[PATCH] scx200_gpio: 1 cdev for N minors: cleanup, prep
this patch is mostly cleanup of scx200_gpio :
- drop #include <linux/config.h>
- s/DEVNAME/DRVNAME/ apparently a convention
- replace variable num_pins with #define MAX_PINS
- s/dev/devid/ to clarify that its a dev_t, not a struct device dev.
- move devid = MKDEV(major,0) into branch where its needed.
2 minor 'changes' :
- reduced MAX_PINS from 64 to 32. Ive never tested other pins, and
theyre all multiplexed with other functions, some of which may be in use
on my soekris 4801, so I dont know what testing should yield.
- +EXPORT_SYMBOL(scx200_access);
This exposes the driver's vtable, which another driver can use along
with #include <linux/nsc_gpio.h>, to manipulate a gpio-pin.
Signed-off-by Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
index 425c587..e7665c1 100644
--- a/drivers/char/scx200_gpio.c
+++ b/drivers/char/scx200_gpio.c
@@ -5,7 +5,6 @@
Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */
-#include <linux/config.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/module.h>
@@ -22,19 +21,20 @@
#include <linux/scx200_gpio.h>
#include <linux/nsc_gpio.h>
-#define NAME "scx200_gpio"
-#define DEVNAME NAME
+#define DRVNAME "scx200_gpio"
static struct platform_device *pdev;
MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
-MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver");
+MODULE_DESCRIPTION("NatSemi/AMD SCx200 GPIO Pin Driver");
MODULE_LICENSE("GPL");
static int major = 0; /* default to dynamic major */
module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number");
+#define MAX_PINS 32 /* 64 later, when known ok */
+
struct nsc_gpio_ops scx200_access = {
.owner = THIS_MODULE,
.gpio_config = scx200_gpio_configure,
@@ -46,13 +46,14 @@
.gpio_change = scx200_gpio_change,
.gpio_current = scx200_gpio_current
};
+EXPORT_SYMBOL(scx200_access);
static int scx200_gpio_open(struct inode *inode, struct file *file)
{
unsigned m = iminor(inode);
file->private_data = &scx200_access;
- if (m > 63)
+ if (m >= MAX_PINS)
return -EINVAL;
return nonseekable_open(inode, file);
}
@@ -72,20 +73,19 @@
};
struct cdev *scx200_devices;
-static int num_pins = 32;
static int __init scx200_gpio_init(void)
{
int rc, i;
- dev_t dev = MKDEV(major, 0);
+ dev_t devid;
if (!scx200_gpio_present()) {
- printk(KERN_ERR NAME ": no SCx200 gpio present\n");
+ printk(KERN_ERR DRVNAME ": no SCx200 gpio present\n");
return -ENODEV;
}
/* support dev_dbg() with pdev->dev */
- pdev = platform_device_alloc(DEVNAME, 0);
+ pdev = platform_device_alloc(DRVNAME, 0);
if (!pdev)
return -ENOMEM;
@@ -96,22 +96,23 @@
/* nsc_gpio uses dev_dbg(), so needs this */
scx200_access.dev = &pdev->dev;
- if (major)
- rc = register_chrdev_region(dev, num_pins, "scx200_gpio");
- else {
- rc = alloc_chrdev_region(&dev, 0, num_pins, "scx200_gpio");
- major = MAJOR(dev);
+ if (major) {
+ devid = MKDEV(major, 0);
+ rc = register_chrdev_region(devid, MAX_PINS, "scx200_gpio");
+ } else {
+ rc = alloc_chrdev_region(&devid, 0, MAX_PINS, "scx200_gpio");
+ major = MAJOR(devid);
}
if (rc < 0) {
dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc);
goto undo_platform_device_add;
}
- scx200_devices = kzalloc(num_pins * sizeof(struct cdev), GFP_KERNEL);
+ scx200_devices = kzalloc(MAX_PINS * sizeof(struct cdev), GFP_KERNEL);
if (!scx200_devices) {
rc = -ENOMEM;
goto undo_chrdev_region;
}
- for (i = 0; i < num_pins; i++) {
+ for (i = 0; i < MAX_PINS; i++) {
struct cdev *cdev = &scx200_devices[i];
cdev_init(cdev, &scx200_gpio_fops);
cdev->owner = THIS_MODULE;
@@ -124,7 +125,7 @@
return 0; /* succeed */
undo_chrdev_region:
- unregister_chrdev_region(dev, num_pins);
+ unregister_chrdev_region(devid, MAX_PINS);
undo_platform_device_add:
platform_device_del(pdev);
undo_malloc:
@@ -136,9 +137,8 @@
static void __exit scx200_gpio_cleanup(void)
{
kfree(scx200_devices);
- unregister_chrdev_region(MKDEV(major, 0), num_pins);
+ unregister_chrdev_region(MKDEV(major, 0), MAX_PINS);
platform_device_unregister(pdev);
- /* kfree(pdev); */
}
module_init(scx200_gpio_init);
