USB: OHCI: make ohci-da8xx a separate driver

Separate the Davinci OHCI host controller driver from ohci-hcd
host code so that it can be built as a separate driver module.
This work is part of enabling multi-platform kernels on ARM

Tested-by: David Lechner <david@lechnology.com>
Signed-off-by: Manjunath Goudar <manjunath.goudar@linaro.org>
[Axel: adapted and rebased, fixed minor comments]
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 74 insertions, 131 deletions

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 83b6cec20b33..6361fc739306 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -479,9 +479,9 @@ config USB_OHCI_HCD_OMAP3
 	  OMAP3 and later chips.
 
 config USB_OHCI_HCD_DAVINCI
-	bool "OHCI support for TI DaVinci DA8xx"
+	tristate "OHCI support for TI DaVinci DA8xx"
 	depends on ARCH_DAVINCI_DA8XX
-	depends on USB_OHCI_HCD=y
+	depends on USB_OHCI_HCD
 	select PHY_DA8XX_USB
 	default y
 	help
diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index 6ef785b0ea8f..2644537b7bcf 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_USB_OHCI_HCD_AT91)	+= ohci-at91.o
 obj-$(CONFIG_USB_OHCI_HCD_S3C2410)	+= ohci-s3c2410.o
 obj-$(CONFIG_USB_OHCI_HCD_LPC32XX)	+= ohci-nxp.o
 obj-$(CONFIG_USB_OHCI_HCD_PXA27X)	+= ohci-pxa27x.o
+obj-$(CONFIG_USB_OHCI_HCD_DAVINCI)	+= ohci-da8xx.o
 
 obj-$(CONFIG_USB_UHCI_HCD)	+= uhci-hcd.o
 obj-$(CONFIG_USB_FHCI_HCD)	+= fhci.o
diff --git a/drivers/usb/host/ohci-da8xx.c b/drivers/usb/host/ohci-da8xx.c
index 3656d7cea58c..30c48789389e 100644
--- a/drivers/usb/host/ohci-da8xx.c
+++ b/drivers/usb/host/ohci-da8xx.c
@@ -11,16 +11,29 @@
  * kind, whether express or implied.
  */
 
+#include <linux/clk.h>
+#include <linux/io.h>
 #include <linux/interrupt.h>
 #include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/platform_device.h>
-#include <linux/clk.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_data/usb-davinci.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <asm/unaligned.h>
 
-#ifndef CONFIG_ARCH_DAVINCI_DA8XX
-#error "This file is DA8xx bus glue.  Define CONFIG_ARCH_DAVINCI_DA8XX."
-#endif
+#include "ohci.h"
+
+#define DRIVER_DESC "DA8XX"
+#define DRV_NAME "ohci"
+
+static struct hc_driver __read_mostly ohci_da8xx_hc_driver;
+
+static int (*orig_ohci_hub_control)(struct usb_hcd  *hcd, u16 typeReq,
+			u16 wValue, u16 wIndex, char *buf, u16 wLength);
+static int (*orig_ohci_hub_status_data)(struct usb_hcd *hcd, char *buf);
 
 static struct clk *usb11_clk;
 static struct phy *usb11_phy;
@@ -74,7 +87,7 @@ static void ohci_da8xx_ocic_handler(struct da8xx_ohci_root_hub *hub,
 		hub->set_power(port, 0);
 }
 
-static int ohci_da8xx_init(struct usb_hcd *hcd)
+static int ohci_da8xx_reset(struct usb_hcd *hcd)
 {
 	struct device *dev		= hcd->self.controller;
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(dev);
@@ -94,7 +107,7 @@ static int ohci_da8xx_init(struct usb_hcd *hcd)
 	 */
 	ohci->num_ports = 1;
 
-	result = ohci_init(ohci);
+	result = ohci_setup(hcd);
 	if (result < 0) {
 		ohci_da8xx_disable();
 		return result;
@@ -122,30 +135,12 @@ static int ohci_da8xx_init(struct usb_hcd *hcd)
 	return result;
 }
 
-static void ohci_da8xx_stop(struct usb_hcd *hcd)
-{
-	ohci_stop(hcd);
-	ohci_da8xx_disable();
-}
-
-static int ohci_da8xx_start(struct usb_hcd *hcd)
-{
-	struct ohci_hcd	*ohci		= hcd_to_ohci(hcd);
-	int result;
-
-	result = ohci_run(ohci);
-	if (result < 0)
-		ohci_da8xx_stop(hcd);
-
-	return result;
-}
-
 /*
  * Update the status data from the hub with the over-current indicator change.
  */
 static int ohci_da8xx_hub_status_data(struct usb_hcd *hcd, char *buf)
 {
-	int length		= ohci_hub_status_data(hcd, buf);
+	int length		= orig_ohci_hub_status_data(hcd, buf);
 
 	/* See if we have OCIC bit set on port 1 */
 	if (ocic_mask & (1 << 1)) {
@@ -227,66 +222,13 @@ check_port:
 		}
 	}
 
-	return ohci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
+	return orig_ohci_hub_control(hcd, typeReq, wValue,
+			wIndex, buf, wLength);
 }
 
-static const struct hc_driver ohci_da8xx_hc_driver = {
-	.description		= hcd_name,
-	.product_desc		= "DA8xx OHCI",
-	.hcd_priv_size		= sizeof(struct ohci_hcd),
-
-	/*
-	 * generic hardware linkage
-	 */
-	.irq			= ohci_irq,
-	.flags			= HCD_USB11 | HCD_MEMORY,
-
-	/*
-	 * basic lifecycle operations
-	 */
-	.reset			= ohci_da8xx_init,
-	.start			= ohci_da8xx_start,
-	.stop			= ohci_da8xx_stop,
-	.shutdown		= ohci_shutdown,
-
-	/*
-	 * managing i/o requests and associated device resources
-	 */
-	.urb_enqueue		= ohci_urb_enqueue,
-	.urb_dequeue		= ohci_urb_dequeue,
-	.endpoint_disable	= ohci_endpoint_disable,
-
-	/*
-	 * scheduling support
-	 */
-	.get_frame_number	= ohci_get_frame,
-
-	/*
-	 * root hub support
-	 */
-	.hub_status_data	= ohci_da8xx_hub_status_data,
-	.hub_control		= ohci_da8xx_hub_control,
-
-#ifdef	CONFIG_PM
-	.bus_suspend		= ohci_bus_suspend,
-	.bus_resume		= ohci_bus_resume,
-#endif
-	.start_port_reset	= ohci_start_port_reset,
-};
-
 /*-------------------------------------------------------------------------*/
 
-
-/**
- * usb_hcd_da8xx_probe - initialize DA8xx-based HCDs
- * Context: !in_interrupt()
- *
- * 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 usb_hcd_da8xx_probe(const struct hc_driver *driver,
-			       struct platform_device *pdev)
+static int ohci_da8xx_probe(struct platform_device *pdev)
 {
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(&pdev->dev);
 	struct usb_hcd	*hcd;
@@ -310,7 +252,8 @@ static int usb_hcd_da8xx_probe(const struct hc_driver *driver,
 		return PTR_ERR(usb11_phy);
 	}
 
-	hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
+	hcd = usb_create_hcd(&ohci_da8xx_hc_driver, &pdev->dev,
+				dev_name(&pdev->dev));
 	if (!hcd)
 		return -ENOMEM;
 
@@ -324,13 +267,12 @@ static int usb_hcd_da8xx_probe(const struct hc_driver *driver,
 	hcd->rsrc_start = mem->start;
 	hcd->rsrc_len = resource_size(mem);
 
-	ohci_hcd_init(hcd_to_ohci(hcd));
-
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		error = -ENODEV;
 		goto err;
 	}
+
 	error = usb_add_hcd(hcd, irq, 0);
 	if (error)
 		goto err;
@@ -349,35 +291,14 @@ err:
 	return error;
 }
 
-/**
- * usb_hcd_da8xx_remove - shutdown processing for DA8xx-based HCDs
- * @dev: USB Host Controller being removed
- * Context: !in_interrupt()
- *
- * Reverses the effect of usb_hcd_da8xx_probe(), first invoking
- * the HCD's stop() method.  It is always called from a thread
- * context, normally "rmmod", "apmd", or something similar.
- */
-static inline void
-usb_hcd_da8xx_remove(struct usb_hcd *hcd, struct platform_device *pdev)
+static int ohci_da8xx_remove(struct platform_device *pdev)
 {
+	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
 	struct da8xx_ohci_root_hub *hub	= dev_get_platdata(&pdev->dev);
 
 	hub->ocic_notify(NULL);
 	usb_remove_hcd(hcd);
 	usb_put_hcd(hcd);
-}
-
-static int ohci_hcd_da8xx_drv_probe(struct platform_device *dev)
-{
-	return usb_hcd_da8xx_probe(&ohci_da8xx_hc_driver, dev);
-}
-
-static int ohci_hcd_da8xx_drv_remove(struct platform_device *dev)
-{
-	struct usb_hcd	*hcd = platform_get_drvdata(dev);
-
-	usb_hcd_da8xx_remove(hcd, dev);
 
 	return 0;
 }
@@ -427,20 +348,59 @@ static int ohci_da8xx_resume(struct platform_device *dev)
 }
 #endif
 
+static const struct ohci_driver_overrides da8xx_overrides __initconst = {
+	.reset		= ohci_da8xx_reset,
+};
+
 /*
  * Driver definition to register with platform structure.
  */
 static struct platform_driver ohci_hcd_da8xx_driver = {
-	.probe		= ohci_hcd_da8xx_drv_probe,
-	.remove		= ohci_hcd_da8xx_drv_remove,
+	.probe		= ohci_da8xx_probe,
+	.remove		= ohci_da8xx_remove,
 	.shutdown 	= usb_hcd_platform_shutdown,
 #ifdef	CONFIG_PM
 	.suspend	= ohci_da8xx_suspend,
 	.resume		= ohci_da8xx_resume,
 #endif
 	.driver		= {
-		.name	= "ohci",
+		.name	= DRV_NAME,
 	},
 };
 
-MODULE_ALIAS("platform:ohci");
+static int __init ohci_da8xx_init(void)
+{
+
+	if (usb_disabled())
+		return -ENODEV;
+
+	pr_info("%s: " DRIVER_DESC "\n", DRV_NAME);
+	ohci_init_driver(&ohci_da8xx_hc_driver, &da8xx_overrides);
+
+	/*
+	 * The Davinci da8xx HW has some unusual quirks, which require
+	 * da8xx-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.
+	 */
+
+	orig_ohci_hub_control = ohci_da8xx_hc_driver.hub_control;
+	orig_ohci_hub_status_data = ohci_da8xx_hc_driver.hub_status_data;
+
+	ohci_da8xx_hc_driver.hub_status_data     = ohci_da8xx_hub_status_data;
+	ohci_da8xx_hc_driver.hub_control         = ohci_da8xx_hub_control;
+
+	return platform_driver_register(&ohci_hcd_da8xx_driver);
+}
+module_init(ohci_da8xx_init);
+
+static void __exit ohci_da8xx_exit(void)
+{
+	platform_driver_unregister(&ohci_hcd_da8xx_driver);
+}
+module_exit(ohci_da8xx_exit);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 1700908b84ef..8de174aa7415 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -1219,11 +1219,6 @@ MODULE_LICENSE ("GPL");
 #define SA1111_DRIVER		ohci_hcd_sa1111_driver
 #endif
 
-#ifdef CONFIG_USB_OHCI_HCD_DAVINCI
-#include "ohci-da8xx.c"
-#define DAVINCI_PLATFORM_DRIVER	ohci_hcd_da8xx_driver
-#endif
-
 #ifdef CONFIG_USB_OHCI_HCD_PPC_OF
 #include "ohci-ppc-of.c"
 #define OF_PLATFORM_DRIVER	ohci_hcd_ppc_of_driver
@@ -1303,19 +1298,9 @@ static int __init ohci_hcd_mod_init(void)
 		goto error_tmio;
 #endif
 
-#ifdef DAVINCI_PLATFORM_DRIVER
-	retval = platform_driver_register(&DAVINCI_PLATFORM_DRIVER);
-	if (retval < 0)
-		goto error_davinci;
-#endif
-
 	return retval;
 
 	/* Error path */
-#ifdef DAVINCI_PLATFORM_DRIVER
-	platform_driver_unregister(&DAVINCI_PLATFORM_DRIVER);
- error_davinci:
-#endif
 #ifdef TMIO_OHCI_DRIVER
 	platform_driver_unregister(&TMIO_OHCI_DRIVER);
  error_tmio:
@@ -1351,9 +1336,6 @@ module_init(ohci_hcd_mod_init);
 
 static void __exit ohci_hcd_mod_exit(void)
 {
-#ifdef DAVINCI_PLATFORM_DRIVER
-	platform_driver_unregister(&DAVINCI_PLATFORM_DRIVER);
-#endif
 #ifdef TMIO_OHCI_DRIVER
 	platform_driver_unregister(&TMIO_OHCI_DRIVER);
 #endif