linux/arch/xtensa/variants/s6000/gpio.c

231 lines
5.5 KiB
C

/*
* s6000 gpio driver
*
* Copyright (c) 2009 emlix GmbH
* Authors: Oskar Schirmer <oskar@scara.com>
* Johannes Weiner <hannes@cmpxchg.org>
* Daniel Gloeckner <dg@emlix.com>
*/
#include <linux/bitops.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <variant/hardware.h>
#define IRQ_BASE XTENSA_NR_IRQS
#define S6_GPIO_DATA 0x000
#define S6_GPIO_IS 0x404
#define S6_GPIO_IBE 0x408
#define S6_GPIO_IEV 0x40C
#define S6_GPIO_IE 0x410
#define S6_GPIO_RIS 0x414
#define S6_GPIO_MIS 0x418
#define S6_GPIO_IC 0x41C
#define S6_GPIO_AFSEL 0x420
#define S6_GPIO_DIR 0x800
#define S6_GPIO_BANK(nr) ((nr) * 0x1000)
#define S6_GPIO_MASK(nr) (4 << (nr))
#define S6_GPIO_OFFSET(nr) \
(S6_GPIO_BANK((nr) >> 3) + S6_GPIO_MASK((nr) & 7))
static int direction_input(struct gpio_chip *chip, unsigned int off)
{
writeb(0, S6_REG_GPIO + S6_GPIO_DIR + S6_GPIO_OFFSET(off));
return 0;
}
static int get(struct gpio_chip *chip, unsigned int off)
{
return readb(S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
}
static int direction_output(struct gpio_chip *chip, unsigned int off, int val)
{
unsigned rel = S6_GPIO_OFFSET(off);
writeb(~0, S6_REG_GPIO + S6_GPIO_DIR + rel);
writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + rel);
return 0;
}
static void set(struct gpio_chip *chip, unsigned int off, int val)
{
writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
}
static int to_irq(struct gpio_chip *chip, unsigned offset)
{
if (offset < 8)
return offset + IRQ_BASE;
return -EINVAL;
}
static struct gpio_chip gpiochip = {
.owner = THIS_MODULE,
.direction_input = direction_input,
.get = get,
.direction_output = direction_output,
.set = set,
.to_irq = to_irq,
.base = 0,
.ngpio = 24,
.can_sleep = 0, /* no blocking io needed */
.exported = 0, /* no exporting to userspace */
};
int s6_gpio_init(u32 afsel)
{
writeb(afsel, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_AFSEL);
writeb(afsel >> 8, S6_REG_GPIO + S6_GPIO_BANK(1) + S6_GPIO_AFSEL);
writeb(afsel >> 16, S6_REG_GPIO + S6_GPIO_BANK(2) + S6_GPIO_AFSEL);
return gpiochip_add(&gpiochip);
}
static void ack(struct irq_data *d)
{
writeb(1 << (d->irq - IRQ_BASE), S6_REG_GPIO + S6_GPIO_IC);
}
static void mask(struct irq_data *d)
{
u8 r = readb(S6_REG_GPIO + S6_GPIO_IE);
r &= ~(1 << (d->irq - IRQ_BASE));
writeb(r, S6_REG_GPIO + S6_GPIO_IE);
}
static void unmask(struct irq_data *d)
{
u8 m = readb(S6_REG_GPIO + S6_GPIO_IE);
m |= 1 << (d->irq - IRQ_BASE);
writeb(m, S6_REG_GPIO + S6_GPIO_IE);
}
static int set_type(struct irq_data *d, unsigned int type)
{
const u8 m = 1 << (d->irq - IRQ_BASE);
irq_flow_handler_t handler;
u8 reg;
if (type == IRQ_TYPE_PROBE) {
if ((readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_AFSEL) & m)
|| (readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IE) & m)
|| readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_DIR
+ S6_GPIO_MASK(irq - IRQ_BASE)))
return 0;
type = IRQ_TYPE_EDGE_BOTH;
}
reg = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IS);
if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) {
reg |= m;
handler = handle_level_irq;
} else {
reg &= ~m;
handler = handle_edge_irq;
}
writeb(reg, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IS);
__irq_set_handler_locked(irq, handler);
reg = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IEV);
if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING))
reg |= m;
else
reg &= ~m;
writeb(reg, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IEV);
reg = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IBE);
if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
reg |= m;
else
reg &= ~m;
writeb(reg, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IBE);
return 0;
}
static struct irq_chip gpioirqs = {
.name = "GPIO",
.irq_ack = ack,
.irq_mask = mask,
.irq_unmask = unmask,
.irq_set_type = set_type,
};
static u8 demux_masks[4];
static void demux_irqs(unsigned int irq, struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
u8 *mask = irq_desc_get_handler_data(desc);
u8 pending;
int cirq;
chip->irq_mask(&desc->irq_data);
chip->irq_ack(&desc->irq_data));
pending = readb(S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_MIS) & *mask;
cirq = IRQ_BASE - 1;
while (pending) {
int n = ffs(pending);
cirq += n;
pending >>= n;
generic_handle_irq(cirq);
}
chip->irq_unmask(&desc->irq_data));
}
extern const signed char *platform_irq_mappings[XTENSA_NR_IRQS];
void __init variant_init_irq(void)
{
int irq, n;
writeb(0, S6_REG_GPIO + S6_GPIO_BANK(0) + S6_GPIO_IE);
for (irq = n = 0; irq < XTENSA_NR_IRQS; irq++) {
const signed char *mapping = platform_irq_mappings[irq];
int alone = 1;
u8 mask;
if (!mapping)
continue;
for(mask = 0; *mapping != -1; mapping++)
switch (*mapping) {
case S6_INTC_GPIO(0):
mask |= 1 << 0;
break;
case S6_INTC_GPIO(1):
mask |= 1 << 1;
break;
case S6_INTC_GPIO(2):
mask |= 1 << 2;
break;
case S6_INTC_GPIO(3):
mask |= 0x1f << 3;
break;
default:
alone = 0;
}
if (mask) {
int cirq, i;
if (!alone) {
printk(KERN_ERR "chained irq chips can't share"
" parent irq %i\n", irq);
continue;
}
demux_masks[n] = mask;
cirq = IRQ_BASE - 1;
do {
i = ffs(mask);
cirq += i;
mask >>= i;
irq_set_chip(cirq, &gpioirqs);
irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
} while (mask);
irq_set_handler_data(irq, demux_masks + n);
irq_set_chained_handler(irq, demux_irqs);
if (++n == ARRAY_SIZE(demux_masks))
break;
}
}
}