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stm32_common/i2c_2: Fix repeated read condition

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Fix the condition to return -ENOPNOTSUPP when i2c repeated read attempted.
Currently the error occures even if a read after write is attempted.
This is the standard way to i2c_read_reg which should be supported.
The -EOPNOTSUPP requires the previous R/W state to be reading.
This means a `I2C_SR2_TRA` must be checked to be 0.
This commit is contained in:
MrKevinWeiss 2019-10-25 10:19:14 +02:00
parent 789cbb9a79
commit df19d33b77
1 changed files with 7 additions and 2 deletions
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9
cpu/stm32_common/periph/i2c_2.c
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@ -218,8 +218,13 @@ int i2c_read_bytes(i2c_t dev, uint16_t address, void *data, size_t length,
I2C_TypeDef *i2c = i2c_config[dev].dev;
DEBUG("[i2c] read_bytes: Starting\n");
/* Do not support repeated start reading */
if ((i2c->SR2 & I2C_SR2_BUSY) && !(flags & I2C_NOSTART)) {
/* Do not support repeated start reading
* The repeated start read requires the bus to be busy (I2C_SR2_BUSY == 1)
* the previous R/W state to be a read (I2C_SR2_TRA == 0)
* and for the command not to be split frame (I2C_NOSTART == 0)
*/
if (((i2c->SR2 & (I2C_SR2_BUSY | I2C_SR2_TRA)) == I2C_SR2_BUSY) &&
!(flags & I2C_NOSTART)) {
return -EOPNOTSUPP;
}
int ret = _start(i2c, (address << 1) | I2C_FLAG_READ, flags, length);