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iio:dac:ad5686: Add AD5681R/AD5682R/AD5683/AD5683R support 

The AD5681R/AD5682R/AD5683/AD5683R are a family of one channel DACs with
12-bit, 14-bit and 16-bit precision respectively. The devices have either
no built-in reference, or built-in 2.5V reference.

These devices are similar to AD5691R/AD5692R/AD5693/AD5693R except
with a few notable differences:
 * they use the SPI interface instead of I2C
 * in the write control register, DB18 and DB17 are used for setting the
   power mode, while DB16 is the REF bit. This is why a new regmap type
   was defined and checked accordingly.
 * the shift register is 24 bits wide, the first four bits are the command
   bits followed by the data bits. As the data comprises of 20-bit, 18-bit
   or 16-bit input code, this means that 4 LSB bits are don't care. This is
   why the data needs to be shifted on the left with four bits. Therefore,
   AD5683_REGMAP is checked inside a switch case in the ad5686_spi_write()
   function. On the other hand, similar devices such as AD5693R family,
   have the 4 MSB command bits followed by 4 don't care bits.

Datasheet:
http://www.analog.com/media/en/technical-documentation/data-sheets/AD5683R_5682R_5681R_5683.pdf

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
hifive-unleashed-5.1
Stefan Popa 2018-05-18 18:23:34 +03:00 committed by Jonathan Cameron
parent be1b24d245
commit 1dbae4c6cd
3 changed files with 72 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
drivers/iio/dac/ad5686-spi.c
View File

@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* AD5672R, AD5676, AD5676R, AD5684, AD5684R, AD5684R, AD5685R, AD5686, AD5686R
* AD5672R, AD5676, AD5676R, AD5681R, AD5682R, AD5683, AD5683R,
* AD5684, AD5684R, AD5685R, AD5686, AD5686R
* Digital to analog converters driver
*
* Copyright 2018 Analog Devices Inc.
@ -15,12 +16,27 @@ static int ad5686_spi_write(struct ad5686_state *st,
u8 cmd, u8 addr, u16 val)
{
struct spi_device *spi = to_spi_device(st->dev);
u8 tx_len, *buf;
st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
AD5686_ADDR(addr) |
val);
switch (st->chip_info->regmap_type) {
case AD5683_REGMAP:
st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
AD5683_DATA(val));
buf = &st->data[0].d8[1];
tx_len = 3;
break;
case AD5686_REGMAP:
st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
AD5686_ADDR(addr) |
val);
buf = &st->data[0].d8[1];
tx_len = 3;
break;
default:
return -EINVAL;
}
return spi_write(spi, &st->data[0].d8[1], 3);
return spi_write(spi, buf, tx_len);
}
static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
@ -37,9 +53,15 @@ static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
},
};
struct spi_device *spi = to_spi_device(st->dev);
u8 cmd = 0;
int ret;
st->data[0].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_READBACK_ENABLE) |
if (st->chip_info->regmap_type == AD5686_REGMAP)
cmd = AD5686_CMD_READBACK_ENABLE;
else if (st->chip_info->regmap_type == AD5683_REGMAP)
cmd = AD5686_CMD_READBACK_ENABLE_V2;
st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
AD5686_ADDR(addr));
st->data[1].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_NOOP));
@ -67,6 +89,10 @@ static const struct spi_device_id ad5686_spi_id[] = {
{"ad5672r", ID_AD5672R},
{"ad5676", ID_AD5676},
{"ad5676r", ID_AD5676R},
{"ad5681r", ID_AD5681R},
{"ad5682r", ID_AD5682R},
{"ad5683", ID_AD5683},
{"ad5683r", ID_AD5683R},
{"ad5684", ID_AD5684},
{"ad5684r", ID_AD5684R},
{"ad5685", ID_AD5685R}, /* Does not exist */

32
drivers/iio/dac/ad5686.c
View File

@ -83,6 +83,10 @@ static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
st->pwr_down_mask &= ~(0x3 << (chan->channel * 2));
switch (st->chip_info->regmap_type) {
case AD5683_REGMAP:
shift = 13;
ref_bit_msk = AD5683_REF_BIT_MSK;
break;
case AD5686_REGMAP:
shift = 0;
ref_bit_msk = 0;
@ -256,6 +260,29 @@ static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {
.num_channels = 8,
.regmap_type = AD5686_REGMAP,
},
[ID_AD5681R] = {
.channels = ad5691r_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5683_REGMAP,
},
[ID_AD5682R] = {
.channels = ad5692r_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5683_REGMAP,
},
[ID_AD5683] = {
.channels = ad5693_channels,
.num_channels = 1,
.regmap_type = AD5683_REGMAP,
},
[ID_AD5683R] = {
.channels = ad5693_channels,
.int_vref_mv = 2500,
.num_channels = 1,
.regmap_type = AD5683_REGMAP,
},
[ID_AD5684] = {
.channels = ad5684_channels,
.num_channels = 4,
@ -385,6 +412,11 @@ int ad5686_probe(struct device *dev,
indio_dev->num_channels = st->chip_info->num_channels;
switch (st->chip_info->regmap_type) {
case AD5683_REGMAP:
cmd = AD5686_CMD_CONTROL_REG;
ref_bit_msk = AD5683_REF_BIT_MSK;
st->use_internal_vref = !voltage_uv;
break;
case AD5686_REGMAP:
cmd = AD5686_CMD_INTERNAL_REFER_SETUP;
ref_bit_msk = 0;

8
drivers/iio/dac/ad5686.h
View File

@ -13,6 +13,7 @@
#include <linux/mutex.h>
#include <linux/kernel.h>
#define AD5683_DATA(x) ((x) << 4)
#define AD5686_ADDR(x) ((x) << 16)
#define AD5686_CMD(x) ((x) << 20)
@ -36,6 +37,8 @@
#define AD5686_LDAC_PWRDN_3STATE 0x3
#define AD5686_CMD_CONTROL_REG 0x4
#define AD5686_CMD_READBACK_ENABLE_V2 0x5
#define AD5683_REF_BIT_MSK BIT(12)
#define AD5693_REF_BIT_MSK BIT(12)
/**
@ -47,6 +50,10 @@ enum ad5686_supported_device_ids {
ID_AD5675R,
ID_AD5676,
ID_AD5676R,
ID_AD5681R,
ID_AD5682R,
ID_AD5683,
ID_AD5683R,
ID_AD5684,
ID_AD5684R,
ID_AD5685R,
@ -64,6 +71,7 @@ enum ad5686_supported_device_ids {
};
enum ad5686_regmap_type {
AD5683_REGMAP,
AD5686_REGMAP,
AD5693_REGMAP
};