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| author | Dr. Matthew Swabey <matthew@swabey.org> | 2023-03-21 15:02:58 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-03-21 15:02:58 -0400 |
| commit | 2466b7a2c6544fb585acb47871c75f2816629a2b (patch) | |
| tree | 911cc498f71e26e891373161aaca2e6b2d003293 /src/avr/i2c.c | |
| parent | e2d7c59812ef192c1d495b6702cb5f56271118a8 (diff) | |
| download | kutter-2466b7a2c6544fb585acb47871c75f2816629a2b.tar.gz kutter-2466b7a2c6544fb585acb47871c75f2816629a2b.tar.xz kutter-2466b7a2c6544fb585acb47871c75f2816629a2b.zip | |
avr: Allow I2C bus speed to be set by Klipper (#6111)
Allow I2C bus speed to be set by appropriate Klipper commands.
Signed-off-by: Matthew Swabey <matthew@swabey.org>
Diffstat (limited to 'src/avr/i2c.c')
| -rw-r--r-- | src/avr/i2c.c | 36 |
1 files changed, 16 insertions, 20 deletions
diff --git a/src/avr/i2c.c b/src/avr/i2c.c index 370582cc..658a30a1 100644 --- a/src/avr/i2c.c +++ b/src/avr/i2c.c @@ -27,31 +27,27 @@ static const uint8_t SCL = GPIO('D', 0), SDA = GPIO('D', 1); DECL_CONSTANT_STR("BUS_PINS_twi", "PD0,PD1"); #endif -static void -i2c_init(void) -{ - if (TWCR & (1<<TWEN)) - // Already setup - return; - - // Setup output pins and enable pullups - gpio_out_setup(SDA, 1); - gpio_out_setup(SCL, 1); - - // Set 100Khz frequency - TWSR = 0; - TWBR = ((CONFIG_CLOCK_FREQ / 100000) - 16) / 2; - - // Enable interface - TWCR = (1<<TWEN); -} - struct i2c_config i2c_setup(uint32_t bus, uint32_t rate, uint8_t addr) { if (bus) shutdown("Unsupported i2c bus"); - i2c_init(); + + if (!(TWCR & (1<<TWEN))) { + // Setup output pins and enable pullups + gpio_out_setup(SDA, 1); + gpio_out_setup(SCL, 1); + + // Set frequency avoiding pulling in integer divide + TWSR = 0; + if (rate >= 400000) + TWBR = ((CONFIG_CLOCK_FREQ / 400000) - 16) / 2; + else + TWBR = ((CONFIG_CLOCK_FREQ / 100000) - 16) / 2; + + // Enable interface + TWCR = (1<<TWEN); + } return (struct i2c_config){ .addr=addr<<1 }; } |