diff options
| author | Daniel Friesel <derf@finalrewind.org> | 2018-10-15 16:22:55 +0200 |
|---|---|---|
| committer | Daniel Friesel <derf@finalrewind.org> | 2018-10-15 16:22:55 +0200 |
| commit | 5471509e033abcddb078383cc4656af06c265ce6 (patch) | |
| tree | 09a49d487135932793e06b748892bed1ffb37120 /src/driver | |
| parent | 2c1afc394913da7cb4823d72f3a11fbc43c9595e (diff) | |
Enable busy waiting in I2C driver to reach selected I2C clock
Diffstat (limited to 'src/driver')
| -rw-r--r-- | src/driver/soft_i2c.cc | 30 |
1 files changed, 18 insertions, 12 deletions
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) { |