tree 746e4100952bb5582e107ed6ba814e00dc899b59
parent ad0f65cd55b88f2e4d49968f9d5aba26fe3e8c1c
author Jean-Francois Dagenais <jeff.dagenais@gmail.com> 1551905766 -0500
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1556350536 +0200

iio: dac: mcp4725: add missing powerdown bits in store eeprom

commit 06003531502d06bc89d32528f6ec96bf978790f9 upstream.

When issuing the write DAC register and write eeprom command, the two
powerdown bits (PD0 and PD1) are assumed by the chip to be present in
the bytes sent. Leaving them at 0 implies "powerdown disabled" which is
a different state that the current one. By adding the current state of
the powerdown in the i2c write, the chip will correctly power-on exactly
like as it is at the moment of store_eeprom call.

This is documented in MCP4725's datasheet, FIGURE 6-2: "Write Commands
for DAC Input Register and EEPROM" and MCP4726's datasheet, FIGURE 6-3:
"Write All Memory Command".

Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Acked-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>