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efm32/i2c: make sure 16-bit register access is done in big endian

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This commit is contained in:
Federico Pellegrin 2019-05-29 11:29:11 +02:00
parent 1779abafb5
commit 617124792c
1 changed files with 17 additions and 2 deletions
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19
cpu/efm32/periph/i2c.c
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@ -22,6 +22,7 @@
#include "cpu.h"
#include "mutex.h"
#include "byteorder.h"
#include "periph_conf.h"
#include "periph/i2c.h"
@ -183,16 +184,23 @@ int i2c_read_bytes(i2c_t dev, uint16_t address, void *data, size_t length, uint8
int i2c_read_regs(i2c_t dev, uint16_t address, uint16_t reg,
void *data, size_t length, uint8_t flags)
{
uint16_t reg_end = reg;
if (flags & (I2C_NOSTART | I2C_NOSTOP)) {
return -EOPNOTSUPP;
}
/* Handle endianess of register if 16 bit */
if (flags & I2C_REG16) {
reg_end = htons(reg); /* Make sure register is in big-endian on I2C bus */
}
/* prepare transfer */
I2C_TransferSeq_TypeDef transfer;
transfer.addr = (address << 1);
transfer.flags = I2C_FLAG_WRITE_READ | ((flags & I2C_ADDR10) ? I2C_FLAG_10BIT_ADDR : 0);
transfer.buf[0].data = (uint8_t *) &reg;
transfer.buf[0].data = (uint8_t *) &reg_end;
transfer.buf[0].len = (flags & I2C_REG16) ? 2 : 1;
transfer.buf[1].data = (uint8_t *) data;
transfer.buf[1].len = length;
@ -222,16 +230,23 @@ int i2c_write_bytes(i2c_t dev, uint16_t address, const void *data, size_t length
int i2c_write_regs(i2c_t dev, uint16_t address, uint16_t reg,
const void *data, size_t length, uint8_t flags)
{
uint16_t reg_end = reg;
if (flags & (I2C_NOSTART | I2C_NOSTOP)) {
return -EOPNOTSUPP;
}
/* Handle endianess of register if 16 bit */
if (flags & I2C_REG16) {
reg_end = htons(reg); /* Make sure register is in big-endian on I2C bus */
}
/* prepare transfer */
I2C_TransferSeq_TypeDef transfer;
transfer.addr = (address << 1);
transfer.flags = I2C_FLAG_WRITE_WRITE | ((flags & I2C_ADDR10) ? I2C_FLAG_10BIT_ADDR : 0);
transfer.buf[0].data = (uint8_t *) &reg;
transfer.buf[0].data = (uint8_t *) &reg_end;
transfer.buf[0].len = (flags & I2C_REG16) ? 2 : 1;
transfer.buf[1].data = (uint8_t *) data;
transfer.buf[1].len = length;