stm32: Add low-level hardware I2C slave driver.

1 files changed, 60 insertions, 0 deletions

diff --git a/ports/stm32/i2cslave.h b/ports/stm32/i2cslave.h
new file mode 100644
index 000000000..ac35c0cc8
--- /dev/null
+++ b/ports/stm32/i2cslave.h
@@ -0,0 +1,60 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef MICROPY_INCLUDED_STM32_I2CSLAVE_H
+#define MICROPY_INCLUDED_STM32_I2CSLAVE_H
+
+#include STM32_HAL_H
+
+typedef I2C_TypeDef i2c_slave_t;
+
+void i2c_slave_init_helper(i2c_slave_t *i2c, int addr);
+
+static inline void i2c_slave_init(i2c_slave_t *i2c, int irqn, int irq_pri, int addr) {
+    int en_bit = RCC_APB1ENR_I2C1EN_Pos + ((uintptr_t)i2c - I2C1_BASE) / (I2C2_BASE - I2C1_BASE);
+    RCC->APB1ENR |= 1 << en_bit;
+    volatile uint32_t tmp = RCC->APB1ENR; // Delay after enabling clock
+    (void)tmp;
+
+    i2c_slave_init_helper(i2c, addr);
+
+    NVIC_SetPriority(irqn, irq_pri);
+    NVIC_EnableIRQ(irqn);
+}
+
+static inline void i2c_slave_shutdown(i2c_slave_t *i2c, int irqn) {
+    i2c->CR1 = 0;
+    NVIC_DisableIRQ(irqn);
+}
+
+void i2c_slave_ev_irq_handler(i2c_slave_t *i2c);
+
+// These should be provided externally
+int i2c_slave_process_addr_match(int rw);
+int i2c_slave_process_rx_byte(uint8_t val);
+void i2c_slave_process_rx_end(void);
+uint8_t i2c_slave_process_tx_byte(void);
+
+#endif // MICROPY_INCLUDED_STM32_I2CSLAVE_H