Add code to talk with the external RTC chip.

1 files changed, 62 insertions, 0 deletions

diff --git a/stm-rtc.h b/stm-rtc.h
new file mode 100644
index 0000000..edbed9d
--- /dev/null
+++ b/stm-rtc.h
@@ -0,0 +1,62 @@
+/*
+ * stm-rtc.h
+ * ---------
+ * Functions and defines to use the externally connected RTC chip.
+ *
+ * Copyright (c) 2015-2016, NORDUnet A/S All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the NORDUnet nor the names of its contributors may
+ *   be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __STM32_RTC_H
+#define __STM32_RTC_H
+
+#include "stm32f4xx_hal.h"
+
+extern I2C_HandleTypeDef hi2c_rtc;
+
+extern HAL_StatusTypeDef rtc_device_ready(uint16_t i2c_addr);
+extern HAL_StatusTypeDef rtc_enable_oscillator();
+extern HAL_StatusTypeDef rtc_send_byte(const uint16_t i2c_addr, const uint8_t value, const uint16_t timeout);
+extern HAL_StatusTypeDef rtc_read_bytes (const uint16_t i2c_addr, uint8_t *buf, const uint8_t len, const uint16_t timeout);
+
+#define RTC_RTC_ADDR			0xdf
+#define RTC_EEPROM_ADDR			0xaf
+
+#define RTC_RTC_ADDR_W			RTC_RTC_ADDR ^ 1	/* turn off LSB to write */
+#define RTC_EEPROM_ADDR_W		RTC_EEPROM_ADDR ^ 1	/* turn off LSB to write */
+
+#define RTC_SRAM_TOTAL_BYTES		0x5f
+#define RTC_EEPROM_TOTAL_BYTES		0x7f
+
+#define RTC_EEPROM_EUI48_OFFSET		0xf0
+#define RTC_EEPROM_EUI48_BYTES		8
+
+#define RTC_TIME_OFFSET			0x0  /* Time is at offest 0 in SRAM */
+#define RTC_TIME_BYTES			8
+
+#endif /* __STM32_RTC_H */