hwmon: Request the I/O regions in platform drivers

My understanding of the resource management in the Linux 2.6 device
driver model is that the devices should declare their resources, and
then when a driver attaches to a device, it should request the
resources it will be using, so as to mark them busy. This is how the
PCI and PNP subsystems work, you can clearly see the two levels of
resources (declaration and request) in /proc/ioports for these
devices.

So I believe that our platform hardware monitoring drivers should
follow the same logic. At the moment, we only declare the resources
but we do not request them. This patch adds the I/O region request
and release calls.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Juerg Haefliger <juergh@gmail.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/hwmon/vt1211.c b/drivers/hwmon/vt1211.c
index 89c23d6add7b..9f3e332c5b7f 100644
--- a/drivers/hwmon/vt1211.c
+++ b/drivers/hwmon/vt1211.c
@@ -31,6 +31,7 @@
 #include <linux/hwmon-vid.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
+#include <linux/ioport.h>
 #include <asm/io.h>
 
 static int uch_config = -1;
@@ -1130,6 +1131,12 @@ static int __devinit vt1211_probe(struct platform_device *pdev)
         }
 
         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+        if (!request_region(res->start, res->end - res->start + 1, DRVNAME)) {
+                err = -EBUSY;
+                dev_err(dev, "Failed to request region 0x%lx-0x%lx\n",
+                        (unsigned long)res->start, (unsigned long)res->end);
+                goto EXIT_KFREE;
+        }
         data->addr = res->start;
         data->name = DRVNAME;
         mutex_init(&data->update_lock);
@@ -1197,6 +1204,8 @@ EXIT_DEV_REMOVE:
         dev_err(dev, "Sysfs interface creation failed (%d)\n", err);
 EXIT_DEV_REMOVE_SILENT:
         vt1211_remove_sysfs(pdev);
+        release_region(res->start, res->end - res->start + 1);
+EXIT_KFREE:
         platform_set_drvdata(pdev, NULL);
         kfree(data);
 EXIT:
@@ -1206,12 +1215,16 @@ EXIT:
 static int __devexit vt1211_remove(struct platform_device *pdev)
 {
         struct vt1211_data *data = platform_get_drvdata(pdev);
+        struct resource *res;
 
         hwmon_device_unregister(data->class_dev);
         vt1211_remove_sysfs(pdev);
         platform_set_drvdata(pdev, NULL);
         kfree(data);
 
+        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+        release_region(res->start, res->end - res->start + 1);
+
         return 0;
 }