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periph/i2c: make sure i2c registers is big-endian on all archs

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This commit is contained in:
Federico Pellegrin 2019-05-22 07:33:12 +02:00
parent f559ccb0c6
commit 1779abafb5
2 changed files with 20 additions and 3 deletions
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2
drivers/include/periph/i2c.h
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@ -195,7 +195,7 @@ typedef enum {
#ifndef HAVE_I2C_FLAGS_T #ifndef HAVE_I2C_FLAGS_T
typedef enum { typedef enum {
I2C_ADDR10 = 0x01, /**< use 10-bit device addressing */ I2C_ADDR10 = 0x01, /**< use 10-bit device addressing */
I2C_REG16 = 0x02, /**< use 16-bit register addressing */ I2C_REG16 = 0x02, /**< use 16-bit register addressing, big-endian */
I2C_NOSTOP = 0x04, /**< do not issue a STOP condition after transfer */ I2C_NOSTOP = 0x04, /**< do not issue a STOP condition after transfer */
I2C_NOSTART = 0x08, /**< skip START sequence, ignores address field */ I2C_NOSTART = 0x08, /**< skip START sequence, ignores address field */
} i2c_flags_t; } i2c_flags_t;

21
drivers/periph_common/i2c.c
View File

@ -22,6 +22,7 @@
#include "board.h" #include "board.h"
#include "cpu.h" #include "cpu.h"
#include "periph/i2c.h" #include "periph/i2c.h"
#include "byteorder.h"
#ifdef I2C_NUMOF #ifdef I2C_NUMOF
@ -37,11 +38,19 @@ int i2c_read_reg(i2c_t dev, uint16_t addr, uint16_t reg,
int i2c_read_regs(i2c_t dev, uint16_t addr, uint16_t reg, int i2c_read_regs(i2c_t dev, uint16_t addr, uint16_t reg,
void *data, size_t len, uint8_t flags) void *data, size_t len, uint8_t flags)
{ {
uint16_t reg_end = reg;
if (flags & (I2C_NOSTOP | I2C_NOSTART)) { if (flags & (I2C_NOSTOP | I2C_NOSTART)) {
return -EOPNOTSUPP; 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 */
}
/* First set ADDR and register with no stop */ /* First set ADDR and register with no stop */
int ret = i2c_write_bytes(dev, addr, &reg, (flags & I2C_REG16) ? 2 : 1, int ret = i2c_write_bytes(dev, addr, &reg_end, (flags & I2C_REG16) ? 2 : 1,
flags | I2C_NOSTOP); flags | I2C_NOSTOP);
if (ret < 0) { if (ret < 0) {
return ret; return ret;
@ -73,11 +82,19 @@ int i2c_write_reg(i2c_t dev, uint16_t addr, uint16_t reg,
int i2c_write_regs(i2c_t dev, uint16_t addr, uint16_t reg, int i2c_write_regs(i2c_t dev, uint16_t addr, uint16_t reg,
const void *data, size_t len, uint8_t flags) const void *data, size_t len, uint8_t flags)
{ {
uint16_t reg_end = reg;
if (flags & (I2C_NOSTOP | I2C_NOSTART)) { if (flags & (I2C_NOSTOP | I2C_NOSTART)) {
return -EOPNOTSUPP; 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 */
}
/* First set ADDR and register with no stop */ /* First set ADDR and register with no stop */
int ret = i2c_write_bytes(dev, addr, &reg, (flags & I2C_REG16) ? 2 : 1, int ret = i2c_write_bytes(dev, addr, &reg_end, (flags & I2C_REG16) ? 2 : 1,
flags | I2C_NOSTOP); flags | I2C_NOSTOP);
if (ret < 0) { if (ret < 0) {
return ret; return ret;