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Subject[PATCH] cs5535: add some additional cs5535-specific GPIO functionality
Date
From: Andres Salomon <dilinger@queued.net>

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>
---
drivers/gpio/Kconfig | 2 +-
drivers/gpio/cs5535-gpio.c | 52 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/cs5535.h | 2 +
3 files changed, 55 insertions(+), 1 deletions(-)

GPIO seems to be without maintainer..?

Needed for further development of the OLPC DCON driver, currently in staging

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 3143ac7..9180165 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -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
diff --git a/drivers/gpio/cs5535-gpio.c b/drivers/gpio/cs5535-gpio.c
index e23c068..7e5ab74 100644
--- a/drivers/gpio/cs5535-gpio.c
+++ b/drivers/gpio/cs5535-gpio.c
@@ -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
@@ -121,6 +122,57 @@ 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.
*/
diff --git a/include/linux/cs5535.h b/include/linux/cs5535.h
index d5a1d48..213cc50 100644
--- a/include/linux/cs5535.h
+++ b/include/linux/cs5535.h
@@ -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 */

--
1.7.3.2


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