From 8f6efe5a7b8a830b6cd17b7c378fc4f2fa92f069 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Mon, 25 Nov 2019 00:25:57 -0500
Subject: [PATCH] stm32: Enable chipid as usb serial number

Signed-off-by: Matt Baker <baker.matt.j@gmail.com>
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 docs/Config_Changes.md |  6 +++---
 src/stm32/Kconfig      |  1 +
 src/stm32/Makefile     |  2 +-
 src/stm32/chipid.c     | 33 +++++++++++++++++++++++++++++++++
 4 files changed, 38 insertions(+), 4 deletions(-)
 create mode 100644 src/stm32/chipid.c

diff --git a/docs/Config_Changes.md b/docs/Config_Changes.md
index f2a5c3c9..7b53b194 100644
--- a/docs/Config_Changes.md
+++ b/docs/Config_Changes.md
@@ -6,9 +6,9 @@ All dates in this document are approximate.
 
 # Changes
 
-20191121: The USB name has changed on lpc176x.  It now uses the unique
-chip id by default.  Update the "serial" setting in the "mcu" config
-section accordingly.
+20191124: The USB names have changed on lpc176x and stm32.  They now
+use the unique chip id by default.  Update the "serial" setting in the
+"mcu" config section accordingly.
 
 20191121: The pressure_advance_lookahead_time parameter has been
 removed.  See example.cfg for alternate configuration settings.
diff --git a/src/stm32/Kconfig b/src/stm32/Kconfig
index 00ec72cd..bf1391b6 100644
--- a/src/stm32/Kconfig
+++ b/src/stm32/Kconfig
@@ -10,6 +10,7 @@ config STM32_SELECT
     select HAVE_GPIO_I2C
     select HAVE_GPIO_SPI
     select HAVE_GPIO_BITBANGING
+    select HAVE_CHIPID
 
 config BOARD_DIRECTORY
     string
diff --git a/src/stm32/Makefile b/src/stm32/Makefile
index c2511ee9..3a063402 100644
--- a/src/stm32/Makefile
+++ b/src/stm32/Makefile
@@ -37,7 +37,7 @@ src-$(CONFIG_MACH_STM32F4) += stm32/adc.c stm32/i2c.c
 src-$(CONFIG_HAVE_GPIO_SPI) += stm32/spi.c
 usb-src-$(CONFIG_HAVE_STM32_USBFS) := stm32/usbfs.c
 usb-src-$(CONFIG_HAVE_STM32_USBOTG) := stm32/usbotg.c
-src-$(CONFIG_USBSERIAL) += $(usb-src-y) generic/usb_cdc.c
+src-$(CONFIG_USBSERIAL) += $(usb-src-y) stm32/chipid.c generic/usb_cdc.c
 serial-src-y := stm32/serial.c
 serial-src-$(CONFIG_MACH_STM32F0) := stm32/stm32f0_serial.c
 src-$(CONFIG_SERIAL) += $(serial-src-y) generic/serial_irq.c
diff --git a/src/stm32/chipid.c b/src/stm32/chipid.c
new file mode 100644
index 00000000..73e27503
--- /dev/null
+++ b/src/stm32/chipid.c
@@ -0,0 +1,33 @@
+// Support for extracting the hardware chip id on stm32
+//
+// Copyright (C) 2019  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "generic/usb_cdc.h" // usb_fill_serial
+#include "generic/usbstd.h" // usb_string_descriptor
+#include "internal.h" // UID_BASE
+#include "sched.h" // DECL_INIT
+
+#define CHIP_UID_LEN 12
+
+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;
+    usb_fill_serial(&cdc_chipid.desc, ARRAY_SIZE(cdc_chipid.data)
+                    , (void*)UID_BASE);
+}
+DECL_INIT(chipid_init);