diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-imx.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index db895fb22e65..886217f1ba61 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -462,6 +462,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) { int i, result; unsigned int temp; + int block_data = msgs->flags & I2C_M_RECV_LEN; dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n", @@ -481,7 +482,12 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) /* setup bus to read data */ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); temp &= ~I2CR_MTX; - if (msgs->len - 1) + + /* + * Reset the I2CR_TXAK flag initially for SMBus block read since the + * length is unknown + */ + if ((msgs->len - 1) || block_data) temp &= ~I2CR_TXAK; imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */ @@ -490,9 +496,24 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) /* read data */ for (i = 0; i < msgs->len; i++) { + u8 len = 0; result = i2c_imx_trx_complete(i2c_imx); if (result) return result; + /* + * First byte is the length of remaining packet + * in the SMBus block data read. Add it to + * msgs->len. + */ + if ((!i) && block_data) { + len = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX)) + return -EPROTO; + dev_dbg(&i2c_imx->adapter.dev, + "<%s> read length: 0x%X\n", + __func__, len); + msgs->len += len; + } if (i == (msgs->len - 1)) { /* It must generate STOP before read I2DR to prevent controller from generating another clock cycle */ @@ -510,7 +531,10 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) temp |= I2CR_TXAK; imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); } - msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + if ((!i) && block_data) + msgs->buf[0] = len; + else + msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); dev_dbg(&i2c_imx->adapter.dev, "<%s> read byte: B%d=0x%X\n", __func__, i, msgs->buf[i]); @@ -583,7 +607,8 @@ fail0: static u32 i2c_imx_func(struct i2c_adapter *adapter) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL + | I2C_FUNC_SMBUS_READ_BLOCK_DATA; } static struct i2c_algorithm i2c_imx_algo = { |