linux/drivers/usb/host/ehci-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

284 lines
6.1 KiB
C

/*
* EHCI HCD (Host Controller Driver) for USB.
*
* Bus Glue for PPC On-Chip EHCI driver on the of_platform bus
* Tested on AMCC PPC 440EPx
*
* Valentine Barshak <vbarshak@ru.mvista.com>
*
* Based on "ehci-ppc-soc.c" by Stefan Roese <sr@denx.de>
* and "ohci-ppc-of.c" by Sylvain Munaut <tnt@246tNt.com>
*
* This file is licenced under the GPL.
*/
#include <linux/signal.h>
#include <linux/of.h>
#include <linux/of_platform.h>
/* called during probe() after chip reset completes */
static int ehci_ppc_of_setup(struct usb_hcd *hcd)
{
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
int retval;
retval = ehci_halt(ehci);
if (retval)
return retval;
retval = ehci_init(hcd);
if (retval)
return retval;
ehci->sbrn = 0x20;
return ehci_reset(ehci);
}
static const struct hc_driver ehci_ppc_of_hc_driver = {
.description = hcd_name,
.product_desc = "OF EHCI",
.hcd_priv_size = sizeof(struct ehci_hcd),
/*
* generic hardware linkage
*/
.irq = ehci_irq,
.flags = HCD_MEMORY | HCD_USB2,
/*
* basic lifecycle operations
*/
.reset = ehci_ppc_of_setup,
.start = ehci_run,
.stop = ehci_stop,
.shutdown = ehci_shutdown,
/*
* managing i/o requests and associated device resources
*/
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
/*
* scheduling support
*/
.get_frame_number = ehci_get_frame,
/*
* root hub support
*/
.hub_status_data = ehci_hub_status_data,
.hub_control = ehci_hub_control,
#ifdef CONFIG_PM
.bus_suspend = ehci_bus_suspend,
.bus_resume = ehci_bus_resume,
#endif
.relinquish_port = ehci_relinquish_port,
.port_handed_over = ehci_port_handed_over,
};
/*
* 440EPx Errata USBH_3
* Fix: Enable Break Memory Transfer (BMT) in INSNREG3
*/
#define PPC440EPX_EHCI0_INSREG_BMT (0x1 << 0)
static int __devinit
ppc44x_enable_bmt(struct device_node *dn)
{
__iomem u32 *insreg_virt;
insreg_virt = of_iomap(dn, 1);
if (!insreg_virt)
return -EINVAL;
out_be32(insreg_virt + 3, PPC440EPX_EHCI0_INSREG_BMT);
iounmap(insreg_virt);
return 0;
}
static int __devinit
ehci_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 ehci_hcd *ehci = NULL;
struct resource res;
int irq;
int rv;
struct device_node *np;
if (usb_disabled())
return -ENODEV;
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(&ehci_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;
}
ehci = hcd_to_ehci(hcd);
np = of_find_compatible_node(NULL, NULL, "ibm,usb-ohci-440epx");
if (np != NULL) {
/* claim we really affected by usb23 erratum */
if (!of_address_to_resource(np, 0, &res))
ehci->ohci_hcctrl_reg = ioremap(res.start +
OHCI_HCCTRL_OFFSET, OHCI_HCCTRL_LEN);
else
pr_debug(__FILE__ ": no ohci offset in fdt\n");
if (!ehci->ohci_hcctrl_reg) {
pr_debug(__FILE__ ": ioremap for ohci hcctrl failed\n");
} else {
ehci->has_amcc_usb23 = 1;
}
}
if (of_get_property(dn, "big-endian", NULL)) {
ehci->big_endian_mmio = 1;
ehci->big_endian_desc = 1;
}
if (of_get_property(dn, "big-endian-regs", NULL))
ehci->big_endian_mmio = 1;
if (of_get_property(dn, "big-endian-desc", NULL))
ehci->big_endian_desc = 1;
ehci->caps = hcd->regs;
ehci->regs = hcd->regs +
HC_LENGTH(ehci_readl(ehci, &ehci->caps->hc_capbase));
/* cache this readonly data; minimize chip reads */
ehci->hcs_params = ehci_readl(ehci, &ehci->caps->hcs_params);
if (of_device_is_compatible(dn, "ibm,usb-ehci-440epx")) {
rv = ppc44x_enable_bmt(dn);
ehci_dbg(ehci, "Break Memory Transfer (BMT) is %senabled!\n",
rv ? "NOT ": "");
}
rv = usb_add_hcd(hcd, irq, 0);
if (rv == 0)
return 0;
iounmap(hcd->regs);
err_ioremap:
irq_dispose_mapping(irq);
err_irq:
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
if (ehci->has_amcc_usb23)
iounmap(ehci->ohci_hcctrl_reg);
err_rmr:
usb_put_hcd(hcd);
return rv;
}
static int ehci_hcd_ppc_of_remove(struct of_device *op)
{
struct usb_hcd *hcd = dev_get_drvdata(&op->dev);
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
struct device_node *np;
struct resource res;
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);
/* use request_mem_region to test if the ohci driver is loaded. if so
* ensure the ohci core is operational.
*/
if (ehci->has_amcc_usb23) {
np = of_find_compatible_node(NULL, NULL, "ibm,usb-ohci-440epx");
if (np != NULL) {
if (!of_address_to_resource(np, 0, &res))
if (!request_mem_region(res.start,
0x4, hcd_name))
set_ohci_hcfs(ehci, 1);
else
release_mem_region(res.start, 0x4);
else
pr_debug(__FILE__ ": no ohci offset in fdt\n");
of_node_put(np);
}
iounmap(ehci->ohci_hcctrl_reg);
}
usb_put_hcd(hcd);
return 0;
}
static int ehci_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 ehci_hcd_ppc_of_match[] = {
{
.compatible = "usb-ehci",
},
{},
};
MODULE_DEVICE_TABLE(of, ehci_hcd_ppc_of_match);
static struct of_platform_driver ehci_hcd_ppc_of_driver = {
.name = "ppc-of-ehci",
.match_table = ehci_hcd_ppc_of_match,
.probe = ehci_hcd_ppc_of_probe,
.remove = ehci_hcd_ppc_of_remove,
.shutdown = ehci_hcd_ppc_of_shutdown,
.driver = {
.name = "ppc-of-ehci",
.owner = THIS_MODULE,
},
};