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cpu/sam0_common: i2c: allow arbitrary I2C frequencies

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The Atmel I2C peripheral supports arbitrary I2C frequencies.
Since the `i2c_speed_t` enum just encodes the raw frequency values,
we can just use them in the peripheral definition.

We just have to remove the switch-case block that will generate an error
for values outside of `i2c_speed_t`.
This commit is contained in:
Benjamin Valentin 2020-06-08 16:19:46 +02:00
parent 42eb044ec6
commit 7269dc4e3a
1 changed files with 5 additions and 12 deletions
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17
cpu/sam0_common/periph/i2c.c
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@ -125,23 +125,16 @@ void i2c_init(i2c_t dev)
/* Find and set baudrate. Read speed configuration. Set transfer
* speed: SERCOM_I2CM_CTRLA_SPEED(0): Standard-mode (Sm) up to 100
* kHz and Fast-mode (Fm) up to 400 kHz */
switch (i2c_config[dev].speed) {
case I2C_SPEED_NORMAL:
case I2C_SPEED_FAST:
bus(dev)->CTRLA.reg |= SERCOM_I2CM_CTRLA_SPEED(0);
break;
case I2C_SPEED_HIGH:
bus(dev)->CTRLA.reg |= SERCOM_I2CM_CTRLA_SPEED(2);
break;
default:
DEBUG("BAD BAUDRATE\n");
return;
if (i2c_config[dev].speed > I2C_SPEED_FAST) {
bus(dev)->CTRLA.reg |= SERCOM_I2CM_CTRLA_SPEED(2);
} else {
bus(dev)->CTRLA.reg |= SERCOM_I2CM_CTRLA_SPEED(0);
}
/* Get the baudrate */
tmp_baud = (int32_t)(((sam0_gclk_freq(i2c_config[dev].gclk_src) +
(2 * (i2c_config[dev].speed)) - 1) /
(2 * (i2c_config[dev].speed))) -
(i2c_config[dev].speed == I2C_SPEED_HIGH ? 1 : 5));
(i2c_config[dev].speed > I2C_SPEED_FAST ? 1 : 5));
/* Ensure baudrate is within limits */
if (tmp_baud < 255 && tmp_baud > 0) {
bus(dev)->BAUD.reg = SERCOM_I2CM_BAUD_BAUD(tmp_baud);