android_kernel_xiaomi_sm8350/drivers/net/ibm_newemac/zmii.c
Benjamin Herrenschmidt 968530643a ibm_newemac: Fix ZMII refcounting bug
When using ZMII for MDIO only (such as 440GX with RGMII for data and ZMII for
MDIO), the ZMII code would fail to properly refcount, thus triggering a
BUG_ON().

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Stefan Roese <sr@denx.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-12-07 15:09:05 -05:00

325 lines
7.3 KiB
C

/*
* drivers/net/ibm_newemac/zmii.c
*
* Driver for PowerPC 4xx on-chip ethernet controller, ZMII bridge support.
*
* Copyright (c) 2004, 2005 Zultys Technologies.
* Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
*
* Based on original work by
* Armin Kuster <akuster@mvista.com>
* Copyright 2001 MontaVista Softare Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/ethtool.h>
#include <asm/io.h>
#include "emac.h"
#include "core.h"
/* ZMIIx_FER */
#define ZMII_FER_MDI(idx) (0x80000000 >> ((idx) * 4))
#define ZMII_FER_MDI_ALL (ZMII_FER_MDI(0) | ZMII_FER_MDI(1) | \
ZMII_FER_MDI(2) | ZMII_FER_MDI(3))
#define ZMII_FER_SMII(idx) (0x40000000 >> ((idx) * 4))
#define ZMII_FER_RMII(idx) (0x20000000 >> ((idx) * 4))
#define ZMII_FER_MII(idx) (0x10000000 >> ((idx) * 4))
/* ZMIIx_SSR */
#define ZMII_SSR_SCI(idx) (0x40000000 >> ((idx) * 4))
#define ZMII_SSR_FSS(idx) (0x20000000 >> ((idx) * 4))
#define ZMII_SSR_SP(idx) (0x10000000 >> ((idx) * 4))
/* ZMII only supports MII, RMII and SMII
* we also support autodetection for backward compatibility
*/
static inline int zmii_valid_mode(int mode)
{
return mode == PHY_MODE_MII ||
mode == PHY_MODE_RMII ||
mode == PHY_MODE_SMII ||
mode == PHY_MODE_NA;
}
static inline const char *zmii_mode_name(int mode)
{
switch (mode) {
case PHY_MODE_MII:
return "MII";
case PHY_MODE_RMII:
return "RMII";
case PHY_MODE_SMII:
return "SMII";
default:
BUG();
}
}
static inline u32 zmii_mode_mask(int mode, int input)
{
switch (mode) {
case PHY_MODE_MII:
return ZMII_FER_MII(input);
case PHY_MODE_RMII:
return ZMII_FER_RMII(input);
case PHY_MODE_SMII:
return ZMII_FER_SMII(input);
default:
return 0;
}
}
int __devinit zmii_attach(struct of_device *ofdev, int input, int *mode)
{
struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
struct zmii_regs __iomem *p = dev->base;
ZMII_DBG(dev, "init(%d, %d)" NL, input, *mode);
if (!zmii_valid_mode(*mode)) {
/* Probably an EMAC connected to RGMII,
* but it still may need ZMII for MDIO so
* we don't fail here.
*/
dev->users++;
return 0;
}
mutex_lock(&dev->lock);
/* Autodetect ZMII mode if not specified.
* This is only for backward compatibility with the old driver.
* Please, always specify PHY mode in your board port to avoid
* any surprises.
*/
if (dev->mode == PHY_MODE_NA) {
if (*mode == PHY_MODE_NA) {
u32 r = dev->fer_save;
ZMII_DBG(dev, "autodetecting mode, FER = 0x%08x" NL, r);
if (r & (ZMII_FER_MII(0) | ZMII_FER_MII(1)))
dev->mode = PHY_MODE_MII;
else if (r & (ZMII_FER_RMII(0) | ZMII_FER_RMII(1)))
dev->mode = PHY_MODE_RMII;
else
dev->mode = PHY_MODE_SMII;
} else
dev->mode = *mode;
printk(KERN_NOTICE "%s: bridge in %s mode\n",
ofdev->node->full_name, zmii_mode_name(dev->mode));
} else {
/* All inputs must use the same mode */
if (*mode != PHY_MODE_NA && *mode != dev->mode) {
printk(KERN_ERR
"%s: invalid mode %d specified for input %d\n",
ofdev->node->full_name, *mode, input);
mutex_unlock(&dev->lock);
return -EINVAL;
}
}
/* Report back correct PHY mode,
* it may be used during PHY initialization.
*/
*mode = dev->mode;
/* Enable this input */
out_be32(&p->fer, in_be32(&p->fer) | zmii_mode_mask(dev->mode, input));
++dev->users;
mutex_unlock(&dev->lock);
return 0;
}
void zmii_get_mdio(struct of_device *ofdev, int input)
{
struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
u32 fer;
ZMII_DBG2(dev, "get_mdio(%d)" NL, input);
mutex_lock(&dev->lock);
fer = in_be32(&dev->base->fer) & ~ZMII_FER_MDI_ALL;
out_be32(&dev->base->fer, fer | ZMII_FER_MDI(input));
}
void zmii_put_mdio(struct of_device *ofdev, int input)
{
struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
ZMII_DBG2(dev, "put_mdio(%d)" NL, input);
mutex_unlock(&dev->lock);
}
void zmii_set_speed(struct of_device *ofdev, int input, int speed)
{
struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
u32 ssr;
mutex_lock(&dev->lock);
ssr = in_be32(&dev->base->ssr);
ZMII_DBG(dev, "speed(%d, %d)" NL, input, speed);
if (speed == SPEED_100)
ssr |= ZMII_SSR_SP(input);
else
ssr &= ~ZMII_SSR_SP(input);
out_be32(&dev->base->ssr, ssr);
mutex_unlock(&dev->lock);
}
void __devexit zmii_detach(struct of_device *ofdev, int input)
{
struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
BUG_ON(!dev || dev->users == 0);
mutex_lock(&dev->lock);
ZMII_DBG(dev, "detach(%d)" NL, input);
/* Disable this input */
out_be32(&dev->base->fer,
in_be32(&dev->base->fer) & ~zmii_mode_mask(dev->mode, input));
--dev->users;
mutex_unlock(&dev->lock);
}
int zmii_get_regs_len(struct of_device *ofdev)
{
return sizeof(struct emac_ethtool_regs_subhdr) +
sizeof(struct zmii_regs);
}
void *zmii_dump_regs(struct of_device *ofdev, void *buf)
{
struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
struct emac_ethtool_regs_subhdr *hdr = buf;
struct zmii_regs *regs = (struct zmii_regs *)(hdr + 1);
hdr->version = 0;
hdr->index = 0; /* for now, are there chips with more than one
* zmii ? if yes, then we'll add a cell_index
* like we do for emac
*/
memcpy_fromio(regs, dev->base, sizeof(struct zmii_regs));
return regs + 1;
}
static int __devinit zmii_probe(struct of_device *ofdev,
const struct of_device_id *match)
{
struct device_node *np = ofdev->node;
struct zmii_instance *dev;
struct resource regs;
int rc;
rc = -ENOMEM;
dev = kzalloc(sizeof(struct zmii_instance), GFP_KERNEL);
if (dev == NULL) {
printk(KERN_ERR "%s: could not allocate ZMII device!\n",
np->full_name);
goto err_gone;
}
mutex_init(&dev->lock);
dev->ofdev = ofdev;
dev->mode = PHY_MODE_NA;
rc = -ENXIO;
if (of_address_to_resource(np, 0, &regs)) {
printk(KERN_ERR "%s: Can't get registers address\n",
np->full_name);
goto err_free;
}
rc = -ENOMEM;
dev->base = (struct zmii_regs __iomem *)ioremap(regs.start,
sizeof(struct zmii_regs));
if (dev->base == NULL) {
printk(KERN_ERR "%s: Can't map device registers!\n",
np->full_name);
goto err_free;
}
/* We may need FER value for autodetection later */
dev->fer_save = in_be32(&dev->base->fer);
/* Disable all inputs by default */
out_be32(&dev->base->fer, 0);
printk(KERN_INFO
"ZMII %s initialized\n", ofdev->node->full_name);
wmb();
dev_set_drvdata(&ofdev->dev, dev);
return 0;
err_free:
kfree(dev);
err_gone:
return rc;
}
static int __devexit zmii_remove(struct of_device *ofdev)
{
struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
dev_set_drvdata(&ofdev->dev, NULL);
WARN_ON(dev->users != 0);
iounmap(dev->base);
kfree(dev);
return 0;
}
static struct of_device_id zmii_match[] =
{
{
.compatible = "ibm,zmii",
},
/* For backward compat with old DT */
{
.type = "emac-zmii",
},
{},
};
static struct of_platform_driver zmii_driver = {
.name = "emac-zmii",
.match_table = zmii_match,
.probe = zmii_probe,
.remove = zmii_remove,
};
int __init zmii_init(void)
{
return of_register_platform_driver(&zmii_driver);
}
void zmii_exit(void)
{
of_unregister_platform_driver(&zmii_driver);
}