linux/drivers/usb/host/ohci-ppc-of.c
Vitaly Bordug 796bcae736 USB: powerpc: Workaround for the PPC440EPX USBH_23 errata [take 3]
A published errata for ppc440epx states, that when running Linux with
both EHCI and OHCI modules loaded, the EHCI module experiences a fatal
error when a high-speed device is connected to the USB2.0, and
functions normally if OHCI module is not loaded.

There used to be recommendation to use only hi-speed or full-speed
devices with specific conditions, when respective module was unloaded.
Later, it was observed that ohci suspend is enough to keep things
going, and it was turned into workaround, as explained below.

Quote from original descriprion:

The 440EPx USB 2.0 Host controller is an EHCI compliant controller.  In
USB 2.0 Host controllers, each EHCI controller has one or more companion
controllers, which may be OHCI or UHCI.  An USB 2.0 Host controller will
contain one or more ports.  For each port, only one of the controllers
is connected at any one time. In the 440EPx, there is only one OHCI
companion controller, and only one USB 2.0 Host port.
All ports on an USB 2.0 controller default to the companion
controller.  If you load only an ohci driver, it will have control of
the ports and any deviceplugged in will operate, although high speed
devices will be forced to operate at full speed.  When an ehci driver
is loaded, it explicitly takes control of the ports.  If there is a
device connected, and / or every time there is a new device connected,
the ehci driver determines if the device is high speed or not.  If it
is high speed, the driver retains control of the port.  If it is not,
the driver explicitly gives the companion controller control of the
port.

The is a software workaround that uses
Initial version of the software workaround was posted to
linux-usb-devel:

http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg54019.html

and later available from amcc.com:
http://www.amcc.com/Embedded/Downloads/download.html?cat=1&family=15&ins=2

The patch below is generally based on the latter, but reworked to
powerpc/of_device USB drivers, and uses a few devicetree inquiries to
get rid of (some) hardcoded defines.

Signed-off-by: Vitaly Bordug <vitb@kernel.crashing.org>
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-07 09:59:52 -08:00

262 lines
5.9 KiB
C

/*
* 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
* (C) Copyright 2006 Sylvain Munaut <tnt@246tNt.com>
*
* Bus glue for OHCI HC on the of_platform bus
*
* Modified for of_platform bus from ohci-sa1111.c
*
* This file is licenced under the GPL.
*/
#include <linux/signal.h>
#include <linux/of_platform.h>
#include <asm/prom.h>
static int __devinit
ohci_ppc_of_start(struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci(hcd);
int ret;
if ((ret = ohci_init(ohci)) < 0)
return ret;
if ((ret = ohci_run(ohci)) < 0) {
err("can't start %s", ohci_to_hcd(ohci)->self.bus_name);
ohci_stop(hcd);
return ret;
}
return 0;
}
static const struct hc_driver ohci_ppc_of_hc_driver = {
.description = hcd_name,
.product_desc = "OF OHCI",
.hcd_priv_size = sizeof(struct ohci_hcd),
/*
* generic hardware linkage
*/
.irq = ohci_irq,
.flags = HCD_USB11 | HCD_MEMORY,
/*
* basic lifecycle operations
*/
.start = ohci_ppc_of_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_hub_status_data,
.hub_control = ohci_hub_control,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
#endif
.start_port_reset = ohci_start_port_reset,
};
static int __devinit
ohci_hcd_ppc_of_probe(struct of_device *op, const struct of_device_id *match)
{
struct device_node *dn = op->node;
struct usb_hcd *hcd;
struct ohci_hcd *ohci;
struct resource res;
int irq;
int rv;
int is_bigendian;
struct device_node *np;
if (usb_disabled())
return -ENODEV;
is_bigendian =
of_device_is_compatible(dn, "ohci-bigendian") ||
of_device_is_compatible(dn, "ohci-be");
dev_dbg(&op->dev, "initializing PPC-OF USB Controller\n");
rv = of_address_to_resource(dn, 0, &res);
if (rv)
return rv;
hcd = usb_create_hcd(&ohci_ppc_of_hc_driver, &op->dev, "PPC-OF USB");
if (!hcd)
return -ENOMEM;
hcd->rsrc_start = res.start;
hcd->rsrc_len = res.end - res.start + 1;
if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
printk(KERN_ERR __FILE__ ": request_mem_region failed\n");
rv = -EBUSY;
goto err_rmr;
}
irq = irq_of_parse_and_map(dn, 0);
if (irq == NO_IRQ) {
printk(KERN_ERR __FILE__ ": irq_of_parse_and_map failed\n");
rv = -EBUSY;
goto err_irq;
}
hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
if (!hcd->regs) {
printk(KERN_ERR __FILE__ ": ioremap failed\n");
rv = -ENOMEM;
goto err_ioremap;
}
ohci = hcd_to_ohci(hcd);
if (is_bigendian) {
ohci->flags |= OHCI_QUIRK_BE_MMIO | OHCI_QUIRK_BE_DESC;
if (of_device_is_compatible(dn, "fsl,mpc5200-ohci"))
ohci->flags |= OHCI_QUIRK_FRAME_NO;
if (of_device_is_compatible(dn, "mpc5200-ohci"))
ohci->flags |= OHCI_QUIRK_FRAME_NO;
}
ohci_hcd_init(ohci);
rv = usb_add_hcd(hcd, irq, IRQF_DISABLED);
if (rv == 0)
return 0;
/* by now, 440epx is known to show usb_23 erratum */
np = of_find_compatible_node(NULL, NULL, "ibm,usb-ehci-440epx");
/* Work around - At this point ohci_run has executed, the
* controller is running, everything, the root ports, etc., is
* set up. If the ehci driver is loaded, put the ohci core in
* the suspended state. The ehci driver will bring it out of
* suspended state when / if a non-high speed USB device is
* attached to the USB Host port. If the ehci driver is not
* loaded, do nothing. request_mem_region is used to test if
* the ehci driver is loaded.
*/
if (np != NULL) {
if (!of_address_to_resource(np, 0, &res)) {
if (!request_mem_region(res.start, 0x4, hcd_name)) {
writel_be((readl_be(&ohci->regs->control) |
OHCI_USB_SUSPEND), &ohci->regs->control);
(void) readl_be(&ohci->regs->control);
} else
release_mem_region(res.start, 0x4);
} else
pr_debug(__FILE__ ": cannot get ehci offset from fdt\n");
}
iounmap(hcd->regs);
err_ioremap:
irq_dispose_mapping(irq);
err_irq:
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
err_rmr:
usb_put_hcd(hcd);
return rv;
}
static int ohci_hcd_ppc_of_remove(struct of_device *op)
{
struct usb_hcd *hcd = dev_get_drvdata(&op->dev);
dev_set_drvdata(&op->dev, NULL);
dev_dbg(&op->dev, "stopping PPC-OF USB Controller\n");
usb_remove_hcd(hcd);
iounmap(hcd->regs);
irq_dispose_mapping(hcd->irq);
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
usb_put_hcd(hcd);
return 0;
}
static int ohci_hcd_ppc_of_shutdown(struct of_device *op)
{
struct usb_hcd *hcd = dev_get_drvdata(&op->dev);
if (hcd->driver->shutdown)
hcd->driver->shutdown(hcd);
return 0;
}
static struct of_device_id ohci_hcd_ppc_of_match[] = {
#ifdef CONFIG_USB_OHCI_HCD_PPC_OF_BE
{
.name = "usb",
.compatible = "ohci-bigendian",
},
{
.name = "usb",
.compatible = "ohci-be",
},
#endif
#ifdef CONFIG_USB_OHCI_HCD_PPC_OF_LE
{
.name = "usb",
.compatible = "ohci-littledian",
},
{
.name = "usb",
.compatible = "ohci-le",
},
#endif
{},
};
MODULE_DEVICE_TABLE(of, ohci_hcd_ppc_of_match);
#if !defined(CONFIG_USB_OHCI_HCD_PPC_OF_BE) && \
!defined(CONFIG_USB_OHCI_HCD_PPC_OF_LE)
#error "No endianess selected for ppc-of-ohci"
#endif
static struct of_platform_driver ohci_hcd_ppc_of_driver = {
.name = "ppc-of-ohci",
.match_table = ohci_hcd_ppc_of_match,
.probe = ohci_hcd_ppc_of_probe,
.remove = ohci_hcd_ppc_of_remove,
.shutdown = ohci_hcd_ppc_of_shutdown,
#ifdef CONFIG_PM
/*.suspend = ohci_hcd_ppc_soc_drv_suspend,*/
/*.resume = ohci_hcd_ppc_soc_drv_resume,*/
#endif
.driver = {
.name = "ppc-of-ohci",
.owner = THIS_MODULE,
},
};