National Semiconductor PC8736x GPIO driver. Allows a user space
process to play with the GPIO pins.
- Copyright (c) 2005 Jim Cromie <jim.cromie@gmail.com>
+ Copyright (c) 2005,2006 Jim Cromie <jim.cromie@gmail.com>
adapted from linux/drivers/char/scx200_gpio.c
Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>,
*/
-#include <linux/config.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/cdev.h>
+#include <linux/io.h>
#include <linux/ioport.h>
+#include <linux/mutex.h>
#include <linux/nsc_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/smp_lock.h>
#include <asm/uaccess.h>
-#include <asm/io.h>
-#define NAME "pc8736x_gpio"
+#define DEVNAME "pc8736x_gpio"
MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
-MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver");
+MODULE_DESCRIPTION("NatSemi/Winbond PC-8736x GPIO Pin Driver");
MODULE_LICENSE("GPL");
static int major; /* default to dynamic major */
module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number");
-static DEFINE_SPINLOCK(pc8736x_gpio_config_lock);
+static DEFINE_MUTEX(pc8736x_gpio_config_lock);
static unsigned pc8736x_gpio_base;
+static u8 pc8736x_gpio_shadow[4];
#define SIO_BASE1 0x2E /* 1st command-reg to check */
#define SIO_BASE2 0x4E /* alt command-reg to check */
-#define SIO_BASE_OFFSET 0x20
#define SIO_SID 0x20 /* SuperI/O ID Register */
#define SIO_SID_VALUE 0xe9 /* Expected value in SuperI/O ID Register */
#define SIO_CF1 0x21 /* chip config, bit0 is chip enable */
+#define PC8736X_GPIO_RANGE 16 /* ioaddr range */
+#define PC8736X_GPIO_CT 32 /* minors matching 4 8 bit ports */
+
#define SIO_UNIT_SEL 0x7 /* unit select reg */
#define SIO_UNIT_ACT 0x30 /* unit enable */
#define SIO_GPIO_UNIT 0x7 /* unit number of GPIO */
#define PORT_EVT_EN 2
#define PORT_EVT_STST 3
+static struct platform_device *pdev; /* use in dev_*() */
+
static inline void superio_outb(int addr, int val)
{
outb_p(addr, superio_cmd);
u32 func_slct)
{
u32 config, new_config;
- unsigned long flags;
- spin_lock_irqsave(&pc8736x_gpio_config_lock, flags);
+ mutex_lock(&pc8736x_gpio_config_lock);
device_select(SIO_GPIO_UNIT);
select_pin(index);
new_config = (config & mask) | bits;
superio_outb(func_slct, new_config);
- spin_unlock_irqrestore(&pc8736x_gpio_config_lock, flags);
+ mutex_unlock(&pc8736x_gpio_config_lock);
return config;
}
val >>= bit;
val &= 1;
- printk(KERN_INFO NAME ": _gpio_get(%d from %x bit %d) == val %d\n",
- minor, pc8736x_gpio_base + port_offset[port] + PORT_IN, bit,
- val);
+ dev_dbg(&pdev->dev, "_gpio_get(%d from %x bit %d) == val %d\n",
+ minor, pc8736x_gpio_base + port_offset[port] + PORT_IN, bit,
+ val);
return val;
}
bit = minor & 7;
curval = inb_p(pc8736x_gpio_base + port_offset[port] + PORT_OUT);
- printk(KERN_INFO NAME
- ": addr:%x cur:%x bit-pos:%d cur-bit:%x + new:%d -> bit-new:%d\n",
- pc8736x_gpio_base + port_offset[port] + PORT_OUT,
- curval, bit, (curval & ~(1 << bit)), val, (val << bit));
+ dev_dbg(&pdev->dev, "addr:%x cur:%x bit-pos:%d cur-bit:%x + new:%d -> bit-new:%d\n",
+ pc8736x_gpio_base + port_offset[port] + PORT_OUT,
+ curval, bit, (curval & ~(1 << bit)), val, (val << bit));
val = (curval & ~(1 << bit)) | (val << bit);
- printk(KERN_INFO NAME ": gpio_set(minor:%d port:%d bit:%d"
- ") %2x -> %2x\n", minor, port, bit, curval, val);
+ dev_dbg(&pdev->dev, "gpio_set(minor:%d port:%d bit:%d)"
+ " %2x -> %2x\n", minor, port, bit, curval, val);
outb_p(val, pc8736x_gpio_base + port_offset[port] + PORT_OUT);
curval = inb_p(pc8736x_gpio_base + port_offset[port] + PORT_OUT);
val = inb_p(pc8736x_gpio_base + port_offset[port] + PORT_IN);
- printk(KERN_INFO NAME ": wrote %x, read: %x\n", curval, val);
-}
-
-static void pc8736x_gpio_set_high(unsigned index)
-{
- pc8736x_gpio_set(index, 1);
-}
-
-static void pc8736x_gpio_set_low(unsigned index)
-{
- pc8736x_gpio_set(index, 0);
+ dev_dbg(&pdev->dev, "wrote %x, read: %x\n", curval, val);
+ pc8736x_gpio_shadow[port] = val;
}
-static int pc8736x_gpio_current(unsigned index)
+static int pc8736x_gpio_current(unsigned minor)
{
- printk(KERN_WARNING NAME ": pc8736x_gpio_current unimplemented\n");
- return 0;
+ int port, bit;
+ minor &= 0x1f;
+ port = minor >> 3;
+ bit = minor & 7;
+ return ((pc8736x_gpio_shadow[port] >> bit) & 0x01);
}
static void pc8736x_gpio_change(unsigned index)
{
- pc8736x_gpio_set(index, !pc8736x_gpio_get(index));
+ pc8736x_gpio_set(index, !pc8736x_gpio_current(index));
}
-extern void nsc_gpio_dump(unsigned iminor);
-
-static struct nsc_gpio_ops pc8736x_access = {
+static struct nsc_gpio_ops pc8736x_gpio_ops = {
.owner = THIS_MODULE,
.gpio_config = pc8736x_gpio_configure,
.gpio_dump = nsc_gpio_dump,
.gpio_get = pc8736x_gpio_get,
.gpio_set = pc8736x_gpio_set,
- .gpio_set_high = pc8736x_gpio_set_high,
- .gpio_set_low = pc8736x_gpio_set_low,
.gpio_change = pc8736x_gpio_change,
.gpio_current = pc8736x_gpio_current
};
static int pc8736x_gpio_open(struct inode *inode, struct file *file)
{
unsigned m = iminor(inode);
- file->private_data = &pc8736x_access;
+ file->private_data = &pc8736x_gpio_ops;
- printk(KERN_NOTICE NAME " open %d\n", m);
+ cycle_kernel_lock();
+ dev_dbg(&pdev->dev, "open %d\n", m);
- if (m > 63)
+ if (m >= PC8736X_GPIO_CT)
return -EINVAL;
return nonseekable_open(inode, file);
}
-static struct file_operations pc8736x_gpio_fops = {
- .owner = THIS_MODULE,
- .open = pc8736x_gpio_open,
- .write = nsc_gpio_write,
- .read = nsc_gpio_read,
+static const struct file_operations pc8736x_gpio_fileops = {
+ .owner = THIS_MODULE,
+ .open = pc8736x_gpio_open,
+ .write = nsc_gpio_write,
+ .read = nsc_gpio_read,
};
+static void __init pc8736x_init_shadow(void)
+{
+ int port;
+
+ /* read the current values driven on the GPIO signals */
+ for (port = 0; port < 4; ++port)
+ pc8736x_gpio_shadow[port]
+ = inb_p(pc8736x_gpio_base + port_offset[port]
+ + PORT_OUT);
+
+}
+
+static struct cdev pc8736x_gpio_cdev;
+
static int __init pc8736x_gpio_init(void)
{
- int r, rc;
+ int rc;
+ dev_t devid;
+
+ pdev = platform_device_alloc(DEVNAME, 0);
+ if (!pdev)
+ return -ENOMEM;
- printk(KERN_DEBUG NAME " initializing\n");
+ rc = platform_device_add(pdev);
+ if (rc) {
+ rc = -ENODEV;
+ goto undo_platform_dev_alloc;
+ }
+ dev_info(&pdev->dev, "NatSemi pc8736x GPIO Driver Initializing\n");
if (!pc8736x_superio_present()) {
- printk(KERN_ERR NAME ": no device found\n");
- return -ENODEV;
+ rc = -ENODEV;
+ dev_err(&pdev->dev, "no device found\n");
+ goto undo_platform_dev_add;
}
+ pc8736x_gpio_ops.dev = &pdev->dev;
/* Verify that chip and it's GPIO unit are both enabled.
My BIOS does this, so I take minimum action here
*/
rc = superio_inb(SIO_CF1);
if (!(rc & 0x01)) {
- printk(KERN_ERR NAME ": device not enabled\n");
- return -ENODEV;
+ rc = -ENODEV;
+ dev_err(&pdev->dev, "device not enabled\n");
+ goto undo_platform_dev_add;
}
device_select(SIO_GPIO_UNIT);
if (!superio_inb(SIO_UNIT_ACT)) {
- printk(KERN_ERR NAME ": GPIO unit not enabled\n");
- return -ENODEV;
+ rc = -ENODEV;
+ dev_err(&pdev->dev, "GPIO unit not enabled\n");
+ goto undo_platform_dev_add;
}
- /* read GPIO unit base address */
+ /* read the GPIO unit base addr that chip responds to */
pc8736x_gpio_base = (superio_inb(SIO_BASE_HADDR) << 8
| superio_inb(SIO_BASE_LADDR));
- if (request_region(pc8736x_gpio_base, 16, NAME))
- printk(KERN_INFO NAME ": GPIO ioport %x reserved\n",
- pc8736x_gpio_base);
+ if (!request_region(pc8736x_gpio_base, PC8736X_GPIO_RANGE, DEVNAME)) {
+ rc = -ENODEV;
+ dev_err(&pdev->dev, "GPIO ioport %x busy\n",
+ pc8736x_gpio_base);
+ goto undo_platform_dev_add;
+ }
+ dev_info(&pdev->dev, "GPIO ioport %x reserved\n", pc8736x_gpio_base);
+
+ if (major) {
+ devid = MKDEV(major, 0);
+ rc = register_chrdev_region(devid, PC8736X_GPIO_CT, DEVNAME);
+ } else {
+ rc = alloc_chrdev_region(&devid, 0, PC8736X_GPIO_CT, DEVNAME);
+ major = MAJOR(devid);
+ }
- r = register_chrdev(major, NAME, &pc8736x_gpio_fops);
- if (r < 0) {
- printk(KERN_ERR NAME ": unable to register character device\n");
- return r;
+ if (rc < 0) {
+ dev_err(&pdev->dev, "register-chrdev failed: %d\n", rc);
+ goto undo_request_region;
}
if (!major) {
- major = r;
- printk(KERN_DEBUG NAME ": got dynamic major %d\n", major);
+ major = rc;
+ dev_dbg(&pdev->dev, "got dynamic major %d\n", major);
}
pc8736x_init_shadow();
+
+ /* ignore minor errs, and succeed */
+ cdev_init(&pc8736x_gpio_cdev, &pc8736x_gpio_fileops);
+ cdev_add(&pc8736x_gpio_cdev, devid, PC8736X_GPIO_CT);
+
return 0;
+
+undo_request_region:
+ release_region(pc8736x_gpio_base, PC8736X_GPIO_RANGE);
+undo_platform_dev_add:
+ platform_device_del(pdev);
+undo_platform_dev_alloc:
+ platform_device_put(pdev);
+
+ return rc;
}
static void __exit pc8736x_gpio_cleanup(void)
{
- printk(KERN_DEBUG NAME " cleanup\n");
+ dev_dbg(&pdev->dev, "cleanup\n");
- release_region(pc8736x_gpio_base, 16);
+ cdev_del(&pc8736x_gpio_cdev);
+ unregister_chrdev_region(MKDEV(major,0), PC8736X_GPIO_CT);
+ release_region(pc8736x_gpio_base, PC8736X_GPIO_RANGE);
- unregister_chrdev(major, NAME);
+ platform_device_del(pdev);
+ platform_device_put(pdev);
}
module_init(pc8736x_gpio_init);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff