[PATCH v4 0/9] Refactor Microchip MCP47FEB02 I2C driver in separate modules to add support for MCP48FEB02 SPI driver

[PATCH v4 0/9] Refactor Microchip MCP47FEB02 I2C driver in separate modules to add support for MCP48FEB02 SPI driver

[Ariana Lazar]

Refactor I2C driver implementation into separate modules in order to add
support for SPI MCP48FxBy1/2/4/8 DAC family on top of the I2C implementation.
The I2C and SPI devices have the same memory map and supported
functionalities.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
---
Changes in v4:
- remove unused headers
- add missing header types.h in protocol files
- create 6 precursor commits before the refactor patch for handling:
    - comment typo
    - renaming command mask define
    - for an invalid label use a debug message instead of probe error
    - correct return value in store_eeprom_store() for false state case
    - correct channel gain formula
    - read DAC value register to initialize channel data struct field at
      probe 
- Link to v3: https://lore.kernel.org/r/20260804-mcp47feb02_refactor-v3-0-97f8b81f3628@microchip.com

Changes in v3:
- renumbering the patch version to include the first patch submision
- fix review comments device tree binding:
   - change 'additionalProperties' to unevaluatedProperties
   - add else branch with spi-max-frequency in the condition which checks
     if a device has SPI interface
   - correct SPI address example
   - add clock polarity and clock phase properties for SPI devices
   - enumerate I2C devices in lexicographic order from the description section
   - specify supported SPI modes using dependencies
- fix review comments driver:
   - remove unneccesarry libraries and add the missing ones
   - correct comment typo
   - return -ENODEV using dev_err_probe() in protocol probe functions
   - use named initializers
   - move defines for registers and enums from the header to the core file
   - add dev_set_drvdata() in probe()
   - move mutex aquiring from mcp47feb02_write_to_eeprom() to
     store_eeprom_store()
   - write correct value into Vref register in resume()
- Link to v2: https://lore.kernel.org/r/20260723-mcp47feb02_refactor-v1-0-ee59e63672bc@microchip.com

v2:
- include in the same patch series the refactoring of the driver and the
  support for SPI devices, but in different patches
- remove changes regarding review comments received not related to the
  code refactoring
- first version of the combined refactoring I2C and adding support for SPI
  driver
- Link to v1: https://lore.kernel.org/all/20260403-mcp47feb02-fix2-v1-1-da60c773550e@microchip.com

v1:
- first version which did not separate the refactoring and adding support for
  SPI devices (into different patches from the same series)

---
Ariana Lazar (9):
      iio: dac: mcp47feb02: initialize dac_data field in channel data struct at probe
      iio: dac: mcp47feb02: correct gain bitshift at probe
      iio: dac: mcp47feb02: correct false state case in store_eeprom_store
      iio: dac: mcp47feb02: use dev_dbg for invalid label
      iio: dac: mcp47feb02: correct typo from a comment
      iio: dac: mcp47feb02: rename command mask define
      iio: dac: mcp47feb02: refactor MCP47FEB02 I2C driver into two modules
      dt-bindings: iio: dac: add support for MCP48FEB02 SPI
      iio: dac: add support for Microchip MCP48FEB02

 .../bindings/iio/dac/microchip,mcp47feb02.yaml     | 221 ++++++++++---
 MAINTAINERS                                        |   5 +-
 drivers/iio/dac/Kconfig                            |  33 +-
 drivers/iio/dac/Makefile                           |   4 +-
 .../iio/dac/{mcp47feb02.c => mcp47feb02-core.c}    | 352 +++------------------
 drivers/iio/dac/mcp47feb02-i2c.c                   | 145 +++++++++
 drivers/iio/dac/mcp47feb02-spi.c                   | 145 +++++++++
 drivers/iio/dac/mcp47feb02.h                       |  46 +++
 8 files changed, 585 insertions(+), 366 deletions(-)
---
base-commit: 9c6acc6e6555d34198e45cb0d309569dfbadf929
change-id: 20260625-mcp47feb02_refactor-fa8420ae3282

Best regards,
-- 
Ariana Lazar <ariana.lazar@microchip.com>

[PATCH v4 1/9] iio: dac: mcp47feb02: initialize dac_data field in channel data struct at probe

[Ariana Lazar]

Read DAC value register to initialize corresponding field in channel_data
struct when the module is inserted.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
---
 drivers/iio/dac/mcp47feb02.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
index a823c2a673a26d70e5829cb587034da435af0451..7502959d98eab27941d58b6b961e6e3dee4222e6 100644
--- a/drivers/iio/dac/mcp47feb02.c
+++ b/drivers/iio/dac/mcp47feb02.c
@@ -1020,7 +1020,12 @@ static int mcp47feb02_init_ctrl_regs(struct mcp47feb02_data *data)
 	gain_ch = gain_ch & MCP47FEB02_GAIN_BITS_MASK;
 	for_each_set_bit(i, &data->active_channels_mask, data->phys_channels) {
 		struct device *dev = regmap_get_device(data->regmap);
-		unsigned int pd_tmp;
+		unsigned int pd_tmp, dac_val;
+
+		ret = regmap_read(data->regmap, REG_ADDR(i), &dac_val);
+		if (ret)
+			return ret;
+		data->chdata[i].dac_data = dac_val;
 
 		data->chdata[i].ref_mode = (vref_ch >> (2 * i)) & MCP47FEB02_DAC_CTRL_MASK;
 		data->chdata[i].use_2x_gain = (gain_ch >> i)  & MCP47FEB02_GAIN_BIT_MASK;

-- 
2.43.0

Re: [PATCH v4 1/9] iio: dac: mcp47feb02: initialize dac_data field in channel data struct at probe

[Andy Shevchenko]

On Wed, Aug 19, 2026 at 03:41:05PM +0300, Ariana Lazar wrote:
> Read DAC value register to initialize corresponding field in channel_data
> struct when the module is inserted.

Since we have a cache enabled for regmap, can we rather read back initial HW
values at the probe time for all non-volatile or precise registers?

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 2/9] iio: dac: mcp47feb02: correct gain bitshift at probe

[Ariana Lazar]

Correct the formula for initializing gain struct field for each channel
with the correct bits from Gain Register.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
---
 drivers/iio/dac/mcp47feb02.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
index 7502959d98eab27941d58b6b961e6e3dee4222e6..bf78618ac2c896b94e494a1ce76ef5b3e520f482 100644
--- a/drivers/iio/dac/mcp47feb02.c
+++ b/drivers/iio/dac/mcp47feb02.c
@@ -1017,7 +1017,6 @@ static int mcp47feb02_init_ctrl_regs(struct mcp47feb02_data *data)
 	if (ret)
 		return ret;
 
-	gain_ch = gain_ch & MCP47FEB02_GAIN_BITS_MASK;
 	for_each_set_bit(i, &data->active_channels_mask, data->phys_channels) {
 		struct device *dev = regmap_get_device(data->regmap);
 		unsigned int pd_tmp, dac_val;
@@ -1028,7 +1027,7 @@ static int mcp47feb02_init_ctrl_regs(struct mcp47feb02_data *data)
 		data->chdata[i].dac_data = dac_val;
 
 		data->chdata[i].ref_mode = (vref_ch >> (2 * i)) & MCP47FEB02_DAC_CTRL_MASK;
-		data->chdata[i].use_2x_gain = (gain_ch >> i)  & MCP47FEB02_GAIN_BIT_MASK;
+		data->chdata[i].use_2x_gain = (gain_ch & DAC_GAIN_MASK(i)) ? 1 : 0;
 
 		/*
 		 * Inform the user that the current voltage reference read from the volatile

-- 
2.43.0

Re: [PATCH v4 2/9] iio: dac: mcp47feb02: correct gain bitshift at probe

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:

Pre-existing issues:
- [High] System suspend and resume forcefully overwrite and lose the user-configured powerdown state.
- [High] System resume corrupts the VREF (voltage reference) configuration by overwriting it with the powerdown mode.
- [High] Sysfs store handler returns 0 on false state, potentially causing userspace infinite loops.
--

--- Patch [2]: [PATCH v4 2/9] iio: dac: mcp47feb02: correct gain bitshift at probe ---
commit f1be9d71af346cda91f297b65aff2d8b9c5d0198
Author: Ariana Lazar <ariana.lazar@microchip.com>

iio: dac: mcp47feb02: correct gain bitshift at probe

This commit corrects the formula for initializing the gain struct field
for each channel. It ensures the correct bits are extracted from the
Gain Register.

> diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
> index 7502959d98eab..bf78618ac2c89 100644
> --- a/drivers/iio/dac/mcp47feb02.c
> +++ b/drivers/iio/dac/mcp47feb02.c
> @@ -1017,7 +1017,6 @@ static int mcp47feb02_init_ctrl_regs(struct mcp47feb02_data *data)
>  	if (ret)
>  		return ret;
>  
> -	gain_ch = gain_ch & MCP47FEB02_GAIN_BITS_MASK;
>  	for_each_set_bit(i, &data->active_channels_mask, data->phys_channels) {
>  		struct device *dev = regmap_get_device(data->regmap);
>  		unsigned int pd_tmp, dac_val;
> @@ -1028,7 +1027,7 @@ static int mcp47feb02_init_ctrl_regs(struct mcp47feb02_data *data)
>  		data->chdata[i].dac_data = dac_val;
>  
>  		data->chdata[i].ref_mode = (vref_ch >> (2 * i)) & MCP47FEB02_DAC_CTRL_MASK;
> -		data->chdata[i].use_2x_gain = (gain_ch >> i)  & MCP47FEB02_GAIN_BIT_MASK;
> +		data->chdata[i].use_2x_gain = (gain_ch & DAC_GAIN_MASK(i)) ? 1 : 0;
>  
>  		/*
>  		 * Inform the user that the current voltage reference read from the volatile

While reviewing this patch, I noticed a few pre-existing issues in this file:

drivers/iio/dac/mcp47feb02.c:mcp47feb02_suspend() {
    ...
	for_each_set_bit(ch, &data->active_channels_mask, data->phys_channels) {
		u8 pd_mode;

		data->chdata[ch].powerdown = true;
    ...
}

drivers/iio/dac/mcp47feb02.c:mcp47feb02_resume() {
    ...
	for_each_set_bit(ch, &data->active_channels_mask, data->phys_channels) {
		u8 pd_mode;
		int ret;

		data->chdata[ch].powerdown = false;
    ...
		ret = regmap_update_bits(data->regmap, MCP47FEB02_POWER_DOWN_REG_ADDR,
					 DAC_CTRL_MASK(ch),
					 DAC_CTRL_VAL(ch, MCP47FEB02_NORMAL_OPERATION));
    ...
}

[Severity: High]
This isn't a bug introduced by this patch, but does system suspend and
resume forcefully overwrite and lose the user-configured powerdown state?

The state is blindly overwritten with true during suspend and false during
resume. The hardware is then unconditionally awakened, ignoring any prior
user configuration to keep the channel powered down.


drivers/iio/dac/mcp47feb02.c:mcp47feb02_resume() {
    ...
		pd_mode = data->chdata[ch].powerdown_mode + 1;

		ret = regmap_write(data->regmap, REG_ADDR(ch), data->chdata[ch].dac_data);
		if (ret)
			return ret;

		ret = regmap_update_bits(data->regmap, MCP47FEB02_VREF_REG_ADDR,
					 DAC_CTRL_MASK(ch), DAC_CTRL_VAL(ch, pd_mode));
    ...
}

[Severity: High]
This is a pre-existing issue, but does system resume corrupt the VREF
configuration by overwriting it with the powerdown mode?

The pd_mode variable appears to be mistakenly passed as the value for the
MCP47FEB02_VREF_REG_ADDR register instead of the correct reference mode.


drivers/iio/dac/mcp47feb02.c:store_eeprom_store() {
    ...
	ret = kstrtobool(buf, &state);
	if (ret)
		return ret;

	if (!state)
		return 0;
    ...
}

[Severity: High]
This isn't a bug introduced by this patch, but is it safe to return 0
here?

Returning 0 from a sysfs store handler instead of the length of the
written buffer can trick userspace tools into an infinite loop as they
repeatedly try to write the remaining bytes.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819-mcp47feb02_refactor-v4-0-beb2aa3bfd09@microchip.com?part=2

Re: [PATCH v4 2/9] iio: dac: mcp47feb02: correct gain bitshift at probe

[Andy Shevchenko]

On Wed, Aug 19, 2026 at 03:41:06PM +0300, Ariana Lazar wrote:
> Correct the formula for initializing gain struct field for each channel
> with the correct bits from Gain Register.

This needs more information, ideally with the reference to the datasheet.
For example, it's unclear what's wrong with the existing calculations.

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 3/9] iio: dac: mcp47feb02: correct false state case in store_eeprom_store

[Ariana Lazar]

Return len also when the state is false instead of 0.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
---
 drivers/iio/dac/mcp47feb02.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
index bf78618ac2c896b94e494a1ce76ef5b3e520f482..2ee981393aa1a2dc0bf65d25ab937132fe2e7bf1 100644
--- a/drivers/iio/dac/mcp47feb02.c
+++ b/drivers/iio/dac/mcp47feb02.c
@@ -469,7 +469,7 @@ static ssize_t store_eeprom_store(struct device *dev, struct device_attribute *a
 		return ret;
 
 	if (!state)
-		return 0;
+		return len;
 
 	/*
 	 * Verify DAC Wiper and DAC Configuration are unlocked. If both are disabled,

-- 
2.43.0

Re: [PATCH v4 3/9] iio: dac: mcp47feb02: correct false state case in store_eeprom_store

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 5 potential issue(s) to consider:

Pre-existing issues:
- [High] This problem wasn't introduced by this patch, but mcp47feb02_resume incorrectly writes the powerdown mode to the Voltage Reference (VREF) register, corrupting the channel's reference voltage setting.
- [High] This problem wasn't introduced by this patch, but mcp47feb02_suspend and mcp47feb02_resume overwrite the software powerdown state, causing all channels to be forcefully activated on resume regardless of user configuration.
- [High] This problem wasn't introduced by this patch, but mcp47feb02_init_ctrl_regs fails to identify the powerdown state when the hardware boots in '1kohm_to_gnd' mode.
- [High] This problem wasn't introduced by this patch, but store_eeprom_store performs a sequence of volatile register reads and EEPROM writes without holding the state mutex, leading to a TOCTOU race condition.
- [High] This problem wasn't introduced by this patch, but mcp47feb02_write_raw does not validate the incoming user value against bounds for IIO_CHAN_INFO_RAW.
--

--- Patch [3]: [PATCH v4 3/9] iio: dac: mcp47feb02: correct false state case in store_eeprom_store ---
commit dc6f30f8cc576f94a887f7f0e174caf833ebb683
Author: Ariana Lazar <ariana.lazar@microchip.com>

iio: dac: mcp47feb02: correct false state case in store_eeprom_store
    
Return len also when the state is false instead of 0.

> diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
> index bf78618ac2c89..2ee981393aa1a 100644
> --- a/drivers/iio/dac/mcp47feb02.c
> +++ b/drivers/iio/dac/mcp47feb02.c
> @@ -469,7 +469,7 @@ static ssize_t store_eeprom_store(struct device *dev, struct device_attribute *a
>  		return ret;
>  
>  	if (!state)
> -		return 0;
> +		return len;
>  
>  	/*
>  	 * Verify DAC Wiper and DAC Configuration are unlocked. If both are disabled,

[ ... ]

[Severity: High]
This isn't a bug introduced by this patch, but store_eeprom_store performs
a sequence of volatile register reads and EEPROM writes without holding the
state mutex, leading to a race condition with concurrent state modifications.

Can an inconsistent combination of driver states be written to the NV EEPROM
because the data->lock is not held across the snapshot sequence?

drivers/iio/dac/mcp47feb02.c:store_eeprom_store() {
    ...
    ret = mcp47feb02_write_to_eeprom(data, NV_REG_ADDR(i),
                                     data->chdata[i].dac_data);
    ...
}

[Severity: High]
This is a pre-existing issue, but mcp47feb02_resume incorrectly writes the
powerdown mode to the Voltage Reference (VREF) register, corrupting the
channel's reference voltage setting.

During system resume, does this corrupt the voltage reference configuration
because it targets MCP47FEB02_VREF_REG_ADDR instead of the powerdown register?

drivers/iio/dac/mcp47feb02.c:mcp47feb02_resume() {
    ...
    ret = regmap_update_bits(data->regmap, MCP47FEB02_VREF_REG_ADDR,
                             DAC_CTRL_MASK(ch), DAC_CTRL_VAL(ch, pd_mode));
    ...
}

[Severity: High]
This is a pre-existing issue, but mcp47feb02_suspend and mcp47feb02_resume
overwrite the software powerdown state, causing all channels to be forcefully
activated on resume regardless of user configuration.

Does this unconditionally wake the channel and destroy the user's previously
configured powerdown preference?

drivers/iio/dac/mcp47feb02.c:mcp47feb02_suspend() {
    ...
    data->chdata[ch].powerdown = true;
    ...
}

drivers/iio/dac/mcp47feb02.c:mcp47feb02_resume() {
    ...
    data->chdata[ch].powerdown = false;
    ...
}

[Severity: High]
This isn't a bug introduced by this patch, but mcp47feb02_init_ctrl_regs
fails to identify the powerdown state when the hardware boots in 1kohm_to_gnd
mode.

When pd_tmp is 1, powerdown_mode becomes 0. Does this cause the powerdown
check to evaluate to false even though the hardware is in a powerdown state?

drivers/iio/dac/mcp47feb02.c:mcp47feb02_init_ctrl_regs() {
    ...
    data->chdata[i].powerdown = !!(data->chdata[i].powerdown_mode);
    ...
}

[Severity: High]
This isn't a bug introduced by this patch, but mcp47feb02_write_raw does not
validate the incoming user value against bounds for IIO_CHAN_INFO_RAW.

Can out-of-bounds values be written directly to the DAC data registers since
the user-supplied value is not validated?

drivers/iio/dac/mcp47feb02.c:mcp47feb02_write_raw() {
    ...
    ret = regmap_write(data->regmap, REG_ADDR(ch->address), val);
    ...
}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819-mcp47feb02_refactor-v4-0-beb2aa3bfd09@microchip.com?part=3

Re: [PATCH v4 3/9] iio: dac: mcp47feb02: correct false state case in store_eeprom_store

[Andy Shevchenko]

On Wed, Aug 19, 2026 at 03:41:07PM +0300, Ariana Lazar wrote:
> Return len also when the state is false instead of 0.

Why? The main problem with your commit messages is that they answer to the Q
"what?" and not "why?". The latter is more important.

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 4/9] iio: dac: mcp47feb02: use dev_dbg for invalid label

[Ariana Lazar]

Correct unneccesarry probe error returned at an invalid label with a debug
message instead.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
---
 drivers/iio/dac/mcp47feb02.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
index 2ee981393aa1a2dc0bf65d25ab937132fe2e7bf1..e5533fa3c31c0006d170764791177879c1e794b0 100644
--- a/drivers/iio/dac/mcp47feb02.c
+++ b/drivers/iio/dac/mcp47feb02.c
@@ -15,6 +15,7 @@
 #include <linux/bits.h>
 #include <linux/bitfield.h>
 #include <linux/delay.h>
+#include <linux/dev_printk.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/iio/iio.h>
@@ -978,8 +979,7 @@ static int mcp47feb02_parse_fw(struct iio_dev *indio_dev,
 
 		ret = fwnode_property_read_string(child, "label", &data->labels[reg]);
 		if (ret)
-			return dev_err_probe(dev, ret, "%pfw: invalid label\n",
-					     fwnode_get_name(child));
+			dev_dbg(dev, "%s: invalid label\n", fwnode_get_name(child));
 
 		chanspec.address = reg;
 		chanspec.channel = reg;

-- 
2.43.0

Re: [PATCH v4 4/9] iio: dac: mcp47feb02: use dev_dbg for invalid label

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Making the label property optional causes the `label` sysfs attribute to return the literal string `(null)` for channels without a label.
--

--- Patch [4]: [PATCH v4 4/9] iio: dac: mcp47feb02: use dev_dbg for invalid label ---
commit 60f7652ad06abf540ec40667fe14b057bf9a477b
Author: Ariana Lazar <ariana.lazar@microchip.com>

iio: dac: mcp47feb02: use dev_dbg for invalid label

This commit modifies the firmware parsing logic to tolerate missing or
invalid label properties. Instead of aborting the probe with an error, it
logs a debug message and continues initialization.

> diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
> index 2ee981393aa1a..e5533fa3c31c0 100644
> --- a/drivers/iio/dac/mcp47feb02.c
> +++ b/drivers/iio/dac/mcp47feb02.c

[ ... ]

> @@ -978,8 +979,7 @@ static int mcp47feb02_parse_fw(struct iio_dev *indio_dev,
>  
>  		ret = fwnode_property_read_string(child, "label", &data->labels[reg]);
>  		if (ret)
> -			return dev_err_probe(dev, ret, "%pfw: invalid label\n",
> -					     fwnode_get_name(child));
> +			dev_dbg(dev, "%s: invalid label\n", fwnode_get_name(child));

[Severity: Medium]
When the label property is invalid or missing, data->labels[reg] will
now remain NULL.

Because the IIO core still registers the label sysfs attribute when
the read_label callback is populated, could this introduce a regression
where mcp47feb02_read_label() outputs the literal string "(null)"?

drivers/iio/dac/mcp47feb02.c:mcp47feb02_read_label() {
	struct mcp47feb02_data *data = iio_priv(indio_dev);

	return sysfs_emit(label, "%s\n", data->labels[ch->address]);
}

Since sysfs_emit() unconditionally formats a NULL pointer as "(null)",
userspace tools might parse "(null)" as the channel's actual label. Should
mcp47feb02_read_label() handle the NULL case and return an error code like
-ENOENT instead?

>  
>  		chanspec.address = reg;
>  		chanspec.channel = reg;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819-mcp47feb02_refactor-v4-0-beb2aa3bfd09@microchip.com?part=4

Re: [PATCH v4 4/9] iio: dac: mcp47feb02: use dev_dbg for invalid label

[Andy Shevchenko]

On Wed, Aug 19, 2026 at 03:41:08PM +0300, Ariana Lazar wrote:
> Correct unneccesarry probe error returned at an invalid label with a debug
> message instead.

Why?!

...

>  		ret = fwnode_property_read_string(child, "label", &data->labels[reg]);
>  		if (ret)
> -			return dev_err_probe(dev, ret, "%pfw: invalid label\n",
> -					     fwnode_get_name(child));
> +			dev_dbg(dev, "%s: invalid label\n", fwnode_get_name(child));

My gosh, the patch before this one should really fix the fwnode_get_name()
usage here.

			return dev_err_probe(dev, ret, "%pfw: invalid label\n", child);

Otherwise it's a good way to Oops.

I haven't checked the rest, but this is how it has to be when %pfw is used.

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 5/9] iio: dac: mcp47feb02: correct typo from a comment

[Ariana Lazar]

Typo corrected to 'Register' in the comment regarding defined masks for the
gain register.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
---
 drivers/iio/dac/mcp47feb02.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
index e5533fa3c31c0006d170764791177879c1e794b0..6f084eb71240b475bf85763139ecfafc006da83d 100644
--- a/drivers/iio/dac/mcp47feb02.c
+++ b/drivers/iio/dac/mcp47feb02.c
@@ -54,7 +54,7 @@
 #define DAC_CTRL_MASK(ch)				(GENMASK(1, 0) << (2 * (ch)))
 #define DAC_CTRL_VAL(ch, val)				((val) << (2 * (ch)))
 
-/* Gain Control and I2C Slave Address Reguster fields */
+/* Gain Control and I2C Slave Address Register fields */
 #define DAC_GAIN_MASK(ch)				(BIT(0) << (8 + (ch)))
 #define DAC_GAIN_VAL(ch, val)				((val) << (8 + (ch)))
 

-- 
2.43.0

[PATCH v4 6/9] iio: dac: mcp47feb02: rename command mask define

[Ariana Lazar]

Use 2 new defines to select the corresponding bits for each channel in VREF
and Power Down registers instead of the initial define without a meaningful
name.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
---
 drivers/iio/dac/mcp47feb02.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
index 6f084eb71240b475bf85763139ecfafc006da83d..8ca67c4021a86a6d5034495c1dbb18772ada354b 100644
--- a/drivers/iio/dac/mcp47feb02.c
+++ b/drivers/iio/dac/mcp47feb02.c
@@ -34,8 +34,9 @@
 /* Register addresses must be left shifted with 3 positions in order to append command mask */
 #define MCP47FEB02_DAC0_REG_ADDR			0x00
 #define MCP47FEB02_VREF_REG_ADDR			0x40
+#define MCP47FEB02_GET_VREF_MODE(reg, ch)		(((reg) >> (2 * (ch))) & GENMASK(1, 0))
 #define MCP47FEB02_POWER_DOWN_REG_ADDR			0x48
-#define MCP47FEB02_DAC_CTRL_MASK			GENMASK(1, 0)
+#define MCP47FEB02_GET_POWER_DOWN_MODE(reg, ch)		(((reg) >> (2 * (ch))) & GENMASK(1, 0))
 
 #define MCP47FEB02_GAIN_CTRL_STATUS_REG_ADDR		0x50
 #define MCP47FEB02_GAIN_BIT_MASK			BIT(0)
@@ -1026,7 +1027,7 @@ static int mcp47feb02_init_ctrl_regs(struct mcp47feb02_data *data)
 			return ret;
 		data->chdata[i].dac_data = dac_val;
 
-		data->chdata[i].ref_mode = (vref_ch >> (2 * i)) & MCP47FEB02_DAC_CTRL_MASK;
+		data->chdata[i].ref_mode = MCP47FEB02_GET_VREF_MODE(vref_ch, i);
 		data->chdata[i].use_2x_gain = (gain_ch & DAC_GAIN_MASK(i)) ? 1 : 0;
 
 		/*
@@ -1070,7 +1071,7 @@ static int mcp47feb02_init_ctrl_regs(struct mcp47feb02_data *data)
 			break;
 		}
 
-		pd_tmp = (pd_ch >> (2 * i)) & MCP47FEB02_DAC_CTRL_MASK;
+		pd_tmp = MCP47FEB02_GET_POWER_DOWN_MODE(pd_ch, i);
 		data->chdata[i].powerdown_mode = pd_tmp ? (pd_tmp - 1) : pd_tmp;
 		data->chdata[i].powerdown = !!(data->chdata[i].powerdown_mode);
 	}

-- 
2.43.0

Re: [PATCH v4 6/9] iio: dac: mcp47feb02: rename command mask define

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Incorrect initialization of the `powerdown` state when the device boots in `1kohm_to_gnd` power-down mode.
--

--- Patch [6]: [PATCH v4 6/9] iio: dac: mcp47feb02: rename command mask define ---
commit 5165e39a3476c86b84b827af722b000649c5b496
Author: Ariana Lazar <ariana.lazar@microchip.com>

iio: dac: mcp47feb02: rename command mask define

This commit replaces a generic mask definition with two new macros,
MCP47FEB02_GET_VREF_MODE and MCP47FEB02_GET_POWER_DOWN_MODE. These
improve code readability when extracting channel configurations.

> diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c
> index 6f084eb71240b..8ca67c4021a86 100644
> --- a/drivers/iio/dac/mcp47feb02.c
> +++ b/drivers/iio/dac/mcp47feb02.c

[ ... ]

> @@ -1070,7 +1071,7 @@ static int mcp47feb02_init_ctrl_regs(struct mcp47feb02_data *data)
>  			break;
>  		}
>  
> -		pd_tmp = (pd_ch >> (2 * i)) & MCP47FEB02_DAC_CTRL_MASK;
> +		pd_tmp = MCP47FEB02_GET_POWER_DOWN_MODE(pd_ch, i);
>  		data->chdata[i].powerdown_mode = pd_tmp ? (pd_tmp - 1) : pd_tmp;
>  		data->chdata[i].powerdown = !!(data->chdata[i].powerdown_mode);

[Severity: High]
This is a pre-existing issue, but does this logic incorrectly set the channel
to an active state when the device boots in 1kohm_to_gnd power-down mode?

When the device is configured in 1kohm_to_gnd mode in
mcp47feb02_init_ctrl_regs(), pd_tmp evaluates to 1. The preceding line sets
powerdown_mode to 0 (1 - 1 = 0). As a result, the check
!!(data->chdata[i].powerdown_mode) evaluates to false.

Does this cause the driver to report the channel as active, desynchronizing
the software state from the actual hardware state?

>  	}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819-mcp47feb02_refactor-v4-0-beb2aa3bfd09@microchip.com?part=6

[PATCH v4 7/9] iio: dac: mcp47feb02: refactor MCP47FEB02 I2C driver into two modules

[Ariana Lazar]

Prepare the driver for the bus-specific code by refactoring into separate
files. The renamed file will contain the common DAC functionality shared by
the MCP47FxBy1/2/4/8 I2C and MCP48FxBy1/2/4/8 SPI drivers. The MCP47FEB02
driver was refactored into two modules: mcp47feb02-core.c and
mcp47feb02-i2c.c in order to prepare the support for SPI MCP48FxBy1/2/4/8
DAC family on top of the current implementation.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
---
 MAINTAINERS                                        |   4 +-
 drivers/iio/dac/Kconfig                            |  10 +-
 drivers/iio/dac/Makefile                           |   3 +-
 .../iio/dac/{mcp47feb02.c => mcp47feb02-core.c}    | 327 ++-------------------
 drivers/iio/dac/mcp47feb02-i2c.c                   | 145 +++++++++
 drivers/iio/dac/mcp47feb02.h                       |  46 +++
 6 files changed, 227 insertions(+), 308 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 6b4560681b51cfabf0b0e98fd89b69d8c527228b..fc87609865f26a9f484edc42058f7df659a0fa4f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16118,7 +16118,9 @@ M:	Ariana Lazar <ariana.lazar@microchip.com>
 L:	linux-iio@vger.kernel.org
 S:	Supported
 F:	Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
-F:	drivers/iio/dac/mcp47feb02.c
+F:	drivers/iio/dac/mcp47feb02-core.c
+F:	drivers/iio/dac/mcp47feb02-i2c.c
+F:	drivers/iio/dac/mcp47feb02.h
 
 MCP4821 DAC DRIVER
 M:	Anshul Dalal <anshulusr@gmail.com>
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 657c68e75542e47ad5603165bcbc3660e90c6450..cc10d43ffd1e89bbf945ef89ea5af0abe1a91084 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -550,8 +550,13 @@ config MCP4728
 	  will be called mcp4728.
 
 config MCP47FEB02
-	tristate "MCP47F(E/V)B01/02/04/08/11/12/14/18/21/22/24/28 DAC driver"
+	tristate
+
+config MCP47FEB02_I2C
+	tristate "MCP47F(E/V)B01/02/04/08/11/12/14/18/21/22/24/28 I2C DAC driver"
 	depends on I2C
+	select REGMAP_I2C
+	select MCP47FEB02
 	help
 	  Say yes here if you want to build the driver for the Microchip:
 	  - 8-bit DAC:
@@ -567,7 +572,8 @@ config MCP47FEB02
 	  (DAC) with I2C interface.
 
 	  To compile this driver as a module, choose M here: the module
-	  will be called mcp47feb02.
+	  will be called mcp47feb02_i2c and you will also get
+	  mcp47feb02_core for the core module.
 
 config MCP4821
 	tristate "MCP4801/02/11/12/21/22 DAC driver"
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 0034317984985035f7987a744899924bfd4612e3..28c8646a987cff1ac4d693fe86898d66c901d5bd 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -54,7 +54,8 @@ obj-$(CONFIG_MAX5522) += max5522.o
 obj-$(CONFIG_MAX5821) += max5821.o
 obj-$(CONFIG_MCP4725) += mcp4725.o
 obj-$(CONFIG_MCP4728) += mcp4728.o
-obj-$(CONFIG_MCP47FEB02) += mcp47feb02.o
+obj-$(CONFIG_MCP47FEB02) += mcp47feb02-core.o
+obj-$(CONFIG_MCP47FEB02_I2C) += mcp47feb02-i2c.o
 obj-$(CONFIG_MCP4821) += mcp4821.o
 obj-$(CONFIG_MCP4922) += mcp4922.o
 obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02-core.c
similarity index 73%
rename from drivers/iio/dac/mcp47feb02.c
rename to drivers/iio/dac/mcp47feb02-core.c
index 8ca67c4021a86a6d5034495c1dbb18772ada354b..8bee01a82367371a590c9a7f23a18a1e8d1fe3ca 100644
--- a/drivers/iio/dac/mcp47feb02.c
+++ b/drivers/iio/dac/mcp47feb02-core.c
@@ -1,8 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * IIO driver for MCP47FEB02 Multi-Channel DAC with I2C interface
+ * IIO driver for MCP47FEB02 Multi-Channel DAC with I2C and SPI interface
  *
- * Copyright (C) 2025 Microchip Technology Inc. and its subsidiaries
+ * Copyright (C) 2025-2026 Microchip Technology Inc. and its subsidiaries
  *
  * Author: Ariana Lazar <ariana.lazar@microchip.com>
  *
@@ -17,12 +17,10 @@
 #include <linux/delay.h>
 #include <linux/dev_printk.h>
 #include <linux/err.h>
-#include <linux/i2c.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/kstrtox.h>
 #include <linux/module.h>
-#include <linux/mod_devicetable.h>
 #include <linux/mutex.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
@@ -31,6 +29,8 @@
 #include <linux/types.h>
 #include <linux/units.h>
 
+#include "mcp47feb02.h"
+
 /* Register addresses must be left shifted with 3 positions in order to append command mask */
 #define MCP47FEB02_DAC0_REG_ADDR			0x00
 #define MCP47FEB02_VREF_REG_ADDR			0x40
@@ -88,220 +88,12 @@ enum mcp47feb02_gain_bit_mode {
 	MCP47FEB02_GAIN_BIT_X2 = 1,
 };
 
-static const char * const mcp47feb02_powerdown_modes[] = {
+const char * const mcp47feb02_powerdown_modes[] = {
 	"1kohm_to_gnd",
 	"100kohm_to_gnd",
 	"open_circuit",
 };
 
-/**
- * struct mcp47feb02_features - chip specific data
- * @name: device name
- * @phys_channels: number of hardware channels
- * @resolution: DAC resolution
- * @have_ext_vref1: does the hardware have an the second external voltage reference?
- * @have_eeprom: does the hardware have an internal eeprom?
- */
-struct mcp47feb02_features {
-	const char *name;
-	unsigned int phys_channels;
-	unsigned int resolution;
-	bool have_ext_vref1;
-	bool have_eeprom;
-};
-
-static const struct mcp47feb02_features mcp47feb01_chip_features = {
-	.name = "mcp47feb01",
-	.phys_channels = 1,
-	.resolution = 8,
-	.have_ext_vref1 = false,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb02_chip_features = {
-	.name = "mcp47feb02",
-	.phys_channels = 2,
-	.resolution = 8,
-	.have_ext_vref1 = false,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb04_chip_features = {
-	.name = "mcp47feb04",
-	.phys_channels = 4,
-	.resolution = 8,
-	.have_ext_vref1 = true,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb08_chip_features = {
-	.name = "mcp47feb08",
-	.phys_channels = 8,
-	.resolution = 8,
-	.have_ext_vref1 = true,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb11_chip_features = {
-	.name = "mcp47feb11",
-	.phys_channels = 1,
-	.resolution = 10,
-	.have_ext_vref1 = false,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb12_chip_features = {
-	.name = "mcp47feb12",
-	.phys_channels = 2,
-	.resolution = 10,
-	.have_ext_vref1 = false,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb14_chip_features = {
-	.name = "mcp47feb14",
-	.phys_channels = 4,
-	.resolution = 10,
-	.have_ext_vref1 = true,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb18_chip_features = {
-	.name = "mcp47feb18",
-	.phys_channels = 8,
-	.resolution = 10,
-	.have_ext_vref1 = true,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb21_chip_features = {
-	.name = "mcp47feb21",
-	.phys_channels = 1,
-	.resolution = 12,
-	.have_ext_vref1 = false,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb22_chip_features = {
-	.name = "mcp47feb22",
-	.phys_channels = 2,
-	.resolution = 12,
-	.have_ext_vref1 = false,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb24_chip_features = {
-	.name = "mcp47feb24",
-	.phys_channels = 4,
-	.resolution = 12,
-	.have_ext_vref1 = true,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47feb28_chip_features = {
-	.name = "mcp47feb28",
-	.phys_channels = 8,
-	.resolution = 12,
-	.have_ext_vref1 = true,
-	.have_eeprom = true,
-};
-
-static const struct mcp47feb02_features mcp47fvb01_chip_features = {
-	.name = "mcp47fvb01",
-	.phys_channels = 1,
-	.resolution = 8,
-	.have_ext_vref1 = false,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb02_chip_features = {
-	.name = "mcp47fvb02",
-	.phys_channels = 2,
-	.resolution = 8,
-	.have_ext_vref1 = false,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb04_chip_features = {
-	.name = "mcp47fvb04",
-	.phys_channels = 4,
-	.resolution = 8,
-	.have_ext_vref1 = true,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb08_chip_features = {
-	.name = "mcp47fvb08",
-	.phys_channels = 8,
-	.resolution = 8,
-	.have_ext_vref1 = true,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb11_chip_features = {
-	.name = "mcp47fvb11",
-	.phys_channels = 1,
-	.resolution = 10,
-	.have_ext_vref1 = false,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb12_chip_features = {
-	.name = "mcp47fvb12",
-	.phys_channels = 2,
-	.resolution = 10,
-	.have_ext_vref1 = false,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb14_chip_features = {
-	.name = "mcp47fvb14",
-	.phys_channels = 4,
-	.resolution = 10,
-	.have_ext_vref1 = true,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb18_chip_features = {
-	.name = "mcp47fvb18",
-	.phys_channels = 8,
-	.resolution = 10,
-	.have_ext_vref1 = true,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb21_chip_features = {
-	.name = "mcp47fvb21",
-	.phys_channels = 1,
-	.resolution = 12,
-	.have_ext_vref1 = false,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb22_chip_features = {
-	.name = "mcp47fvb22",
-	.phys_channels = 2,
-	.resolution = 12,
-	.have_ext_vref1 = false,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb24_chip_features = {
-	.name = "mcp47fvb24",
-	.phys_channels = 4,
-	.resolution = 12,
-	.have_ext_vref1 = true,
-	.have_eeprom = false,
-};
-
-static const struct mcp47feb02_features mcp47fvb28_chip_features = {
-	.name = "mcp47fvb28",
-	.phys_channels = 8,
-	.resolution = 12,
-	.have_ext_vref1 = true,
-	.have_eeprom = false,
-};
-
 /**
  * struct mcp47feb02_channel_data - channel configuration
  * @ref_mode: chosen voltage for reference
@@ -382,7 +174,7 @@ static const struct regmap_access_table mcp47feb02_volatile_table = {
 	.n_yes_ranges = ARRAY_SIZE(mcp47feb02_volatile_ranges),
 };
 
-static const struct regmap_config mcp47feb02_regmap_config = {
+const struct regmap_config mcp47feb02_regmap_config = {
 	.name = "mcp47feb02_regmap",
 	.reg_bits = 8,
 	.val_bits = 16,
@@ -394,6 +186,7 @@ static const struct regmap_config mcp47feb02_regmap_config = {
 	.cache_type = REGCACHE_MAPLE,
 	.val_format_endian = REGMAP_ENDIAN_BIG,
 };
+EXPORT_SYMBOL_NS_GPL(mcp47feb02_regmap_config, "IIO_MCP47FEB02");
 
 /* For devices that doesn't have nonvolatile memory */
 static const struct regmap_range mcp47fvb02_readable_ranges[] = {
@@ -424,7 +217,7 @@ static const struct regmap_access_table mcp47fvb02_volatile_table = {
 	.n_yes_ranges = ARRAY_SIZE(mcp47fvb02_volatile_ranges),
 };
 
-static const struct regmap_config mcp47fvb02_regmap_config = {
+const struct regmap_config mcp47fvb02_regmap_config = {
 	.name = "mcp47fvb02_regmap",
 	.reg_bits = 8,
 	.val_bits = 16,
@@ -436,6 +229,7 @@ static const struct regmap_config mcp47fvb02_regmap_config = {
 	.cache_type = REGCACHE_MAPLE,
 	.val_format_endian = REGMAP_ENDIAN_BIG,
 };
+EXPORT_SYMBOL_NS_GPL(mcp47fvb02_regmap_config, "IIO_MCP47FEB02");
 
 static int mcp47feb02_write_to_eeprom(struct mcp47feb02_data *data, unsigned int reg,
 				      unsigned int val)
@@ -446,8 +240,6 @@ static int mcp47feb02_write_to_eeprom(struct mcp47feb02_data *data, unsigned int
 	 * Wait until the currently occurring EEPROM Write Cycle is completed.
 	 * Only serial commands to the volatile memory are allowed.
 	 */
-	guard(mutex)(&data->lock);
-
 	ret = regmap_read_poll_timeout(data->regmap, MCP47FEB02_GAIN_CTRL_STATUS_REG_ADDR,
 				       eewa_val,
 				       !(eewa_val & MCP47FEB02_GAIN_BIT_STATUS_EEWA_MASK),
@@ -473,6 +265,8 @@ static ssize_t store_eeprom_store(struct device *dev, struct device_attribute *a
 	if (!state)
 		return len;
 
+	guard(mutex)(&data->lock);
+
 	/*
 	 * Verify DAC Wiper and DAC Configuration are unlocked. If both are disabled,
 	 * writing to EEPROM is available.
@@ -579,18 +373,17 @@ static int mcp47feb02_resume(struct device *dev)
 	guard(mutex)(&data->lock);
 
 	for_each_set_bit(ch, &data->active_channels_mask, data->phys_channels) {
-		u8 pd_mode;
 		int ret;
 
 		data->chdata[ch].powerdown = false;
-		pd_mode = data->chdata[ch].powerdown_mode + 1;
 
 		ret = regmap_write(data->regmap, REG_ADDR(ch), data->chdata[ch].dac_data);
 		if (ret)
 			return ret;
 
 		ret = regmap_update_bits(data->regmap, MCP47FEB02_VREF_REG_ADDR,
-					 DAC_CTRL_MASK(ch), DAC_CTRL_VAL(ch, pd_mode));
+					 DAC_CTRL_MASK(ch),
+					 DAC_CTRL_VAL(ch, data->chdata[ch].ref_mode));
 		if (ret)
 			return ret;
 
@@ -668,7 +461,7 @@ static ssize_t mcp47feb02_write_powerdown(struct iio_dev *indio_dev, uintptr_t p
 	return len;
 }
 
-static DEFINE_SIMPLE_DEV_PM_OPS(mcp47feb02_pm_ops, mcp47feb02_suspend, mcp47feb02_resume);
+EXPORT_SIMPLE_DEV_PM_OPS(mcp47feb02_pm_ops, mcp47feb02_suspend, mcp47feb02_resume);
 
 static const struct iio_enum mcp47febxx_powerdown_mode_enum = {
 	.items = mcp47feb02_powerdown_modes,
@@ -1096,10 +889,10 @@ static int mcp47feb02_init_ch_scales(struct mcp47feb02_data *data, int vdd_uV,
 	return 0;
 }
 
-static int mcp47feb02_probe(struct i2c_client *client)
+int mcp47feb02_common_probe(const struct mcp47feb02_features *chip_features,
+			    struct regmap *regmap)
 {
-	const struct mcp47feb02_features *chip_features;
-	struct device *dev = &client->dev;
+	struct device *dev = regmap_get_device(regmap);
 	struct mcp47feb02_data *data;
 	struct iio_dev *indio_dev;
 	int vref1_uV, vref_uV, vdd_uV, ret;
@@ -1108,22 +901,16 @@ static int mcp47feb02_probe(struct i2c_client *client)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	data = iio_priv(indio_dev);
-	chip_features = i2c_get_match_data(client);
-	if (!chip_features)
-		return -EINVAL;
+	dev_set_drvdata(dev, indio_dev);
 
+	data = iio_priv(indio_dev);
 	data->chip_features = chip_features;
+	data->regmap = regmap;
 
-	if (chip_features->have_eeprom) {
-		data->regmap = devm_regmap_init_i2c(client, &mcp47feb02_regmap_config);
+	if (chip_features->have_eeprom)
 		indio_dev->info = &mcp47feb02_info;
-	} else {
-		data->regmap = devm_regmap_init_i2c(client, &mcp47fvb02_regmap_config);
+	else
 		indio_dev->info = &mcp47fvb02_info;
-	}
-	if (IS_ERR(data->regmap))
-		return dev_err_probe(dev, PTR_ERR(data->regmap), "Error initializing i2c regmap\n");
 
 	indio_dev->name = chip_features->name;
 
@@ -1180,75 +967,7 @@ static int mcp47feb02_probe(struct i2c_client *client)
 
 	return devm_iio_device_register(dev, indio_dev);
 }
-
-static const struct i2c_device_id mcp47feb02_id[] = {
-	{ .name = "mcp47feb01", .driver_data = (kernel_ulong_t)&mcp47feb01_chip_features },
-	{ .name = "mcp47feb02", .driver_data = (kernel_ulong_t)&mcp47feb02_chip_features },
-	{ .name = "mcp47feb04", .driver_data = (kernel_ulong_t)&mcp47feb04_chip_features },
-	{ .name = "mcp47feb08", .driver_data = (kernel_ulong_t)&mcp47feb08_chip_features },
-	{ .name = "mcp47feb11", .driver_data = (kernel_ulong_t)&mcp47feb11_chip_features },
-	{ .name = "mcp47feb12", .driver_data = (kernel_ulong_t)&mcp47feb12_chip_features },
-	{ .name = "mcp47feb14", .driver_data = (kernel_ulong_t)&mcp47feb14_chip_features },
-	{ .name = "mcp47feb18", .driver_data = (kernel_ulong_t)&mcp47feb18_chip_features },
-	{ .name = "mcp47feb21", .driver_data = (kernel_ulong_t)&mcp47feb21_chip_features },
-	{ .name = "mcp47feb22", .driver_data = (kernel_ulong_t)&mcp47feb22_chip_features },
-	{ .name = "mcp47feb24", .driver_data = (kernel_ulong_t)&mcp47feb24_chip_features },
-	{ .name = "mcp47feb28", .driver_data = (kernel_ulong_t)&mcp47feb28_chip_features },
-	{ .name = "mcp47fvb01", .driver_data = (kernel_ulong_t)&mcp47fvb01_chip_features },
-	{ .name = "mcp47fvb02", .driver_data = (kernel_ulong_t)&mcp47fvb02_chip_features },
-	{ .name = "mcp47fvb04", .driver_data = (kernel_ulong_t)&mcp47fvb04_chip_features },
-	{ .name = "mcp47fvb08", .driver_data = (kernel_ulong_t)&mcp47fvb08_chip_features },
-	{ .name = "mcp47fvb11", .driver_data = (kernel_ulong_t)&mcp47fvb11_chip_features },
-	{ .name = "mcp47fvb12", .driver_data = (kernel_ulong_t)&mcp47fvb12_chip_features },
-	{ .name = "mcp47fvb14", .driver_data = (kernel_ulong_t)&mcp47fvb14_chip_features },
-	{ .name = "mcp47fvb18", .driver_data = (kernel_ulong_t)&mcp47fvb18_chip_features },
-	{ .name = "mcp47fvb21", .driver_data = (kernel_ulong_t)&mcp47fvb21_chip_features },
-	{ .name = "mcp47fvb22", .driver_data = (kernel_ulong_t)&mcp47fvb22_chip_features },
-	{ .name = "mcp47fvb24", .driver_data = (kernel_ulong_t)&mcp47fvb24_chip_features },
-	{ .name = "mcp47fvb28", .driver_data = (kernel_ulong_t)&mcp47fvb28_chip_features },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, mcp47feb02_id);
-
-static const struct of_device_id mcp47feb02_of_match[] = {
-	{ .compatible = "microchip,mcp47feb01", .data = &mcp47feb01_chip_features },
-	{ .compatible = "microchip,mcp47feb02", .data = &mcp47feb02_chip_features },
-	{ .compatible = "microchip,mcp47feb04", .data = &mcp47feb04_chip_features },
-	{ .compatible = "microchip,mcp47feb08", .data = &mcp47feb08_chip_features },
-	{ .compatible = "microchip,mcp47feb11", .data = &mcp47feb11_chip_features },
-	{ .compatible = "microchip,mcp47feb12", .data = &mcp47feb12_chip_features },
-	{ .compatible = "microchip,mcp47feb14", .data = &mcp47feb14_chip_features },
-	{ .compatible = "microchip,mcp47feb18", .data = &mcp47feb18_chip_features },
-	{ .compatible = "microchip,mcp47feb21", .data = &mcp47feb21_chip_features },
-	{ .compatible = "microchip,mcp47feb22", .data = &mcp47feb22_chip_features },
-	{ .compatible = "microchip,mcp47feb24", .data = &mcp47feb24_chip_features },
-	{ .compatible = "microchip,mcp47feb28", .data = &mcp47feb28_chip_features },
-	{ .compatible = "microchip,mcp47fvb01", .data = &mcp47fvb01_chip_features },
-	{ .compatible = "microchip,mcp47fvb02", .data = &mcp47fvb02_chip_features },
-	{ .compatible = "microchip,mcp47fvb04", .data = &mcp47fvb04_chip_features },
-	{ .compatible = "microchip,mcp47fvb08", .data = &mcp47fvb08_chip_features },
-	{ .compatible = "microchip,mcp47fvb11", .data = &mcp47fvb11_chip_features },
-	{ .compatible = "microchip,mcp47fvb12", .data = &mcp47fvb12_chip_features },
-	{ .compatible = "microchip,mcp47fvb14",	.data = &mcp47fvb14_chip_features },
-	{ .compatible = "microchip,mcp47fvb18", .data = &mcp47fvb18_chip_features },
-	{ .compatible = "microchip,mcp47fvb21", .data = &mcp47fvb21_chip_features },
-	{ .compatible = "microchip,mcp47fvb22", .data = &mcp47fvb22_chip_features },
-	{ .compatible = "microchip,mcp47fvb24", .data = &mcp47fvb24_chip_features },
-	{ .compatible = "microchip,mcp47fvb28", .data = &mcp47fvb28_chip_features },
-	{ }
-};
-MODULE_DEVICE_TABLE(of, mcp47feb02_of_match);
-
-static struct i2c_driver mcp47feb02_driver = {
-	.driver = {
-		.name	= "mcp47feb02",
-		.of_match_table = mcp47feb02_of_match,
-		.pm	= pm_sleep_ptr(&mcp47feb02_pm_ops),
-	},
-	.probe		= mcp47feb02_probe,
-	.id_table	= mcp47feb02_id,
-};
-module_i2c_driver(mcp47feb02_driver);
+EXPORT_SYMBOL_NS(mcp47feb02_common_probe, "IIO_MCP47FEB02");
 
 MODULE_AUTHOR("Ariana Lazar <ariana.lazar@microchip.com>");
 MODULE_DESCRIPTION("IIO driver for MCP47FEB02 Multi-Channel DAC with I2C interface");
diff --git a/drivers/iio/dac/mcp47feb02-i2c.c b/drivers/iio/dac/mcp47feb02-i2c.c
new file mode 100644
index 0000000000000000000000000000000000000000..7e49503e3abc91225b6ede89fdab03f5ca3799f3
--- /dev/null
+++ b/drivers/iio/dac/mcp47feb02-i2c.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IIO driver for MCP47FEB02 Multi-Channel DAC with I2C interface
+ *
+ * Copyright (C) 2025-2026 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Ariana Lazar <ariana.lazar@microchip.com>
+ *
+ * Datasheet links for devices with I2C interface:
+ * [MCP47FEBxx] https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005375A.pdf
+ * [MCP47FVBxx] https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005405A.pdf
+ * [MCP47FxBx4/8] https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP47FXBX48-Data-Sheet-DS200006368A.pdf
+ */
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#include "mcp47feb02.h"
+
+/* Parts with EEPROM memory */
+MCP47FEB02_CHIP_INFO(mcp47feb01, 1, 8,  false, true);
+MCP47FEB02_CHIP_INFO(mcp47feb02, 2, 8,  false, true);
+MCP47FEB02_CHIP_INFO(mcp47feb04, 4, 8,  true,  true);
+MCP47FEB02_CHIP_INFO(mcp47feb08, 8, 8,  true,  true);
+MCP47FEB02_CHIP_INFO(mcp47feb11, 1, 10, false, true);
+MCP47FEB02_CHIP_INFO(mcp47feb12, 2, 10, false, true);
+MCP47FEB02_CHIP_INFO(mcp47feb14, 4, 10, true,  true);
+MCP47FEB02_CHIP_INFO(mcp47feb18, 8, 10, true,  true);
+MCP47FEB02_CHIP_INFO(mcp47feb21, 1, 12, false, true);
+MCP47FEB02_CHIP_INFO(mcp47feb22, 2, 12, false, true);
+MCP47FEB02_CHIP_INFO(mcp47feb24, 4, 12, true,  true);
+MCP47FEB02_CHIP_INFO(mcp47feb28, 8, 12, true,  true);
+
+/* Parts without EEPROM memory */
+MCP47FEB02_CHIP_INFO(mcp47fvb01, 1, 8,  false, false);
+MCP47FEB02_CHIP_INFO(mcp47fvb02, 2, 8,  false, false);
+MCP47FEB02_CHIP_INFO(mcp47fvb04, 4, 8,  true,  false);
+MCP47FEB02_CHIP_INFO(mcp47fvb08, 8, 8,  true,  false);
+MCP47FEB02_CHIP_INFO(mcp47fvb11, 1, 10, false, false);
+MCP47FEB02_CHIP_INFO(mcp47fvb12, 2, 10, false, false);
+MCP47FEB02_CHIP_INFO(mcp47fvb14, 4, 10, true,  false);
+MCP47FEB02_CHIP_INFO(mcp47fvb18, 8, 10, true,  false);
+MCP47FEB02_CHIP_INFO(mcp47fvb21, 1, 12, false, false);
+MCP47FEB02_CHIP_INFO(mcp47fvb22, 2, 12, false, false);
+MCP47FEB02_CHIP_INFO(mcp47fvb24, 4, 12, true,  false);
+MCP47FEB02_CHIP_INFO(mcp47fvb28, 8, 12, true,  false);
+
+static int mcp47feb02_i2c_probe(struct i2c_client *client)
+{
+	const struct mcp47feb02_features *chip_features;
+	struct device *dev = &client->dev;
+	struct regmap *regmap;
+
+	chip_features = i2c_get_match_data(client);
+	if (!chip_features)
+		return dev_err_probe(dev, -ENODEV, "No I2C device found\n");
+
+	if (chip_features->have_eeprom)
+		regmap = devm_regmap_init_i2c(client, &mcp47feb02_regmap_config);
+	else
+		regmap = devm_regmap_init_i2c(client, &mcp47fvb02_regmap_config);
+
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap), "Error initializing I2C regmap\n");
+
+	return mcp47feb02_common_probe(chip_features, regmap);
+}
+
+static const struct i2c_device_id mcp47feb02_i2c_id[] = {
+	{ .name = "mcp47feb01", .driver_data = (kernel_ulong_t)&mcp47feb01_chip_features },
+	{ .name = "mcp47feb02", .driver_data = (kernel_ulong_t)&mcp47feb02_chip_features },
+	{ .name = "mcp47feb04", .driver_data = (kernel_ulong_t)&mcp47feb04_chip_features },
+	{ .name = "mcp47feb08", .driver_data = (kernel_ulong_t)&mcp47feb08_chip_features },
+	{ .name = "mcp47feb11", .driver_data = (kernel_ulong_t)&mcp47feb11_chip_features },
+	{ .name = "mcp47feb12", .driver_data = (kernel_ulong_t)&mcp47feb12_chip_features },
+	{ .name = "mcp47feb14", .driver_data = (kernel_ulong_t)&mcp47feb14_chip_features },
+	{ .name = "mcp47feb18", .driver_data = (kernel_ulong_t)&mcp47feb18_chip_features },
+	{ .name = "mcp47feb21", .driver_data = (kernel_ulong_t)&mcp47feb21_chip_features },
+	{ .name = "mcp47feb22", .driver_data = (kernel_ulong_t)&mcp47feb22_chip_features },
+	{ .name = "mcp47feb24", .driver_data = (kernel_ulong_t)&mcp47feb24_chip_features },
+	{ .name = "mcp47feb28", .driver_data = (kernel_ulong_t)&mcp47feb28_chip_features },
+	{ .name = "mcp47fvb01", .driver_data = (kernel_ulong_t)&mcp47fvb01_chip_features },
+	{ .name = "mcp47fvb02", .driver_data = (kernel_ulong_t)&mcp47fvb02_chip_features },
+	{ .name = "mcp47fvb04", .driver_data = (kernel_ulong_t)&mcp47fvb04_chip_features },
+	{ .name = "mcp47fvb08", .driver_data = (kernel_ulong_t)&mcp47fvb08_chip_features },
+	{ .name = "mcp47fvb11", .driver_data = (kernel_ulong_t)&mcp47fvb11_chip_features },
+	{ .name = "mcp47fvb12", .driver_data = (kernel_ulong_t)&mcp47fvb12_chip_features },
+	{ .name = "mcp47fvb14", .driver_data = (kernel_ulong_t)&mcp47fvb14_chip_features },
+	{ .name = "mcp47fvb18", .driver_data = (kernel_ulong_t)&mcp47fvb18_chip_features },
+	{ .name = "mcp47fvb21", .driver_data = (kernel_ulong_t)&mcp47fvb21_chip_features },
+	{ .name = "mcp47fvb22", .driver_data = (kernel_ulong_t)&mcp47fvb22_chip_features },
+	{ .name = "mcp47fvb24", .driver_data = (kernel_ulong_t)&mcp47fvb24_chip_features },
+	{ .name = "mcp47fvb28", .driver_data = (kernel_ulong_t)&mcp47fvb28_chip_features },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mcp47feb02_i2c_id);
+
+static const struct of_device_id mcp47feb02_of_i2c_match[] = {
+	{ .compatible = "microchip,mcp47feb01", .data = &mcp47feb01_chip_features },
+	{ .compatible = "microchip,mcp47feb02", .data = &mcp47feb02_chip_features },
+	{ .compatible = "microchip,mcp47feb04", .data = &mcp47feb04_chip_features },
+	{ .compatible = "microchip,mcp47feb08", .data = &mcp47feb08_chip_features },
+	{ .compatible = "microchip,mcp47feb11", .data = &mcp47feb11_chip_features },
+	{ .compatible = "microchip,mcp47feb12", .data = &mcp47feb12_chip_features },
+	{ .compatible = "microchip,mcp47feb14", .data = &mcp47feb14_chip_features },
+	{ .compatible = "microchip,mcp47feb18", .data = &mcp47feb18_chip_features },
+	{ .compatible = "microchip,mcp47feb21", .data = &mcp47feb21_chip_features },
+	{ .compatible = "microchip,mcp47feb22", .data = &mcp47feb22_chip_features },
+	{ .compatible = "microchip,mcp47feb24", .data = &mcp47feb24_chip_features },
+	{ .compatible = "microchip,mcp47feb28", .data = &mcp47feb28_chip_features },
+	{ .compatible = "microchip,mcp47fvb01", .data = &mcp47fvb01_chip_features },
+	{ .compatible = "microchip,mcp47fvb02", .data = &mcp47fvb02_chip_features },
+	{ .compatible = "microchip,mcp47fvb04", .data = &mcp47fvb04_chip_features },
+	{ .compatible = "microchip,mcp47fvb08", .data = &mcp47fvb08_chip_features },
+	{ .compatible = "microchip,mcp47fvb11", .data = &mcp47fvb11_chip_features },
+	{ .compatible = "microchip,mcp47fvb12", .data = &mcp47fvb12_chip_features },
+	{ .compatible = "microchip,mcp47fvb14",	.data = &mcp47fvb14_chip_features },
+	{ .compatible = "microchip,mcp47fvb18", .data = &mcp47fvb18_chip_features },
+	{ .compatible = "microchip,mcp47fvb21", .data = &mcp47fvb21_chip_features },
+	{ .compatible = "microchip,mcp47fvb22", .data = &mcp47fvb22_chip_features },
+	{ .compatible = "microchip,mcp47fvb24", .data = &mcp47fvb24_chip_features },
+	{ .compatible = "microchip,mcp47fvb28", .data = &mcp47fvb28_chip_features },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mcp47feb02_of_i2c_match);
+
+static struct i2c_driver mcp47feb02_i2c_driver = {
+	.driver = {
+		.name = "mcp47feb02",
+		.of_match_table = mcp47feb02_of_i2c_match,
+		.pm = pm_sleep_ptr(&mcp47feb02_pm_ops),
+	},
+	.probe = mcp47feb02_i2c_probe,
+	.id_table = mcp47feb02_i2c_id,
+};
+module_i2c_driver(mcp47feb02_i2c_driver);
+
+MODULE_AUTHOR("Ariana Lazar <ariana.lazar@microchip.com>");
+MODULE_DESCRIPTION("IIO driver for MCP47FEB02 Multi-Channel DAC with I2C interface");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("IIO_MCP47FEB02");
diff --git a/drivers/iio/dac/mcp47feb02.h b/drivers/iio/dac/mcp47feb02.h
new file mode 100644
index 0000000000000000000000000000000000000000..64620c865871254f5db373f951ffad3b9c273f29
--- /dev/null
+++ b/drivers/iio/dac/mcp47feb02.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef __DRIVERS_IIO_DAC_MCP47FEB02_H__
+#define __DRIVERS_IIO_DAC_MCP47FEB02_H__
+
+#include <linux/pm.h>
+#include <linux/types.h>
+
+extern const char * const mcp47feb02_powerdown_modes[];
+
+/* Macro used for generating chip features structures */
+#define MCP47FEB02_CHIP_INFO(_name, _channels, _res, _vref1, _eeprom) \
+static const struct mcp47feb02_features _name##_chip_features = { \
+	.name = #_name, \
+	.phys_channels = _channels, \
+	.resolution = _res, \
+	.have_ext_vref1 = _vref1, \
+	.have_eeprom = _eeprom, \
+}
+
+/**
+ * struct mcp47feb02_features - chip specific data
+ * @name: device name
+ * @phys_channels: number of hardware channels
+ * @resolution: DAC resolution
+ * @have_ext_vref1: does the hardware have an the second external voltage reference?
+ * @have_eeprom: does the hardware have an internal eeprom?
+ */
+struct mcp47feb02_features {
+	const char *name;
+	unsigned int phys_channels;
+	unsigned int resolution;
+	bool have_ext_vref1;
+	bool have_eeprom;
+};
+
+extern const struct regmap_config mcp47feb02_regmap_config;
+extern const struct regmap_config mcp47fvb02_regmap_config;
+
+/* Properties shared by I2C and SPI families */
+int mcp47feb02_common_probe(const struct mcp47feb02_features *chip_features,
+			    struct regmap *regmap);
+
+extern const struct dev_pm_ops mcp47feb02_pm_ops;
+
+#endif /* __DRIVERS_IIO_DAC_MCP47FEB02_H__ */
+

-- 
2.43.0

Re: [PATCH v4 7/9] iio: dac: mcp47feb02: refactor MCP47FEB02 I2C driver into two modules

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Making the device tree 'label' property optional causes the literal string '(null)' to be printed to sysfs.
--

--- Patch [7]: [PATCH v4 7/9] iio: dac: mcp47feb02: refactor MCP47FEB02 I2C driver into two modules ---
commit ed5f5f581011130b05d16462d5287ab79c40d657
Author: Ariana Lazar <ariana.lazar@microchip.com>

iio: dac: mcp47feb02: refactor MCP47FEB02 I2C driver into two modules

This commit refactors the MCP47FEB02 driver into a core module and an
I2C-specific module to prepare for future SPI support.

> diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02-core.c
> rename from drivers/iio/dac/mcp47feb02.c
> rename to drivers/iio/dac/mcp47feb02-core.c
> index a823c2a673a26..8bee01a823673 100644
> --- a/drivers/iio/dac/mcp47feb02.c
> +++ b/drivers/iio/dac/mcp47feb02-core.c
[ ... ]
> @@ -978,8 +773,7 @@ static int mcp47feb02_parse_fw(struct iio_dev *indio_dev,
>  
>  		ret = fwnode_property_read_string(child, "label", &data->labels[reg]);
>  		if (ret)
> -			return dev_err_probe(dev, ret, "%pfw: invalid label\n",
> -					     fwnode_get_name(child));
> +			dev_dbg(dev, "%s: invalid label\n", fwnode_get_name(child));
>  
>  		chanspec.address = reg;
>  		chanspec.channel = reg;

[Severity: Medium]
Will this cause an unintended sysfs output when a channel lacks the label
property?

By continuing the probe without an error, data->labels[reg] remains NULL.
When userspace later reads the label via sysfs, mcp47feb02_read_label()
passes this pointer to sysfs_emit():

mcp47feb02_read_label() {
	...
	return sysfs_emit(label, "%s\n", data->labels[ch->address]);
}

Passing a NULL pointer to sysfs_emit() will print the literal string
"(null)\n" to userspace instead of returning a standard error like -ENOENT.

Would it be better to add a NULL check in mcp47feb02_read_label() before
emitting the string?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819-mcp47feb02_refactor-v4-0-beb2aa3bfd09@microchip.com?part=7

[PATCH v4 8/9] dt-bindings: iio: dac: add support for MCP48FEB02 SPI

[Ariana Lazar]

Add the SPI MCP48FxBy1/2/4/8 part numbers, the spi-max-frequency property
and a devicetree example for SPI usage to the existing binding.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
---
 .../bindings/iio/dac/microchip,mcp47feb02.yaml     | 221 ++++++++++++++++-----
 1 file changed, 173 insertions(+), 48 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml b/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
index d131f136bd15161666932261bcacd6d124b23ede..a86d094f0d4b54f9d9cc39fd54222f5968714668 100644
--- a/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
+++ b/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
@@ -4,58 +4,92 @@
 $id: http://devicetree.org/schemas/iio/dac/microchip,mcp47feb02.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Microchip MCP47F(E/V)B(0/1/2)(1/2/4/8) DAC with I2C Interface Families
+title: Microchip MCP4(7/8)F(E/V)B(0/1/2)(1/2/4/8) DAC with I2C/SPI Interface Families
 
 maintainers:
   - Ariana Lazar <ariana.lazar@microchip.com>
 
 description: |
-  Datasheet for MCP47FEB01, MCP47FEB11, MCP47FEB21, MCP47FEB02, MCP47FEB12,
-  MCP47FEB22 can be found here:
-    https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005375A.pdf
-  Datasheet for MCP47FVB01, MCP47FVB11, MCP47FVB21, MCP47FVB02, MCP47FVB12,
-  MCP47FVB22 can be found here:
-    https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005405A.pdf
-  Datasheet for MCP47FEB04, MCP47FEB14, MCP47FEB24, MCP47FEB08, MCP47FEB18,
-  MCP47FEB28, MCP47FVB04, MCP47FVB14, MCP47FVB24, MCP47FVB08, MCP47FVB18,
-  MCP47FVB28 can be found here:
-    https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP47FXBX48-Data-Sheet-DS200006368A.pdf
-
-  +------------+--------------+-------------+-------------+------------+
-  | Device     |  Resolution  |   Channels  | Vref number | Memory     |
-  |------------|--------------|-------------|-------------|------------|
-  | MCP47FEB01 |     8-bit    |      1      |      1      |   EEPROM   |
-  | MCP47FEB11 |    10-bit    |      1      |      1      |   EEPROM   |
-  | MCP47FEB21 |    12-bit    |      1      |      1      |   EEPROM   |
-  |------------|--------------|-------------|-------------|------------|
-  | MCP47FEB02 |     8-bit    |      2      |      1      |   EEPROM   |
-  | MCP47FEB12 |    10-bit    |      2      |      1      |   EEPROM   |
-  | MCP47FEB22 |    12-bit    |      2      |      1      |   EEPROM   |
-  |------------|--------------|-------------|-------------|------------|
-  | MCP47FVB01 |     8-bit    |      1      |      1      |      RAM   |
-  | MCP47FVB11 |    10-bit    |      1      |      1      |      RAM   |
-  | MCP47FVB21 |    12-bit    |      1      |      1      |      RAM   |
-  |------------|--------------|-------------|-------------|------------|
-  | MCP47FVB02 |     8-bit    |      2      |      1      |      RAM   |
-  | MCP47FVB12 |    10-bit    |      2      |      1      |      RAM   |
-  | MCP47FVB22 |    12-bit    |      2      |      1      |      RAM   |
-  |------------|--------------|-------------|-------------|------------|
-  | MCP47FVB04 |     8-bit    |      4      |      2      |      RAM   |
-  | MCP47FVB14 |    10-bit    |      4      |      2      |      RAM   |
-  | MCP47FVB24 |    12-bit    |      4      |      2      |      RAM   |
-  |------------|--------------|-------------|-------------|------------|
-  | MCP47FVB08 |     8-bit    |      8      |      2      |      RAM   |
-  | MCP47FVB18 |    10-bit    |      8      |      2      |      RAM   |
-  | MCP47FVB28 |    12-bit    |      8      |      2      |      RAM   |
-  |------------|--------------|-------------|-------------|------------|
-  | MCP47FEB04 |     8-bit    |      4      |      2      |   EEPROM   |
-  | MCP47FEB14 |    10-bit    |      4      |      2      |   EEPROM   |
-  | MCP47FEB24 |    12-bit    |      4      |      2      |   EEPROM   |
-  |------------|--------------|-------------|-------------|------------|
-  | MCP47FEB08 |     8-bit    |      8      |      2      |   EEPROM   |
-  | MCP47FEB18 |    10-bit    |      8      |      2      |   EEPROM   |
-  | MCP47FEB28 |    12-bit    |      8      |      2      |   EEPROM   |
-  +------------+--------------+-------------+-------------+------------+
+  Datasheets for MCP47F(E/V)B(0/1/2)(1/2/4/8) DAC with I2C Interface Families:
+   Datasheet for MCP47FEB01, MCP47FEB02, MCP47FEB11, MCP47FEB12, MCP47FEB21,
+   MCP47FEB22 can be found here:
+     https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005375A.pdf
+   Datasheet for MCP47FVB01, MCP47FVB02, MCP47FVB11, MCP47FVB12, MCP47FVB21,
+   MCP47FVB22 can be found here:
+     https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005405A.pdf
+   Datasheet for MCP47FEB04, MCP47FEB08, MCP47FEB14, MCP47FEB18, MCP47FEB24,
+   MCP47FEB28, MCP47FVB04, MCP47FVB08, MCP47FVB14, MCP47FVB18, MCP47FVB24,
+   MCP47FVB28 can be found here:
+     https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP47FXBX48-Data-Sheet-DS200006368A.pdf
+   Datasheets for MCP48F(E/V)B(0/1/2)(1/2/4/8) DAC with SPI Interface Families:
+   Datasheet for MCP48FEB01, MCP48FEB02, MCP48FEB11, MCP48FEB12, MCP48FEB21,
+   MCP48FEB22 can be found here:
+     https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005429B.pdf
+   Datasheet for MCP48FVB01, MCP48FVB02, MCP48FVB11, MCP48FVB12, MCP48FVB21,
+   MCP48FVB22 can be found here:
+     https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005466A.pdf
+   Datasheet for MCP48FEB04, MCP48FEB14, MCP48FEB24, MCP48FEB08, MCP48FEB18,
+   MCP48FEB28, MCP48FVB04, MCP48FVB14, MCP48FVB24, MCP48FVB08, MCP48FVB18,
+   MCP48FVB28 can be found here:
+     https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP48FXBX4-8-Family-Data-Sheet-DS20006362A.pdf
+
+  +------------+--------------+-------------+-------------+------------+------------+
+  | Device     |  Resolution  |   Channels  | Vref number |   Memory   | Interface  |
+  |------------|--------------|-------------|-------------|------------|------------|
+  | MCP47FEB01 |              |      1      |      1      |   EEPROM   |    I2C     |
+  | MCP47FEB02 |              |      2      |      1      |   EEPROM   |    I2C     |
+  | MCP47FEB04 |              |      4      |      2      |   EEPROM   |    I2C     |
+  | MCP47FEB08 |     8-bit    |      8      |      2      |   EEPROM   |    I2C     |
+  | MCP48FEB01 |              |      1      |      1      |   EEPROM   |    SPI     |
+  | MCP48FEB02 |              |      2      |      1      |   EEPROM   |    SPI     |
+  | MCP48FEB04 |              |      4      |      2      |   EEPROM   |    SPI     |
+  | MCP48FEB08 |              |      8      |      2      |   EEPROM   |    SPI     |
+  |------------|--------------|-------------|-------------|------------|------------|
+  | MCP47FEB11 |              |      1      |      1      |   EEPROM   |    I2C     |
+  | MCP47FEB12 |              |      2      |      1      |   EEPROM   |    I2C     |
+  | MCP47FEB14 |              |      4      |      2      |   EEPROM   |    I2C     |
+  | MCP47FEB18 |    10-bit    |      8      |      2      |   EEPROM   |    I2C     |
+  | MCP48FEB11 |              |      1      |      1      |   EEPROM   |    SPI     |
+  | MCP48FEB12 |              |      2      |      1      |   EEPROM   |    SPI     |
+  | MCP48FEB14 |              |      4      |      2      |   EEPROM   |    SPI     |
+  | MCP48FEB18 |              |      8      |      2      |   EEPROM   |    SPI     |
+  |------------|--------------|-------------|-------------|------------|------------|
+  | MCP47FEB21 |              |      1      |      1      |   EEPROM   |    I2C     |
+  | MCP47FEB22 |              |      2      |      1      |   EEPROM   |    I2C     |
+  | MCP47FEB24 |              |      4      |      2      |   EEPROM   |    I2C     |
+  | MCP47FEB28 |    12-bit    |      8      |      2      |   EEPROM   |    I2C     |
+  | MCP48FEB21 |              |      1      |      1      |   EEPROM   |    SPI     |
+  | MCP48FEB22 |              |      2      |      1      |   EEPROM   |    SPI     |
+  | MCP48FEB24 |              |      4      |      2      |   EEPROM   |    SPI     |
+  | MCP48FEB28 |              |      8      |      2      |   EEPROM   |    SPI     |
+  |------------|--------------|-------------|-------------|------------|------------|
+  | MCP47FVB01 |              |      1      |      1      |   RAM      |    I2C     |
+  | MCP47FVB02 |              |      2      |      1      |   RAM      |    I2C     |
+  | MCP47FVB04 |              |      4      |      2      |   RAM      |    I2C     |
+  | MCP47FVB08 |     8-bit    |      8      |      2      |   RAM      |    I2C     |
+  | MCP48FVB01 |              |      1      |      1      |   RAM      |    SPI     |
+  | MCP48FVB02 |              |      2      |      1      |   RAM      |    SPI     |
+  | MCP48FVB04 |              |      4      |      2      |   RAM      |    SPI     |
+  | MCP48FVB08 |              |      8      |      2      |   RAM      |    SPI     |
+  |------------|--------------|-------------|-------------|------------|------------|
+  | MCP47FVB11 |              |      1      |      1      |   RAM      |    I2C     |
+  | MCP47FVB12 |              |      2      |      1      |   RAM      |    I2C     |
+  | MCP47FVB14 |              |      4      |      2      |   RAM      |    I2C     |
+  | MCP47FVB18 |    10-bit    |      8      |      2      |   RAM      |    I2C     |
+  | MCP48FVB11 |              |      1      |      1      |   RAM      |    SPI     |
+  | MCP48FVB12 |              |      2      |      1      |   RAM      |    SPI     |
+  | MCP48FVB14 |              |      4      |      2      |   RAM      |    SPI     |
+  | MCP48FVB18 |              |      8      |      2      |   RAM      |    SPI     |
+  |------------|--------------|-------------|-------------|------------|------------|
+  | MCP47FVB21 |              |      1      |      1      |   RAM      |    I2C     |
+  | MCP47FVB22 |              |      2      |      1      |   RAM      |    I2C     |
+  | MCP47FVB24 |              |      4      |      2      |   RAM      |    I2C     |
+  | MCP47FVB28 |    12-bit    |      8      |      2      |   RAM      |    I2C     |
+  | MCP48FVB21 |              |      1      |      1      |   RAM      |    SPI     |
+  | MCP48FVB22 |              |      2      |      1      |   RAM      |    SPI     |
+  | MCP48FVB24 |              |      4      |      2      |   RAM      |    SPI     |
+  | MCP48FVB28 |              |      8      |      2      |   RAM      |    SPI     |
+  +------------+--------------+-------------+-------------+------------+------------+
 
 properties:
   compatible:
@@ -84,10 +118,37 @@ properties:
       - microchip,mcp47feb08
       - microchip,mcp47feb18
       - microchip,mcp47feb28
+      - microchip,mcp48feb01
+      - microchip,mcp48feb02
+      - microchip,mcp48feb04
+      - microchip,mcp48feb08
+      - microchip,mcp48feb11
+      - microchip,mcp48feb12
+      - microchip,mcp48feb14
+      - microchip,mcp48feb18
+      - microchip,mcp48feb21
+      - microchip,mcp48feb22
+      - microchip,mcp48feb24
+      - microchip,mcp48feb28
+      - microchip,mcp48fvb01
+      - microchip,mcp48fvb02
+      - microchip,mcp48fvb04
+      - microchip,mcp48fvb08
+      - microchip,mcp48fvb11
+      - microchip,mcp48fvb12
+      - microchip,mcp48fvb14
+      - microchip,mcp48fvb18
+      - microchip,mcp48fvb21
+      - microchip,mcp48fvb22
+      - microchip,mcp48fvb24
+      - microchip,mcp48fvb28
 
   reg:
     maxItems: 1
 
+  spi-max-frequency:
+    maximum: 10000000
+
   "#address-cells":
     const: 1
 
@@ -178,6 +239,21 @@ required:
   - vdd-supply
 
 allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            pattern: "^microchip,mcp48f[ev]b[0-2][1248]$"
+    then:
+      $ref: /schemas/spi/spi-peripheral-props.yaml#
+      dependencies:
+        spi-cpha: [ spi-cpol ]
+        spi-cpol: [ spi-cpha ]
+    else:
+      properties:
+        spi-max-frequency: false
+        spi-cpha: false
+        spi-cpol: false
   - if:
       properties:
         compatible:
@@ -189,6 +265,12 @@ allOf:
               - microchip,mcp47fvb01
               - microchip,mcp47fvb11
               - microchip,mcp47fvb21
+              - microchip,mcp48feb01
+              - microchip,mcp48feb11
+              - microchip,mcp48feb21
+              - microchip,mcp48fvb01
+              - microchip,mcp48fvb11
+              - microchip,mcp48fvb21
     then:
       properties:
         lat1-gpios: false
@@ -211,6 +293,12 @@ allOf:
               - microchip,mcp47fvb02
               - microchip,mcp47fvb12
               - microchip,mcp47fvb22
+              - microchip,mcp48feb02
+              - microchip,mcp48feb12
+              - microchip,mcp48feb22
+              - microchip,mcp48fvb02
+              - microchip,mcp48fvb12
+              - microchip,mcp48fvb22
     then:
       properties:
         lat1-gpios: false
@@ -233,6 +321,12 @@ allOf:
               - microchip,mcp47feb04
               - microchip,mcp47feb14
               - microchip,mcp47feb24
+              - microchip,mcp48feb04
+              - microchip,mcp48feb14
+              - microchip,mcp48feb24
+              - microchip,mcp48fvb04
+              - microchip,mcp48fvb14
+              - microchip,mcp48fvb24
     then:
       patternProperties:
         "^channel@[0-3]$":
@@ -251,6 +345,12 @@ allOf:
               - microchip,mcp47feb08
               - microchip,mcp47feb18
               - microchip,mcp47feb28
+              - microchip,mcp48feb08
+              - microchip,mcp48feb18
+              - microchip,mcp48feb28
+              - microchip,mcp48fvb08
+              - microchip,mcp48fvb18
+              - microchip,mcp48fvb28
     then:
       patternProperties:
         "^channel@[0-7]$":
@@ -272,7 +372,7 @@ allOf:
       properties:
         microchip,vref1-buffered: false
 
-additionalProperties: false
+unevaluatedProperties: false
 
 examples:
   - |
@@ -299,4 +399,29 @@ examples:
             };
         };
     };
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        dac@0 {
+          compatible = "microchip,mcp48feb02";
+          reg = <0x0>;
+          vdd-supply = <&vdac_vdd>;
+          vref-supply = <&vref_reg>;
+          spi-max-frequency = <10000000>;
+
+          #address-cells = <1>;
+          #size-cells = <0>;
+          channel@0 {
+            reg = <0>;
+            label = "Adjustable_voltage_ch0";
+          };
+
+          channel@1 {
+            reg = <0x1>;
+            label = "Adjustable_voltage_ch1";
+          };
+        };
+    };
 ...

-- 
2.43.0

[PATCH v4 9/9] iio: dac: add support for Microchip MCP48FEB02

[Ariana Lazar]

This is the iio driver for Microchip MCP48FxBy1/2/4/8 series of buffered
voltage output Digital-to-Analog Converters with nonvolatile or volatile
memory and an SPI Interface.

The families support up to 8 output channels.

The devices can be 8-bit, 10-bit and 12-bit.

Signed-off-by: Ariana Lazar <ariana.lazar@microchip.com>
---
 MAINTAINERS                      |   1 +
 drivers/iio/dac/Kconfig          |  23 +++++++
 drivers/iio/dac/Makefile         |   1 +
 drivers/iio/dac/mcp47feb02-spi.c | 145 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 170 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index fc87609865f26a9f484edc42058f7df659a0fa4f..b2ffcc0161ba0d147df35558312cbf99052ed13e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16120,6 +16120,7 @@ S:	Supported
 F:	Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
 F:	drivers/iio/dac/mcp47feb02-core.c
 F:	drivers/iio/dac/mcp47feb02-i2c.c
+F:	drivers/iio/dac/mcp47feb02-spi.c
 F:	drivers/iio/dac/mcp47feb02.h
 
 MCP4821 DAC DRIVER
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index cc10d43ffd1e89bbf945ef89ea5af0abe1a91084..d941f78f7110b185fee6f025be829bae1e4534da 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -575,6 +575,29 @@ config MCP47FEB02_I2C
 	  will be called mcp47feb02_i2c and you will also get
 	  mcp47feb02_core for the core module.
 
+config MCP47FEB02_SPI
+	tristate "MCP48F(E/V)B01/02/04/08/11/12/14/18/21/22/24/28 SPI DAC driver"
+	depends on SPI
+	select REGMAP_SPI
+	select MCP47FEB02
+	help
+	  Say yes here if you want to build the driver for the Microchip:
+	  - 8-bit DAC:
+	    MCP48FEB01, MCP48FEB02, MCP48FEB04, MCP48FEB08,
+	    MCP48FVB01, MCP48FVB02, MCP48FVB04, MCP48FVB08
+	  - 10-bit DAC:
+	    MCP48FEB11, MCP48FEB12, MCP48FEB14, MCP48FEB18,
+	    MCP48FVB11, MCP48FVB12, MCP48FVB14, MCP48FVB18
+	  - 12-bit DAC:
+	    MCP48FEB21, MCP48FEB22, MCP48FEB24, MCP48FEB28,
+	    MCP48FVB21, MCP48FVB22, MCP48FVB24, MCP48FVB28
+	  having 1 to 8 channels, 8/10/12-bit digital-to-analog converter
+	  (DAC) with SPI interface.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called mcp47feb02_spi and you will also get
+	  mcp47feb02_core for the core module.
+
 config MCP4821
 	tristate "MCP4801/02/11/12/21/22 DAC driver"
 	depends on SPI
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 28c8646a987cff1ac4d693fe86898d66c901d5bd..9903198b934e8b66a4ea6562b662d8073ed9cc59 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_MCP4725) += mcp4725.o
 obj-$(CONFIG_MCP4728) += mcp4728.o
 obj-$(CONFIG_MCP47FEB02) += mcp47feb02-core.o
 obj-$(CONFIG_MCP47FEB02_I2C) += mcp47feb02-i2c.o
+obj-$(CONFIG_MCP47FEB02_SPI) += mcp47feb02-spi.o
 obj-$(CONFIG_MCP4821) += mcp4821.o
 obj-$(CONFIG_MCP4922) += mcp4922.o
 obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
diff --git a/drivers/iio/dac/mcp47feb02-spi.c b/drivers/iio/dac/mcp47feb02-spi.c
new file mode 100644
index 0000000000000000000000000000000000000000..0c68d7c318cb2269a9d713d3c6ec0854a576c19e
--- /dev/null
+++ b/drivers/iio/dac/mcp47feb02-spi.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IIO driver for MCP48FEB02 Multi-Channel DAC with SPI interface
+ *
+ * Copyright (C) 2025-2026 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Ariana Lazar <ariana.lazar@microchip.com>
+ *
+ * Datasheet links for devices with SPI interface:
+ * [MCP48FEBxx] https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005429B.pdf
+ * [MCP48FVBxx] https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005466A.pdf
+ * [MCP48FxBx4/8] https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP48FXBX4-8-Family-Data-Sheet-DS20006362A.pdf
+ */
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+
+#include "mcp47feb02.h"
+
+/* Parts with EEPROM memory */
+MCP47FEB02_CHIP_INFO(mcp48feb01, 1, 8,  false, true);
+MCP47FEB02_CHIP_INFO(mcp48feb02, 2, 8,  false, true);
+MCP47FEB02_CHIP_INFO(mcp48feb04, 4, 8,  true,  true);
+MCP47FEB02_CHIP_INFO(mcp48feb08, 8, 8,  true,  true);
+MCP47FEB02_CHIP_INFO(mcp48feb11, 1, 10, false, true);
+MCP47FEB02_CHIP_INFO(mcp48feb12, 2, 10, false, true);
+MCP47FEB02_CHIP_INFO(mcp48feb14, 4, 10, true,  true);
+MCP47FEB02_CHIP_INFO(mcp48feb18, 8, 10, true,  true);
+MCP47FEB02_CHIP_INFO(mcp48feb21, 1, 12, false, true);
+MCP47FEB02_CHIP_INFO(mcp48feb22, 2, 12, false, true);
+MCP47FEB02_CHIP_INFO(mcp48feb24, 4, 12, true,  true);
+MCP47FEB02_CHIP_INFO(mcp48feb28, 8, 12, true,  true);
+
+/* Parts without EEPROM memory */
+MCP47FEB02_CHIP_INFO(mcp48fvb01, 1, 8,  false, false);
+MCP47FEB02_CHIP_INFO(mcp48fvb02, 2, 8,  false, false);
+MCP47FEB02_CHIP_INFO(mcp48fvb04, 4, 8,  true,  false);
+MCP47FEB02_CHIP_INFO(mcp48fvb08, 8, 8,  true,  false);
+MCP47FEB02_CHIP_INFO(mcp48fvb11, 1, 10, false, false);
+MCP47FEB02_CHIP_INFO(mcp48fvb12, 2, 10, false, false);
+MCP47FEB02_CHIP_INFO(mcp48fvb14, 4, 10, true,  false);
+MCP47FEB02_CHIP_INFO(mcp48fvb18, 8, 10, true,  false);
+MCP47FEB02_CHIP_INFO(mcp48fvb21, 1, 12, false, false);
+MCP47FEB02_CHIP_INFO(mcp48fvb22, 2, 12, false, false);
+MCP47FEB02_CHIP_INFO(mcp48fvb24, 4, 12, true,  false);
+MCP47FEB02_CHIP_INFO(mcp48fvb28, 8, 12, true,  false);
+
+static int mcp47feb02_spi_probe(struct spi_device *spi)
+{
+	const struct mcp47feb02_features *chip_features;
+	struct device *dev = &spi->dev;
+	struct regmap *regmap;
+
+	chip_features = spi_get_device_match_data(spi);
+	if (!chip_features)
+		return dev_err_probe(dev, -ENODEV, "No SPI device found\n");
+
+	if (chip_features->have_eeprom)
+		regmap = devm_regmap_init_spi(spi, &mcp47feb02_regmap_config);
+	else
+		regmap = devm_regmap_init_spi(spi, &mcp47fvb02_regmap_config);
+
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap), "Error initializing SPI regmap\n");
+
+	return mcp47feb02_common_probe(chip_features, regmap);
+}
+
+static const struct spi_device_id mcp47feb02_spi_id[] = {
+	{ .name = "mcp48feb01", .driver_data = (kernel_ulong_t)&mcp48feb01_chip_features },
+	{ .name = "mcp48feb02", .driver_data = (kernel_ulong_t)&mcp48feb02_chip_features },
+	{ .name = "mcp48feb04", .driver_data = (kernel_ulong_t)&mcp48feb04_chip_features },
+	{ .name = "mcp48feb08", .driver_data = (kernel_ulong_t)&mcp48feb08_chip_features },
+	{ .name = "mcp48feb11", .driver_data = (kernel_ulong_t)&mcp48feb11_chip_features },
+	{ .name = "mcp48feb12", .driver_data = (kernel_ulong_t)&mcp48feb12_chip_features },
+	{ .name = "mcp48feb14", .driver_data = (kernel_ulong_t)&mcp48feb14_chip_features },
+	{ .name = "mcp48feb18", .driver_data =  (kernel_ulong_t)&mcp48feb18_chip_features },
+	{ .name = "mcp48feb21", .driver_data = (kernel_ulong_t)&mcp48feb21_chip_features },
+	{ .name = "mcp48feb22", .driver_data = (kernel_ulong_t)&mcp48feb22_chip_features },
+	{ .name = "mcp48feb24", .driver_data = (kernel_ulong_t)&mcp48feb24_chip_features },
+	{ .name = "mcp48feb28", .driver_data = (kernel_ulong_t)&mcp48feb28_chip_features },
+	{ .name = "mcp48fvb01", .driver_data = (kernel_ulong_t)&mcp48fvb01_chip_features },
+	{ .name = "mcp48fvb02", .driver_data = (kernel_ulong_t)&mcp48fvb02_chip_features },
+	{ .name = "mcp48fvb04", .driver_data = (kernel_ulong_t)&mcp48fvb04_chip_features },
+	{ .name = "mcp48fvb08", .driver_data = (kernel_ulong_t)&mcp48fvb08_chip_features },
+	{ .name = "mcp48fvb11", .driver_data = (kernel_ulong_t)&mcp48fvb11_chip_features },
+	{ .name = "mcp48fvb12", .driver_data = (kernel_ulong_t)&mcp48fvb12_chip_features },
+	{ .name = "mcp48fvb14", .driver_data = (kernel_ulong_t)&mcp48fvb14_chip_features },
+	{ .name = "mcp48fvb18", .driver_data = (kernel_ulong_t)&mcp48fvb18_chip_features },
+	{ .name = "mcp48fvb21", .driver_data = (kernel_ulong_t)&mcp48fvb21_chip_features },
+	{ .name = "mcp48fvb22", .driver_data = (kernel_ulong_t)&mcp48fvb22_chip_features },
+	{ .name = "mcp48fvb24", .driver_data = (kernel_ulong_t)&mcp48fvb24_chip_features },
+	{ .name = "mcp48fvb28", .driver_data = (kernel_ulong_t)&mcp48fvb28_chip_features },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, mcp47feb02_spi_id);
+
+static const struct of_device_id mcp47feb02_of_spi_match[] = {
+	{ .compatible = "microchip,mcp48feb01", .data = &mcp48feb01_chip_features },
+	{ .compatible = "microchip,mcp48feb02", .data = &mcp48feb02_chip_features },
+	{ .compatible = "microchip,mcp48feb04", .data = &mcp48feb04_chip_features },
+	{ .compatible = "microchip,mcp48feb08", .data = &mcp48feb08_chip_features },
+	{ .compatible = "microchip,mcp48feb11", .data = &mcp48feb11_chip_features },
+	{ .compatible = "microchip,mcp48feb12", .data = &mcp48feb12_chip_features },
+	{ .compatible = "microchip,mcp48feb14", .data = &mcp48feb14_chip_features },
+	{ .compatible = "microchip,mcp48feb18", .data = &mcp48feb18_chip_features },
+	{ .compatible = "microchip,mcp48feb21", .data = &mcp48feb21_chip_features },
+	{ .compatible = "microchip,mcp48feb22", .data = &mcp48feb22_chip_features },
+	{ .compatible = "microchip,mcp48feb24", .data = &mcp48feb24_chip_features },
+	{ .compatible = "microchip,mcp48feb28", .data = &mcp48feb28_chip_features },
+	{ .compatible = "microchip,mcp48fvb01", .data = &mcp48fvb01_chip_features },
+	{ .compatible = "microchip,mcp48fvb02", .data = &mcp48fvb02_chip_features },
+	{ .compatible = "microchip,mcp48fvb04", .data = &mcp48fvb04_chip_features },
+	{ .compatible = "microchip,mcp48fvb08", .data = &mcp48fvb08_chip_features },
+	{ .compatible = "microchip,mcp48fvb11", .data = &mcp48fvb11_chip_features },
+	{ .compatible = "microchip,mcp48fvb12", .data = &mcp48fvb12_chip_features },
+	{ .compatible = "microchip,mcp48fvb14",	.data = &mcp48fvb14_chip_features },
+	{ .compatible = "microchip,mcp48fvb18", .data = &mcp48fvb18_chip_features },
+	{ .compatible = "microchip,mcp48fvb21", .data = &mcp48fvb21_chip_features },
+	{ .compatible = "microchip,mcp48fvb22", .data = &mcp48fvb22_chip_features },
+	{ .compatible = "microchip,mcp48fvb24", .data = &mcp48fvb24_chip_features },
+	{ .compatible = "microchip,mcp48fvb28", .data = &mcp48fvb28_chip_features },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mcp47feb02_of_spi_match);
+
+static struct spi_driver mcp47feb02_spi_driver = {
+	.driver = {
+		.name = "mcp47feb02",
+		.of_match_table = mcp47feb02_of_spi_match,
+		.pm = pm_sleep_ptr(&mcp47feb02_pm_ops),
+	},
+	.probe = mcp47feb02_spi_probe,
+	.id_table = mcp47feb02_spi_id,
+};
+module_spi_driver(mcp47feb02_spi_driver);
+
+MODULE_AUTHOR("Ariana Lazar <ariana.lazar@microchip.com>");
+MODULE_DESCRIPTION("IIO driver for MCP48FEB02 Multi-Channel DAC with SPI interface");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("IIO_MCP47FEB02");

-- 
2.43.0

Re: [PATCH v4 9/9] iio: dac: add support for Microchip MCP48FEB02

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The EEPROM write cycle polling timeout is too short, leading to sporadic -ETIMEDOUT errors and partial EEPROM updates.
--

--- Patch [9]: [PATCH v4 9/9] iio: dac: add support for Microchip MCP48FEB02 ---
commit f9a8ca3d3f3e9e1b7296c59e5fdc69c68349d1ae
Author: Ariana Lazar <ariana.lazar@microchip.com>

iio: dac: add support for Microchip MCP48FEB02

This patch adds SPI support for the Microchip MCP48FxBy1/2/4/8 series of DACs.
It introduces a new SPI driver module that registers devices using the common
core probe function.

[ ... ]

> diff --git a/drivers/iio/dac/mcp47feb02-spi.c b/drivers/iio/dac/mcp47feb02-spi.c
> new file mode 100644
> index 0000000000000..0c68d7c318cb2
> --- /dev/null
> +++ b/drivers/iio/dac/mcp47feb02-spi.c
> @@ -0,0 +1,145 @@
[ ... ]
> +static int mcp47feb02_spi_probe(struct spi_device *spi)
> +{
> +	const struct mcp47feb02_features *chip_features;
> +	struct device *dev = &spi->dev;
> +	struct regmap *regmap;
> +
> +	chip_features = spi_get_device_match_data(spi);
> +	if (!chip_features)
> +		return dev_err_probe(dev, -ENODEV, "No SPI device found\n");
> +
> +	if (chip_features->have_eeprom)
> +		regmap = devm_regmap_init_spi(spi, &mcp47feb02_regmap_config);
> +	else
> +		regmap = devm_regmap_init_spi(spi, &mcp47fvb02_regmap_config);
> +
> +	if (IS_ERR(regmap))
> +		return dev_err_probe(dev, PTR_ERR(regmap), "Error initializing SPI regmap\n");
> +
> +	return mcp47feb02_common_probe(chip_features, regmap);
> +}

[Severity: High]
This isn't a bug introduced by this patch, but I noticed a potential timeout
problem in the core driver that might affect these newly supported SPI devices.

In drivers/iio/dac/mcp47feb02-core.c:mcp47feb02_write_to_eeprom(), the EEPROM
write cycle polling timeout is set to 5 ms:

	ret = regmap_read_poll_timeout(data->regmap, MCP47FEB02_GAIN_CTRL_STATUS_REG_ADDR,
				       eewa_val,
				       !(eewa_val & MCP47FEB02_GAIN_BIT_STATUS_EEWA_MASK),
				       USEC_PER_MSEC, USEC_PER_MSEC * 5);

Could this short timeout cause sporadic -ETIMEDOUT errors during EEPROM writes?

The EEPROM write cycle (t_WC) for the MCP47/48FEBxx series can take up to 10 ms.
When a user writes to the store_eeprom sysfs attribute, this function is called
in a loop. Could a timeout here cause the sequence to abort midway, leaving
the EEPROM in an inconsistent, partially updated state?

The same 5 ms timeout appears again in store_eeprom_store():

	ret = regmap_read_poll_timeout(data->regmap, MCP47FEB02_GAIN_CTRL_STATUS_REG_ADDR, eewa_val,
				       !(eewa_val & MCP47FEB02_GAIN_BIT_STATUS_EEWA_MASK),
				       USEC_PER_MSEC, USEC_PER_MSEC * 5);

Would it be better to increase the timeout to at least 10 ms to match the
hardware maximum?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819-mcp47feb02_refactor-v4-0-beb2aa3bfd09@microchip.com?part=9