hdata: Check the Host I2C devices array version

Currently this is not populated on FSP machines which causes some
obnoxious errors to appear in the boot log. We also only want to
parse version 1 of this structure since future versions will completely
change the array item format.

Cc: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[stewart@linux.vnet.ibm.com: return -1 on error rather than 1]
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

hdata/i2c.c

@@ -149,14 +149,21 @@ static bool is_zeros(const void *p, size_t size)
 	return true;
 }
 
+struct host_i2c_hdr {
+	const struct HDIF_array_hdr hdr;
+	__be32 version;
+};
+
 int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
 	struct dt_node *xscom)
 {
 	struct dt_node *i2cm, *bus, *node;
 	const struct hdat_i2c_type *type;
 	const struct i2c_dev *dev;
 	const char *label, *name, *compat;
+	const struct host_i2c_hdr *ahdr;
 	uint32_t i2c_addr;
+	uint32_t version;
 	uint32_t size;
 	int i, count;
 
@@ -166,6 +173,32 @@ int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
 	 */
 	assert(proc_gen == proc_gen_p9);
 
+	/*
+	 * Emit an error if we get a newer version. This is an interim measure
+	 * until the new version format is finalised.
+	 */
+	ahdr = HDIF_get_idata(hdr, idata_index, &size);
+	if (!ahdr || !size)
+		return -1;
+
+	/*
+	 * Some hostboots don't correctly fill the version field. On these
+	 * the offset from the start of the header to the start of the array
+	 * is 16 bytes.
+	 */
+	if (be32_to_cpu(ahdr->hdr.offset) == 16) {
+		version = 1;
+		prerror("I2C: HDAT device array has no version! Assuming v1\n");
+	} else {
+		version = be32_to_cpu(hdr->version);
+	}
+
+	if (version != 1) {
+		prerror("I2C: HDAT version %d not supported! THIS IS A BUG\n",
+			version);
+		return -1;
+	}
+
 	count = HDIF_get_iarray_size(hdr, idata_index);
 	for (i = 0; i < count; i++) {
 		dev = HDIF_get_iarray_item(hdr, idata_index, i, &size);