powerpc/macio: Add devres support to macio_device

This adds some basic devres support. When enabled via macio_enable_devres()
resources requested by drivers will be automatically released.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/drivers/macintosh/macio_asic.c b/drivers/macintosh/macio_asic.c
index 588a5b0bc4b5..5200acfc9d38 100644
--- a/drivers/macintosh/macio_asic.c
+++ b/drivers/macintosh/macio_asic.c
@@ -538,6 +538,42 @@ void macio_unregister_driver(struct macio_driver *drv)
         driver_unregister(&drv->driver);
 }
 
+/* Managed MacIO resources */
+struct macio_devres {
+        u32     res_mask;
+};
+
+static void maciom_release(struct device *gendev, void *res)
+{
+        struct macio_dev *dev = to_macio_device(gendev);
+        struct macio_devres *dr = res;
+        int i, max;
+
+        max = min(dev->n_resources, 32);
+        for (i = 0; i < max; i++) {
+                if (dr->res_mask & (1 << i))
+                        macio_release_resource(dev, i);
+        }
+}
+
+int macio_enable_devres(struct macio_dev *dev)
+{
+        struct macio_devres *dr;
+
+        dr = devres_find(&dev->ofdev.dev, maciom_release, NULL, NULL);
+        if (!dr) {
+                dr = devres_alloc(maciom_release, sizeof(*dr), GFP_KERNEL);
+                if (!dr)
+                        return -ENOMEM;
+        }
+        return devres_get(&dev->ofdev.dev, dr, NULL, NULL) != NULL;
+}
+
+static struct macio_devres * find_macio_dr(struct macio_dev *dev)
+{
+        return devres_find(&dev->ofdev.dev, maciom_release, NULL, NULL);
+}
+
 /**
  *      macio_request_resource - Request an MMIO resource
  *      @dev: pointer to the device holding the resource
@@ -555,6 +591,8 @@ void macio_unregister_driver(struct macio_driver *drv)
 int macio_request_resource(struct macio_dev *dev, int resource_no,
                            const char *name)
 {
+        struct macio_devres *dr = find_macio_dr(dev);
+
         if (macio_resource_len(dev, resource_no) == 0)
                 return 0;
                 
@@ -562,6 +600,9 @@ int macio_request_resource(struct macio_dev *dev, int resource_no,
                                 macio_resource_len(dev, resource_no),
                                 name))
                 goto err_out;
+
+        if (dr && resource_no < 32)
+                dr->res_mask |= 1 << resource_no;
         
         return 0;
 
@@ -582,10 +623,14 @@ err_out:
  */
 void macio_release_resource(struct macio_dev *dev, int resource_no)
 {
+        struct macio_devres *dr = find_macio_dr(dev);
+
         if (macio_resource_len(dev, resource_no) == 0)
                 return;
         release_mem_region(macio_resource_start(dev, resource_no),
                            macio_resource_len(dev, resource_no));
+        if (dr && resource_no < 32)
+                dr->res_mask &= ~(1 << resource_no);
 }
 
 /**
@@ -744,3 +789,5 @@ EXPORT_SYMBOL(macio_request_resource);
 EXPORT_SYMBOL(macio_release_resource);
 EXPORT_SYMBOL(macio_request_resources);
 EXPORT_SYMBOL(macio_release_resources);
+EXPORT_SYMBOL(macio_enable_devres);
+