soc: qcom: wcnss_ctrl: Allow reading firmware-name from DT

The WLAN NV firmware blob differs between platforms, and possibly
devices, so add support in the wcnss_ctrl driver for reading the path of
this file from DT in order to allow these files to live in a generic
file system (or linux-firmware).

The new property is optional and the code falls back to the old filename
if the property isn't specified.
Tested-by: NBryan O'Donoghue <bryan.odonoghue@linaro.org>
Tested-by: NAníbal Limón <anibal.limon@linaro.org>
Link: https://lore.kernel.org/r/20210312003318.3273536-5-bjorn.andersson@linaro.orgSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

drivers/soc/qcom/wcnss_ctrl.c

@@ -200,6 +200,7 @@ static int wcnss_download_nv(struct wcnss_ctrl *wcnss, bool *expect_cbc)
 	struct wcnss_download_nv_req *req;
 	const struct firmware *fw;
 	struct device *dev = wcnss->dev;
+	const char *nvbin = NVBIN_FILE;
 	const void *data;
 	ssize_t left;
 	int ret;
@@ -208,10 +209,13 @@ static int wcnss_download_nv(struct wcnss_ctrl *wcnss, bool *expect_cbc)
 	if (!req)
 		return -ENOMEM;
 
-	ret = request_firmware(&fw, NVBIN_FILE, dev);
+	ret = of_property_read_string(dev->of_node, "firmware-name", &nvbin);
+	if (ret < 0 && ret != -EINVAL)
+		goto free_req;
+
+	ret = request_firmware(&fw, nvbin, dev);
 	if (ret < 0) {
-		dev_err(dev, "Failed to load nv file %s: %d\n",
-			NVBIN_FILE, ret);
+		dev_err(dev, "Failed to load nv file %s: %d\n", nvbin, ret);
 		goto free_req;
 	}