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, 14 insertions, 1 deletions

diff --git a/drivers/hwmon/pc87427.c b/drivers/hwmon/pc87427.c
index affa21a5ccfd..29354fa26f81 100644
--- a/drivers/hwmon/pc87427.c
+++ b/drivers/hwmon/pc87427.c
@@ -31,6 +31,7 @@
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/sysfs.h>
+#include <linux/ioport.h>
 #include <asm/io.h>
 
 static struct platform_device *pdev;
@@ -429,6 +430,12 @@ static int __devinit pc87427_probe(struct platform_device *pdev)
         /* This will need to be revisited when we add support for
            temperature and voltage monitoring. */
         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+        if (!request_region(res->start, res->end - res->start + 1, DRVNAME)) {
+                err = -EBUSY;
+                dev_err(&pdev->dev, "Failed to request region 0x%lx-0x%lx\n",
+                        (unsigned long)res->start, (unsigned long)res->end);
+                goto exit_kfree;
+        }
         data->address[0] = res->start;
 
         mutex_init(&data->lock);
@@ -438,7 +445,7 @@ static int __devinit pc87427_probe(struct platform_device *pdev)
 
         /* Register sysfs hooks */
         if ((err = device_create_file(&pdev->dev, &dev_attr_name)))
-                goto exit_kfree;
+                goto exit_release_region;
         for (i = 0; i < 8; i++) {
                 if (!(data->fan_enabled & (1 << i)))
                         continue;
@@ -462,6 +469,8 @@ exit_remove_files:
                         continue;
                 sysfs_remove_group(&pdev->dev.kobj, &pc87427_group_fan[i]);
         }
+exit_release_region:
+        release_region(res->start, res->end - res->start + 1);
 exit_kfree:
         platform_set_drvdata(pdev, NULL);
         kfree(data);
@@ -472,6 +481,7 @@ exit:
 static int __devexit pc87427_remove(struct platform_device *pdev)
 {
         struct pc87427_data *data = platform_get_drvdata(pdev);
+        struct resource *res;
         int i;
 
         platform_set_drvdata(pdev, NULL);
@@ -484,6 +494,9 @@ static int __devexit pc87427_remove(struct platform_device *pdev)
         }
         kfree(data);
 
+        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+        release_region(res->start, res->end - res->start + 1);
+
         return 0;
 }