linux/drivers/usb/host/ehci-ath79.c

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/*
* Bus Glue for Atheros AR7XXX/AR9XXX built-in EHCI controller.
*
* Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
*
* Parts of this file are based on Atheros' 2.6.15 BSP
* Copyright (C) 2007 Atheros Communications, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include <linux/platform_device.h>
enum {
EHCI_ATH79_IP_V1 = 0,
EHCI_ATH79_IP_V2,
};
static const struct platform_device_id ehci_ath79_id_table[] = {
{
.name = "ar71xx-ehci",
.driver_data = EHCI_ATH79_IP_V1,
},
{
.name = "ar724x-ehci",
.driver_data = EHCI_ATH79_IP_V2,
},
{
.name = "ar913x-ehci",
.driver_data = EHCI_ATH79_IP_V2,
},
{
/* terminating entry */
},
};
MODULE_DEVICE_TABLE(platform, ehci_ath79_id_table);
static int ehci_ath79_init(struct usb_hcd *hcd)
{
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
struct platform_device *pdev = to_platform_device(hcd->self.controller);
const struct platform_device_id *id;
int hclength;
int ret;
id = platform_get_device_id(pdev);
if (!id) {
dev_err(hcd->self.controller, "missing device id\n");
return -EINVAL;
}
hclength = HC_LENGTH(ehci, ehci_readl(ehci, &ehci->caps->hc_capbase));
switch (id->driver_data) {
case EHCI_ATH79_IP_V1:
USB: ehci: add workaround for Synopsys HC bug A Synopsys USB core used in various SoCs has a bug which might cause that the host controller not issuing ping. When software uses the Doorbell mechanism to remove queue heads, the host controller still has references to the removed queue head even after indicating an Interrupt on Async Advance. This happens if the last executed queue head's Next Link queue head is removed. Consequences of the defect: The Host controller fetches the removed queue head, using memory that would otherwise be deallocated.This results in incorrect transactions on both the USB and system memory. This may result in undefined behavior. Workarounds: 1) If no queue head is active (no Status field's Active bit is set) after removing the queue heads, the software can write one of the valid queue head addresses to the ASYNCLISTADDR register and deallocate the removed queue head's memory after 2 microframes. If one or more of the queue heads is active (the Active bit is set in the Status field) after removing the queue heads, the software can delay memory deallocation after time X, where X is the time required for the Host Controller to go through all the queue heads once. X varies with the number of queue heads and the time required to process periodic transactions: if more periodic transactions must be performed, the Host Controller has less time to process asynchronous transaction processing. 2) Do not use the Doorbell mechanism to remove the queue heads. Disable the Asynchronous Schedule Enable bit instead. The bug has been discussed on the linux-usb-devel mailing-list four years ago, the original thread can be found here: http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg45345.html This patch implements the first workaround as suggested by David Brownell. The built-in USB host controller of the Atheros AR7130/AR7141/AR7161 SoCs requires this to work properly. Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-13 08:54:23 +00:00
ehci->has_synopsys_hc_bug = 1;
ehci->caps = hcd->regs;
ehci->regs = hcd->regs + hclength;
break;
case EHCI_ATH79_IP_V2:
hcd->has_tt = 1;
ehci->caps = hcd->regs + 0x100;
ehci->regs = hcd->regs + 0x100 + hclength;
break;
default:
BUG();
}
dbg_hcs_params(ehci, "reset");
dbg_hcc_params(ehci, "reset");
ehci->hcs_params = ehci_readl(ehci, &ehci->caps->hcs_params);
ehci->sbrn = 0x20;
ehci_reset(ehci);
ret = ehci_init(hcd);
if (ret)
return ret;
ehci_port_power(ehci, 0);
return 0;
}
static const struct hc_driver ehci_ath79_hc_driver = {
.description = hcd_name,
.product_desc = "Atheros built-in EHCI controller",
.hcd_priv_size = sizeof(struct ehci_hcd),
.irq = ehci_irq,
.flags = HCD_MEMORY | HCD_USB2,
.reset = ehci_ath79_init,
.start = ehci_run,
.stop = ehci_stop,
.shutdown = ehci_shutdown,
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
.endpoint_reset = ehci_endpoint_reset,
.get_frame_number = ehci_get_frame,
.hub_status_data = ehci_hub_status_data,
.hub_control = ehci_hub_control,
.relinquish_port = ehci_relinquish_port,
.port_handed_over = ehci_port_handed_over,
.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
};
static int ehci_ath79_probe(struct platform_device *pdev)
{
struct usb_hcd *hcd;
struct resource *res;
int irq;
int ret;
if (usb_disabled())
return -ENODEV;
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res) {
dev_dbg(&pdev->dev, "no IRQ specified\n");
return -ENODEV;
}
irq = res->start;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_dbg(&pdev->dev, "no base address specified\n");
return -ENODEV;
}
hcd = usb_create_hcd(&ehci_ath79_hc_driver, &pdev->dev,
dev_name(&pdev->dev));
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)) {
dev_dbg(&pdev->dev, "controller already in use\n");
ret = -EBUSY;
goto err_put_hcd;
}
hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
if (!hcd->regs) {
dev_dbg(&pdev->dev, "error mapping memory\n");
ret = -EFAULT;
goto err_release_region;
}
ret = usb_add_hcd(hcd, irq, IRQF_DISABLED | IRQF_SHARED);
if (ret)
goto err_iounmap;
return 0;
err_iounmap:
iounmap(hcd->regs);
err_release_region:
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
err_put_hcd:
usb_put_hcd(hcd);
return ret;
}
static int ehci_ath79_remove(struct platform_device *pdev)
{
struct usb_hcd *hcd = platform_get_drvdata(pdev);
usb_remove_hcd(hcd);
iounmap(hcd->regs);
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
usb_put_hcd(hcd);
return 0;
}
static struct platform_driver ehci_ath79_driver = {
.probe = ehci_ath79_probe,
.remove = ehci_ath79_remove,
.id_table = ehci_ath79_id_table,
.driver = {
.owner = THIS_MODULE,
.name = "ath79-ehci",
}
};
MODULE_ALIAS(PLATFORM_MODULE_PREFIX "ath79-ehci");