brcmfmac: Add support for first trying to get a board specific nvram file

The nvram files which some brcmfmac chips need are board-specific. To be
able to distribute these as part of linux-firmware, so that devices with
such a wifi chip will work OOTB, multiple (one per board) versions must
co-exist under /lib/firmware.

This commit adds support for callers of the brcmfmac/firmware.c code to
pass in a board_type parameter through the request structure.

If that parameter is set then the code will first try to load
chipmodel.board_type.txt before falling back to the old chipmodel.txt name.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

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

@@ -532,6 +532,31 @@ static int brcmf_fw_complete_request(const struct firmware *fw,
 	return (cur->flags & BRCMF_FW_REQF_OPTIONAL) ? 0 : ret;
 }
 
+static int brcmf_fw_request_firmware(const struct firmware **fw,
+				     struct brcmf_fw *fwctx)
+{
+	struct brcmf_fw_item *cur = &fwctx->req->items[fwctx->curpos];
+	int ret;
+
+	/* nvram files are board-specific, first try a board-specific path */
+	if (cur->type == BRCMF_FW_TYPE_NVRAM && fwctx->req->board_type) {
+		char alt_path[BRCMF_FW_NAME_LEN];
+
+		strlcpy(alt_path, cur->path, BRCMF_FW_NAME_LEN);
+		/* strip .txt at the end */
+		alt_path[strlen(alt_path) - 4] = 0;
+		strlcat(alt_path, ".", BRCMF_FW_NAME_LEN);
+		strlcat(alt_path, fwctx->req->board_type, BRCMF_FW_NAME_LEN);
+		strlcat(alt_path, ".txt", BRCMF_FW_NAME_LEN);
+
+		ret = request_firmware(fw, alt_path, fwctx->dev);
+		if (ret == 0)
+			return ret;
+	}
+
+	return request_firmware(fw, cur->path, fwctx->dev);
+}
+
 static void brcmf_fw_request_done(const struct firmware *fw, void *ctx)
 {
 	struct brcmf_fw *fwctx = ctx;
@@ -544,7 +569,7 @@ static void brcmf_fw_request_done(const struct firmware *fw, void *ctx)
 
 	while (ret == 0 && ++fwctx->curpos < fwctx->req->n_items) {
 		cur = &fwctx->req->items[fwctx->curpos];
-		request_firmware(&fw, cur->path, fwctx->dev);
+		brcmf_fw_request_firmware(&fw, fwctx);
 		ret = brcmf_fw_complete_request(fw, ctx);
 	}
 

drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.h

@@ -70,6 +70,7 @@ struct brcmf_fw_request {
 	u16 domain_nr;
 	u16 bus_nr;
 	u32 n_items;
+	const char *board_type;
 	struct brcmf_fw_item items[0];
 };