am7xxx: pass the context to add_new_device() and find_device()

This is preparation for when we will track the context in am7xxx_device
as well, and as a side effect those functions now look more consistent
with the other ones.

diff --git a/src/am7xxx.c b/src/am7xxx.c
index 11c259d..1ece881 100644 (file)
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -321,10 +321,18 @@ static int send_header(am7xxx_device *dev, struct am7xxx_header *h)
        return ret;
 }
 
-static am7xxx_device *add_new_device(am7xxx_device **devices_list)
+static am7xxx_device *add_new_device(am7xxx_context *ctx)
 {
+       am7xxx_device **devices_list;
        am7xxx_device *new_device;
 
+       if (ctx == NULL) {
+               fprintf(stderr, "%s: context must not be NULL!\n", __func__);
+               return NULL;
+       }
+
+       devices_list = &(ctx->devices_list);
+
        new_device = malloc(sizeof(*new_device));
        if (new_device == NULL) {
                perror("malloc");
@@ -343,12 +351,18 @@ static am7xxx_device *add_new_device(am7xxx_device **devices_list)
        return new_device;
 }
 
-static am7xxx_device *find_device(am7xxx_device *devices_list,
+static am7xxx_device *find_device(am7xxx_context *ctx,
                                  unsigned int device_index)
 {
        unsigned int i = 0;
-       am7xxx_device *current = devices_list;
+       am7xxx_device *current;
 
+       if (ctx == NULL) {
+               fprintf(stderr, "%s: context must not be NULL!\n", __func__);
+               return NULL;
+       }
+
+       current = ctx->devices_list;
        while (current && i++ < device_index)
                current = current->next;
 
@@ -420,7 +434,7 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
                                        printf("am7xxx device found, index: %d, name: %s\n",
                                               current_index,
                                               supported_devices[j].name);
-                                       new_device = add_new_device(&(ctx->devices_list));
+                                       new_device = add_new_device(ctx);
                                        if (new_device == NULL) {
                                                /* XXX, the caller may want
                                                 * to call am7xxx_shutdown() if
@@ -433,7 +447,7 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
                                } else if (op == SCAN_OP_OPEN_DEVICE &&
                                           current_index == open_device_index) {
 
-                                       *dev = find_device(ctx->devices_list, open_device_index);
+                                       *dev = find_device(ctx, open_device_index);
                                        if (*dev == NULL) {
                                                ret = -ENODEV;
                                                goto out;