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>

diff --git a/drivers/iio/dac/ad5686-spi.c b/drivers/iio/dac/ad5686-spi.c
index 6bb09e9259e63b8c1a6df1b8c7baefc1f773aa7d..1df9143f55e986af3b3549cfecd7accc455b65f8 100644 (file)
--- a/drivers/iio/dac/ad5686-spi.c
+++ b/drivers/iio/dac/ad5686-spi.c
@@ -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);
-
-       st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
-                                     AD5686_ADDR(addr) |
-                                     val);
-
-       return spi_write(spi, &st->data[0].d8[1], 3);
+       u8 tx_len, *buf;
+
+       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, 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 */

diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c
index 1fc0c564220976b8b89a81ef205a18aa07bb49c0..e136f0fd38f04ee7e6d0a2875f2ed9b89aab2e03 100644 (file)
--- a/drivers/iio/dac/ad5686.c
+++ b/drivers/iio/dac/ad5686.c
@@ -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;

diff --git a/drivers/iio/dac/ad5686.h b/drivers/iio/dac/ad5686.h
index 6c6879db60e4820b6cdcb0bee7857949addd0492..d05cda9f1edd77eef2cdc33d224e3ae5eabbe82e 100644 (file)
--- a/drivers/iio/dac/ad5686.h
+++ b/drivers/iio/dac/ad5686.h
@@ -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
 };