fel: Add fel_readl_n() and fel_writel_n() wrappers

These functions solve the problem that large readl/writel
transfers might be limited by insufficient (scratch) buffer
size. To solve this, chunks of no more than LCODE_MAX_WORDS
get transferred individually.
Signed-off-by: Bernhard Nortmann <bernhard.nortmann@web.de>

fel.c

@@ -550,6 +550,22 @@ uint32_t aw_fel_readl(libusb_device_handle *usb, uint32_t addr)
 	return val;
 }
 
+/*
+ * aw_fel_readl_n() wrapper that can handle large transfers. If necessary,
+ * those will be done in separate 'chunks' of no more than LCODE_MAX_WORDS.
+ */
+void fel_readl_n(libusb_device_handle *usb, uint32_t addr,
+		 uint32_t *dst, size_t count)
+{
+	while (count > 0) {
+		size_t n = count > LCODE_MAX_WORDS ? LCODE_MAX_WORDS : count;
+		aw_fel_readl_n(usb, addr, dst, n);
+		addr += n * sizeof(uint32_t);
+		dst += n;
+		count -= n;
+	}
+}
+
 /* multiple "writel" from a source buffer to sequential addresses */
 void aw_fel_writel_n(libusb_device_handle *usb, uint32_t addr,
 		     uint32_t *src, size_t count)
@@ -601,6 +617,22 @@ void aw_fel_writel(libusb_device_handle *usb, uint32_t addr, uint32_t val)
 	aw_fel_writel_n(usb, addr, &val, 1);
 }
 
+/*
+ * aw_fel_writel_n() wrapper that can handle large transfers. If necessary,
+ * those will be done in separate 'chunks' of no more than LCODE_MAX_WORDS.
+ */
+void fel_writel_n(libusb_device_handle *usb, uint32_t addr,
+		  uint32_t *src, size_t count)
+{
+	while (count > 0) {
+		size_t n = count > LCODE_MAX_WORDS ? LCODE_MAX_WORDS : count;
+		aw_fel_writel_n(usb, addr, src, n);
+		addr += n * sizeof(uint32_t);
+		src += n;
+		count -= n;
+	}
+}
+
 void aw_fel_print_sid(libusb_device_handle *usb)
 {
 	soc_info_t *soc_info = aw_fel_get_soc_info(usb);