbg(&dev->dev, "s3c2410_start_hc:\n");

 	clk_prepare_enable(usb_clk);
 	mdelay(2);			/* let the bus clock stabilise */

 	clk_prepare_enable(clk);

 	if (info != NULL) {
 		info->hcd	= hcd;
 		info->report_oc = s3c2410_hcd_oc;

 		if (info->enable_oc != NULL)
 			(info->enable_oc)(info, 1);
 	}
 }

 static void s3c2410_stop_hc(struct platform_device *dev)
 {
 	struct s3c2410_hcd_info *info = dev_get_platdata(&dev->dev);

 	dev_dbg(&dev->dev, "s3c2410_stop_hc:\n");

 	if (info != NULL) {
 		info->report_oc = NULL;
 		info->hcd	= NULL;

 		if (info->enable_oc != NULL)
 			(info->enable_oc)(info, 0);
 	}

 	clk_disable_unprepare(clk);
 	clk_disable_unprepare(usb_clk);
 }

 /* ohci_s3c2410_hub_status_data
  *
  * update the status data from the hub with anything that
  * has been detected by our system
 */

 static int
 ohci_s3c2410_hub_status_data(struct usb_hcd *hcd, char *buf)
 {
 	struct s3c2410_hcd_info *info = to_s3c2410_info(hcd);
 	struct s3c2410_hcd_port *port;
 	int orig;
 	int portno;

 	orig = ohci_hub_status_data(hcd, buf);

 	if (info == NULL)
 		return orig;

 	port = &info->port[0];

 	/* mark any changed port as changed */

 	for (portno = 0; portno < 2; port++, portno++) {
 		if (port->oc_changed == 1 &&
 		    port->flags & S3C_HCDFLG_USED) {
 			dev_dbg(hcd->self.controller,
 				"oc change on port %d\n", portno);

 			if (orig < 1)
 				orig = 1;

 			buf[0] |= 1<<(portno+1);
 		}
 	}

 	return orig;
 }

 /* s3c2410_usb_set_power
  *
  * configure the power on a port, by calling the platform device
  * routine registered with the platform device
 */

 static void s3c2410_usb_set_power(struct s3c2410_hcd_info *info,
 				  int port, int to)
 {
 	if (info == NULL)
 		return;

 	if (info->power_control != NULL) {
 		info->port[port-1].power = to;
 		(info->power_control)(port-1, to);
 	}
 }

 /* ohci_s3c2410_hub_control
  *
  * look at control requests to the hub, and see if we need
  * to take any action or over-ride the results from the
  * request.
 */

 static int ohci_s3c2410_hub_control(
 	struct usb_hcd	*hcd,
 	u16		typeReq,
 	u16		wValue,
 	u16		wIndex,
 	char		*buf,
 	u16		wLength)
 {
 	struct s3c2410_hcd_info *info = to_s3c2410_info(hcd);
 	struct usb_hub_descriptor *desc;
 	int ret = -EINVAL;
 	u32 *data = (u32 *)buf;

 	dev_dbg(hcd->self.controller,
 		"s3c2410_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
 		hcd, typeReq, wValue, wIndex, buf, wLength);

 	/* if we are only an humble host without any special capabilities
 	 * process the request straight away and exit */

 	if (info == NULL) {
 		ret = ohci_hub_control(hcd, typeReq, wValue,
 				       wIndex, buf, wLength);
 		goto out;
 	}

 	/* check the request to see if it needs handling */

 	switch (typeReq) {
 	case SetPortFeature:
 		if (wValue == USB_PORT_FEAT_POWER) {
 			dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
 			s3c2410_usb_set_power(info, wIndex, 1);
 			goto out;
 		}
 		break;

 	case ClearPortFeature:
 		switch (wValue) {
 		case USB_PORT_FEAT_C_OVER_CURRENT:
 			dev_dbg(hcd->self.controller,
 				"ClearPortFeature: C_OVER_CURRENT\n");

 			if (valid_port(wIndex)) {
 				info->port[wIndex-1].oc_changed = 0;
 				info->port[wIndex-1].oc_status = 0;
 			}

 			goto out;

 		case USB_PORT_FEAT_OVER_CURRENT:
 			dev_dbg(hcd->self.controller,
 				"ClearPortFeature: OVER_CURRENT\n");

 			if (valid_port(wIndex))
 				info->port[wIndex-1].oc_status = 0;

 			goto out;

 		case USB_PORT_FEAT_POWER:
 			dev_dbg(hcd->self.controller,
 				"ClearPortFeature: POWER\n");

 			if (valid_port(wIndex)) {
 				s3c2410_usb_set_power(info, wIndex, 0);
 				return 0;
 			}
 		}
 		break;
 	}

 	ret = ohci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
 	if (ret)
 		goto out;

 	switch (typeReq) {
 	case GetHubDescriptor:

 		/* update the hub's descriptor */

 		desc = (struct usb_hub_descriptor *)buf;

 		if (info->power_control == NULL)
 			return ret;

 		dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
 			desc->wHubCharacteristics);

 		/* remove the old configurations for power-switching, and
 		 * over-current protection, and insert our new configuration
 		 */

 		desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
 		desc->wHubCharacteristics |= cpu_to_le16(
 			HUB_CHAR_INDV_PORT_LPSM);

 		if (info->enable_oc) {
 			desc->wHubCharacteristics &= ~cpu_to_le16(
 				HUB_CHAR_OCPM);
 			desc->wHubCharacteristics |=  cpu_to_le16(
 				HUB_CHAR_INDV_PORT_OCPM);
 		}

 		dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
 			desc->wHubCharacteristics);

 		return ret;

 	case GetPortStatus:
 		/* check port status */

 		dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);

 		if (valid_port(wIndex)) {
 			if (info->port[wIndex-1].oc_changed)
 				*data |= cpu_to_le32(RH_PS_OCIC);

 			if (info->port[wIndex-1].oc_status)
 				*data |= cpu_to_le32(RH_PS_POCI);
 		}
 	}

  out:
 	return ret;
 }

 /* s3c2410_hcd_oc
  *
  * handle an over-current report
 */

 static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc)
 {
 	struct s3c2410_hcd_port *port;
 	unsigned long flags;
 	int portno;

 	if (info == NULL)
 		return;

 	port = &info->port[0];

 	local_irq_save(flags);

 	for (portno = 0; portno < 2; port++, portno++) {
 		if (port_oc & (1<<portno) &&
 		    port->flags & S3C_HCDFLG_USED) {
 			port->oc_status = 1;
 			port->oc_changed = 1;

 			/* ok, once over-current is detected,
 			   the port needs to be powered down */
 			s3c2410_usb_set_power(info, portno+1, 0);
 		}
 	}

 	local_irq_restore(flags);
 }

 /* may be called without controller electrically present */
 /* may be called with controller, bus, and devices active */

 /*
  * ohci_hcd_s3c2410_remove - shutdown processing for HCD
  * @dev: USB Host Controller being removed
  *
  * Context: task context, might sleep
  *
  * Reverses the effect of ohci_hcd_3c2410_probe(), first invoking
  * the HCD's stop() method.  It is always called from a thread
  * context, normally "rmmod", "apmd", or something similar.
  */
 static int
 ohci_hcd_s3c2410_remove(struct platform_device *dev)
 {
 	struct usb_hcd *hcd = platform_get_drvdata(dev);

 	usb_remove_hcd(hcd);
 	s3c2410_stop_hc(dev);
 	usb_put_hcd(hcd);
 	return 0;
 }

 /*
  * ohci_hcd_s3c2410_probe - initialize S3C2410-based HCDs
  * @dev: USB Host Controller to be probed
  *
  * Context: task context, might sleep
  *
  * Allocates basic resources for this USB host controller, and
  * then invokes the start() method for the HCD associated with it
  * through the hotplug entry's driver_data.
  */
 static int ohci_hcd_s3c2410_probe(struct platform_device *dev)
 {
 	struct usb_hcd *hcd = NULL;
 	struct s3c2410_hcd_info *info = dev_get_platdata(&dev->dev);
 	int retval, irq;

 	s3c2410_usb_set_power(info, 1, 1);
 	s3c2410_usb_set_power(info, 2, 1);

 	hcd = usb_create_hcd(&ohci_s3c2410_hc_driver, &dev->dev, "s3c24xx");
 	if (hcd == NULL)
 		return -ENOMEM;

 	hcd->rsrc_start = dev->resource[0].start;
 	hcd->rsrc_len	= resource_size(&dev->resource[0]);

 	hcd->regs = devm_ioremap_resource(&dev->dev, &dev->resource[0]);
 	if (IS_ERR(hcd->regs)) {
 		retval = PTR_ERR(hcd->regs);
 		goto err_put;
 	}

 	clk = devm_clk_get(&dev->dev, "usb-host");
 	if (IS_ERR(clk)) {
 		dev_err(&dev->dev, "cannot get usb-host clock\n");
 		retval = PTR_ERR(clk);
 		goto err_put;
 	}

 	usb_clk = devm_clk_get(&dev->dev, "usb-bus-host");
 	if (IS_ERR(usb_clk)) {
 		dev_err(&dev->dev, "cannot get usb-bus-host clock\n");
 		retval = PTR_ERR(usb_clk);
 		goto err_put;
 	}

 	irq = platform_get_irq(dev, 0);
 	if (irq < 0) {
 		retval = irq;
 		goto err_put;
 	}

 	s3c2410_start_hc(dev, hcd);

 	retval = usb_add_hcd(hcd, irq, 0);
 	if (retval != 0)
 		goto err_ioremap;

 	device_wakeup_enable(hcd->self.controller);
 	return 0;

  err_ioremap:
 	s3c2410_stop_hc(dev);

  err_put:
 	usb_put_hcd(hcd);
 	return retval;
 }

 /*-------------------------------------------------------------------------*/

 #ifdef CONFIG_PM
 static int ohci_hcd_s3c2410_drv_suspend(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
 	struct platform_device *pdev = to_platform_device(dev);
 	bool do_wakeup = device_may_wakeup(dev);
 	int rc = 0;

 	rc = ohci_suspend(hcd, do_wakeup);
 	if (rc)
 		return rc;

 	s3c2410_stop_hc(pdev);

 	return rc;
 }

 static int ohci_hcd_s3c2410_drv_resume(struct device *dev)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(dev);
 	struct platform_device *pdev = to_platform_device(dev);

 	s3c2410_start_hc(pdev, hcd);

 	ohci_resume(hcd, false);

 	return 0;
 }
 #else
 #define ohci_hcd_s3c2410_drv_suspend	NULL
 #define ohci_hcd_s3c2410_drv_resume	NULL
 #endif

 static const struct dev_pm_ops ohci_hcd_s3c2410_pm_ops = {
 	.suspend	= ohci_hcd_s3c2410_drv_suspend,
 	.resume		= ohci_hcd_s3c2410_drv_resume,
 };

 static const struct of_device_id ohci_hcd_s3c2410_dt_ids[] = {
 	{ .compatible = "samsung,s3c2410-ohci" },
 	{ /* sentinel */ }
 };

 MODULE_DEVICE_TABLE(of, ohci_hcd_s3c2410_dt_ids);

 static struct platform_driver ohci_hcd_s3c2410_driver = {
 	.probe		= ohci_hcd_s3c2410_probe,
 	.remove		= ohci_hcd_s3c2410_remove,
 	.shutdown	= usb_hcd_platform_shutdown,
 	.driver		= {
 		.name	= "s3c2410-ohci",
 		.pm	= &ohci_hcd_s3c2410_pm_ops,
 		.of_match_table	= ohci_hcd_s3c2410_dt_ids,
 	},
 };

 static int __init ohci_s3c2410_init(void)
 {
 	if (usb_disabled())
 		return -ENODEV;

 	ohci_init_driver(&ohci_s3c2410_hc_driver, NULL);

 	/*
 	 * The Samsung HW has some unusual quirks, which require
 	 * Sumsung-specific workarounds. We override certain hc_driver
 	 * functions here to achieve that. We explicitly do not enhance
 	 * ohci_driver_overrides to allow this more easily, since this
 	 * is an unusual case, and we don't want to encourage others to
 	 * override these functions by making it too easy.
 	 */

 	ohci_s3c2410_hc_driver.hub_status_data	= ohci_s3c2410_hub_status_data;
 	ohci_s3c2410_hc_driver.hub_control	= ohci_s3c2410_hub_control;

 	return platform_driver_register(&ohci_hcd_s3c2410_driver);
 }
 module_init(ohci_s3c2410_init);

 static void __exit ohci_s3c2410_cleanup(void)
 {
 	platform_driver_unregister(&ohci_hcd_s3c2410_driver);
 }
 module_exit(ohci_s3c2410_cleanup);

 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:s3c2410-ohci");
	// SPDX-License-Identifier: GPL-1.0+
	/*
	* OHCI HCD (Host Controller Driver) for USB.
	*
	* (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
	* (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
	* (C) Copyright 2002 Hewlett-Packard Company
	*
	* USB Bus Glue for Samsung S3C2410
	*
	* Written by Christopher Hoover <ch@hpl.hp.com>
	* Based on fragments of previous driver by Russell King et al.
	*
	* Modified for S3C2410 from ohci-sa1111.c, ohci-omap.c and ohci-lh7a40.c
	* by Ben Dooks, <ben@simtec.co.uk>
	* Copyright (C) 2004 Simtec Electronics
	*
	* Thanks to basprog@mail.ru for updates to newer kernels
	*
	* This file is licenced under the GPL.
	*/

	#include <linux/clk.h>
	#include <linux/io.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/platform_data/usb-ohci-s3c2410.h>
	#include <linux/usb.h>
	#include <linux/usb/hcd.h>

	#include "ohci.h"


	#define valid_port(idx) ((idx) == 1 \|\| (idx) == 2)

	/* clock device associated with the hcd */


	#define DRIVER_DESC "OHCI S3C2410 driver"

	static struct clk *clk;
	static struct clk *usb_clk;

	static struct hc_driver __read_mostly ohci_s3c2410_hc_driver;

	/* forward definitions */

	static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc);

	/* conversion functions */

	static struct s3c2410_hcd_info to_s3c2410_info(struct usb_hcd hcd)
	{
	return dev_get_platdata(hcd->self.controller);
	}

	static void s3c2410_start_hc(struct platform_device dev, struct usb_hcd hcd)
	{
	struct s3c2410_hcd_info *info = dev_get_platdata(&dev->dev);

	dev_dbg(&dev->dev, "s3c2410_start_hc:\n");

	clk_prepare_enable(usb_clk);
	mdelay(2); /* let the bus clock stabilise */

	clk_prepare_enable(clk);

	if (info != NULL) {
	info->hcd = hcd;
	info->report_oc = s3c2410_hcd_oc;

	if (info->enable_oc != NULL)
	(info->enable_oc)(info, 1);
	}
	}

	static void s3c2410_stop_hc(struct platform_device *dev)
	{
	struct s3c2410_hcd_info *info = dev_get_platdata(&dev->dev);

	dev_dbg(&dev->dev, "s3c2410_stop_hc:\n");

	if (info != NULL) {
	info->report_oc = NULL;
	info->hcd = NULL;

	if (info->enable_oc != NULL)
	(info->enable_oc)(info, 0);
	}

	clk_disable_unprepare(clk);
	clk_disable_unprepare(usb_clk);
	}

	/* ohci_s3c2410_hub_status_data
	*
	* update the status data from the hub with anything that
	* has been detected by our system
	*/

	static int
	ohci_s3c2410_hub_status_data(struct usb_hcd hcd, char buf)
	{
	struct s3c2410_hcd_info *info = to_s3c2410_info(hcd);
	struct s3c2410_hcd_port *port;
	int orig;
	int portno;

	orig = ohci_hub_status_data(hcd, buf);

	if (info == NULL)
	return orig;

	port = &info->port[0];

	/* mark any changed port as changed */

	for (portno = 0; portno < 2; port++, portno++) {
	if (port->oc_changed == 1 &&
	port->flags & S3C_HCDFLG_USED) {
	dev_dbg(hcd->self.controller,
	"oc change on port %d\n", portno);

	if (orig < 1)
	orig = 1;

	buf[0] \|= 1<<(portno+1);
	}
	}

	return orig;
	}

	/* s3c2410_usb_set_power
	*
	* configure the power on a port, by calling the platform device
	* routine registered with the platform device
	*/

	static void s3c2410_usb_set_power(struct s3c2410_hcd_info *info,
	int port, int to)
	{
	if (info == NULL)
	return;

	if (info->power_control != NULL) {
	info->port[port-1].power = to;
	(info->power_control)(port-1, to);
	}
	}

	/* ohci_s3c2410_hub_control
	*
	* look at control requests to the hub, and see if we need
	* to take any action or over-ride the results from the
	* request.
	*/

	static int ohci_s3c2410_hub_control(
	struct usb_hcd *hcd,
	u16 typeReq,
	u16 wValue,
	u16 wIndex,
	char *buf,
	u16 wLength)
	{
	struct s3c2410_hcd_info *info = to_s3c2410_info(hcd);
	struct usb_hub_descriptor *desc;
	int ret = -EINVAL;
	u32 data = (u32 )buf;

	dev_dbg(hcd->self.controller,
	"s3c2410_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
	hcd, typeReq, wValue, wIndex, buf, wLength);

	/* if we are only an humble host without any special capabilities
	* process the request straight away and exit */

	if (info == NULL) {
	ret = ohci_hub_control(hcd, typeReq, wValue,
	wIndex, buf, wLength);
	goto out;
	}

	/* check the request to see if it needs handling */

	switch (typeReq) {
	case SetPortFeature:
	if (wValue == USB_PORT_FEAT_POWER) {
	dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
	s3c2410_usb_set_power(info, wIndex, 1);
	goto out;
	}
	break;

	case ClearPortFeature:
	switch (wValue) {
	case USB_PORT_FEAT_C_OVER_CURRENT:
	dev_dbg(hcd->self.controller,
	"ClearPortFeature: C_OVER_CURRENT\n");

	if (valid_port(wIndex)) {
	info->port[wIndex-1].oc_changed = 0;
	info->port[wIndex-1].oc_status = 0;
	}

	goto out;

	case USB_PORT_FEAT_OVER_CURRENT:
	dev_dbg(hcd->self.controller,
	"ClearPortFeature: OVER_CURRENT\n");

	if (valid_port(wIndex))
	info->port[wIndex-1].oc_status = 0;

	goto out;

	case USB_PORT_FEAT_POWER:
	dev_dbg(hcd->self.controller,
	"ClearPortFeature: POWER\n");

	if (valid_port(wIndex)) {
	s3c2410_usb_set_power(info, wIndex, 0);
	return 0;
	}
	}
	break;
	}

	ret = ohci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
	if (ret)
	goto out;

	switch (typeReq) {
	case GetHubDescriptor:

	/* update the hub's descriptor */

	desc = (struct usb_hub_descriptor *)buf;

	if (info->power_control == NULL)
	return ret;

	dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
	desc->wHubCharacteristics);

	/* remove the old configurations for power-switching, and
	* over-current protection, and insert our new configuration
	*/

	desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
	desc->wHubCharacteristics \|= cpu_to_le16(
	HUB_CHAR_INDV_PORT_LPSM);

	if (info->enable_oc) {
	desc->wHubCharacteristics &= ~cpu_to_le16(
	HUB_CHAR_OCPM);
	desc->wHubCharacteristics \|= cpu_to_le16(
	HUB_CHAR_INDV_PORT_OCPM);
	}

	dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
	desc->wHubCharacteristics);

	return ret;

	case GetPortStatus:
	/* check port status */

	dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);

	if (valid_port(wIndex)) {
	if (info->port[wIndex-1].oc_changed)
	*data \|= cpu_to_le32(RH_PS_OCIC);

	if (info->port[wIndex-1].oc_status)
	*data \|= cpu_to_le32(RH_PS_POCI);
	}
	}

	out:
	return ret;
	}

	/* s3c2410_hcd_oc
	*
	* handle an over-current report
	*/

	static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc)
	{
	struct s3c2410_hcd_port *port;
	unsigned long flags;
	int portno;

	if (info == NULL)
	return;

	port = &info->port[0];

	local_irq_save(flags);

	for (portno = 0; portno < 2; port++, portno++) {
	if (port_oc & (1<<portno) &&
	port->flags & S3C_HCDFLG_USED) {
	port->oc_status = 1;
	port->oc_changed = 1;

	/* ok, once over-current is detected,
	the port needs to be powered down */
	s3c2410_usb_set_power(info, portno+1, 0);
	}
	}

	local_irq_restore(flags);
	}

	/* may be called without controller electrically present */
	/* may be called with controller, bus, and devices active */

	/*
	* ohci_hcd_s3c2410_remove - shutdown processing for HCD
	* @dev: USB Host Controller being removed
	*
	* Context: task context, might sleep
	*
	* Reverses the effect of ohci_hcd_3c2410_probe(), first invoking
	* the HCD's stop() method. It is always called from a thread
	* context, normally "rmmod", "apmd", or something similar.
	*/
	static int
	ohci_hcd_s3c2410_remove(struct platform_device *dev)
	{
	struct usb_hcd *hcd = platform_get_drvdata(dev);

	usb_remove_hcd(hcd);
	s3c2410_stop_hc(dev);
	usb_put_hcd(hcd);
	return 0;
	}

	/*
	* ohci_hcd_s3c2410_probe - initialize S3C2410-based HCDs
	* @dev: USB Host Controller to be probed
	*
	* Context: task context, might sleep
	*
	* Allocates basic resources for this USB host controller, and
	* then invokes the start() method for the HCD associated with it
	* through the hotplug entry's driver_data.
	*/
	static int ohci_hcd_s3c2410_probe(struct platform_device *dev)
	{
	struct usb_hcd *hcd = NULL;
	struct s3c2410_hcd_info *info = dev_get_platdata(&dev->dev);
	int retval, irq;

	s3c2410_usb_set_power(info, 1, 1);
	s3c2410_usb_set_power(info, 2, 1);

	hcd = usb_create_hcd(&ohci_s3c2410_hc_driver, &dev->dev, "s3c24xx");
	if (hcd == NULL)
	return -ENOMEM;

	hcd->rsrc_start = dev->resource[0].start;
	hcd->rsrc_len = resource_size(&dev->resource[0]);

	hcd->regs = devm_ioremap_resource(&dev->dev, &dev->resource[0]);
	if (IS_ERR(hcd->regs)) {
	retval = PTR_ERR(hcd->regs);
	goto err_put;
	}

	clk = devm_clk_get(&dev->dev, "usb-host");
	if (IS_ERR(clk)) {
	dev_err(&dev->dev, "cannot get usb-host clock\n");
	retval = PTR_ERR(clk);
	goto err_put;
	}

	usb_clk = devm_clk_get(&dev->dev, "usb-bus-host");
	if (IS_ERR(usb_clk)) {
	dev_err(&dev->dev, "cannot get usb-bus-host clock\n");
	retval = PTR_ERR(usb_clk);
	goto err_put;
	}

	irq = platform_get_irq(dev, 0);
	if (irq < 0) {
	retval = irq;
	goto err_put;
	}

	s3c2410_start_hc(dev, hcd);

	retval = usb_add_hcd(hcd, irq, 0);
	if (retval != 0)
	goto err_ioremap;

	device_wakeup_enable(hcd->self.controller);
	return 0;

	err_ioremap:
	s3c2410_stop_hc(dev);

	err_put:
	usb_put_hcd(hcd);
	return retval;
	}

	/-------------------------------------------------------------------------/

	#ifdef CONFIG_PM
	static int ohci_hcd_s3c2410_drv_suspend(struct device *dev)
	{
	struct usb_hcd *hcd = dev_get_drvdata(dev);
	struct platform_device *pdev = to_platform_device(dev);
	bool do_wakeup = device_may_wakeup(dev);
	int rc = 0;

	rc = ohci_suspend(hcd, do_wakeup);
	if (rc)
	return rc;

	s3c2410_stop_hc(pdev);

	return rc;
	}

	static int ohci_hcd_s3c2410_drv_resume(struct device *dev)
	{
	struct usb_hcd *hcd = dev_get_drvdata(dev);
	struct platform_device *pdev = to_platform_device(dev);

	s3c2410_start_hc(pdev, hcd);

	ohci_resume(hcd, false);

	return 0;
	}
	#else
	#define ohci_hcd_s3c2410_drv_suspend NULL
	#define ohci_hcd_s3c2410_drv_resume NULL
	#endif

	static const struct dev_pm_ops ohci_hcd_s3c2410_pm_ops = {
	.suspend = ohci_hcd_s3c2410_drv_suspend,
	.resume = ohci_hcd_s3c2410_drv_resume,
	};

	static const struct of_device_id ohci_hcd_s3c2410_dt_ids[] = {
	{ .compatible = "samsung,s3c2410-ohci" },
	{ /* sentinel */ }
	};

	MODULE_DEVICE_TABLE(of, ohci_hcd_s3c2410_dt_ids);

	static struct platform_driver ohci_hcd_s3c2410_driver = {
	.probe = ohci_hcd_s3c2410_probe,
	.remove = ohci_hcd_s3c2410_remove,
	.shutdown = usb_hcd_platform_shutdown,
	.driver = {
	.name = "s3c2410-ohci",
	.pm = &ohci_hcd_s3c2410_pm_ops,
	.of_match_table = ohci_hcd_s3c2410_dt_ids,
	},
	};

	static int __init ohci_s3c2410_init(void)
	{
	if (usb_disabled())
	return -ENODEV;

	ohci_init_driver(&ohci_s3c2410_hc_driver, NULL);

	/*
	* The Samsung HW has some unusual quirks, which require
	* Sumsung-specific workarounds. We override certain hc_driver
	* functions here to achieve that. We explicitly do not enhance
	* ohci_driver_overrides to allow this more easily, since this
	* is an unusual case, and we don't want to encourage others to
	* override these functions by making it too easy.
	*/

	ohci_s3c2410_hc_driver.hub_status_data = ohci_s3c2410_hub_status_data;
	ohci_s3c2410_hc_driver.hub_control = ohci_s3c2410_hub_control;

	return platform_driver_register(&ohci_hcd_s3c2410_driver);
	}
	module_init(ohci_s3c2410_init);

	static void __exit ohci_s3c2410_cleanup(void)
	{
	platform_driver_unregister(&ohci_hcd_s3c2410_driver);
	}
	module_exit(ohci_s3c2410_cleanup);

	MODULE_DESCRIPTION(DRIVER_DESC);
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:s3c2410-ohci");