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linux/drivers/gpio/cs5535-gpio.c
Andres Salomon 1b912c1bca 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>
2011-01-13 08:03:13 -08:00

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/*
* AMD CS5535/CS5536 GPIO driver
* Copyright (C) 2006 Advanced Micro Devices, Inc.
* Copyright (C) 2007-2009 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.
*/
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/pci.h>
#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
/*
* Some GPIO pins
* 31-29,23 : reserved (always mask out)
* 28 : Power Button
* 26 : PME#
* 22-16 : LPC
* 14,15 : SMBus
* 9,8 : UART1
* 7 : PCI INTB
* 3,4 : UART2/DDC
* 2 : IDE_IRQ0
* 1 : AC_BEEP
* 0 : PCI INTA
*
* If a mask was not specified, allow all except
* reserved and Power Button
*/
#define GPIO_DEFAULT_MASK 0x0F7FFFFF
static ulong mask = GPIO_DEFAULT_MASK;
module_param_named(mask, mask, ulong, 0444);
MODULE_PARM_DESC(mask, "GPIO channel mask.");
static struct cs5535_gpio_chip {
struct gpio_chip chip;
resource_size_t base;
struct pci_dev *pdev;
spinlock_t lock;
} cs5535_gpio_chip;
/*
* The CS5535/CS5536 GPIOs support a number of extra features not defined
* by the gpio_chip API, so these are exported. For a full list of the
* registers, see include/linux/cs5535.h.
*/
static void errata_outl(struct cs5535_gpio_chip *chip, u32 val,
unsigned int reg)
{
unsigned long addr = chip->base + 0x80 + reg;
/*
* According to the CS5536 errata (#36), after suspend
* a write to the high bank GPIO register will clear all
* non-selected bits; the recommended workaround is a
* read-modify-write operation.
*
* Don't apply this errata to the edge status GPIOs, as writing
* to their lower bits will clear them.
*/
if (reg != GPIO_POSITIVE_EDGE_STS && reg != GPIO_NEGATIVE_EDGE_STS) {
if (val & 0xffff)
val |= (inl(addr) & 0xffff); /* ignore the high bits */
else
val |= (inl(addr) ^ (val >> 16));
}
outl(val, addr);
}
static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset,
unsigned int reg)
{
if (offset < 16)
/* low bank register */
outl(1 << offset, chip->base + reg);
else
/* high bank register */
errata_outl(chip, 1 << (offset - 16), reg);
}
void cs5535_gpio_set(unsigned offset, unsigned int reg)
{
struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
__cs5535_gpio_set(chip, offset, reg);
spin_unlock_irqrestore(&chip->lock, flags);
}
EXPORT_SYMBOL_GPL(cs5535_gpio_set);
static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset,
unsigned int reg)
{
if (offset < 16)
/* low bank register */
outl(1 << (offset + 16), chip->base + reg);
else
/* high bank register */
errata_outl(chip, 1 << offset, reg);
}
void cs5535_gpio_clear(unsigned offset, unsigned int reg)
{
struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
__cs5535_gpio_clear(chip, offset, reg);
spin_unlock_irqrestore(&chip->lock, flags);
}
EXPORT_SYMBOL_GPL(cs5535_gpio_clear);
int cs5535_gpio_isset(unsigned offset, unsigned int reg)
{
struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
unsigned long flags;
long val;
spin_lock_irqsave(&chip->lock, flags);
if (offset < 16)
/* low bank register */
val = inl(chip->base + reg);
else {
/* high bank register */
val = inl(chip->base + 0x80 + reg);
offset -= 16;
}
spin_unlock_irqrestore(&chip->lock, flags);
return (val & (1 << offset)) ? 1 : 0;
}
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.
*/
static int chip_gpio_request(struct gpio_chip *c, unsigned offset)
{
struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
/* check if this pin is available */
if ((mask & (1 << offset)) == 0) {
dev_info(&chip->pdev->dev,
"pin %u is not available (check mask)\n", offset);
spin_unlock_irqrestore(&chip->lock, flags);
return -EINVAL;
}
/* disable output aux 1 & 2 on this pin */
__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX1);
__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX2);
/* disable input aux 1 on this pin */
__cs5535_gpio_clear(chip, offset, GPIO_INPUT_AUX1);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static int chip_gpio_get(struct gpio_chip *chip, unsigned offset)
{
return cs5535_gpio_isset(offset, GPIO_READ_BACK);
}
static void chip_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
if (val)
cs5535_gpio_set(offset, GPIO_OUTPUT_VAL);
else
cs5535_gpio_clear(offset, GPIO_OUTPUT_VAL);
}
static int chip_direction_input(struct gpio_chip *c, unsigned offset)
{
struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_ENABLE);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static int chip_direction_output(struct gpio_chip *c, unsigned offset, int val)
{
struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_ENABLE);
if (val)
__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_VAL);
else
__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_VAL);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static const char * const cs5535_gpio_names[] = {
"GPIO0", "GPIO1", "GPIO2", "GPIO3",
"GPIO4", "GPIO5", "GPIO6", "GPIO7",
"GPIO8", "GPIO9", "GPIO10", "GPIO11",
"GPIO12", "GPIO13", "GPIO14", "GPIO15",
"GPIO16", "GPIO17", "GPIO18", "GPIO19",
"GPIO20", "GPIO21", "GPIO22", NULL,
"GPIO24", "GPIO25", "GPIO26", "GPIO27",
"GPIO28", NULL, NULL, NULL,
};
static struct cs5535_gpio_chip cs5535_gpio_chip = {
.chip = {
.owner = THIS_MODULE,
.label = DRV_NAME,
.base = 0,
.ngpio = 32,
.names = cs5535_gpio_names,
.request = chip_gpio_request,
.get = chip_gpio_get,
.set = chip_gpio_set,
.direction_input = chip_direction_input,
.direction_output = chip_direction_output,
},
};
static int __init cs5535_gpio_probe(struct pci_dev *pdev,
const struct pci_device_id *pci_id)
{
int err;
ulong mask_orig = mask;
/* There are two ways to get the GPIO base address; one is by
* fetching it from MSR_LBAR_GPIO, 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.. */
err = pci_enable_device_io(pdev);
if (err) {
dev_err(&pdev->dev, "can't enable device IO\n");
goto done;
}
err = pci_request_region(pdev, GPIO_BAR, DRV_NAME);
if (err) {
dev_err(&pdev->dev, "can't alloc PCI BAR #%d\n", GPIO_BAR);
goto done;
}
/* set up the driver-specific struct */
cs5535_gpio_chip.base = pci_resource_start(pdev, GPIO_BAR);
cs5535_gpio_chip.pdev = pdev;
spin_lock_init(&cs5535_gpio_chip.lock);
dev_info(&pdev->dev, "allocated PCI BAR #%d: base 0x%llx\n", GPIO_BAR,
(unsigned long long) cs5535_gpio_chip.base);
/* mask out reserved pins */
mask &= 0x1F7FFFFF;
/* do not allow pin 28, Power Button, as there's special handling
* in the PMC needed. (note 12, p. 48) */
mask &= ~(1 << 28);
if (mask_orig != mask)
dev_info(&pdev->dev, "mask changed from 0x%08lX to 0x%08lX\n",
mask_orig, mask);
/* finally, register with the generic GPIO API */
err = gpiochip_add(&cs5535_gpio_chip.chip);
if (err)
goto release_region;
dev_info(&pdev->dev, DRV_NAME ": GPIO support successfully loaded.\n");
return 0;
release_region:
pci_release_region(pdev, GPIO_BAR);
done:
return err;
}
static void __exit cs5535_gpio_remove(struct pci_dev *pdev)
{
int err;
err = gpiochip_remove(&cs5535_gpio_chip.chip);
if (err) {
/* uhh? */
dev_err(&pdev->dev, "unable to remove gpio_chip?\n");
}
pci_release_region(pdev, GPIO_BAR);
}
static struct pci_device_id cs5535_gpio_pci_tbl[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA) },
{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
{ 0, },
};
MODULE_DEVICE_TABLE(pci, cs5535_gpio_pci_tbl);
/*
* We can't use the standard PCI driver registration stuff here, since
* that allows only one driver to bind to each PCI device (and we want
* multiple drivers to be able to bind to the device). Instead, manually
* scan for the PCI device, request a single region, and keep track of the
* devices that we're using.
*/
static int __init cs5535_gpio_scan_pci(void)
{
struct pci_dev *pdev;
int err = -ENODEV;
int i;
for (i = 0; i < ARRAY_SIZE(cs5535_gpio_pci_tbl); i++) {
pdev = pci_get_device(cs5535_gpio_pci_tbl[i].vendor,
cs5535_gpio_pci_tbl[i].device, NULL);
if (pdev) {
err = cs5535_gpio_probe(pdev, &cs5535_gpio_pci_tbl[i]);
if (err)
pci_dev_put(pdev);
/* we only support a single CS5535/6 southbridge */
break;
}
}
return err;
}
static void __exit cs5535_gpio_free_pci(void)
{
cs5535_gpio_remove(cs5535_gpio_chip.pdev);
pci_dev_put(cs5535_gpio_chip.pdev);
}
static int __init cs5535_gpio_init(void)
{
return cs5535_gpio_scan_pci();
}
static void __exit cs5535_gpio_exit(void)
{
cs5535_gpio_free_pci();
}
module_init(cs5535_gpio_init);
module_exit(cs5535_gpio_exit);
MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO driver");
MODULE_LICENSE("GPL");
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