From 917e6e0ab982f0794615bc4b16082400a5eadb58 Mon Sep 17 00:00:00 2001
From: deadprogram <ron@hybridgroup.com>
Date: Wed, 11 Oct 2023 21:26:09 +0200
Subject: [PATCH] machine/nrf: implement i2c.SetBaudRate()

Signed-off-by: deadprogram <ron@hybridgroup.com>
---
 src/machine/machine_nrf.go   | 25 ++++++++++++++++++++++++-
 src/machine/machine_nrf5x.go |  9 ---------
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/src/machine/machine_nrf.go b/src/machine/machine_nrf.go
index 1256319fe9..3b79e376a3 100644
--- a/src/machine/machine_nrf.go
+++ b/src/machine/machine_nrf.go
@@ -246,7 +246,30 @@ func (i2c *I2C) Configure(config I2CConfig) error {
 	i2c.setPins(config.SCL, config.SDA)
 
 	i2c.mode = config.Mode
-	i2c.Bus.ENABLE.Set(nrf.TWI_ENABLE_ENABLE_Enabled)
+	if i2c.mode == I2CModeController {
+		i2c.SetBaudRate(config.Frequency)
+
+		i2c.enableAsController()
+	} else {
+		i2c.enableAsTarget()
+	}
+
+	return nil
+}
+
+// SetBaudRate sets the I2C frequency. It has the side effect of also
+// enabling the I2C hardware if disabled beforehand.
+//
+//go:inline
+func (i2c *I2C) SetBaudRate(br uint32) error {
+	switch {
+	case br >= 400*KHz:
+		i2c.Bus.SetFREQUENCY(nrf.TWI_FREQUENCY_FREQUENCY_K400)
+	case br >= 250*KHz:
+		i2c.Bus.SetFREQUENCY(nrf.TWI_FREQUENCY_FREQUENCY_K250)
+	default:
+		i2c.Bus.SetFREQUENCY(nrf.TWI_FREQUENCY_FREQUENCY_K100)
+	}
 
 	return nil
 }
diff --git a/src/machine/machine_nrf5x.go b/src/machine/machine_nrf5x.go
index 3b22af7993..d8d2790343 100644
--- a/src/machine/machine_nrf5x.go
+++ b/src/machine/machine_nrf5x.go
@@ -31,15 +31,6 @@ func (i2c *I2C) disable() {
 	i2c.Bus.ENABLE.Set(0)
 }
 
-// SetBaudRate sets the I2C frequency. It has the side effect of also
-// enabling the I2C hardware if disabled beforehand.
-//
-//go:inline
-func (i2c *I2C) SetBaudRate(br uint32) error {
-	// TODO: implement
-	return nil
-}
-
 // Tx does a single I2C transaction at the specified address.
 // It clocks out the given address, writes the bytes in w, reads back len(r)
 // bytes and stores them in r, and generates a stop condition on the bus.