linux/drivers/ssb/sprom.c
Michael Buesch e79c1ba84c ssb: Add SPROM fallback support
This adds SSB functionality to register a fallback SPROM image from the
architecture setup code.

Weird architectures exist that have half-assed SSB devices without SPROM attached to
their PCI busses. The architecture can register a fallback SPROM image that is
used if no SPROM is found on the SSB device.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Florian Fainelli <florian@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-05 14:39:32 -05:00

170 lines
4.4 KiB
C

/*
* Sonics Silicon Backplane
* Common SPROM support routines
*
* Copyright (C) 2005-2008 Michael Buesch <mb@bu3sch.de>
* Copyright (C) 2005 Martin Langer <martin-langer@gmx.de>
* Copyright (C) 2005 Stefano Brivio <st3@riseup.net>
* Copyright (C) 2005 Danny van Dyk <kugelfang@gentoo.org>
* Copyright (C) 2005 Andreas Jaggi <andreas.jaggi@waterwave.ch>
*
* Licensed under the GNU/GPL. See COPYING for details.
*/
#include "ssb_private.h"
static const struct ssb_sprom *fallback_sprom;
static int sprom2hex(const u16 *sprom, char *buf, size_t buf_len,
size_t sprom_size_words)
{
int i, pos = 0;
for (i = 0; i < sprom_size_words; i++)
pos += snprintf(buf + pos, buf_len - pos - 1,
"%04X", swab16(sprom[i]) & 0xFFFF);
pos += snprintf(buf + pos, buf_len - pos - 1, "\n");
return pos + 1;
}
static int hex2sprom(u16 *sprom, const char *dump, size_t len,
size_t sprom_size_words)
{
char tmp[5] = { 0 };
int cnt = 0;
unsigned long parsed;
if (len < sprom_size_words * 2)
return -EINVAL;
while (cnt < sprom_size_words) {
memcpy(tmp, dump, 4);
dump += 4;
parsed = simple_strtoul(tmp, NULL, 16);
sprom[cnt++] = swab16((u16)parsed);
}
return 0;
}
/* Common sprom device-attribute show-handler */
ssize_t ssb_attr_sprom_show(struct ssb_bus *bus, char *buf,
int (*sprom_read)(struct ssb_bus *bus, u16 *sprom))
{
u16 *sprom;
int err = -ENOMEM;
ssize_t count = 0;
size_t sprom_size_words = bus->sprom_size;
sprom = kcalloc(sprom_size_words, sizeof(u16), GFP_KERNEL);
if (!sprom)
goto out;
/* Use interruptible locking, as the SPROM write might
* be holding the lock for several seconds. So allow userspace
* to cancel operation. */
err = -ERESTARTSYS;
if (mutex_lock_interruptible(&bus->sprom_mutex))
goto out_kfree;
err = sprom_read(bus, sprom);
mutex_unlock(&bus->sprom_mutex);
if (!err)
count = sprom2hex(sprom, buf, PAGE_SIZE, sprom_size_words);
out_kfree:
kfree(sprom);
out:
return err ? err : count;
}
/* Common sprom device-attribute store-handler */
ssize_t ssb_attr_sprom_store(struct ssb_bus *bus,
const char *buf, size_t count,
int (*sprom_check_crc)(const u16 *sprom, size_t size),
int (*sprom_write)(struct ssb_bus *bus, const u16 *sprom))
{
u16 *sprom;
int res = 0, err = -ENOMEM;
size_t sprom_size_words = bus->sprom_size;
sprom = kcalloc(bus->sprom_size, sizeof(u16), GFP_KERNEL);
if (!sprom)
goto out;
err = hex2sprom(sprom, buf, count, sprom_size_words);
if (err) {
err = -EINVAL;
goto out_kfree;
}
err = sprom_check_crc(sprom, sprom_size_words);
if (err) {
err = -EINVAL;
goto out_kfree;
}
/* Use interruptible locking, as the SPROM write might
* be holding the lock for several seconds. So allow userspace
* to cancel operation. */
err = -ERESTARTSYS;
if (mutex_lock_interruptible(&bus->sprom_mutex))
goto out_kfree;
err = ssb_devices_freeze(bus);
if (err == -EOPNOTSUPP) {
ssb_printk(KERN_ERR PFX "SPROM write: Could not freeze devices. "
"No suspend support. Is CONFIG_PM enabled?\n");
goto out_unlock;
}
if (err) {
ssb_printk(KERN_ERR PFX "SPROM write: Could not freeze all devices\n");
goto out_unlock;
}
res = sprom_write(bus, sprom);
err = ssb_devices_thaw(bus);
if (err)
ssb_printk(KERN_ERR PFX "SPROM write: Could not thaw all devices\n");
out_unlock:
mutex_unlock(&bus->sprom_mutex);
out_kfree:
kfree(sprom);
out:
if (res)
return res;
return err ? err : count;
}
/**
* ssb_arch_set_fallback_sprom - Set a fallback SPROM for use if no SPROM is found.
*
* @sprom: The SPROM data structure to register.
*
* With this function the architecture implementation may register a fallback
* SPROM data structure. The fallback is only used for PCI based SSB devices,
* where no valid SPROM can be found in the shadow registers.
*
* This function is useful for weird architectures that have a half-assed SSB device
* hardwired to their PCI bus.
*
* Note that it does only work with PCI attached SSB devices. PCMCIA devices currently
* don't use this fallback.
* Architectures must provide the SPROM for native SSB devices anyway,
* so the fallback also isn't used for native devices.
*
* This function is available for architecture code, only. So it is not exported.
*/
int ssb_arch_set_fallback_sprom(const struct ssb_sprom *sprom)
{
if (fallback_sprom)
return -EEXIST;
fallback_sprom = sprom;
return 0;
}
const struct ssb_sprom *ssb_get_fallback_sprom(void)
{
return fallback_sprom;
}