Re: [patchset 2/3 -2.6.18-rc1] pc8736x_gpio: fix re-modprobe errors - undo region reservation

Jim Cromie
2006-07-08T14:29:43Z

2 - pc-init-fix-undo-region-rollup

this patch fixes module-init-func by repairing usage of
platform_device_del/put in module-exit-func.
IOW, it imitates Ingo's 'mishaps' patch, which fixed the
module-init-func's undo handling.
Also fixes lack of release_region to undo the earlier registration.

Also starts to 'use a cdev' which was originally intended (its present
in scx200_gpio).
Code compiles and runs, exhibits a lesser error than previously.
(re-register-chrdev fails)

Since I had to add "include <linux/cdev.h>", I went ahead and made 2
tweaks that fell into diff-context-window:
- remove include <linux/config.h> everyone's doing it
- copyright updates - current date is 'wrong'

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>

---

$ diffstat fxd1/pc-init-fix-undo-region-rollup
pc8736x_gpio.c | 19 +++++++++++++------
1 files changed, 13 insertions(+), 6 deletions(-)
[jimc@harpo gpio-stuff]$

---

diff -ruNp -X dontdiff -X exclude-diffs x4h-1/drivers/char/pc8736x_gpio.c x4h-2/drivers/char/pc8736x_gpio.c
--- x4h-1/drivers/char/pc8736x_gpio.c 2006-07-07 16:59:14.000000000 -0600
+++ x4h-2/drivers/char/pc8736x_gpio.c 2006-07-07 17:02:17.000000000 -0600
@@ -3,18 +3,18 @@
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>
@@ -255,6 +255,8 @@ static void __init pc8736x_init_shadow(v

}

+static struct cdev pc8736x_gpio_cdev;
+
static int __init pc8736x_gpio_init(void)
{
int rc = 0;
@@ -308,7 +310,7 @@ static int __init pc8736x_gpio_init(void
rc = register_chrdev(major, DEVNAME, &pc8736x_gpio_fops);
if (rc < 0) {
dev_err(&pdev->dev, "register-chrdev failed: %d\n", rc);
- goto undo_platform_dev_add;
+ goto undo_request_region;
}
if (!major) {
major = rc;
@@ -318,6 +320,8 @@ static int __init pc8736x_gpio_init(void
pc8736x_init_shadow();
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:
@@ -328,11 +332,14 @@ undo_platform_dev_alloc:

static void __exit pc8736x_gpio_cleanup(void)
{
- dev_dbg(&pdev->dev, " 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, DEVNAME);
+ platform_device_del(pdev);
+ platform_device_put(pdev);
}

EXPORT_SYMBOL(pc8736x_access);