linux/drivers/usb/host/ehci-ppc-of.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

242 lines
5.2 KiB
C

// SPDX-License-Identifier: GPL-1.0+
/*
* 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/err.h>
#include <linux/signal.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
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_DMA | HCD_USB2 | HCD_BH,
/*
* basic lifecycle operations
*/
.reset = ehci_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,
.endpoint_reset = ehci_endpoint_reset,
/*
* 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,
.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
};
/*
* 440EPx Errata USBH_3
* Fix: Enable Break Memory Transfer (BMT) in INSNREG3
*/
#define PPC440EPX_EHCI0_INSREG_BMT (0x1 << 0)
static int
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 ehci_hcd_ppc_of_probe(struct platform_device *op)
{
struct device_node *dn = op->dev.of_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 = resource_size(&res);
irq = irq_of_parse_and_map(dn, 0);
if (!irq) {
dev_err(&op->dev, "%s: irq_of_parse_and_map failed\n",
__FILE__);
rv = -EBUSY;
goto err_irq;
}
hcd->regs = devm_ioremap_resource(&op->dev, &res);
if (IS_ERR(hcd->regs)) {
rv = PTR_ERR(hcd->regs);
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 =
devm_ioremap(&op->dev,
res.start + OHCI_HCCTRL_OFFSET,
OHCI_HCCTRL_LEN);
else
pr_debug("%s: no ohci offset in fdt\n", __FILE__);
if (!ehci->ohci_hcctrl_reg) {
pr_debug("%s: ioremap for ohci hcctrl failed\n", __FILE__);
} else {
ehci->has_amcc_usb23 = 1;
}
of_node_put(np);
}
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;
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)
goto err_ioremap;
device_wakeup_enable(hcd->self.controller);
return 0;
err_ioremap:
irq_dispose_mapping(irq);
err_irq:
usb_put_hcd(hcd);
return rv;
}
static int ehci_hcd_ppc_of_remove(struct platform_device *op)
{
struct usb_hcd *hcd = platform_get_drvdata(op);
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
struct device_node *np;
struct resource res;
dev_dbg(&op->dev, "stopping PPC-OF USB Controller\n");
usb_remove_hcd(hcd);
irq_dispose_mapping(hcd->irq);
/* 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("%s: no ohci offset in fdt\n", __FILE__);
of_node_put(np);
}
}
usb_put_hcd(hcd);
return 0;
}
static const struct of_device_id ehci_hcd_ppc_of_match[] = {
{
.compatible = "usb-ehci",
},
{},
};
MODULE_DEVICE_TABLE(of, ehci_hcd_ppc_of_match);
static struct platform_driver ehci_hcd_ppc_of_driver = {
.probe = ehci_hcd_ppc_of_probe,
.remove = ehci_hcd_ppc_of_remove,
.shutdown = usb_hcd_platform_shutdown,
.driver = {
.name = "ppc-of-ehci",
.of_match_table = ehci_hcd_ppc_of_match,
},
};