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linux/drivers/char/vr41xx_giu.c
Jonathan Corbet f2b9857eee Add a bunch of cycle_kernel_lock() calls 
All of the open() functions which don't need the BKL on their face may
still depend on its acquisition to serialize opens against driver
initialization.  So make those functions acquire then release the BKL to be
on the safe side.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-06-20 14:05:53 -06:00

680 lines
15 KiB
C
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/*
* Driver for NEC VR4100 series General-purpose I/O Unit.
*
* Copyright (C) 2002 MontaVista Software Inc.
* Author: Yoichi Yuasa <yyuasa@mvista.com or source@mvista.com>
* Copyright (C) 2003-2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <asm/io.h>
#include <asm/vr41xx/giu.h>
#include <asm/vr41xx/irq.h>
#include <asm/vr41xx/vr41xx.h>
MODULE_AUTHOR("Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>");
MODULE_DESCRIPTION("NEC VR4100 series General-purpose I/O Unit driver");
MODULE_LICENSE("GPL");
static int major; /* default is dynamic major device number */
module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number");
#define GIUIOSELL 0x00
#define GIUIOSELH 0x02
#define GIUPIODL 0x04
#define GIUPIODH 0x06
#define GIUINTSTATL 0x08
#define GIUINTSTATH 0x0a
#define GIUINTENL 0x0c
#define GIUINTENH 0x0e
#define GIUINTTYPL 0x10
#define GIUINTTYPH 0x12
#define GIUINTALSELL 0x14
#define GIUINTALSELH 0x16
#define GIUINTHTSELL 0x18
#define GIUINTHTSELH 0x1a
#define GIUPODATL 0x1c
#define GIUPODATEN 0x1c
#define GIUPODATH 0x1e
#define PIOEN0 0x0100
#define PIOEN1 0x0200
#define GIUPODAT 0x1e
#define GIUFEDGEINHL 0x20
#define GIUFEDGEINHH 0x22
#define GIUREDGEINHL 0x24
#define GIUREDGEINHH 0x26
#define GIUUSEUPDN 0x1e0
#define GIUTERMUPDN 0x1e2
#define GPIO_HAS_PULLUPDOWN_IO 0x0001
#define GPIO_HAS_OUTPUT_ENABLE 0x0002
#define GPIO_HAS_INTERRUPT_EDGE_SELECT 0x0100
static spinlock_t giu_lock;
static unsigned long giu_flags;
static unsigned int giu_nr_pins;
static void __iomem *giu_base;
#define giu_read(offset) readw(giu_base + (offset))
#define giu_write(offset, value) writew((value), giu_base + (offset))
#define GPIO_PIN_OF_IRQ(irq) ((irq) - GIU_IRQ_BASE)
#define GIUINT_HIGH_OFFSET 16
#define GIUINT_HIGH_MAX 32
static inline uint16_t giu_set(uint16_t offset, uint16_t set)
{
uint16_t data;
data = giu_read(offset);
data |= set;
giu_write(offset, data);
return data;
}
static inline uint16_t giu_clear(uint16_t offset, uint16_t clear)
{
uint16_t data;
data = giu_read(offset);
data &= ~clear;
giu_write(offset, data);
return data;
}
static void ack_giuint_low(unsigned int irq)
{
giu_write(GIUINTSTATL, 1 << GPIO_PIN_OF_IRQ(irq));
}
static void mask_giuint_low(unsigned int irq)
{
giu_clear(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(irq));
}
static void mask_ack_giuint_low(unsigned int irq)
{
unsigned int pin;
pin = GPIO_PIN_OF_IRQ(irq);
giu_clear(GIUINTENL, 1 << pin);
giu_write(GIUINTSTATL, 1 << pin);
}
static void unmask_giuint_low(unsigned int irq)
{
giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(irq));
}
static struct irq_chip giuint_low_irq_chip = {
.name = "GIUINTL",
.ack = ack_giuint_low,
.mask = mask_giuint_low,
.mask_ack = mask_ack_giuint_low,
.unmask = unmask_giuint_low,
};
static void ack_giuint_high(unsigned int irq)
{
giu_write(GIUINTSTATH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
}
static void mask_giuint_high(unsigned int irq)
{
giu_clear(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
}
static void mask_ack_giuint_high(unsigned int irq)
{
unsigned int pin;
pin = GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET;
giu_clear(GIUINTENH, 1 << pin);
giu_write(GIUINTSTATH, 1 << pin);
}
static void unmask_giuint_high(unsigned int irq)
{
giu_set(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
}
static struct irq_chip giuint_high_irq_chip = {
.name = "GIUINTH",
.ack = ack_giuint_high,
.mask = mask_giuint_high,
.mask_ack = mask_ack_giuint_high,
.unmask = unmask_giuint_high,
};
static int giu_get_irq(unsigned int irq)
{
uint16_t pendl, pendh, maskl, maskh;
int i;
pendl = giu_read(GIUINTSTATL);
pendh = giu_read(GIUINTSTATH);
maskl = giu_read(GIUINTENL);
maskh = giu_read(GIUINTENH);
maskl &= pendl;
maskh &= pendh;
if (maskl) {
for (i = 0; i < 16; i++) {
if (maskl & (1 << i))
return GIU_IRQ(i);
}
} else if (maskh) {
for (i = 0; i < 16; i++) {
if (maskh & (1 << i))
return GIU_IRQ(i + GIUINT_HIGH_OFFSET);
}
}
printk(KERN_ERR "spurious GIU interrupt: %04x(%04x),%04x(%04x)\n",
maskl, pendl, maskh, pendh);
atomic_inc(&irq_err_count);
return -EINVAL;
}
void vr41xx_set_irq_trigger(unsigned int pin, irq_trigger_t trigger, irq_signal_t signal)
{
uint16_t mask;
if (pin < GIUINT_HIGH_OFFSET) {
mask = 1 << pin;
if (trigger != IRQ_TRIGGER_LEVEL) {
giu_set(GIUINTTYPL, mask);
if (signal == IRQ_SIGNAL_HOLD)
giu_set(GIUINTHTSELL, mask);
else
giu_clear(GIUINTHTSELL, mask);
if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
switch (trigger) {
case IRQ_TRIGGER_EDGE_FALLING:
giu_set(GIUFEDGEINHL, mask);
giu_clear(GIUREDGEINHL, mask);
break;
case IRQ_TRIGGER_EDGE_RISING:
giu_clear(GIUFEDGEINHL, mask);
giu_set(GIUREDGEINHL, mask);
break;
default:
giu_set(GIUFEDGEINHL, mask);
giu_set(GIUREDGEINHL, mask);
break;
}
}
set_irq_chip_and_handler(GIU_IRQ(pin),
&giuint_low_irq_chip,
handle_edge_irq);
} else {
giu_clear(GIUINTTYPL, mask);
giu_clear(GIUINTHTSELL, mask);
set_irq_chip_and_handler(GIU_IRQ(pin),
&giuint_low_irq_chip,
handle_level_irq);
}
giu_write(GIUINTSTATL, mask);
} else if (pin < GIUINT_HIGH_MAX) {
mask = 1 << (pin - GIUINT_HIGH_OFFSET);
if (trigger != IRQ_TRIGGER_LEVEL) {
giu_set(GIUINTTYPH, mask);
if (signal == IRQ_SIGNAL_HOLD)
giu_set(GIUINTHTSELH, mask);
else
giu_clear(GIUINTHTSELH, mask);
if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
switch (trigger) {
case IRQ_TRIGGER_EDGE_FALLING:
giu_set(GIUFEDGEINHH, mask);
giu_clear(GIUREDGEINHH, mask);
break;
case IRQ_TRIGGER_EDGE_RISING:
giu_clear(GIUFEDGEINHH, mask);
giu_set(GIUREDGEINHH, mask);
break;
default:
giu_set(GIUFEDGEINHH, mask);
giu_set(GIUREDGEINHH, mask);
break;
}
}
set_irq_chip_and_handler(GIU_IRQ(pin),
&giuint_high_irq_chip,
handle_edge_irq);
} else {
giu_clear(GIUINTTYPH, mask);
giu_clear(GIUINTHTSELH, mask);
set_irq_chip_and_handler(GIU_IRQ(pin),
&giuint_high_irq_chip,
handle_level_irq);
}
giu_write(GIUINTSTATH, mask);
}
}
EXPORT_SYMBOL_GPL(vr41xx_set_irq_trigger);
void vr41xx_set_irq_level(unsigned int pin, irq_level_t level)
{
uint16_t mask;
if (pin < GIUINT_HIGH_OFFSET) {
mask = 1 << pin;
if (level == IRQ_LEVEL_HIGH)
giu_set(GIUINTALSELL, mask);
else
giu_clear(GIUINTALSELL, mask);
giu_write(GIUINTSTATL, mask);
} else if (pin < GIUINT_HIGH_MAX) {
mask = 1 << (pin - GIUINT_HIGH_OFFSET);
if (level == IRQ_LEVEL_HIGH)
giu_set(GIUINTALSELH, mask);
else
giu_clear(GIUINTALSELH, mask);
giu_write(GIUINTSTATH, mask);
}
}
EXPORT_SYMBOL_GPL(vr41xx_set_irq_level);
gpio_data_t vr41xx_gpio_get_pin(unsigned int pin)
{
uint16_t reg, mask;
if (pin >= giu_nr_pins)
return GPIO_DATA_INVAL;
if (pin < 16) {
reg = giu_read(GIUPIODL);
mask = (uint16_t)1 << pin;
} else if (pin < 32) {
reg = giu_read(GIUPIODH);
mask = (uint16_t)1 << (pin - 16);
} else if (pin < 48) {
reg = giu_read(GIUPODATL);
mask = (uint16_t)1 << (pin - 32);
} else {
reg = giu_read(GIUPODATH);
mask = (uint16_t)1 << (pin - 48);
}
if (reg & mask)
return GPIO_DATA_HIGH;
return GPIO_DATA_LOW;
}
EXPORT_SYMBOL_GPL(vr41xx_gpio_get_pin);
int vr41xx_gpio_set_pin(unsigned int pin, gpio_data_t data)
{
uint16_t offset, mask, reg;
unsigned long flags;
if (pin >= giu_nr_pins)
return -EINVAL;
if (pin < 16) {
offset = GIUPIODL;
mask = (uint16_t)1 << pin;
} else if (pin < 32) {
offset = GIUPIODH;
mask = (uint16_t)1 << (pin - 16);
} else if (pin < 48) {
offset = GIUPODATL;
mask = (uint16_t)1 << (pin - 32);
} else {
offset = GIUPODATH;
mask = (uint16_t)1 << (pin - 48);
}
spin_lock_irqsave(&giu_lock, flags);
reg = giu_read(offset);
if (data == GPIO_DATA_HIGH)
reg |= mask;
else
reg &= ~mask;
giu_write(offset, reg);
spin_unlock_irqrestore(&giu_lock, flags);
return 0;
}
EXPORT_SYMBOL_GPL(vr41xx_gpio_set_pin);
int vr41xx_gpio_set_direction(unsigned int pin, gpio_direction_t dir)
{
uint16_t offset, mask, reg;
unsigned long flags;
if (pin >= giu_nr_pins)
return -EINVAL;
if (pin < 16) {
offset = GIUIOSELL;
mask = (uint16_t)1 << pin;
} else if (pin < 32) {
offset = GIUIOSELH;
mask = (uint16_t)1 << (pin - 16);
} else {
if (giu_flags & GPIO_HAS_OUTPUT_ENABLE) {
offset = GIUPODATEN;
mask = (uint16_t)1 << (pin - 32);
} else {
switch (pin) {
case 48:
offset = GIUPODATH;
mask = PIOEN0;
break;
case 49:
offset = GIUPODATH;
mask = PIOEN1;
break;
default:
return -EINVAL;
}
}
}
spin_lock_irqsave(&giu_lock, flags);
reg = giu_read(offset);
if (dir == GPIO_OUTPUT)
reg |= mask;
else
reg &= ~mask;
giu_write(offset, reg);
spin_unlock_irqrestore(&giu_lock, flags);
return 0;
}
EXPORT_SYMBOL_GPL(vr41xx_gpio_set_direction);
int vr41xx_gpio_pullupdown(unsigned int pin, gpio_pull_t pull)
{
uint16_t reg, mask;
unsigned long flags;
if ((giu_flags & GPIO_HAS_PULLUPDOWN_IO) != GPIO_HAS_PULLUPDOWN_IO)
return -EPERM;
if (pin >= 15)
return -EINVAL;
mask = (uint16_t)1 << pin;
spin_lock_irqsave(&giu_lock, flags);
if (pull == GPIO_PULL_UP || pull == GPIO_PULL_DOWN) {
reg = giu_read(GIUTERMUPDN);
if (pull == GPIO_PULL_UP)
reg |= mask;
else
reg &= ~mask;
giu_write(GIUTERMUPDN, reg);
reg = giu_read(GIUUSEUPDN);
reg |= mask;
giu_write(GIUUSEUPDN, reg);
} else {
reg = giu_read(GIUUSEUPDN);
reg &= ~mask;
giu_write(GIUUSEUPDN, reg);
}
spin_unlock_irqrestore(&giu_lock, flags);
return 0;
}
EXPORT_SYMBOL_GPL(vr41xx_gpio_pullupdown);
static ssize_t gpio_read(struct file *file, char __user *buf, size_t len,
loff_t *ppos)
{
unsigned int pin;
char value = '0';
pin = iminor(file->f_path.dentry->d_inode);
if (pin >= giu_nr_pins)
return -EBADF;
if (vr41xx_gpio_get_pin(pin) == GPIO_DATA_HIGH)
value = '1';
if (len <= 0)
return -EFAULT;
if (put_user(value, buf))
return -EFAULT;
return 1;
}
static ssize_t gpio_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
unsigned int pin;
size_t i;
char c;
int retval = 0;
pin = iminor(file->f_path.dentry->d_inode);
if (pin >= giu_nr_pins)
return -EBADF;
for (i = 0; i < len; i++) {
if (get_user(c, data + i))
return -EFAULT;
switch (c) {
case '0':
retval = vr41xx_gpio_set_pin(pin, GPIO_DATA_LOW);
break;
case '1':
retval = vr41xx_gpio_set_pin(pin, GPIO_DATA_HIGH);
break;
case 'D':
printk(KERN_INFO "GPIO%d: pull down\n", pin);
retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DOWN);
break;
case 'd':
printk(KERN_INFO "GPIO%d: pull up/down disable\n", pin);
retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DISABLE);
break;
case 'I':
printk(KERN_INFO "GPIO%d: input\n", pin);
retval = vr41xx_gpio_set_direction(pin, GPIO_INPUT);
break;
case 'O':
printk(KERN_INFO "GPIO%d: output\n", pin);
retval = vr41xx_gpio_set_direction(pin, GPIO_OUTPUT);
break;
case 'o':
printk(KERN_INFO "GPIO%d: output disable\n", pin);
retval = vr41xx_gpio_set_direction(pin, GPIO_OUTPUT_DISABLE);
break;
case 'P':
printk(KERN_INFO "GPIO%d: pull up\n", pin);
retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_UP);
break;
case 'p':
printk(KERN_INFO "GPIO%d: pull up/down disable\n", pin);
retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DISABLE);
break;
default:
break;
}
if (retval < 0)
break;
}
return i;
}
static int gpio_open(struct inode *inode, struct file *file)
{
unsigned int pin;
cycle_kernel_lock();
pin = iminor(inode);
if (pin >= giu_nr_pins)
return -EBADF;
return nonseekable_open(inode, file);
}
static int gpio_release(struct inode *inode, struct file *file)
{
unsigned int pin;
pin = iminor(inode);
if (pin >= giu_nr_pins)
return -EBADF;
return 0;
}
static const struct file_operations gpio_fops = {
.owner = THIS_MODULE,
.read = gpio_read,
.write = gpio_write,
.open = gpio_open,
.release = gpio_release,
};
static int __devinit giu_probe(struct platform_device *dev)
{
struct resource *res;
unsigned int trigger, i, pin;
struct irq_chip *chip;
int irq, retval;
switch (dev->id) {
case GPIO_50PINS_PULLUPDOWN:
giu_flags = GPIO_HAS_PULLUPDOWN_IO;
giu_nr_pins = 50;
break;
case GPIO_36PINS:
giu_nr_pins = 36;
break;
case GPIO_48PINS_EDGE_SELECT:
giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
giu_nr_pins = 48;
break;
default:
printk(KERN_ERR "GIU: unknown ID %d\n", dev->id);
return -ENODEV;
}
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (!res)
return -EBUSY;
giu_base = ioremap(res->start, res->end - res->start + 1);
if (!giu_base)
return -ENOMEM;
retval = register_chrdev(major, "GIU", &gpio_fops);
if (retval < 0) {
iounmap(giu_base);
giu_base = NULL;
return retval;
}
if (major == 0) {
major = retval;
printk(KERN_INFO "GIU: major number %d\n", major);
}
spin_lock_init(&giu_lock);
giu_write(GIUINTENL, 0);
giu_write(GIUINTENH, 0);
trigger = giu_read(GIUINTTYPH) << 16;
trigger |= giu_read(GIUINTTYPL);
for (i = GIU_IRQ_BASE; i <= GIU_IRQ_LAST; i++) {
pin = GPIO_PIN_OF_IRQ(i);
if (pin < GIUINT_HIGH_OFFSET)
chip = &giuint_low_irq_chip;
else
chip = &giuint_high_irq_chip;
if (trigger & (1 << pin))
set_irq_chip_and_handler(i, chip, handle_edge_irq);
else
set_irq_chip_and_handler(i, chip, handle_level_irq);
}
irq = platform_get_irq(dev, 0);
if (irq < 0 || irq >= NR_IRQS)
return -EBUSY;
return cascade_irq(irq, giu_get_irq);
}
static int __devexit giu_remove(struct platform_device *dev)
{
if (giu_base) {
iounmap(giu_base);
giu_base = NULL;
}
return 0;
}
static struct platform_driver giu_device_driver = {
.probe = giu_probe,
.remove = __devexit_p(giu_remove),
.driver = {
.name = "GIU",
.owner = THIS_MODULE,
},
};
static int __init vr41xx_giu_init(void)
{
return platform_driver_register(&giu_device_driver);
}
static void __exit vr41xx_giu_exit(void)
{
platform_driver_unregister(&giu_device_driver);
}
module_init(vr41xx_giu_init);
module_exit(vr41xx_giu_exit);
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