[RFC PATCH v3] drivers: bus: add ARM CCI support

On Mon, May 20, 2013 at 01:11:21PM +0100, Jon Medhurst (Tixy) wrote:

On Thu, 2013-05-09 at 11:34 +0100, Lorenzo Pieralisi wrote:
[...]

quoted

+static int __init cci_probe(void)
+{
+	struct cci_nb_ports const *cci_config;
+	int ret, i, nb_ace = 0, nb_ace_lite = 0;
+	struct device_node *np, *cp;
+	const char *match_str;
+	bool is_ace;
+
+	np = of_find_matching_node(NULL, arm_cci_matches);
+	if (!np)
+		return -ENODEV;
+
+	cci_config = of_match_node(arm_cci_matches, np)->data;
+	if (!cci_config)
+		return -ENODEV;
+
+	nb_cci_ports = cci_config->nb_ace + cci_config->nb_ace_lite;
+
+	ports = kcalloc(sizeof(*ports), nb_cci_ports, GFP_KERNEL);
+	if (!ports)
+		return -ENOMEM;
+
+	cci_ctrl_base = of_iomap(np, 0);
+
+	if (!cci_ctrl_base) {
+		WARN(1, "unable to ioremap CCI ctrl\n");
+		ret = -ENXIO;
+		goto memalloc_err;
+	}
+
+	for_each_child_of_node(np, cp) {
+		i = nb_ace + nb_ace_lite;
+
+		if (i >= nb_cci_ports)
+			break;

I know this is a bit late, but...

Would it not be best to check here that the node type is in fact
"slave-if", that way if we add support in later versions for other node
types (e.g. for the PMU) then we don't cause backward compatibility
issues. I'm thinking here of the same concerns that Rob raised with
"ARM: kernel: fix arm_dt_init_cpu_maps() to skip non-cpu nodes"

The node name, not type, but point is taken. I prefer to add a
compatible property to slave-if nodes (eg "arm,cci-400-control-if"),
I do not think that checking the node name is the standard way of doing
things in DT world.

Thoughts ?

Thanks,
Lorenzo

quoted

+		if (of_property_read_string(cp, "interface-type",
+					&match_str)) {
+			WARN(1, "node %s missing interface-type property\n",
+				  cp->full_name);
+			continue;
+		}
+

[..]

-- 
Tixy