Re: [PATCH v4 2/2] iio: dac: driver for MCP4821

From: Jonathan Cameron
Date: Wed Dec 20 2023 - 09:49:15 EST


On Tue, 19 Dec 2023 14:32:51 +0530
Anshul Dalal <anshulusr@xxxxxxxxx> wrote:

> Adds driver for the MCP48xx series of DACs.
>
> Device uses a simplex SPI channel. To set the value of an output channel,
> a 16-bit data of following format must be written:
>
> Bit field | Description
> 15 [MSB] | Channel selection bit
> 0 -> Channel A
> 1 -> Channel B
> 13 | Output Gain Selection bit
> 0 -> 2x Gain (Vref = 4.096V)
> 1 -> 1x Gain (Vref = 2.048V)
> 12 | Output Shutdown Control bit
> 0 -> Shutdown the selected channel
> 1 -> Active mode operation
> 11-0 [LSB]| DAC Input Data bits
> Value's big endian representation is taken as input for the
> selected DAC channel. For devices with a resolution of less
> than 12-bits, only the x most significant bits are considered
> where x is the resolution of the device.
> Reference: Page#22 [MCP48x2 Datasheet]
>
> Supported devices:
> +---------+--------------+-------------+
> | Device | Resolution | Channels |
> |---------|--------------|-------------|
> | MCP4801 | 8-bit | 1 |
> | MCP4802 | 8-bit | 2 |
> | MCP4811 | 10-bit | 1 |
> | MCP4812 | 10-bit | 2 |
> | MCP4821 | 12-bit | 1 |
> | MCP4822 | 12-bit | 2 |
> +---------+--------------+-------------+
>
> Devices tested:
> MCP4821 [12-bit single channel]
> MCP4802 [8-bit dual channel]
>
> Tested on Raspberry Pi Zero 2W
>
> Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/22244B.pdf #MCP48x1
> Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/20002249B.pdf #MCP48x2
> Signed-off-by: Anshul Dalal <anshulusr@xxxxxxxxx>
>
> ---
>
> Changes for v3,4:
> - no updates
Comments were on v2 from me.