1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/arm/i2c_master.c b/drivers/arm/i2c_master.c
new file mode 100644
index 000000000..2fdd9f65e
--- /dev/null
+++ b/drivers/arm/i2c_master.c
@@ -0,0 +1,103 @@
+/* Copyright 2018 Jack Humbert
+ * Copyright 2018 Yiancar
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* This library follows the convention of the AVR i2c_master library.
+ * As a result addresses are expected to be already shifted (addr << 1).
+ * I2CD1 is the default driver which corresponds to pins B6 and B7. This
+ * can be changed.
+ * Please ensure that HAL_USE_I2C is TRUE in the halconf.h file and that
+ * STM32_I2C_USE_I2C1 is TRUE in the mcuconf.h file.
+ */
+
+#include "i2c_master.h"
+#include <string.h>
+#include <hal.h>
+
+static uint8_t i2c_address;
+
+// This configures the I2C clock to 400Mhz assuming a 72Mhz clock
+// For more info : https://www.st.com/en/embedded-software/stsw-stm32126.html
+static const I2CConfig i2cconfig = {
+  STM32_TIMINGR_PRESC(15U) |
+  STM32_TIMINGR_SCLDEL(4U) | STM32_TIMINGR_SDADEL(2U) |
+  STM32_TIMINGR_SCLH(15U)  | STM32_TIMINGR_SCLL(21U),
+  0,
+  0
+};
+
+void i2c_init(void)
+{
+  palSetGroupMode(GPIOB,6,7, PAL_MODE_INPUT);       // Try releasing special pins for a short time
+  chThdSleepMilliseconds(10);
+
+  palSetPadMode(GPIOB, 6, PAL_MODE_ALTERNATE(4) | PAL_STM32_OTYPE_OPENDRAIN | PAL_STM32_PUPDR_PULLUP);
+  palSetPadMode(GPIOB, 7, PAL_MODE_ALTERNATE(4) | PAL_STM32_OTYPE_OPENDRAIN | PAL_STM32_PUPDR_PULLUP);
+
+  //i2cInit(); //This is invoked by halInit() so no need to redo it.
+}
+
+// This is usually not needed
+uint8_t i2c_start(uint8_t address)
+{
+  i2c_address = address;
+  i2cStart(&I2C_DRIVER, &i2cconfig);
+  return 0;
+}
+
+uint8_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
+{
+  i2c_address = address;
+  i2cStart(&I2C_DRIVER, &i2cconfig);
+  return i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, 0, 0, MS2ST(timeout));
+}
+
+uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
+{
+  i2c_address = address;
+  i2cStart(&I2C_DRIVER, &i2cconfig);
+  return i2cMasterReceiveTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, MS2ST(timeout));
+}
+
+uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
+{
+  i2c_address = devaddr;
+  i2cStart(&I2C_DRIVER, &i2cconfig);
+
+  uint8_t complete_packet[length + 1];
+  for(uint8_t i = 0; i < length; i++)
+  {
+    complete_packet[i+1] = data[i];
+  }
+  complete_packet[0] = regaddr
+
+  return i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), complete_packet, length + 1, 0, 0, MS2ST(timeout));
+}
+
+uint8_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
+{
+  i2c_address = devaddr;
+  i2cStart(&I2C_DRIVER, &i2cconfig);
+  return i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), regaddr, 1, data, length, MS2ST(timeout));
+}
+
+// This is usually not needed. It releases the driver to allow pins to become GPIO again.
+uint8_t i2c_stop(uint16_t timeout)
+{
+  i2c_address = address;
+  i2cStop(&I2C_DRIVER);
+  return 0;
+}