[PATCH v7 2/7] iio: dac: ad5686: refactor command/data macros
From: Rodrigo Alencar via B4 Relay
Date: Fri Jul 10 2026 - 07:24:02 EST
From: Rodrigo Alencar <rodrigo.alencar@xxxxxxxxxx>
Replace usage of bit shifting macros for FIELD_PREP(), which would not
ignore bit masking when preparing SPI/I2C commands. This change is a code
hardening measure to be paired with the upcoming triggered buffer support.
For the AD5310 regmap case, 16-bit data coming from the buffer may overlap
with command bits if the data field is unmasked.
*_REF_BIT_MSK and *_PD_MSK bit position macros are renamed (with a DATA
prefix) so to indicate that they are relative to the DATA field.
Reported-by: sashiko-bot@xxxxxxxxxx
Link: https://lore.kernel.org/all/20260628143026.EC6CA1F000E9@xxxxxxxxxxxxxxx/#t
Signed-off-by: Rodrigo Alencar <rodrigo.alencar@xxxxxxxxxx>
---
drivers/iio/dac/ad5686-spi.c | 21 +++++++++++----------
drivers/iio/dac/ad5686.c | 10 +++++-----
drivers/iio/dac/ad5686.h | 22 ++++++++++++----------
drivers/iio/dac/ad5696-i2c.c | 11 ++++++-----
4 files changed, 34 insertions(+), 30 deletions(-)
diff --git a/drivers/iio/dac/ad5686-spi.c b/drivers/iio/dac/ad5686-spi.c
index 6b6ef1d7071f..d3b64b4361d5 100644
--- a/drivers/iio/dac/ad5686-spi.c
+++ b/drivers/iio/dac/ad5686-spi.c
@@ -9,6 +9,7 @@
*/
#include <linux/array_size.h>
+#include <linux/bitfield.h>
#include <linux/errno.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
@@ -26,21 +27,21 @@ static int ad5686_spi_write(struct ad5686_state *st,
switch (st->chip_info->regmap_type) {
case AD5310_REGMAP:
- st->data[0].d16 = cpu_to_be16(AD5310_CMD(cmd) |
- val);
+ st->data[0].d16 = cpu_to_be16(FIELD_PREP(AD5310_CMD_MSK, cmd) |
+ FIELD_PREP(AD5310_DATA_MSK, val));
buf = &st->data[0].d8[0];
tx_len = 2;
break;
case AD5683_REGMAP:
- st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
- AD5683_DATA(val));
+ st->data[0].d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, cmd) |
+ FIELD_PREP(AD5683_DATA_MSK, 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);
+ st->data[0].d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, cmd) |
+ FIELD_PREP(AD5686_ADDR_MSK, addr) |
+ FIELD_PREP(AD5686_DATA_MSK, val));
buf = &st->data[0].d8[1];
tx_len = 3;
break;
@@ -81,9 +82,9 @@ static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
return -EINVAL;
}
- 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));
+ st->data[0].d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, cmd) |
+ FIELD_PREP(AD5686_ADDR_MSK, addr));
+ st->data[1].d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, AD5686_CMD_NOOP));
ret = spi_sync_transfer(spi, t, ARRAY_SIZE(t));
if (ret < 0)
diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c
index 713fe71ad1e7..120dd095dd2e 100644
--- a/drivers/iio/dac/ad5686.c
+++ b/drivers/iio/dac/ad5686.c
@@ -35,8 +35,8 @@ static int ad5310_control_sync(struct ad5686_state *st)
unsigned int pd_val = st->pwr_down_mask & st->pwr_down_mode;
return ad5686_write(st, AD5686_CMD_CONTROL_REG, 0,
- FIELD_PREP(AD5310_PD_MSK, pd_val & AD5686_PD_MSK) |
- FIELD_PREP(AD5310_REF_BIT_MSK, st->use_internal_vref ? 0 : 1));
+ FIELD_PREP(AD5310_DATA_PD_MSK, pd_val & AD5686_PD_MSK) |
+ FIELD_PREP(AD5310_DATA_REF_MSK, st->use_internal_vref ? 0 : 1));
}
static int ad5683_control_sync(struct ad5686_state *st)
@@ -44,8 +44,8 @@ static int ad5683_control_sync(struct ad5686_state *st)
unsigned int pd_val = st->pwr_down_mask & st->pwr_down_mode;
return ad5686_write(st, AD5686_CMD_CONTROL_REG, 0,
- FIELD_PREP(AD5683_PD_MSK, pd_val & AD5686_PD_MSK) |
- FIELD_PREP(AD5683_REF_BIT_MSK, st->use_internal_vref ? 0 : 1));
+ FIELD_PREP(AD5683_DATA_PD_MSK, pd_val & AD5686_PD_MSK) |
+ FIELD_PREP(AD5683_DATA_REF_MSK, st->use_internal_vref ? 0 : 1));
}
static inline unsigned int ad5686_pd_mask_shift(const struct iio_chan_spec *chan)
@@ -562,7 +562,7 @@ int ad5686_probe(struct device *dev,
break;
case AD5686_REGMAP:
ret = ad5686_write(st, AD5686_CMD_INTERNAL_REFER_SETUP, 0,
- st->use_internal_vref ? 0 : AD5686_REF_BIT_MSK);
+ st->use_internal_vref ? 0 : AD5686_DATA_REF_MSK);
if (ret)
return ret;
break;
diff --git a/drivers/iio/dac/ad5686.h b/drivers/iio/dac/ad5686.h
index c424720f8f72..32cb3931413c 100644
--- a/drivers/iio/dac/ad5686.h
+++ b/drivers/iio/dac/ad5686.h
@@ -14,12 +14,14 @@
#include <linux/iio/iio.h>
-#define AD5310_CMD(x) ((x) << 12)
+#define AD5310_CMD_MSK GENMASK(15, 12)
+#define AD5310_DATA_MSK GENMASK(11, 0)
-#define AD5683_DATA(x) ((x) << 4)
+#define AD5683_DATA_MSK GENMASK(19, 4)
-#define AD5686_ADDR(x) ((x) << 16)
-#define AD5686_CMD(x) ((x) << 20)
+#define AD5686_CMD_MSK GENMASK(23, 20)
+#define AD5686_ADDR_MSK GENMASK(19, 16)
+#define AD5686_DATA_MSK GENMASK(15, 0)
#define AD5686_ADDR_DAC(chan) (0x1 << (chan))
#define AD5686_ADDR_ALL_DAC 0xF
@@ -38,15 +40,15 @@
#define AD5686_CMD_CONTROL_REG 0x4
#define AD5686_CMD_READBACK_ENABLE_V2 0x5
-#define AD5310_REF_BIT_MSK BIT(8)
-#define AD5310_PD_MSK GENMASK(10, 9)
+#define AD5310_DATA_REF_MSK BIT(8)
+#define AD5310_DATA_PD_MSK GENMASK(10, 9)
-#define AD5683_REF_BIT_MSK BIT(12)
-#define AD5683_PD_MSK GENMASK(14, 13)
+#define AD5683_DATA_REF_MSK BIT(12) /* DB16 */
+#define AD5683_DATA_PD_MSK GENMASK(14, 13) /* DB18:DB17 */
+
+#define AD5686_DATA_REF_MSK BIT(0)
-#define AD5686_REF_BIT_MSK BIT(0)
#define AD5686_PD_MSK GENMASK(1, 0)
-
#define AD5686_PD_MODE_1K_TO_GND 0x1
#define AD5686_PD_MODE_100K_TO_GND 0x2
#define AD5686_PD_MODE_THREE_STATE 0x3
diff --git a/drivers/iio/dac/ad5696-i2c.c b/drivers/iio/dac/ad5696-i2c.c
index 6f726e6301a6..73dcd2e6f51b 100644
--- a/drivers/iio/dac/ad5696-i2c.c
+++ b/drivers/iio/dac/ad5696-i2c.c
@@ -7,6 +7,7 @@
* Copyright 2018 Analog Devices Inc.
*/
+#include <linux/bitfield.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/mod_devicetable.h>
@@ -35,9 +36,8 @@ static int ad5686_i2c_read(struct ad5686_state *st, u8 addr)
};
int ret;
- st->data[0].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_NOOP) |
- AD5686_ADDR(addr) |
- 0x00);
+ st->data[0].d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, AD5686_CMD_NOOP) |
+ FIELD_PREP(AD5686_ADDR_MSK, addr));
ret = i2c_transfer(i2c->adapter, msg, 2);
if (ret != 2)
@@ -52,8 +52,9 @@ static int ad5686_i2c_write(struct ad5686_state *st,
struct i2c_client *i2c = to_i2c_client(st->dev);
int ret;
- st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) | AD5686_ADDR(addr)
- | val);
+ st->data[0].d32 = cpu_to_be32(FIELD_PREP(AD5686_CMD_MSK, cmd) |
+ FIELD_PREP(AD5686_ADDR_MSK, addr) |
+ FIELD_PREP(AD5686_DATA_MSK, val));
ret = i2c_master_send(i2c, &st->data[0].d8[1], 3);
if (ret < 0)
--
2.43.0