linux/drivers/usb/host/uhci-grlib.c
Christophe Leroy 8836402d4b usb: Check !irq instead of irq == NO_IRQ
NO_IRQ is a relic from the old days. It is not used anymore in core
functions. By the way, function irq_of_parse_and_map() returns value 0
on error.

In some drivers, NO_IRQ is erroneously used to check the return of
irq_of_parse_and_map().

It is not a real bug today because the only architectures using the
drivers being fixed by this patch define NO_IRQ as 0, but there are
architectures which define NO_IRQ as -1. If one day those
architectures start using the non fixed drivers, there will be a
problem.

Long time ago Linus advocated for not using NO_IRQ, see
https://lkml.org/lkml/2005/11/21/221 . He re-iterated the same view
recently in https://lkml.org/lkml/2022/10/12/622

So test !irq instead of tesing irq == NO_IRQ.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/13feefdf6b240817944e6441e26a8ddc1d81ced1.1668102802.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-11 10:28:38 +01:00

195 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* UHCI HCD (Host Controller Driver) for GRLIB GRUSBHC
*
* Copyright (c) 2011 Jan Andersson <jan@gaisler.com>
*
* This file is based on UHCI PCI HCD:
* (C) Copyright 1999 Linus Torvalds
* (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
* (C) Copyright 1999 Randy Dunlap
* (C) Copyright 1999 Georg Acher, acher@in.tum.de
* (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
* (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
* (C) Copyright 1999 Roman Weissgaerber, weissg@vienna.at
* (C) Copyright 2000 Yggdrasil Computing, Inc. (port of new PCI interface
* support from usb-ohci.c by Adam Richter, adam@yggdrasil.com).
* (C) Copyright 1999 Gregory P. Smith (from usb-ohci.c)
* (C) Copyright 2004-2007 Alan Stern, stern@rowland.harvard.edu
*/
#include <linux/device.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
static int uhci_grlib_init(struct usb_hcd *hcd)
{
struct uhci_hcd *uhci = hcd_to_uhci(hcd);
/*
* Probe to determine the endianness of the controller.
* We know that bit 7 of the PORTSC1 register is always set
* and bit 15 is always clear. If uhci_readw() yields a value
* with bit 7 (0x80) turned on then the current little-endian
* setting is correct. Otherwise we assume the value was
* byte-swapped; hence the register interface and presumably
* also the descriptors are big-endian.
*/
if (!(uhci_readw(uhci, USBPORTSC1) & 0x80)) {
uhci->big_endian_mmio = 1;
uhci->big_endian_desc = 1;
}
uhci->rh_numports = uhci_count_ports(hcd);
/* Set up pointers to generic functions */
uhci->reset_hc = uhci_generic_reset_hc;
uhci->check_and_reset_hc = uhci_generic_check_and_reset_hc;
/* No special actions need to be taken for the functions below */
uhci->configure_hc = NULL;
uhci->resume_detect_interrupts_are_broken = NULL;
uhci->global_suspend_mode_is_broken = NULL;
/* Reset if the controller isn't already safely quiescent. */
check_and_reset_hc(uhci);
return 0;
}
static const struct hc_driver uhci_grlib_hc_driver = {
.description = hcd_name,
.product_desc = "GRLIB GRUSBHC UHCI Host Controller",
.hcd_priv_size = sizeof(struct uhci_hcd),
/* Generic hardware linkage */
.irq = uhci_irq,
.flags = HCD_MEMORY | HCD_DMA | HCD_USB11,
/* Basic lifecycle operations */
.reset = uhci_grlib_init,
.start = uhci_start,
#ifdef CONFIG_PM
.pci_suspend = NULL,
.pci_resume = NULL,
.bus_suspend = uhci_rh_suspend,
.bus_resume = uhci_rh_resume,
#endif
.stop = uhci_stop,
.urb_enqueue = uhci_urb_enqueue,
.urb_dequeue = uhci_urb_dequeue,
.endpoint_disable = uhci_hcd_endpoint_disable,
.get_frame_number = uhci_hcd_get_frame_number,
.hub_status_data = uhci_hub_status_data,
.hub_control = uhci_hub_control,
};
static int uhci_hcd_grlib_probe(struct platform_device *op)
{
struct device_node *dn = op->dev.of_node;
struct usb_hcd *hcd;
struct uhci_hcd *uhci = NULL;
struct resource res;
int irq;
int rv;
if (usb_disabled())
return -ENODEV;
dev_dbg(&op->dev, "initializing GRUSBHC UHCI USB Controller\n");
rv = of_address_to_resource(dn, 0, &res);
if (rv)
return rv;
/* usb_create_hcd requires dma_mask != NULL */
op->dev.dma_mask = &op->dev.coherent_dma_mask;
hcd = usb_create_hcd(&uhci_grlib_hc_driver, &op->dev,
"GRUSBHC UHCI USB");
if (!hcd)
return -ENOMEM;
hcd->rsrc_start = res.start;
hcd->rsrc_len = resource_size(&res);
irq = irq_of_parse_and_map(dn, 0);
if (!irq) {
printk(KERN_ERR "%s: irq_of_parse_and_map failed\n", __FILE__);
rv = -EBUSY;
goto err_usb;
}
hcd->regs = devm_ioremap_resource(&op->dev, &res);
if (IS_ERR(hcd->regs)) {
rv = PTR_ERR(hcd->regs);
goto err_irq;
}
uhci = hcd_to_uhci(hcd);
uhci->regs = hcd->regs;
rv = usb_add_hcd(hcd, irq, 0);
if (rv)
goto err_irq;
device_wakeup_enable(hcd->self.controller);
return 0;
err_irq:
irq_dispose_mapping(irq);
err_usb:
usb_put_hcd(hcd);
return rv;
}
static int uhci_hcd_grlib_remove(struct platform_device *op)
{
struct usb_hcd *hcd = platform_get_drvdata(op);
dev_dbg(&op->dev, "stopping GRLIB GRUSBHC UHCI USB Controller\n");
usb_remove_hcd(hcd);
irq_dispose_mapping(hcd->irq);
usb_put_hcd(hcd);
return 0;
}
/* Make sure the controller is quiescent and that we're not using it
* any more. This is mainly for the benefit of programs which, like kexec,
* expect the hardware to be idle: not doing DMA or generating IRQs.
*
* This routine may be called in a damaged or failing kernel. Hence we
* do not acquire the spinlock before shutting down the controller.
*/
static void uhci_hcd_grlib_shutdown(struct platform_device *op)
{
struct usb_hcd *hcd = platform_get_drvdata(op);
uhci_hc_died(hcd_to_uhci(hcd));
}
static const struct of_device_id uhci_hcd_grlib_of_match[] = {
{ .name = "GAISLER_UHCI", },
{ .name = "01_027", },
{},
};
MODULE_DEVICE_TABLE(of, uhci_hcd_grlib_of_match);
static struct platform_driver uhci_grlib_driver = {
.probe = uhci_hcd_grlib_probe,
.remove = uhci_hcd_grlib_remove,
.shutdown = uhci_hcd_grlib_shutdown,
.driver = {
.name = "grlib-uhci",
.of_match_table = uhci_hcd_grlib_of_match,
},
};