/*
* MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
*
* Based on code from Freescale,
* Copyright 2004-2006 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/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;
/* 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(u32 irq)
{
u32 gpio = irq_to_gpio(irq);
_clear_gpio_irqstatus(&mxc_gpio_ports[gpio / 32], gpio & 0x1f);
}
static void gpio_mask_irq(u32 irq)
{
u32 gpio = irq_to_gpio(irq);
_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 0);
}
static void gpio_unmask_irq(u32 irq)
{
u32 gpio = irq_to_gpio(irq);
_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 1);
}
static int gpio_set_irq_type(u32 irq, u32 type)
{
u32 gpio = irq_to_gpio(irq);
struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32];
u32 bit, val;
int edge;
void __iomem *reg = port->base;
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_LEVEL_LOW:
edge = GPIO_INT_LOW_LEV;
break;
case IRQ_TYPE_LEVEL_HIGH:
edge = GPIO_INT_HIGH_LEV;
break;
default: /* this includes IRQ_TYPE_EDGE_BOTH */
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;
}
/* handle n interrupts in one status register */
static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
{
u32 gpio_irq_no;
gpio_irq_no = port->virtual_irq_start;
for (; irq_stat != 0; irq_stat >>= 1, gpio_irq_no++) {
if ((irq_stat & 1) == 0)
continue;
BUG_ON(!(irq_desc[gpio_irq_no].handle_irq));
irq_desc[gpio_irq_no].handle_irq(gpio_irq_no,
&irq_desc[gpio_irq_no]);
}
}
#ifdef CONFIG_ARCH_MX3
/* 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 = (struct mxc_gpio_port *)get_irq_data(irq);
irq_stat = __raw_readl(port->base + GPIO_ISR) &
__raw_readl(port->base + GPIO_IMR);
BUG_ON(!irq_stat);
mxc_gpio_irq_handler(port, irq_stat);
}
#endif
#ifdef CONFIG_ARCH_MX2
/* 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 = (struct mxc_gpio_port *)get_irq_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);
}
}
#endif
static struct irq_chip gpio_irq_chip = {
.ack = gpio_ack_irq,
.mask = gpio_mask_irq,
.unmask = gpio_unmask_irq,
.set_type = gpio_set_irq_type,
};
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;
l = __raw_readl(port->base + GPIO_GDIR);
if (dir)
l |= 1 << offset;
else
l &= ~(1 << offset);
__raw_writel(l, port->base + GPIO_GDIR);
}
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;
l = (__raw_readl(reg) & (~(1 << offset))) | (value << offset);
__raw_writel(l, reg);
}
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)
{
_set_gpio_direction(chip, offset, 1);
mxc_gpio_set(chip, offset, value);
return 0;
}
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++) {
set_irq_chip(j, &gpio_irq_chip);
set_irq_handler(j, handle_edge_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;
/* its a serious configuration bug when it fails */
BUG_ON( gpiochip_add(&port[i].chip) < 0 );
#ifdef CONFIG_ARCH_MX3
/* setup one handler for each entry */
set_irq_chained_handler(port[i].irq, mx3_gpio_irq_handler);
set_irq_data(port[i].irq, &port[i]);
#endif
}
#ifdef CONFIG_ARCH_MX2
/* setup one handler for all GPIO interrupts */
set_irq_chained_handler(port[0].irq, mx2_gpio_irq_handler);
set_irq_data(port[0].irq, port);
#endif
return 0;
}
