/*
* GPIO support for RDC SoC R3210/R8610
*
* Copyright (C) 2007, Florian Fainelli <florian@openwrt.org>
* Copyright (C) 2008, Volker Weiss <dev@tintuc.de>
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/types.h>
#include <linux/module.h>
#include <asm/gpio.h>
#include <asm/mach-rdc321x/rdc321x_defs.h>
/* spin lock to protect our private copy of GPIO data register plus
the access to PCI conf registers. */
static DEFINE_SPINLOCK(gpio_lock);
/* copy of GPIO data registers */
static u32 gpio_data_reg1;
static u32 gpio_data_reg2;
static u32 gpio_request_data[2];
static inline void rdc321x_conf_write(unsigned addr, u32 value)
{
outl((1 << 31) | (7 << 11) | addr, RDC3210_CFGREG_ADDR);
outl(value, RDC3210_CFGREG_DATA);
}
static inline void rdc321x_conf_or(unsigned addr, u32 value)
{
outl((1 << 31) | (7 << 11) | addr, RDC3210_CFGREG_ADDR);
value |= inl(RDC3210_CFGREG_DATA);
outl(value, RDC3210_CFGREG_DATA);
}
static inline u32 rdc321x_conf_read(unsigned addr)
{
outl((1 << 31) | (7 << 11) | addr, RDC3210_CFGREG_ADDR);
return inl(RDC3210_CFGREG_DATA);
}
/* configure pin as GPIO */
static void rdc321x_configure_gpio(unsigned gpio)
{
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
rdc321x_conf_or(gpio < 32
? RDC321X_GPIO_CTRL_REG1 : RDC321X_GPIO_CTRL_REG2,
1 << (gpio & 0x1f));
spin_unlock_irqrestore(&gpio_lock, flags);
}
/* initially setup the 2 copies of the gpio data registers.
This function must be called by the platform setup code. */
void __init rdc321x_gpio_setup()
{
/* this might not be, what others (BIOS, bootloader, etc.)
wrote to these registers before, but it's a good guess. Still
better than just using 0xffffffff. */
gpio_data_reg1 = rdc321x_conf_read(RDC321X_GPIO_DATA_REG1);
gpio_data_reg2 = rdc321x_conf_read(RDC321X_GPIO_DATA_REG2);
}
/* determine, if gpio number is valid */
static inline int rdc321x_is_gpio(unsigned gpio)
{
return gpio <= RDC321X_MAX_GPIO;
}
/* request GPIO */
int rdc_gpio_request(unsigned gpio, const char *label)
{
unsigned long flags;
if (!rdc321x_is_gpio(gpio))
return -EINVAL;
spin_lock_irqsave(&gpio_lock, flags);
if (gpio_request_data[(gpio & 0x20) ? 1 : 0] & (1 << (gpio & 0x1f)))
goto inuse;
gpio_request_data[(gpio & 0x20) ? 1 : 0] |= (1 << (gpio & 0x1f));
spin_unlock_irqrestore(&gpio_lock, flags);
return 0;
inuse:
spin_unlock_irqrestore(&gpio_lock, flags);
return -EINVAL;
}
EXPORT_SYMBOL(rdc_gpio_request);
/* release previously-claimed GPIO */
void rdc_gpio_free(unsigned gpio)
{
unsigned long flags;
if (!rdc321x_is_gpio(gpio))
return;
spin_lock_irqsave(&gpio_lock, flags);
gpio_request_data[(gpio & 0x20) ? 1 : 0] &= ~(1 << (gpio & 0x1f));
spin_unlock_irqrestore(&gpio_lock, flags);
}
EXPORT_SYMBOL(rdc_gpio_free);
/* read GPIO pin */
int rdc_gpio_get_value(unsigned gpio)
{
u32 reg;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
reg = rdc321x_conf_read(gpio < 32
? RDC321X_GPIO_DATA_REG1 : RDC321X_GPIO_DATA_REG2);
spin_unlock_irqrestore(&gpio_lock, flags);
return (1 << (gpio & 0x1f)) & reg ? 1 : 0;
}
EXPORT_SYMBOL(rdc_gpio_get_value);
/* set GPIO pin to value */
void rdc_gpio_set_value(unsigned gpio, int value)
{
unsigned long flags;
u32 reg;
reg = 1 << (gpio & 0x1f);
if (gpio < 32) {
spin_lock_irqsave(&gpio_lock, flags);
if (value)
gpio_data_reg1 |= reg;
else
gpio_data_reg1 &= ~reg;
rdc321x_conf_write(RDC321X_GPIO_DATA_REG1, gpio_data_reg1);
spin_unlock_irqrestore(&gpio_lock, flags);
} else {
spin_lock_irqsave(&gpio_lock, flags);
if (value)
gpio_data_reg2 |= reg;
else
gpio_data_reg2 &= ~reg;
rdc321x_conf_write(RDC321X_GPIO_DATA_REG2, gpio_data_reg2);
spin_unlock_irqrestore(&gpio_lock, flags);
}
}
EXPORT_SYMBOL(rdc_gpio_set_value);
/* configure GPIO pin as input */
int rdc_gpio_direction_input(unsigned gpio)
{
if (!rdc321x_is_gpio(gpio))
return -EINVAL;
rdc321x_configure_gpio(gpio);
return 0;
}
EXPORT_SYMBOL(rdc_gpio_direction_input);
/* configure GPIO pin as output and set value */
int rdc_gpio_direction_output(unsigned gpio, int value)
{
if (!rdc321x_is_gpio(gpio))
return -EINVAL;
gpio_set_value(gpio, value);
rdc321x_configure_gpio(gpio);
return 0;
}
EXPORT_SYMBOL(rdc_gpio_direction_output);
