Add support for the I2C_M_STOP flag to the i2c-imx driver. This allows devices requiring a stop between messages to work with this controller.
Signed-off-by: Mans Rullgard <[email protected]> --- drivers/i2c/busses/i2c-imx.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 7bd409eaf0ac..a7f801bb5dc9 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -908,10 +908,17 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter, /* read/write data */ for (i = 0; i < num; i++) { - if (i == num - 1) - is_lastmsg = true; + if (is_lastmsg) { + /* previous message had I2C_M_STOP flag set */ + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + temp |= I2CR_MSTA; + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + result = i2c_imx_bus_busy(i2c_imx, 1); + if (result) + goto fail0; + } - if (i) { + if (i && !is_lastmsg) { dev_dbg(&i2c_imx->adapter.dev, "<%s> repeated start\n", __func__); temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); @@ -921,6 +928,10 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter, if (result) goto fail0; } + + if (i == num - 1 || (msgs[i].flags & I2C_M_STOP)) + is_lastmsg = true; + dev_dbg(&i2c_imx->adapter.dev, "<%s> transfer message: %d\n", __func__, i); /* write/read data */ @@ -948,6 +959,13 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter, result = i2c_imx_dma_write(i2c_imx, &msgs[i]); else result = i2c_imx_write(i2c_imx, &msgs[i]); + + if (msgs[i].flags & I2C_M_STOP) { + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + temp &= ~I2CR_MSTA; + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + i2c_imx_bus_busy(i2c_imx, 0); + } } if (result) goto fail0; @@ -1034,7 +1052,7 @@ static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx, static u32 i2c_imx_func(struct i2c_adapter *adapter) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL + return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_READ_BLOCK_DATA; } -- 2.22.0
