ihex: request_ihex_firmware() function to load and validate firmware

Provide a helper to load the file and validate it in one call, to
simplify error handling in the drivers which are going to use it.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

include/linux/ihex.h

@@ -9,6 +9,7 @@
 
 #include <linux/types.h>
 #include <linux/firmware.h>
+#include <linux/device.h>
 
 /* Intel HEX files actually limit the length to 256 bytes, but we have
    drivers which would benefit from using separate records which are
@@ -47,4 +48,27 @@ static inline int ihex_validate_fw(const struct firmware *fw)
 	}
 	return -EINVAL;
 }
+
+/* Request firmware and validate it so that we can trust we won't
+ * run off the end while reading records... */
+static inline int request_ihex_firmware(const struct firmware **fw,
+					const char *fw_name,
+					struct device *dev)
+{
+	const struct firmware *lfw;
+	int ret;
+
+	ret = request_firmware(&lfw, fw_name, dev);
+	if (ret)
+		return ret;
+	ret = ihex_validate_fw(lfw);
+	if (ret) {
+		dev_err(dev, "Firmware \"%s\" not valid IHEX records\n",
+			fw_name);
+		release_firmware(lfw);
+		return ret;
+	}
+	*fw = lfw;
+	return 0;
+}
 #endif /* __LINUX_IHEX_H__ */