/*
* MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
*
* Based on code from Freescale,
* Copyright (C) 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <mach/hardware.h>
#include <asm-generic/bug.h>
static struct mxc_gpio_port *mxc_gpio_ports;
static int gpio_table_size;
#define cpu_is_mx1_mx2() (cpu_is_mx1() || cpu_is_mx2())
#define GPIO_DR (cpu_is_mx1_mx2() ? 0x1c : 0x00)
#define GPIO_GDIR (cpu_is_mx1_mx2() ? 0x00 : 0x04)
#define GPIO_PSR (cpu_is_mx1_mx2() ? 0x24 : 0x08)
#define GPIO_ICR1 (cpu_is_mx1_mx2() ? 0x28 : 0x0C)
#define GPIO_ICR2 (cpu_is_mx1_mx2() ? 0x2C : 0x10)
#define GPIO_IMR (cpu_is_mx1_mx2() ? 0x30 : 0x14)
#define GPIO_ISR (cpu_is_mx1_mx2() ? 0x34 : 0x18)
#define GPIO_INT_LOW_LEV (cpu_is_mx1_mx2() ? 0x3 : 0x0)
#define GPIO_INT_HIGH_LEV (cpu_is_mx1_mx2() ? 0x2 : 0x1)
#define GPIO_INT_RISE_EDGE (cpu_is_mx1_mx2() ? 0x0 : 0x2)
#define GPIO_INT_FALL_EDGE (cpu_is_mx1_mx2() ? 0x1 : 0x3)
#define GPIO_INT_NONE 0x4
/* Note: This driver assumes 32 GPIOs are handled in one register */
static void _clear_gpio_irqstatus(struct mxc_gpio_port *port, u32 index)
{
__raw_writel(1 << index, port->base + GPIO_ISR);
}
static void _set_gpio_irqenable(struct mxc_gpio_port *port, u32 index,
int enable)
{
u32 l;
l = __raw_readl(port->base + GPIO_IMR);
l = (l & (~(1 << index))) | (!!enable << index);
__raw_writel(l, port->base + GPIO_IMR);
}
static void gpio_ack_irq(struct irq_data *d)
{
u32 gpio = irq_to_gpio(d->irq);
_clear_gpio_irqstatus(&mxc_gpio_ports[gpio / 32], gpio & 0x1f);
}
static void gpio_mask_irq(struct irq_data *d)
{
u32 gpio = irq_to_gpio(d->irq);
_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 0);
}
static void gpio_unmask_irq(struct irq_data *d)
{
u32 gpio = irq_to_gpio(d->irq);
_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 1);
}
static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset);
static int gpio_set_irq_type(struct irq_data *d, u32 type)
{
u32 gpio = irq_to_gpio(d->irq);
struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32];
u32 bit, val;
int edge;
void __iomem *reg = port->base;
port->both_edges &= ~(1 << (gpio & 31));
switch (type) {
case IRQ_TYPE_EDGE_RISING:
edge = GPIO_INT_RISE_EDGE;
break;
case IRQ_TYPE_EDGE_FALLING:
edge = GPIO_INT_FALL_EDGE;
break;
case IRQ_TYPE_EDGE_BOTH:
val = mxc_gpio_get(&port->chip, gpio & 31);
if (val) {
edge = GPIO_INT_LOW_LEV;
pr_debug("mxc: set GPIO %d to low trigger\n", gpio);
} else {
edge = GPIO_INT_HIGH_LEV;
pr_debug("mxc: set GPIO %d to high trigger\n", gpio);
}
port->both_edges |= 1 << (gpio & 31);
break;
case IRQ_TYPE_LEVEL_LOW:
edge = GPIO_INT_LOW_LEV;
break;
case IRQ_TYPE_LEVEL_HIGH:
edge = GPIO_INT_HIGH_LEV;
break;
default:
return -EINVAL;
}
reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
bit = gpio & 0xf;
val = __raw_readl(reg) & ~(0x3 << (bit << 1));
__raw_writel(val | (edge << (bit << 1)), reg);
_clear_gpio_irqstatus(port, gpio & 0x1f);
return 0;
}
static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio)
{
void __iomem *reg = port->base;
u32 bit, val;
int edge;
reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
bit = gpio & 0xf;
val = __raw_readl(reg);
edge = (val >> (bit << 1)) & 3;
val &= ~(0x3 << (bit << 1));
if (edge == GPIO_INT_HIGH_LEV) {
edge = GPIO_INT_LOW_LEV;
pr_debug("mxc: switch GPIO %d to low trigger\n", gpio);
} else if (edge == GPIO_INT_LOW_LEV) {
edge = GPIO_INT_HIGH_LEV;
pr_debug("mxc: switch GPIO %d to high trigger\n", gpio);
} else {
pr_err("mxc: invalid configuration for GPIO %d: %x\n",
gpio, edge);
return;
}
__raw_writel(val | (edge << (bit << 1)), reg);
}
/* handle 32 interrupts in one status register */
static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
{
u32 gpio_irq_no_base = port->virtual_irq_start;
while (irq_stat != 0) {
int irqoffset = fls(irq_stat) - 1;
if (port->both_edges & (1 << irqoffset))
mxc_flip_edge(port, irqoffset);
generic_handle_irq(gpio_irq_no_base + irqoffset);
irq_stat &= ~(1 << irqoffset);
}
}
/* MX1 and MX3 has one interrupt *per* gpio port */
static void mx3_gpio_irq_handler(u32 irq, struct irq_desc *desc)
{
u32 irq_stat;
struct mxc_gpio_port *port = irq_get_handler_data(irq);
irq_stat = __raw_readl(port->base + GPIO_ISR) &
__raw_readl(port->base + GPIO_IMR);
mxc_gpio_irq_handler(port, irq_stat);
}
/* MX2 has one interrupt *for all* gpio ports */
static void mx2_gpio_irq_handler(u32 irq, struct irq_desc *desc)
{
int i;
u32 irq_msk, irq_stat;
struct mxc_gpio_port *port = irq_get_handler_data(irq);
/* walk through all interrupt status registers */
for (i = 0; i < gpio_table_size; i++) {
irq_msk = __raw_readl(port[i].base + GPIO_IMR);
if (!irq_msk)
continue;
irq_stat = __raw_readl(port[i].base + GPIO_ISR) & irq_msk;
if (irq_stat)
mxc_gpio_irq_handler(&port[i], irq_stat);
}
}
/*
* Set interrupt number "irq" in the GPIO as a wake-up source.
* While system is running, all registered GPIO interrupts need to have
* wake-up enabled. When system is suspended, only selected GPIO interrupts
* need to have wake-up enabled.
* @param irq interrupt source number
* @param enable enable as wake-up if equal to non-zero
* @return This function returns 0 on success.
*/
static int gpio_set_wake_irq(struct irq_data *d, u32 enable)
{
u32 gpio = irq_to_gpio(d->irq);
u32 gpio_idx = gpio & 0x1F;
struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32];
if (enable) {
if (port->irq_high && (gpio_idx >= 16))
enable_irq_wake(port->irq_high);
else
enable_irq_wake(port->irq);
} else {
if (port->irq_high && (gpio_idx >= 16))
disable_irq_wake(port->irq_high);
else
disable_irq_wake(port->irq);
}
return 0;
}
static struct irq_chip gpio_irq_chip = {
.name = "GPIO",
.irq_ack = gpio_ack_irq,
.irq_mask = gpio_mask_irq,
.irq_unmask = gpio_unmask_irq,
.irq_set_type = gpio_set_irq_type,
.irq_set_wake = gpio_set_wake_irq,
};
static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset,
int dir)
{
struct mxc_gpio_port *port =
container_of(chip, struct mxc_gpio_port, chip);
u32 l;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
l = __raw_readl(port->base + GPIO_GDIR);
if (dir)
l |= 1 << offset;
else
l &= ~(1 << offset);
__raw_writel(l, port->base + GPIO_GDIR);
spin_unlock_irqrestore(&port->lock, flags);
}
static void mxc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct mxc_gpio_port *port =
container_of(chip, struct mxc_gpio_port, chip);
void __iomem *reg = port->base + GPIO_DR;
u32 l;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
l = (__raw_readl(reg) & (~(1 << offset))) | (!!value << offset);
__raw_writel(l, reg);
spin_unlock_irqrestore(&port->lock, flags);
}
static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct mxc_gpio_port *port =
container_of(chip, struct mxc_gpio_port, chip);
return (__raw_readl(port->base + GPIO_PSR) >> offset) & 1;
}
static int mxc_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
_set_gpio_direction(chip, offset, 0);
return 0;
}
static int mxc_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
mxc_gpio_set(chip, offset, value);
_set_gpio_direction(chip, offset, 1);
return 0;
}
/*
* This lock class tells lockdep that GPIO irqs are in a different
* category than their parents, so it won't report false recursion.
*/
static struct lock_class_key gpio_lock_class;
int __init mxc_gpio_init(struct mxc_gpio_port *port, int cnt)
{
int i, j;
/* save for local usage */
mxc_gpio_ports = port;
gpio_table_size = cnt;
printk(KERN_INFO "MXC GPIO hardware\n");
for (i = 0; i < cnt; i++) {
/* disable the interrupt and clear the status */
__raw_writel(0, port[i].base + GPIO_IMR);
__raw_writel(~0, port[i].base + GPIO_ISR);
for (j = port[i].virtual_irq_start;
j < port[i].virtual_irq_start + 32; j++) {
irq_set_lockdep_class(j, &gpio_lock_class);
irq_set_chip_and_handler(j, &gpio_irq_chip,
handle_level_irq);
set_irq_flags(j, IRQF_VALID);
}
/* register gpio chip */
port[i].chip.direction_input = mxc_gpio_direction_input;
port[i].chip.direction_output = mxc_gpio_direction_output;
port[i].chip.get = mxc_gpio_get;
port[i].chip.set = mxc_gpio_set;
port[i].chip.base = i * 32;
port[i].chip.ngpio = 32;
spin_lock_init(&port[i].lock);
/* its a serious configuration bug when it fails */
BUG_ON( gpiochip_add(&port[i].chip) < 0 );
if (cpu_is_mx1() || cpu_is_mx3() || cpu_is_mx25() || cpu_is_mx51()) {
/* setup one handler for each entry */
irq_set_chained_handler(port[i].irq,
mx3_gpio_irq_handler);
irq_set_handler_data(port[i].irq, &port[i]);
if (port[i].irq_high) {
/* setup handler for GPIO 16 to 31 */
irq_set_chained_handler(port[i].irq_high,
mx3_gpio_irq_handler);
irq_set_handler_data(port[i].irq_high,
&port[i]);
}
}
}
if (cpu_is_mx2()) {
/* setup one handler for all GPIO interrupts */
irq_set_chained_handler(port[0].irq, mx2_gpio_irq_handler);
irq_set_handler_data(port[0].irq, port);
}
return 0;
}
