atsamd: Enable chipid as usb serial number

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 45 insertions, 0 deletions

diff --git a/src/atsamd/chipid.c b/src/atsamd/chipid.c
new file mode 100644
index 00000000..a4e378bc
--- /dev/null
+++ b/src/atsamd/chipid.c
@@ -0,0 +1,45 @@
+// Support for extracting the hardware chip id on atsamd
+//
+// Copyright (C) 2019  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "autoconf.h" // CONFIG_USB_SERIAL_NUMBER_CHIPID
+#include "generic/usb_cdc.h" // usb_fill_serial
+#include "generic/usbstd.h" // usb_string_descriptor
+#include "sched.h" // DECL_INIT
+
+#define CHIP_UID_LEN 16
+
+static struct {
+    struct usb_string_descriptor desc;
+    uint16_t data[CHIP_UID_LEN * 2];
+} cdc_chipid;
+
+struct usb_string_descriptor *
+usbserial_get_serialid(void)
+{
+   return &cdc_chipid.desc;
+}
+
+void
+chipid_init(void)
+{
+    if (!CONFIG_USB_SERIAL_NUMBER_CHIPID)
+        return;
+
+    uint32_t id[4];
+    if (CONFIG_MACH_SAMD21) {
+        id[0] = *(uint32_t*)0x0080A00C;
+        id[1] = *(uint32_t*)0x0080A040;
+        id[2] = *(uint32_t*)0x0080A044;
+        id[3] = *(uint32_t*)0x0080A048;
+    } else {
+        id[0] = *(uint32_t*)0x008061FC;
+        id[1] = *(uint32_t*)0x00806010;
+        id[2] = *(uint32_t*)0x00806014;
+        id[3] = *(uint32_t*)0x00806018;
+    }
+    usb_fill_serial(&cdc_chipid.desc, ARRAY_SIZE(cdc_chipid.data), id);
+}
+DECL_INIT(chipid_init);