- 根目录:
- arch
- arm
- plat-orion
- gpio.c
/*
* arch/arm/plat-orion/gpio.c
*
* Marvell Orion SoC GPIO handling.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/gpio.h>
/*
* GPIO unit register offsets.
*/
#define GPIO_OUT_OFF 0x0000
#define GPIO_IO_CONF_OFF 0x0004
#define GPIO_BLINK_EN_OFF 0x0008
#define GPIO_IN_POL_OFF 0x000c
#define GPIO_DATA_IN_OFF 0x0010
#define GPIO_EDGE_CAUSE_OFF 0x0014
#define GPIO_EDGE_MASK_OFF 0x0018
#define GPIO_LEVEL_MASK_OFF 0x001c
struct orion_gpio_chip {
struct gpio_chip chip;
spinlock_t lock;
void __iomem *base;
unsigned long valid_input;
unsigned long valid_output;
int mask_offset;
int secondary_irq_base;
};
static void __iomem *GPIO_OUT(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_OUT_OFF;
}
static void __iomem *GPIO_IO_CONF(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_IO_CONF_OFF;
}
static void __iomem *GPIO_BLINK_EN(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_BLINK_EN_OFF;
}
static void __iomem *GPIO_IN_POL(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_IN_POL_OFF;
}
static void __iomem *GPIO_DATA_IN(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_DATA_IN_OFF;
}
static void __iomem *GPIO_EDGE_CAUSE(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_EDGE_CAUSE_OFF;
}
static void __iomem *GPIO_EDGE_MASK(struct orion_gpio_chip *ochip)
{
return ochip->base + ochip->mask_offset + GPIO_EDGE_MASK_OFF;
}
static void __iomem *GPIO_LEVEL_MASK(struct orion_gpio_chip *ochip)
{
return ochip->base + ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
}
static struct orion_gpio_chip orion_gpio_chips[2];
static int orion_gpio_chip_count;
static inline void
__set_direction(struct orion_gpio_chip *ochip, unsigned pin, int input)
{
u32 u;
u = readl(GPIO_IO_CONF(ochip));
if (input)
u |= 1 << pin;
else
u &= ~(1 << pin);
writel(u, GPIO_IO_CONF(ochip));
}
static void __set_level(struct orion_gpio_chip *ochip, unsigned pin, int high)
{
u32 u;
u = readl(GPIO_OUT(ochip));
if (high)
u |= 1 << pin;
else
u &= ~(1 << pin);
writel(u, GPIO_OUT(ochip));
}
static inline void
__set_blinking(struct orion_gpio_chip *ochip, unsigned pin, int blink)
{
u32 u;
u = readl(GPIO_BLINK_EN(ochip));
if (blink)
u |= 1 << pin;
else
u &= ~(1 << pin);
writel(u, GPIO_BLINK_EN(ochip));
}
static inline int
orion_gpio_is_valid(struct orion_gpio_chip *ochip, unsigned pin, int mode)
{
if (pin >= ochip->chip.ngpio)
goto err_out;
if ((mode & GPIO_INPUT_OK) && !test_bit(pin, &ochip->valid_input))
goto err_out;
if ((mode & GPIO_OUTPUT_OK) && !test_bit(pin, &ochip->valid_output))
goto err_out;
return 1;
err_out:
pr_debug("%s: invalid GPIO %d\n", __func__, pin);
return false;
}
/*
* GENERIC_GPIO primitives.
*/
static int orion_gpio_request(struct gpio_chip *chip, unsigned pin)
{
struct orion_gpio_chip *ochip =
container_of(chip, struct orion_gpio_chip, chip);
if (orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK) ||
orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
return 0;
return -EINVAL;
}
static int orion_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
{
struct orion_gpio_chip *ochip =
container_of(chip, struct orion_gpio_chip, chip);
unsigned long flags;
if (!orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK))
return -EINVAL;
spin_lock_irqsave(&ochip->lock, flags);
__set_direction(ochip, pin, 1);
spin_unlock_irqrestore(&ochip->lock, flags);
return 0;
}
static int orion_gpio_get(struct gpio_chip *chip, unsigned pin)
{
struct orion_gpio_chip *ochip =
container_of(chip, struct orion_gpio_chip, chip);
int val;
if (readl(GPIO_IO_CONF(ochip)) & (1 << pin)) {
val = readl(GPIO_DATA_IN(ochip)) ^ readl(GPIO_IN_POL(ochip));
} else {
val = readl(GPIO_OUT(ochip));
}
return (val >> pin) & 1;
}
static int
orion_gpio_direction_output(struct gpio_chip *chip, unsigned pin, int value)
{
struct orion_gpio_chip *ochip =
container_of(chip, struct orion_gpio_chip, chip);
unsigned long flags;
if (!orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
return -EINVAL;
spin_lock_irqsave(&ochip->lock, flags);
__set_blinking(ochip, pin, 0);
__set_level(ochip, pin, value);
__set_direction(ochip, pin, 0);
spin_unlock_irqrestore(&ochip->lock, flags);
return 0;
}
static void orion_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
{
struct orion_gpio_chip *ochip =
container_of(chip, struct orion_gpio_chip, chip);
unsigned long flags;
spin_lock_irqsave(&ochip->lock, flags);
__set_level(ochip, pin, value);
spin_unlock_irqrestore(&ochip->lock, flags);
}
static int orion_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
{
struct orion_gpio_chip *ochip =
container_of(chip, struct orion_gpio_chip, chip);
return ochip->secondary_irq_base + pin;
}
/*
* Orion-specific GPIO API extensions.
*/
static struct orion_gpio_chip *orion_gpio_chip_find(int pin)
{
int i;
for (i = 0; i < orion_gpio_chip_count; i++) {
struct orion_gpio_chip *ochip = orion_gpio_chips + i;
struct gpio_chip *chip = &ochip->chip;
if (pin >= chip->base && pin < chip->base + chip->ngpio)
return ochip;
}
return NULL;
}
void __init orion_gpio_set_unused(unsigned pin)
{
struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
if (ochip == NULL)
return;
pin -= ochip->chip.base;
/* Configure as output, drive low. */
__set_level(ochip, pin, 0);
__set_direction(ochip, pin, 0);
}
void __init orion_gpio_set_valid(unsigned pin, int mode)
{
struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
if (ochip == NULL)
return;
pin -= ochip->chip.base;
if (mode == 1)
mode = GPIO_INPUT_OK | GPIO_OUTPUT_OK;
if (mode & GPIO_INPUT_OK)
__set_bit(pin, &ochip->valid_input);
else
__clear_bit(pin, &ochip->valid_input);
if (mode & GPIO_OUTPUT_OK)
__set_bit(pin, &ochip->valid_output);
else
__clear_bit(pin, &ochip->valid_output);
}
void orion_gpio_set_blink(unsigned pin, int blink)
{
struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
unsigned long flags;
if (ochip == NULL)
return;
spin_lock_irqsave(&ochip->lock, flags);
__set_level(ochip, pin, 0);
__set_blinking(ochip, pin, blink);
spin_unlock_irqrestore(&ochip->lock, flags);
}
EXPORT_SYMBOL(orion_gpio_set_blink);
/*****************************************************************************
* Orion GPIO IRQ
*
* GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
* value of the line or the opposite value.
*
* Level IRQ handlers: DATA_IN is used directly as cause register.
* Interrupt are masked by LEVEL_MASK registers.
* Edge IRQ handlers: Change in DATA_IN are latched in EDGE_CAUSE.
* Interrupt are masked by EDGE_MASK registers.
* Both-edge handlers: Similar to regular Edge handlers, but also swaps
* the polarity to catch the next line transaction.
* This is a race condition that might not perfectly
* work on some use cases.
*
* Every eight GPIO lines are grouped (OR'ed) before going up to main
* cause register.
*
* EDGE cause mask
* data-in /--------| |-----| |----\
* -----| |----- ---- to main cause reg
* X \----------------| |----/
* polarity LEVEL mask
*
****************************************************************************/
static int gpio_irq_set_type(struct irq_data *d, u32 type)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct irq_chip_type *ct = irq_data_get_chip_type(d);
struct orion_gpio_chip *ochip = gc->private;
int pin;
u32 u;
pin = d->irq - gc->irq_base;
u = readl(GPIO_IO_CONF(ochip)) & (1 << pin);
if (!u) {
printk(KERN_ERR "orion gpio_irq_set_type failed "
"(irq %d, pin %d).\n", d->irq, pin);
return -EINVAL;
}
type &= IRQ_TYPE_SENSE_MASK;
if (type == IRQ_TYPE_NONE)
return -EINVAL;
/* Check if we need to change chip and handler */
if (!(ct->type & type))
if (irq_setup_alt_chip(d, type))
return -EINVAL;
/*
* Configure interrupt polarity.
*/
if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
u = readl(GPIO_IN_POL(ochip));
u &= ~(1 << pin);
writel(u, GPIO_IN_POL(ochip));
} else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
u = readl(GPIO_IN_POL(ochip));
u |= 1 << pin;
writel(u, GPIO_IN_POL(ochip));
} else if (type == IRQ_TYPE_EDGE_BOTH) {
u32 v;
v = readl(GPIO_IN_POL(ochip)) ^ readl(GPIO_DATA_IN(ochip));
/*
* set initial polarity based on current input level
*/
u = readl(GPIO_IN_POL(ochip));
if (v & (1 << pin))
u |= 1 << pin; /* falling */
else
u &= ~(1 << pin); /* rising */
writel(u, GPIO_IN_POL(ochip));
}
return 0;
}
void __init orion_gpio_init(int gpio_base, int ngpio,
u32 base, int mask_offset, int secondary_irq_base)
{
struct orion_gpio_chip *ochip;
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
char gc_label[16];
if (orion_gpio_chip_count == ARRAY_SIZE(orion_gpio_chips))
return;
snprintf(gc_label, sizeof(gc_label), "orion_gpio%d",
orion_gpio_chip_count);
ochip = orion_gpio_chips + orion_gpio_chip_count;
ochip->chip.label = kstrdup(gc_label, GFP_KERNEL);
ochip->chip.request = orion_gpio_request;
ochip->chip.direction_input = orion_gpio_direction_input;
ochip->chip.get = orion_gpio_get;
ochip->chip.direction_output = orion_gpio_direction_output;
ochip->chip.set = orion_gpio_set;
ochip->chip.to_irq = orion_gpio_to_irq;
ochip->chip.base = gpio_base;
ochip->chip.ngpio = ngpio;
ochip->chip.can_sleep = 0;
spin_lock_init(&ochip->lock);
ochip->base = (void __iomem *)base;
ochip->valid_input = 0;
ochip->valid_output = 0;
ochip->mask_offset = mask_offset;
ochip->secondary_irq_base = secondary_irq_base;
gpiochip_add(&ochip->chip);
orion_gpio_chip_count++;
/*
* Mask and clear GPIO interrupts.
*/
writel(0, GPIO_EDGE_CAUSE(ochip));
writel(0, GPIO_EDGE_MASK(ochip));
writel(0, GPIO_LEVEL_MASK(ochip));
gc = irq_alloc_generic_chip("orion_gpio_irq", 2, secondary_irq_base,
ochip->base, handle_level_irq);
gc->private = ochip;
ct = gc->chip_types;
ct->regs.mask = ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
ct->chip.irq_mask = irq_gc_mask_clr_bit;
ct->chip.irq_unmask = irq_gc_mask_set_bit;
ct->chip.irq_set_type = gpio_irq_set_type;
ct++;
ct->regs.mask = ochip->mask_offset + GPIO_EDGE_MASK_OFF;
ct->regs.ack = GPIO_EDGE_CAUSE_OFF;
ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
ct->chip.irq_ack = irq_gc_ack_clr_bit;
ct->chip.irq_mask = irq_gc_mask_clr_bit;
ct->chip.irq_unmask = irq_gc_mask_set_bit;
ct->chip.irq_set_type = gpio_irq_set_type;
ct->handler = handle_edge_irq;
irq_setup_generic_chip(gc, IRQ_MSK(ngpio), IRQ_GC_INIT_MASK_CACHE,
IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
}
void orion_gpio_irq_handler(int pinoff)
{
struct orion_gpio_chip *ochip;
u32 cause, type;
int i;
ochip = orion_gpio_chip_find(pinoff);
if (ochip == NULL)
return;
cause = readl(GPIO_DATA_IN(ochip)) & readl(GPIO_LEVEL_MASK(ochip));
cause |= readl(GPIO_EDGE_CAUSE(ochip)) & readl(GPIO_EDGE_MASK(ochip));
for (i = 0; i < ochip->chip.ngpio; i++) {
int irq;
irq = ochip->secondary_irq_base + i;
if (!(cause & (1 << i)))
continue;
type = irqd_get_trigger_type(irq_get_irq_data(irq));
if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
/* Swap polarity (race with GPIO line) */
u32 polarity;
polarity = readl(GPIO_IN_POL(ochip));
polarity ^= 1 << i;
writel(polarity, GPIO_IN_POL(ochip));
}
generic_handle_irq(irq);
}
}