From: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
To: Rodrigo Alencar via B4 Relay
<devnull+rodrigo.alencar.analog.com@kernel.org>
Cc: rodrigo.alencar@analog.com,
Michael Auchter <michael.auchter@ni.com>,
linux@analog.com, linux-iio@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org,
Michael Hennerich <Michael.Hennerich@analog.com>,
David Lechner <dlechner@baylibre.com>,
Andy Shevchenko <andy@kernel.org>, Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
Kees Cook <kees@kernel.org>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
sashiko-bot@kernel.org
Subject: Re: [PATCH v8 3/8] iio: dac: ad5686: refactor command/data macros
Date: Sun, 19 Jul 2026 00:59:18 +0100 [thread overview]
Message-ID: <20260719005918.1e58ebf4@jic23-huawei> (raw)
In-Reply-To: <20260716-ad5686-new-features-v8-3-ebb0051af5e5@analog.com>
On Thu, 16 Jul 2026 13:14:19 +0100
Rodrigo Alencar via B4 Relay <devnull+rodrigo.alencar.analog.com@kernel.org> wrote:
> From: Rodrigo Alencar <rodrigo.alencar@analog.com>
>
> 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@kernel.org
> Closes: https://lore.kernel.org/all/20260628143026.EC6CA1F000E9@smtp.kernel.org/
> Reviewed-by: David Lechner <dlechner@baylibre.com>
> Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
Some fuzz when applying this due at least partly to crossing with various
header cleanup related series. Please check I didn't mess it up!
Thanks,
Jonathan
> ---
> 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 d34250647aa4..c285aeed44d1 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)
> @@ -565,7 +565,7 @@ 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 551b200bfe14..2c95d394a1c0 100644
> --- a/drivers/iio/dac/ad5696-i2c.c
> +++ b/drivers/iio/dac/ad5696-i2c.c
> @@ -8,6 +8,7 @@
> */
>
> #include <linux/array_size.h>
> +#include <linux/bitfield.h>
> #include <linux/errno.h>
> #include <linux/i2c.h>
> #include <linux/mod_devicetable.h>
> @@ -36,9 +37,8 @@ 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, ARRAY_SIZE(msg));
> if (ret < 0)
> @@ -55,8 +55,9 @@ 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)
>
next prev parent reply other threads:[~2026-07-18 23:59 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-16 12:14 [PATCH v8 0/8] New features for the AD5686 IIO driver Rodrigo Alencar via B4 Relay
2026-07-16 12:14 ` [PATCH v8 1/8] iio: dac: ad5696: properly check i2c_transfer() return value Rodrigo Alencar via B4 Relay
2026-07-16 12:28 ` sashiko-bot
2026-07-18 23:40 ` Jonathan Cameron
2026-07-16 12:14 ` [PATCH v8 2/8] iio: dac: ad5686: missing NULL check on match data Rodrigo Alencar via B4 Relay
2026-07-16 12:27 ` sashiko-bot
2026-07-16 13:05 ` Joshua Crofts
2026-07-16 18:42 ` Andy Shevchenko
2026-07-16 19:08 ` Joshua Crofts
2026-07-17 6:51 ` Rodrigo Alencar
2026-07-17 8:15 ` Andy Shevchenko
2026-07-17 9:31 ` Rodrigo Alencar
2026-07-17 10:28 ` Andy Shevchenko
2026-07-18 23:55 ` Jonathan Cameron
2026-07-19 0:09 ` Jonathan Cameron
2026-07-19 8:50 ` Andy Shevchenko
2026-07-16 12:14 ` [PATCH v8 3/8] iio: dac: ad5686: refactor command/data macros Rodrigo Alencar via B4 Relay
2026-07-18 23:46 ` Jonathan Cameron
2026-07-18 23:59 ` Jonathan Cameron [this message]
2026-07-16 12:14 ` [PATCH v8 4/8] iio: dac: ad5686: introduce sync operation Rodrigo Alencar via B4 Relay
2026-07-16 12:14 ` [PATCH v8 5/8] iio: dac: ad5686: implement new sync() op for the spi bus Rodrigo Alencar via B4 Relay
2026-07-16 12:32 ` sashiko-bot
2026-07-16 12:14 ` [PATCH v8 6/8] iio: dac: ad5686: read_raw/write_raw: use guard(mutex)() Rodrigo Alencar via B4 Relay
2026-07-16 12:14 ` [PATCH v8 7/8] iio: dac: ad5686: add triggered buffer support Rodrigo Alencar via B4 Relay
2026-07-16 12:14 ` [PATCH v8 8/8] iio: dac: ad5686: add gain control support Rodrigo Alencar via B4 Relay
2026-07-19 0:15 ` [PATCH v8 0/8] New features for the AD5686 IIO driver Jonathan Cameron
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