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. If you (AKPM) think it should stay unchanged, please feel free to s/32/64/ the patch directly, and consider this my Ack. Otherwize I'll defer, go read the datasheet, and see what I can do, when.

+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 <[email protected]>

---

$ diffstat diff.scx-normalize
scx200_gpio.c |   38 +++++++++++++++++++-------------------
1 files changed, 19 insertions(+), 19 deletions(-)

diff -ruNp -X dontdiff -X exclude-diffs x-0/drivers/char/scx200_gpio.c x-1/drivers/char/scx200_gpio.c
@@ -5,7 +5,6 @@
 
   Copyright (c) 2001,2002 Christer Weinigel <[email protected]> */
 
-#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 <[email protected]>"); -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 @@ struct nsc_gpio_ops scx200_access = {
	.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 @@ static const struct file_operations scx2 };

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 @@ static int __init scx200_gpio_init(void)

	/* 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 @@ static int __init scx200_gpio_init(void)
	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 @@ undo_malloc:
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);