Subject: [PATCH 6/6] USB: OHCI: make ohci-s3c2410 a separate driver

From: [email-masked] (Tomasz Figa)
Date: Tue, 23 Jul 2013 10:23:17 +0200

Hi Manjunath,

Please see some comments inline.

On Monday 22 of July 2013 14:49:30 Manjunath Goudar wrote:
> Separate the Samsung OHCI S3CXXXX 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;
> it would be nice to have in 3.12.
> 
> Signed-off-by: Manjunath Goudar <[email-masked]>
> Acked-by: Alan Stern <[email-masked]>
> Cc: Arnd Bergmann <[email-masked]>
> Cc: Greg KH <[email-masked]>
> Cc: linux-usb at vger.kernel.org
> 
> V2:
>  -Set non-standard fields in ohci_s3c2410_hc_driver manually, rather
> than relying on an expanded struct ohci_driver_overrides.
>  -Save orig_ohci_hub_control and orig_ohci_hub_status_data rather than
>   relying on ohci_hub_control and hub_status_data being exported.
> 
> V3:
>  -Kconfig wrong parentheses discription fixed.
>  -ohci_setup() has been removed because it is called in .reset member
>   of the ohci_hc_driver structure.
> 
> V4:
>  - Removed extra space before the '='.
>  - Moved  /* forward definitions */ line before the declarations of
> functions. ---
>  drivers/usb/host/Kconfig        |    8 +++
>  drivers/usb/host/Makefile       |    1 +
>  drivers/usb/host/ohci-hcd.c     |   18 ------
>  drivers/usb/host/ohci-s3c2410.c |  128
> +++++++++++++++++---------------------- 4 files changed, 66
> insertions(+), 89 deletions(-)
> 
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index 693560a..795d14d 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -390,6 +390,14 @@ config USB_OHCI_HCD_SPEAR
>            Enables support for the on-chip OHCI controller on
>            ST SPEAr chips.
> 
> +config USB_OHCI_HCD_S3CXXXX
> +        tristate "Support for S3CXXXX on-chip OHCI USB controller"
> +        depends on USB_OHCI_HCD && (ARCH_S3C24XX || ARCH_S3C64XX)
> +        default y
> +        ---help---
> +          Enables support for the on-chip OHCI controller on
> +          S3CXXXX chips.
> +

Please keep the name s3c2410 for consistency. Having all the names come 
from the first SoC with this hardware is somewhat deterministic as opposed 
to some other naming methods, e.g. ohci-exynos2, while later on a 
different SoC from Exynos 2 shows up that needs a different driver.

>  config USB_OHCI_HCD_AT91
>          tristate "Support for Atmel on-chip OHCI USB controller"
>          depends on USB_OHCI_HCD && ARCH_AT91
> diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
> index a70b044..9dffe81 100644
> --- a/drivers/usb/host/Makefile
> +++ b/drivers/usb/host/Makefile
> @@ -51,6 +51,7 @@ obj-$(CONFIG_USB_OHCI_HCD_OMAP1)	+= ohci-omap.o
>  obj-$(CONFIG_USB_OHCI_HCD_OMAP3)	+= ohci-omap3.o
>  obj-$(CONFIG_USB_OHCI_HCD_SPEAR)	+= ohci-spear.o
>  obj-$(CONFIG_USB_OHCI_HCD_AT91)	+= ohci-at91.o
> +obj-$(CONFIG_USB_OHCI_HCD_S3CXXXX)	+= ohci-s3c2410.o
> 
>  obj-$(CONFIG_USB_UHCI_HCD)	+= uhci-hcd.o
>  obj-$(CONFIG_USB_FHCI_HCD)	+= fhci.o
> diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
> index b48c892..b69a49e 100644
> --- a/drivers/usb/host/ohci-hcd.c
> +++ b/drivers/usb/host/ohci-hcd.c
> @@ -1177,11 +1177,6 @@ MODULE_LICENSE ("GPL");
>  #define SA1111_DRIVER		ohci_hcd_sa1111_driver
>  #endif
> 
> -#if defined(CONFIG_ARCH_S3C24XX) || defined(CONFIG_ARCH_S3C64XX)
> -#include "ohci-s3c2410.c"
> -#define S3C2410_PLATFORM_DRIVER	ohci_hcd_s3c2410_driver
> -#endif
> -
>  #if defined(CONFIG_PXA27x) || defined(CONFIG_PXA3xx)
>  #include "ohci-pxa27x.c"
>  #define PLATFORM_DRIVER		ohci_hcd_pxa27x_driver
> @@ -1293,12 +1288,6 @@ static int __init ohci_hcd_mod_init(void)
>  		goto error_tmio;
>  #endif
> 
> -#ifdef S3C2410_PLATFORM_DRIVER
> -	retval = platform_driver_register(&S3C2410_PLATFORM_DRIVER);
> -	if (retval < 0)
> -		goto error_s3c2410;
> -#endif
> -
>  #ifdef EP93XX_PLATFORM_DRIVER
>  	retval = platform_driver_register(&EP93XX_PLATFORM_DRIVER);
>  	if (retval < 0)
> @@ -1332,10 +1321,6 @@ static int __init ohci_hcd_mod_init(void)
>  	platform_driver_unregister(&EP93XX_PLATFORM_DRIVER);
>   error_ep93xx:
>  #endif
> -#ifdef S3C2410_PLATFORM_DRIVER
> -	platform_driver_unregister(&S3C2410_PLATFORM_DRIVER);
> - error_s3c2410:
> -#endif
>  #ifdef TMIO_OHCI_DRIVER
>  	platform_driver_unregister(&TMIO_OHCI_DRIVER);
>   error_tmio:
> @@ -1382,9 +1367,6 @@ static void __exit ohci_hcd_mod_exit(void)
>  #ifdef EP93XX_PLATFORM_DRIVER
>  	platform_driver_unregister(&EP93XX_PLATFORM_DRIVER);
>  #endif
> -#ifdef S3C2410_PLATFORM_DRIVER
> -	platform_driver_unregister(&S3C2410_PLATFORM_DRIVER);
> -#endif
>  #ifdef TMIO_OHCI_DRIVER
>  	platform_driver_unregister(&TMIO_OHCI_DRIVER);
>  #endif
> diff --git a/drivers/usb/host/ohci-s3c2410.c
> b/drivers/usb/host/ohci-s3c2410.c index e125770..48b5948 100644
> --- a/drivers/usb/host/ohci-s3c2410.c
> +++ b/drivers/usb/host/ohci-s3c2410.c
> @@ -19,19 +19,36 @@
>   * This file is licenced under the GPL.
>  */
> 
> -#include <linux/platform_device.h>
>  #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 S3CXXXX driver"
> +
> +static const char hcd_name[] = "ohci-s3cxxxx";
> +

Ditto.

>  static struct clk *clk;
>  static struct clk *usb_clk;
> 
>  /* forward definitions */
> 
> +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 void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc);
> 
>  /* conversion functions */
> @@ -93,7 +110,7 @@ ohci_s3c2410_hub_status_data(struct usb_hcd *hcd,
> char *buf) int orig;
>  	int portno;
> 
> -	orig  = ohci_hub_status_data(hcd, buf);
> +	orig = orig_ohci_hub_status_data(hcd, buf);
> 
>  	if (info == NULL)
>  		return orig;
> @@ -164,7 +181,7 @@ static int ohci_s3c2410_hub_control(
>  	 * process the request straight away and exit */
> 
>  	if (info == NULL) {
> -		ret = ohci_hub_control(hcd, typeReq, wValue,
> +		ret = orig_ohci_hub_control(hcd, typeReq, wValue,
>  				       wIndex, buf, wLength);
>  		goto out;
>  	}
> @@ -214,7 +231,7 @@ static int ohci_s3c2410_hub_control(
>  		break;
>  	}
> 
> -	ret = ohci_hub_control(hcd, typeReq, wValue, wIndex, buf, 
wLength);
> +	ret = orig_ohci_hub_control(hcd, typeReq, wValue, wIndex, buf,
> wLength); if (ret)
>  		goto out;
> 
> @@ -373,8 +390,6 @@ static int usb_hcd_s3c2410_probe(const struct
> hc_driver *driver,
> 
>  	s3c2410_start_hc(dev, hcd);
> 
> -	ohci_hcd_init(hcd_to_ohci(hcd));
> -
>  	retval = usb_add_hcd(hcd, dev->resource[1].start, 0);
>  	if (retval != 0)
>  		goto err_ioremap;
> @@ -391,71 +406,7 @@ static int usb_hcd_s3c2410_probe(const struct
> hc_driver *driver,
> 
>  /*---------------------------------------------------------------------
> ----*/
> 
> -static int
> -ohci_s3c2410_start(struct usb_hcd *hcd)
> -{
> -	struct ohci_hcd	*ohci = hcd_to_ohci(hcd);
> -	int ret;
> -
> -	ret = ohci_init(ohci);
> -	if (ret < 0)
> -		return ret;
> -
> -	ret = ohci_run(ohci);
> -	if (ret < 0) {
> -		dev_err(hcd->self.controller, "can't start %s\n",
> -			hcd->self.bus_name);
> -		ohci_stop(hcd);
> -		return ret;
> -	}
> -
> -	return 0;
> -}
> -
> -
> -static const struct hc_driver ohci_s3c2410_hc_driver = {
> -	.description =		hcd_name,
> -	.product_desc =		"S3C24XX OHCI",
> -	.hcd_priv_size =	sizeof(struct ohci_hcd),
> -
> -	/*
> -	 * generic hardware linkage
> -	 */
> -	.irq =			ohci_irq,
> -	.flags =		HCD_USB11 | HCD_MEMORY,
> -
> -	/*
> -	 * basic lifecycle operations
> -	 */
> -	.start =		ohci_s3c2410_start,
> -	.stop =			ohci_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_s3c2410_hub_status_data,
> -	.hub_control =		ohci_s3c2410_hub_control,
> -#ifdef	CONFIG_PM
> -	.bus_suspend =		ohci_bus_suspend,
> -	.bus_resume =		ohci_bus_resume,
> -#endif
> -	.start_port_reset =	ohci_start_port_reset,
> -};
> -
> -/* device driver */
> +static struct hc_driver __read_mostly ohci_s3c2410_hc_driver;
> 
>  static int ohci_hcd_s3c2410_drv_probe(struct platform_device *pdev)
>  {
> @@ -532,4 +483,39 @@ static struct platform_driver
> ohci_hcd_s3c2410_driver = { },
>  };
> 
> +static int __init ohci_s3cxxxx_init(void)
> +{
> +	if (usb_disabled())
> +		return -ENODEV;
> +
> +	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
> +	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.
> +	 */
> +
> +	orig_ohci_hub_control = ohci_s3c2410_hc_driver.hub_control;
> +	orig_ohci_hub_status_data = 
ohci_s3c2410_hc_driver.hub_status_data;
> +
> +	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_s3cxxxx_init);
> +
> +static void __exit ohci_s3cxxxx_cleanup(void)
> +{
> +	platform_driver_unregister(&ohci_hcd_s3c2410_driver);
> +}
> +module_exit(ohci_s3cxxxx_cleanup);
> +
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_LICENSE("GPL");
>  MODULE_ALIAS("platform:s3c2410-ohci");

Otherwise looks good to me. I will try to test this on S3C6410 in next 
days.

Best regards,
Tomasz