linux/drivers/misc/cs5535-mfgpt.c

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/*
* Driver for the CS5535/CS5536 Multi-Function General Purpose Timers (MFGPT)
*
* Copyright (C) 2006, Advanced Micro Devices, Inc.
* Copyright (C) 2007 Andres Salomon <dilinger@debian.org>
* Copyright (C) 2009 Andres Salomon <dilinger@collabora.co.uk>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public License
* as published by the Free Software Foundation.
*
* The MFGPTs are documented in AMD Geode CS5536 Companion Device Data Book.
*/
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/cs5535.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#define DRV_NAME "cs5535-mfgpt"
static int mfgpt_reset_timers;
module_param_named(mfgptfix, mfgpt_reset_timers, int, 0644);
MODULE_PARM_DESC(mfgptfix, "Reset the MFGPT timers during init; "
"required by some broken BIOSes (ie, TinyBIOS < 0.99).");
struct cs5535_mfgpt_timer {
struct cs5535_mfgpt_chip *chip;
int nr;
};
static struct cs5535_mfgpt_chip {
DECLARE_BITMAP(avail, MFGPT_MAX_TIMERS);
resource_size_t base;
struct platform_device *pdev;
spinlock_t lock;
int initialized;
} cs5535_mfgpt_chip;
int cs5535_mfgpt_toggle_event(struct cs5535_mfgpt_timer *timer, int cmp,
int event, int enable)
{
uint32_t msr, mask, value, dummy;
int shift = (cmp == MFGPT_CMP1) ? 0 : 8;
if (!timer) {
WARN_ON(1);
return -EIO;
}
/*
* The register maps for these are described in sections 6.17.1.x of
* the AMD Geode CS5536 Companion Device Data Book.
*/
switch (event) {
case MFGPT_EVENT_RESET:
/*
* XXX: According to the docs, we cannot reset timers above
* 6; that is, resets for 7 and 8 will be ignored. Is this
* a problem? -dilinger
*/
msr = MSR_MFGPT_NR;
mask = 1 << (timer->nr + 24);
break;
case MFGPT_EVENT_NMI:
msr = MSR_MFGPT_NR;
mask = 1 << (timer->nr + shift);
break;
case MFGPT_EVENT_IRQ:
msr = MSR_MFGPT_IRQ;
mask = 1 << (timer->nr + shift);
break;
default:
return -EIO;
}
rdmsr(msr, value, dummy);
if (enable)
value |= mask;
else
value &= ~mask;
wrmsr(msr, value, dummy);
return 0;
}
EXPORT_SYMBOL_GPL(cs5535_mfgpt_toggle_event);
int cs5535_mfgpt_set_irq(struct cs5535_mfgpt_timer *timer, int cmp, int *irq,
int enable)
{
uint32_t zsel, lpc, dummy;
int shift;
if (!timer) {
WARN_ON(1);
return -EIO;
}
/*
* Unfortunately, MFGPTs come in pairs sharing their IRQ lines. If VSA
* is using the same CMP of the timer's Siamese twin, the IRQ is set to
* 2, and we mustn't use nor change it.
* XXX: Likewise, 2 Linux drivers might clash if the 2nd overwrites the
* IRQ of the 1st. This can only happen if forcing an IRQ, calling this
* with *irq==0 is safe. Currently there _are_ no 2 drivers.
*/
rdmsr(MSR_PIC_ZSEL_LOW, zsel, dummy);
shift = ((cmp == MFGPT_CMP1 ? 0 : 4) + timer->nr % 4) * 4;
if (((zsel >> shift) & 0xF) == 2)
return -EIO;
/* Choose IRQ: if none supplied, keep IRQ already set or use default */
if (!*irq)
*irq = (zsel >> shift) & 0xF;
if (!*irq)
*irq = CONFIG_CS5535_MFGPT_DEFAULT_IRQ;
/* Can't use IRQ if it's 0 (=disabled), 2, or routed to LPC */
if (*irq < 1 || *irq == 2 || *irq > 15)
return -EIO;
rdmsr(MSR_PIC_IRQM_LPC, lpc, dummy);
if (lpc & (1 << *irq))
return -EIO;
/* All chosen and checked - go for it */
if (cs5535_mfgpt_toggle_event(timer, cmp, MFGPT_EVENT_IRQ, enable))
return -EIO;
if (enable) {
zsel = (zsel & ~(0xF << shift)) | (*irq << shift);
wrmsr(MSR_PIC_ZSEL_LOW, zsel, dummy);
}
return 0;
}
EXPORT_SYMBOL_GPL(cs5535_mfgpt_set_irq);
struct cs5535_mfgpt_timer *cs5535_mfgpt_alloc_timer(int timer_nr, int domain)
{
struct cs5535_mfgpt_chip *mfgpt = &cs5535_mfgpt_chip;
struct cs5535_mfgpt_timer *timer = NULL;
unsigned long flags;
int max;
if (!mfgpt->initialized)
goto done;
/* only allocate timers from the working domain if requested */
if (domain == MFGPT_DOMAIN_WORKING)
max = 6;
else
max = MFGPT_MAX_TIMERS;
if (timer_nr >= max) {
/* programmer error. silly programmers! */
WARN_ON(1);
goto done;
}
spin_lock_irqsave(&mfgpt->lock, flags);
if (timer_nr < 0) {
unsigned long t;
/* try to find any available timer */
t = find_first_bit(mfgpt->avail, max);
/* set timer_nr to -1 if no timers available */
timer_nr = t < max ? (int) t : -1;
} else {
/* check if the requested timer's available */
if (test_bit(timer_nr, mfgpt->avail))
timer_nr = -1;
}
if (timer_nr >= 0)
/* if timer_nr is not -1, it's an available timer */
__clear_bit(timer_nr, mfgpt->avail);
spin_unlock_irqrestore(&mfgpt->lock, flags);
if (timer_nr < 0)
goto done;
timer = kmalloc(sizeof(*timer), GFP_KERNEL);
if (!timer) {
/* aw hell */
spin_lock_irqsave(&mfgpt->lock, flags);
__set_bit(timer_nr, mfgpt->avail);
spin_unlock_irqrestore(&mfgpt->lock, flags);
goto done;
}
timer->chip = mfgpt;
timer->nr = timer_nr;
dev_info(&mfgpt->pdev->dev, "registered timer %d\n", timer_nr);
done:
return timer;
}
EXPORT_SYMBOL_GPL(cs5535_mfgpt_alloc_timer);
/*
* XXX: This frees the timer memory, but never resets the actual hardware
* timer. The old geode_mfgpt code did this; it would be good to figure
* out a way to actually release the hardware timer. See comments below.
*/
void cs5535_mfgpt_free_timer(struct cs5535_mfgpt_timer *timer)
{
unsigned long flags;
uint16_t val;
/* timer can be made available again only if never set up */
val = cs5535_mfgpt_read(timer, MFGPT_REG_SETUP);
if (!(val & MFGPT_SETUP_SETUP)) {
spin_lock_irqsave(&timer->chip->lock, flags);
__set_bit(timer->nr, timer->chip->avail);
spin_unlock_irqrestore(&timer->chip->lock, flags);
}
kfree(timer);
}
EXPORT_SYMBOL_GPL(cs5535_mfgpt_free_timer);
uint16_t cs5535_mfgpt_read(struct cs5535_mfgpt_timer *timer, uint16_t reg)
{
return inw(timer->chip->base + reg + (timer->nr * 8));
}
EXPORT_SYMBOL_GPL(cs5535_mfgpt_read);
void cs5535_mfgpt_write(struct cs5535_mfgpt_timer *timer, uint16_t reg,
uint16_t value)
{
outw(value, timer->chip->base + reg + (timer->nr * 8));
}
EXPORT_SYMBOL_GPL(cs5535_mfgpt_write);
/*
* This is a sledgehammer that resets all MFGPT timers. This is required by
* some broken BIOSes which leave the system in an unstable state
* (TinyBIOS 0.98, for example; fixed in 0.99). It's uncertain as to
* whether or not this secret MSR can be used to release individual timers.
* Jordan tells me that he and Mitch once played w/ it, but it's unclear
* what the results of that were (and they experienced some instability).
*/
static void __init reset_all_timers(void)
{
uint32_t val, dummy;
/* The following undocumented bit resets the MFGPT timers */
val = 0xFF; dummy = 0;
wrmsr(MSR_MFGPT_SETUP, val, dummy);
}
/*
* Check whether any MFGPTs are available for the kernel to use. In most
* cases, firmware that uses AMD's VSA code will claim all timers during
* bootup; we certainly don't want to take them if they're already in use.
* In other cases (such as with VSAless OpenFirmware), the system firmware
* leaves timers available for us to use.
*/
static int __init scan_timers(struct cs5535_mfgpt_chip *mfgpt)
{
struct cs5535_mfgpt_timer timer = { .chip = mfgpt };
unsigned long flags;
int timers = 0;
uint16_t val;
int i;
/* bios workaround */
if (mfgpt_reset_timers)
reset_all_timers();
/* just to be safe, protect this section w/ lock */
spin_lock_irqsave(&mfgpt->lock, flags);
for (i = 0; i < MFGPT_MAX_TIMERS; i++) {
timer.nr = i;
val = cs5535_mfgpt_read(&timer, MFGPT_REG_SETUP);
if (!(val & MFGPT_SETUP_SETUP)) {
__set_bit(i, mfgpt->avail);
timers++;
}
}
spin_unlock_irqrestore(&mfgpt->lock, flags);
return timers;
}
static int __devinit cs5535_mfgpt_probe(struct platform_device *pdev)
{
struct resource *res;
int err = -EIO, t;
/* There are two ways to get the MFGPT base address; one is by
* fetching it from MSR_LBAR_MFGPT, the other is by reading the
* PCI BAR info. The latter method is easier (especially across
* different architectures), so we'll stick with that for now. If
* it turns out to be unreliable in the face of crappy BIOSes, we
* can always go back to using MSRs.. */
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (!res) {
dev_err(&pdev->dev, "can't fetch device resource info\n");
goto done;
}
if (!request_region(res->start, resource_size(res), pdev->name)) {
dev_err(&pdev->dev, "can't request region\n");
goto done;
}
/* set up the driver-specific struct */
cs5535_mfgpt_chip.base = res->start;
cs5535_mfgpt_chip.pdev = pdev;
spin_lock_init(&cs5535_mfgpt_chip.lock);
dev_info(&pdev->dev, "reserved resource region %pR\n", res);
/* detect the available timers */
t = scan_timers(&cs5535_mfgpt_chip);
dev_info(&pdev->dev, "%d MFGPT timers available\n", t);
cs5535_mfgpt_chip.initialized = 1;
return 0;
done:
return err;
}
static struct platform_driver cs5535_mfgpt_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
.probe = cs5535_mfgpt_probe,
};
static int __init cs5535_mfgpt_init(void)
{
return platform_driver_register(&cs5535_mfgpt_driver);
}
module_init(cs5535_mfgpt_init);
MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
MODULE_DESCRIPTION("CS5535/CS5536 MFGPT timer driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);