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gpio: add Penwell gpio support
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Intel Penwell chip has two 96 pins GPIO blocks, which are very similiar as
Intel Langwell chip GPIO block, except for pin number difference. This
patch expends the original Langwell GPIO driver to support Penwell's.

Signed-off-by: Alek Du <[email protected]>
Cc: David Brownell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@alekdu @torvalds
alekdu authored and torvalds committed May 27, 2010
1 parent 8156fae commit 8081c84
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Showing 2 changed files with 53 additions and 34 deletions.
4 changes: 2 additions & 2 deletions drivers/gpio/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -271,10 +271,10 @@ config GPIO_BT8XX
If unsure, say N.

config GPIO_LANGWELL
bool "Intel Moorestown Platform Langwell GPIO support"
bool "Intel Langwell/Penwell GPIO support"
depends on PCI
help
Say Y here to support Intel Moorestown platform GPIO.
Say Y here to support Intel Langwell/Penwell GPIO.

config GPIO_TIMBERDALE
bool "Support for timberdale GPIO IP"
Expand Down
83 changes: 51 additions & 32 deletions drivers/gpio/langwell_gpio.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,7 @@

/* Supports:
* Moorestown platform Langwell chip.
* Medfield platform Penwell chip.
*/

#include <linux/module.h>
Expand All @@ -31,57 +32,76 @@
#include <linux/gpio.h>
#include <linux/slab.h>

struct lnw_gpio_register {
u32 GPLR[2];
u32 GPDR[2];
u32 GPSR[2];
u32 GPCR[2];
u32 GRER[2];
u32 GFER[2];
u32 GEDR[2];
/*
* Langwell chip has 64 pins and thus there are 2 32bit registers to control
* each feature, while Penwell chip has 96 pins for each block, and need 3 32bit
* registers to control them, so we only define the order here instead of a
* structure, to get a bit offset for a pin (use GPDR as an example):
*
* nreg = ngpio / 32;
* reg = offset / 32;
* bit = offset % 32;
* reg_addr = reg_base + GPDR * nreg * 4 + reg * 4;
*
* so the bit of reg_addr is to control pin offset's GPDR feature
*/

enum GPIO_REG {
GPLR = 0, /* pin level read-only */
GPDR, /* pin direction */
GPSR, /* pin set */
GPCR, /* pin clear */
GRER, /* rising edge detect */
GFER, /* falling edge detect */
GEDR, /* edge detect result */
};

struct lnw_gpio {
struct gpio_chip chip;
struct lnw_gpio_register *reg_base;
void *reg_base;
spinlock_t lock;
unsigned irq_base;
};

static int lnw_gpio_get(struct gpio_chip *chip, unsigned offset)
static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned offset,
enum GPIO_REG reg_type)
{
struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
unsigned nreg = chip->ngpio / 32;
u8 reg = offset / 32;
void __iomem *gplr;
void __iomem *ptr;

ptr = (void __iomem *)(lnw->reg_base + reg_type * nreg * 4 + reg * 4);
return ptr;
}

static int lnw_gpio_get(struct gpio_chip *chip, unsigned offset)
{
void __iomem *gplr = gpio_reg(chip, offset, GPLR);

gplr = (void __iomem *)(&lnw->reg_base->GPLR[reg]);
return readl(gplr) & BIT(offset % 32);
}

static void lnw_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
u8 reg = offset / 32;
void __iomem *gpsr, *gpcr;

if (value) {
gpsr = (void __iomem *)(&lnw->reg_base->GPSR[reg]);
gpsr = gpio_reg(chip, offset, GPSR);
writel(BIT(offset % 32), gpsr);
} else {
gpcr = (void __iomem *)(&lnw->reg_base->GPCR[reg]);
gpcr = gpio_reg(chip, offset, GPCR);
writel(BIT(offset % 32), gpcr);
}
}

static int lnw_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
u8 reg = offset / 32;
void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
u32 value;
unsigned long flags;
void __iomem *gpdr;

gpdr = (void __iomem *)(&lnw->reg_base->GPDR[reg]);
spin_lock_irqsave(&lnw->lock, flags);
value = readl(gpdr);
value &= ~BIT(offset % 32);
Expand All @@ -94,12 +114,10 @@ static int lnw_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
u8 reg = offset / 32;
void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
unsigned long flags;
void __iomem *gpdr;

lnw_gpio_set(chip, offset, value);
gpdr = (void __iomem *)(&lnw->reg_base->GPDR[reg]);
spin_lock_irqsave(&lnw->lock, flags);
value = readl(gpdr);
value |= BIT(offset % 32);;
Expand All @@ -118,11 +136,10 @@ static int lnw_irq_type(unsigned irq, unsigned type)
{
struct lnw_gpio *lnw = get_irq_chip_data(irq);
u32 gpio = irq - lnw->irq_base;
u8 reg = gpio / 32;
unsigned long flags;
u32 value;
void __iomem *grer = (void __iomem *)(&lnw->reg_base->GRER[reg]);
void __iomem *gfer = (void __iomem *)(&lnw->reg_base->GFER[reg]);
void __iomem *grer = gpio_reg(&lnw->chip, gpio, GRER);
void __iomem *gfer = gpio_reg(&lnw->chip, gpio, GFER);

if (gpio >= lnw->chip.ngpio)
return -EINVAL;
Expand Down Expand Up @@ -158,26 +175,28 @@ static struct irq_chip lnw_irqchip = {
.set_type = lnw_irq_type,
};

static struct pci_device_id lnw_gpio_ids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080f) },
static DEFINE_PCI_DEVICE_TABLE(lnw_gpio_ids) = { /* pin number */
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080f), .driver_data = 64 },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081f), .driver_data = 96 },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081a), .driver_data = 96 },
{ 0, }
};
MODULE_DEVICE_TABLE(pci, lnw_gpio_ids);

static void lnw_irq_handler(unsigned irq, struct irq_desc *desc)
{
struct lnw_gpio *lnw = (struct lnw_gpio *)get_irq_data(irq);
u32 reg, gpio;
u32 base, gpio;
void __iomem *gedr;
u32 gedr_v;

/* check GPIO controller to check which pin triggered the interrupt */
for (reg = 0; reg < lnw->chip.ngpio / 32; reg++) {
gedr = (void __iomem *)(&lnw->reg_base->GEDR[reg]);
for (base = 0; base < lnw->chip.ngpio; base += 32) {
gedr = gpio_reg(&lnw->chip, base, GEDR);
gedr_v = readl(gedr);
if (!gedr_v)
continue;
for (gpio = reg*32; gpio < reg*32+32; gpio++)
for (gpio = base; gpio < base + 32; gpio++)
if (gedr_v & BIT(gpio % 32)) {
pr_debug("pin %d triggered\n", gpio);
generic_handle_irq(lnw->irq_base + gpio);
Expand Down Expand Up @@ -245,7 +264,7 @@ static int __devinit lnw_gpio_probe(struct pci_dev *pdev,
lnw->chip.set = lnw_gpio_set;
lnw->chip.to_irq = lnw_gpio_to_irq;
lnw->chip.base = gpio_base;
lnw->chip.ngpio = 64;
lnw->chip.ngpio = id->driver_data;
lnw->chip.can_sleep = 0;
pci_set_drvdata(pdev, lnw);
retval = gpiochip_add(&lnw->chip);
Expand Down

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