Re: [RFC][PATCH 6/7] USB: OHCI: make ohci-at91 a separate driver

On Fri, 7 Jun 2013, Manjunath Goudar wrote:

Separate the TI OHCI Atmel 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.

--- a/drivers/usb/host/Kconfig +++ b/drivers/usb/host/Kconfig @@ -411,6 +411,14 @@ config USB_OHCI_HCD_SPEAR Enables support for the on-chip OHCI controller on ST SPEAr chips. +config USB_OHCI_HCD_AT91

•    tristate  "Support for Atmel on-chip OHCI USB controller"
  

•    depends on USB_OHCI_HCD && ARCH_AT91
  

•    default y
  

•    ---help---
  

•      Enables support for the on-chip OHCI controller on
  

•      Atmel chips.
  

Notice the "depends on" line you added here?

diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c index a0cb44f..b4a88a6 100644 --- a/drivers/usb/host/ohci-at91.c +++ b/drivers/usb/host/ohci-at91.c @@ -13,16 +13,25 @@

...

#ifndef CONFIG_ARCH_AT91 #error "CONFIG_ARCH_AT91 must be defined." #endif

As a result of the "depends on" line, this test will never succeed. You can remove these three lines.

@@ -111,6 +126,8 @@ static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *); static int usb_hcd_at91_probe(const struct hc_driver *driver, struct platform_device *pdev) {

• struct at91_usbh_data *board;

Tab character where it should be a space.

• struct ohci_hcd *ohci; int retval; struct usb_hcd *hcd = NULL;

@@ -163,8 +180,11 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver, goto err5; }

• board = hcd->self.controller->platform_data;
• ohci = hcd_to_ohci(hcd);
• ohci->num_ports = board->ports; at91_start_hc(pdev);

• ohci_hcd_init(hcd_to_ohci(hcd));

• ohci_setup(hcd);

Don't call ohci_setup().

@@ -727,3 +672,37 @@ static struct platform_driver ohci_hcd_at91_driver = { .of_match_table = of_match_ptr(at91_ohci_dt_ids), }, };

+static int __init ohci_at91_init(void) +{

• if (usb_disabled())

• return -ENODEV;
  

• pr_info("%s: " DRIVER_DESC "\n", hcd_name);
• ohci_init_driver(&ohci_at91_hc_driver, NULL);
• /*
• • The Atmel HW has some unusual quirks, which require Atmel-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_at91_hc_driver.hub_status_data = ohci_at91_hub_status_data;
• ohci_at91_hc_driver.hub_control = ohci_at91_hub_control;

Since the hub_status_data and hub_control routines aren't going to be exported, you can't do it like this. Instead, save the values of ohci_at91_hc_driver.hub_status_data and ohci_at91_hc_driver.hub_control before overwriting them.

Alan Stern