From 5471509e033abcddb078383cc4656af06c265ce6 Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Mon, 15 Oct 2018 16:22:55 +0200
Subject: [PATCH] Enable busy waiting in I2C driver to reach selected I2C clock
---
include/arch.h | 4 ++--
src/arch/arduino-nano/arch.cc | 4 ++--
src/arch/blinkenrocket/arch.cc | 4 ++--
src/arch/msp430fr5969lp/arch.cc | 8 ++++----
src/driver/soft_i2c.cc | 30 ++++++++++++++++++------------
5 files changed, 28 insertions(+), 22 deletions(-)
diff --git a/include/arch.h b/include/arch.h
index 8024818..094b230 100644
--- a/include/arch.h
+++ b/include/arch.h
@@ -10,8 +10,8 @@ class Arch {
void setup();
void idle_loop();
void idle();
- void delay_us(unsigned char const us);
- void delay_ms(unsigned char const ms);
+ void delay_us(unsigned int const us);
+ void delay_ms(unsigned int const ms);
};
extern Arch arch;
diff --git a/src/arch/arduino-nano/arch.cc b/src/arch/arduino-nano/arch.cc
index 3009637..b034348 100644
--- a/src/arch/arduino-nano/arch.cc
+++ b/src/arch/arduino-nano/arch.cc
@@ -67,12 +67,12 @@ void Arch::idle(void)
asm("wdr");
}
-void Arch::delay_us(unsigned char const us)
+void Arch::delay_us(unsigned int const us)
{
_delay_us(us);
}
-void Arch::delay_ms(unsigned char const ms)
+void Arch::delay_ms(unsigned int const ms)
{
_delay_ms(ms);
}
diff --git a/src/arch/blinkenrocket/arch.cc b/src/arch/blinkenrocket/arch.cc
index 8042679..1261515 100644
--- a/src/arch/blinkenrocket/arch.cc
+++ b/src/arch/blinkenrocket/arch.cc
@@ -64,12 +64,12 @@ void Arch::idle(void)
asm("wdr");
}
-void Arch::delay_us(unsigned char const us)
+void Arch::delay_us(unsigned int const us)
{
_delay_us(us);
}
-void Arch::delay_ms(unsigned char const ms)
+void Arch::delay_ms(unsigned int const ms)
{
_delay_ms(ms);
}
diff --git a/src/arch/msp430fr5969lp/arch.cc b/src/arch/msp430fr5969lp/arch.cc
index b475c5f..b5b23b6 100644
--- a/src/arch/msp430fr5969lp/arch.cc
+++ b/src/arch/msp430fr5969lp/arch.cc
@@ -93,15 +93,15 @@ extern void loop();
volatile char run_loop = 0;
#endif
-void Arch::delay_us(unsigned char const us)
+void Arch::delay_us(unsigned int const us)
{
- for (int i = 0; i < us/10; i++) {
+ for (unsigned int i = 0; i < us/10; i++) {
__delay_cycles(160);
}
}
-void Arch::delay_ms(unsigned char const ms)
+void Arch::delay_ms(unsigned int const ms)
{
- for (int i = 0; i < ms; i++) {
+ for (unsigned int i = 0; i < ms; i++) {
__delay_cycles(16000);
}
}
diff --git a/src/driver/soft_i2c.cc b/src/driver/soft_i2c.cc
index e69bd2c..39754a3 100644
--- a/src/driver/soft_i2c.cc
+++ b/src/driver/soft_i2c.cc
@@ -27,6 +27,12 @@
#ifndef SOFTI2C_TIMER
+#if F_I2C < 50000
+#define I2C_WAIT arch.delay_us((500000UL / F_I2C) - 10)
+#else
+#define I2C_WAIT
+#endif
+
signed char SoftI2C::setup()
{
SDA_HIGH;
@@ -38,20 +44,20 @@ void SoftI2C::start()
{
SDA_HIGH;
SCL_HIGH;
- //
+ I2C_WAIT;
SDA_LOW;
- //
+ I2C_WAIT;
SCL_LOW;
}
void SoftI2C::stop()
{
SCL_LOW;
- //
+ I2C_WAIT;
SDA_LOW;
- //
+ I2C_WAIT;
SCL_HIGH;
- //
+ I2C_WAIT;
SDA_HIGH;
}
@@ -65,17 +71,17 @@ bool SoftI2C::tx(unsigned char byte)
SDA_LOW;
}
byte <<= 1;
- //
+ I2C_WAIT;
SCL_HIGH;
while (!gpio.read(scl)) ;
- //
+ I2C_WAIT;
if (i == 8) {
if (!gpio.read(sda)) {
got_ack = 1;
}
}
SCL_LOW;
- //
+ I2C_WAIT;
}
return got_ack;
}
@@ -85,16 +91,16 @@ unsigned char SoftI2C::rx(bool send_ack)
unsigned char byte = 0;
SDA_HIGH;
for (unsigned char i = 0; i <= 8; i++) {
- //
+ I2C_WAIT;
SCL_HIGH;
while (!gpio.read(scl)) ;
- //
+ I2C_WAIT;
if ((i < 8) && gpio.read(sda)) {
byte |= 1 << (7 - i);
}
- //
+ I2C_WAIT;
SCL_LOW;
- //
+ I2C_WAIT;
if ((i == 7) && send_ack) {
SDA_LOW;
} else if ((i == 8) && send_ack) {
--
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