drivers/gpio/cs5535-gpio.c: add some additional cs5535-specific GPIO functionality

This adds (well, re-adds actually) handling for events/IRQs through cs5535
GPIOs.  In the wild and wooly world of CS5535, setup_event() is for
assigning an IRQ to a GPIO filter/event pair, and set_irq() sets up the
pair to trigger IRQs.

These should really only be used in highly platform-specific drivers (such
as OLPC's DCON driver).  Sadly, because set_irq() uses MSRs, this causes
the driver to become X86-specific.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Daniel Drake <dsd@laptop.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andres Salomon 2011-01-12 17:00:10 -08:00 committed by Linus Torvalds
parent 5f003feba2
commit 1b912c1bca
3 changed files with 55 additions and 1 deletions

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@ -295,7 +295,7 @@ comment "PCI GPIO expanders:"
config GPIO_CS5535
tristate "AMD CS5535/CS5536 GPIO support"
depends on PCI && !CS5535_GPIO
depends on PCI && X86 && !CS5535_GPIO
help
The AMD CS5535 and CS5536 southbridges support 28 GPIO pins that
can be used for quite a number of things. The CS5535/6 is found on

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@ -15,6 +15,7 @@
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/cs5535.h>
#include <asm/msr.h>
#define DRV_NAME "cs5535-gpio"
#define GPIO_BAR 1
@ -144,6 +145,57 @@ int cs5535_gpio_isset(unsigned offset, unsigned int reg)
}
EXPORT_SYMBOL_GPL(cs5535_gpio_isset);
int cs5535_gpio_set_irq(unsigned group, unsigned irq)
{
uint32_t lo, hi;
if (group > 7 || irq > 15)
return -EINVAL;
rdmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
lo &= ~(0xF << (group * 4));
lo |= (irq & 0xF) << (group * 4);
wrmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
return 0;
}
EXPORT_SYMBOL_GPL(cs5535_gpio_set_irq);
void cs5535_gpio_setup_event(unsigned offset, int pair, int pme)
{
struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
uint32_t shift = (offset % 8) * 4;
unsigned long flags;
uint32_t val;
if (offset >= 24)
offset = GPIO_MAP_W;
else if (offset >= 16)
offset = GPIO_MAP_Z;
else if (offset >= 8)
offset = GPIO_MAP_Y;
else
offset = GPIO_MAP_X;
spin_lock_irqsave(&chip->lock, flags);
val = inl(chip->base + offset);
/* Clear whatever was there before */
val &= ~(0xF << shift);
/* Set the new value */
val |= ((pair & 7) << shift);
/* Set the PME bit if this is a PME event */
if (pme)
val |= (1 << (shift + 3));
outl(val, chip->base + offset);
spin_unlock_irqrestore(&chip->lock, flags);
}
EXPORT_SYMBOL_GPL(cs5535_gpio_setup_event);
/*
* Generic gpio_chip API support.
*/

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@ -111,6 +111,8 @@ static inline int cs5535_has_vsa2(void)
void cs5535_gpio_set(unsigned offset, unsigned int reg);
void cs5535_gpio_clear(unsigned offset, unsigned int reg);
int cs5535_gpio_isset(unsigned offset, unsigned int reg);
int cs5535_gpio_set_irq(unsigned group, unsigned irq);
void cs5535_gpio_setup_event(unsigned offset, int pair, int pme);
/* MFGPTs */