stm32f7: Add I²C driver. With fast mode!

1 files changed, 38 insertions, 0 deletions

diff --git a/src/arch/stm32f746zg-nucleo/driver/i2c.cc b/src/arch/stm32f746zg-nucleo/driver/i2c.cc
new file mode 100644
index 0000000..035f273
--- /dev/null
+++ b/src/arch/stm32f746zg-nucleo/driver/i2c.cc
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2024 Birte Kristina Friesel
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+#include "driver/i2c.h"
+#include "arch.h"
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/i2c.h>
+
+signed char I2C::setup()
+{
+
+	rcc_periph_clock_enable(RCC_I2C1);
+	gpio_set_af(GPIOB, GPIO_AF4, GPIO8 | GPIO9);
+	gpio_set_output_options(GPIOB, GPIO_OTYPE_OD, GPIO_OSPEED_2MHZ, GPIO8|GPIO9);
+	gpio_mode_setup(GPIOB, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO8 | GPIO9);
+	i2c_peripheral_disable(I2C1);
+#ifdef CONFIG_arch_stm32f746zg_nucleo_driver_i2c_fast_mode
+	i2c_set_speed(I2C1, i2c_speed_fm_400k, rcc_apb1_frequency / 1000000);
+#else
+	i2c_set_speed(I2C1, i2c_speed_sm_100k, rcc_apb1_frequency / 1000000);
+#endif
+	i2c_peripheral_enable(I2C1);
+
+	return 0;
+}
+
+signed char I2C::xmit(unsigned char address,
+		unsigned char tx_len, unsigned char *tx_buf,
+		unsigned char rx_len, unsigned char *rx_buf)
+{
+	i2c_transfer7(I2C1, address, tx_buf, tx_len, rx_buf, rx_len);
+	return 0;
+}
+
+I2C i2c;