brcmfmac: support parse country code map from DT

With any regulatory domain requests coming from either user space or
802.11 IE (Information Element), the country is coded in ISO3166
standard.  It needs to be translated to firmware country code and
revision with the mapping info in settings->country_codes table.
Support populate country_codes table by parsing the mapping from DT.

The BRCMF_BUSTYPE_SDIO bus_type check gets separated from general DT
validation, so that country code can be handled as general part rather
than SDIO bus specific one.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210417075428.2671-1-shawn.guo@linaro.org

drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c

@@ -12,12 +12,59 @@
 #include "common.h"
 #include "of.h"
 
+static int brcmf_of_get_country_codes(struct device *dev,
+				      struct brcmf_mp_device *settings)
+{
+	struct device_node *np = dev->of_node;
+	struct brcmfmac_pd_cc_entry *cce;
+	struct brcmfmac_pd_cc *cc;
+	int count;
+	int i;
+
+	count = of_property_count_strings(np, "brcm,ccode-map");
+	if (count < 0) {
+		/* The property is optional, so return success if it doesn't
+		 * exist. Otherwise propagate the error code.
+		 */
+		return (count == -EINVAL) ? 0 : count;
+	}
+
+	cc = devm_kzalloc(dev, sizeof(*cc) + count * sizeof(*cce), GFP_KERNEL);
+	if (!cc)
+		return -ENOMEM;
+
+	cc->table_size = count;
+
+	for (i = 0; i < count; i++) {
+		const char *map;
+
+		cce = &cc->table[i];
+
+		if (of_property_read_string_index(np, "brcm,ccode-map",
+						  i, &map))
+			continue;
+
+		/* String format e.g. US-Q2-86 */
+		if (sscanf(map, "%2c-%2c-%d", cce->iso3166, cce->cc,
+			   &cce->rev) != 3)
+			brcmf_err("failed to read country map %s\n", map);
+		else
+			brcmf_dbg(INFO, "%s-%s-%d\n", cce->iso3166, cce->cc,
+				  cce->rev);
+	}
+
+	settings->country_codes = cc;
+
+	return 0;
+}
+
 void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
 		    struct brcmf_mp_device *settings)
 {
 	struct brcmfmac_sdio_pd *sdio = &settings->bus.sdio;
 	struct device_node *root, *np = dev->of_node;
 	int irq;
+	int err;
 	u32 irqf;
 	u32 val;
 
@@ -43,8 +90,14 @@ void brcmf_of_probe(struct device *dev, enum brcmf_bus_type bus_type,
 		of_node_put(root);
 	}
 
-	if (!np || bus_type != BRCMF_BUSTYPE_SDIO ||
-	    !of_device_is_compatible(np, "brcm,bcm4329-fmac"))
+	if (!np || !of_device_is_compatible(np, "brcm,bcm4329-fmac"))
+		return;
+
+	err = brcmf_of_get_country_codes(dev, settings);
+	if (err)
+		brcmf_err("failed to get OF country code map (err=%d)\n", err);
+
+	if (bus_type != BRCMF_BUSTYPE_SDIO)
 		return;
 
 	if (of_property_read_u32(np, "brcm,drive-strength", &val) == 0)