diff options
| -rw-r--r-- | chip/stm32/i2c.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/chip/stm32/i2c.c b/chip/stm32/i2c.c index b42f415273..e2f1a9fbd8 100644 --- a/chip/stm32/i2c.c +++ b/chip/stm32/i2c.c @@ -21,6 +21,9 @@ #define CPUTS(outstr) cputs(CC_I2C, outstr) #define CPRINTF(format, args...) cprintf(CC_I2C, format, ## args) +/* Maximum transfer of a SMBUS block transfer */ +#define SMBUS_MAX_BLOCK 32 + /* 8-bit I2C slave address */ #define I2C_ADDRESS 0x3c @@ -919,10 +922,23 @@ int i2c_write8(int port, int slave_addr, int offset, int data) int i2c_read_string(int port, int slave_addr, int offset, uint8_t *data, int len) { - /* TODO: implement i2c_read_block and i2c_read_string */ + int rv; + uint8_t reg, block_length; + uint8_t buffer[SMBUS_MAX_BLOCK + 1]; + + if ((len <= 0) || (len > SMBUS_MAX_BLOCK)) + return EC_ERROR_INVAL; + + reg = offset; + rv = i2c_xfer(port, slave_addr, ®, 1, buffer, SMBUS_MAX_BLOCK + 1); + if (rv) + return rv; + + /* the length of the block is the first byte of the returned buffer */ + block_length = MIN(buffer[0], len - 1); + buffer[block_length + 1] = 0; - if (len && data) - *data = 0; + memcpy(data, buffer+1, block_length + 1); return EC_SUCCESS; } |