[PATCH v2 0/4] dev_printk: add dev_errp_probe() helper

[PATCH v2 0/4] dev_printk: add dev_errp_probe() helper

[Nuno Sa]

Hi,

Here it goes the second version of this. Main difference is the
introduction of dev_err_cast_probe(). Full log:

v1:
 * https://lore.kernel.org/all/20240404-dev-add_dev_errp_probe-v1-0-d18e3eb7ec3f@analog.com/

v2:
 * Patch 1:
   - Renamed dev_errp_probe() -> dev_err_ptr_probe();
   - Added dev_err_cast_probe().
 * Patch 2:
   - Make use of dev_err_cast_probe();
   - Also use dev_err_ptr_probe() in __ltc2983_custom_sensor_new().  
 * Patch 3:
   - Use dev_err_cast_probe().

---
Nuno Sa (4):
      dev_printk: add new dev_err_probe() helpers
      iio: temperature: ltc2983: convert to dev_err_probe()
      iio: backend: make use of dev_err_cast_probe()
      iio: common: scmi_iio: convert to dev_err_probe()

 drivers/iio/common/scmi_sensors/scmi_iio.c |  45 ++---
 drivers/iio/industrialio-backend.c         |   8 +-
 drivers/iio/temperature/ltc2983.c          | 282 +++++++++++++----------------
 include/linux/dev_printk.h                 |   9 +
 4 files changed, 158 insertions(+), 186 deletions(-)
---
base-commit: a59668a9397e7245b26e9be85d23f242ff757ae8
change-id: 20240423-dev-add_dev_errp_probe-1dd04573f4a5
--

Thanks!
- Nuno Sá

[PATCH v2 0/4] dev_printk: add dev_errp_probe() helper

[Nuno Sa via B4 Relay]

Hi,

Here it goes the second version of this. Main difference is the
introduction of dev_err_cast_probe(). Full log:

v1:
 * https://lore.kernel.org/all/20240404-dev-add_dev_errp_probe-v1-0-d18e3eb7ec3f@analog.com/

v2:
 * Patch 1:
   - Renamed dev_errp_probe() -> dev_err_ptr_probe();
   - Added dev_err_cast_probe().
 * Patch 2:
   - Make use of dev_err_cast_probe();
   - Also use dev_err_ptr_probe() in __ltc2983_custom_sensor_new().  
 * Patch 3:
   - Use dev_err_cast_probe().

---
Nuno Sa (4):
      dev_printk: add new dev_err_probe() helpers
      iio: temperature: ltc2983: convert to dev_err_probe()
      iio: backend: make use of dev_err_cast_probe()
      iio: common: scmi_iio: convert to dev_err_probe()

 drivers/iio/common/scmi_sensors/scmi_iio.c |  45 ++---
 drivers/iio/industrialio-backend.c         |   8 +-
 drivers/iio/temperature/ltc2983.c          | 282 +++++++++++++----------------
 include/linux/dev_printk.h                 |   9 +
 4 files changed, 158 insertions(+), 186 deletions(-)
---
base-commit: a59668a9397e7245b26e9be85d23f242ff757ae8
change-id: 20240423-dev-add_dev_errp_probe-1dd04573f4a5
--

Thanks!
- Nuno Sá

[PATCH v2 1/4] dev_printk: add new dev_err_probe() helpers

[Nuno Sa]

This is similar to dev_err_probe() but for cases where an ERR_PTR() or
ERR_CAST() is to be returned simplifying patterns like:

	dev_err_probe(dev, ret, ...);
	return ERR_PTR(ret)
or
	dev_err_probe(dev, PTR_ERR(ptr), ...);
	return ERR_CAST(ptr)

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 include/linux/dev_printk.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/dev_printk.h b/include/linux/dev_printk.h
index ae80a303c216..b9623ec22350 100644
--- a/include/linux/dev_printk.h
+++ b/include/linux/dev_printk.h
@@ -277,4 +277,13 @@ do {									\
 
 __printf(3, 4) int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
 
+/* Simple helper for dev_err_probe() when ERR_PTR() is to be returned. */
+#define dev_err_ptr_probe(dev, ___err, fmt, ...)	({		\
+	ERR_PTR(dev_err_probe(dev, ___err, fmt, ##__VA_ARGS__));	\
+})
+
+/* Simple helper for dev_err_probe() when ERR_CAST() is to be returned. */
+#define dev_err_cast_probe(dev, ___err_ptr, fmt, ...)	({			\
+	ERR_PTR(dev_err_probe(dev, PTR_ERR(___err_ptr), fmt, ##__VA_ARGS__));	\
+})
 #endif /* _DEVICE_PRINTK_H_ */

-- 
2.44.0

[PATCH v2 1/4] dev_printk: add new dev_err_probe() helpers

[Nuno Sa via B4 Relay]

From: Nuno Sa <nuno.sa@analog.com>

This is similar to dev_err_probe() but for cases where an ERR_PTR() or
ERR_CAST() is to be returned simplifying patterns like:

	dev_err_probe(dev, ret, ...);
	return ERR_PTR(ret)
or
	dev_err_probe(dev, PTR_ERR(ptr), ...);
	return ERR_CAST(ptr)

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 include/linux/dev_printk.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/dev_printk.h b/include/linux/dev_printk.h
index ae80a303c216..b9623ec22350 100644
--- a/include/linux/dev_printk.h
+++ b/include/linux/dev_printk.h
@@ -277,4 +277,13 @@ do {									\
 
 __printf(3, 4) int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
 
+/* Simple helper for dev_err_probe() when ERR_PTR() is to be returned. */
+#define dev_err_ptr_probe(dev, ___err, fmt, ...)	({		\
+	ERR_PTR(dev_err_probe(dev, ___err, fmt, ##__VA_ARGS__));	\
+})
+
+/* Simple helper for dev_err_probe() when ERR_CAST() is to be returned. */
+#define dev_err_cast_probe(dev, ___err_ptr, fmt, ...)	({			\
+	ERR_PTR(dev_err_probe(dev, PTR_ERR(___err_ptr), fmt, ##__VA_ARGS__));	\
+})
 #endif /* _DEVICE_PRINTK_H_ */

-- 
2.44.0

Re: [PATCH v2 1/4] dev_printk: add new dev_err_probe() helpers

[Andy Shevchenko]

On Tue, Apr 23, 2024 at 05:20:30PM +0200, Nuno Sa via B4 Relay wrote:
> From: Nuno Sa <nuno.sa@analog.com>
> 
> This is similar to dev_err_probe() but for cases where an ERR_PTR() or
> ERR_CAST() is to be returned simplifying patterns like:
> 
> 	dev_err_probe(dev, ret, ...);
> 	return ERR_PTR(ret)
> or
> 	dev_err_probe(dev, PTR_ERR(ptr), ...);
> 	return ERR_CAST(ptr)

...

> +/* Simple helper for dev_err_probe() when ERR_PTR() is to be returned. */
> +#define dev_err_ptr_probe(dev, ___err, fmt, ...)	({		\
> +	ERR_PTR(dev_err_probe(dev, ___err, fmt, ##__VA_ARGS__));	\
> +})

Why ; and hence why ({}) ?

I even believe the compiler may warn if you have double ;; in some cases.

...

> +#define dev_err_cast_probe(dev, ___err_ptr, fmt, ...)	({			\
> +	ERR_PTR(dev_err_probe(dev, PTR_ERR(___err_ptr), fmt, ##__VA_ARGS__));	\
> +})

Ditto.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 1/4] dev_printk: add new dev_err_probe() helpers

[Andy Shevchenko]

On Tue, Apr 23, 2024 at 06:31:20PM +0300, Andy Shevchenko wrote:
> On Tue, Apr 23, 2024 at 05:20:30PM +0200, Nuno Sa via B4 Relay wrote:
> > From: Nuno Sa <nuno.sa@analog.com>

...

> > +#define dev_err_cast_probe(dev, ___err_ptr, fmt, ...)	({			\
> > +	ERR_PTR(dev_err_probe(dev, PTR_ERR(___err_ptr), fmt, ##__VA_ARGS__));	\
> > +})

After looking into the next patch I think this should be rewritten to use %pe,
hence should be an exported function. Or dev_err_probe() should be split to
a version that makes the difference between int and const void * (maybe using
_Generic()).

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 1/4] dev_printk: add new dev_err_probe() helpers

[Nuno Sá]

On Tue, 2024-04-23 at 18:45 +0300, Andy Shevchenko wrote:
> On Tue, Apr 23, 2024 at 06:31:20PM +0300, Andy Shevchenko wrote:
> > On Tue, Apr 23, 2024 at 05:20:30PM +0200, Nuno Sa via B4 Relay wrote:
> > > From: Nuno Sa <nuno.sa@analog.com>
> 
> ...
> 
> > > +#define dev_err_cast_probe(dev, ___err_ptr, fmt,
> > > ...)	({			\
> > > +	ERR_PTR(dev_err_probe(dev, PTR_ERR(___err_ptr), fmt,
> > > ##__VA_ARGS__));	\
> > > +})
> 
> After looking into the next patch I think this should be rewritten to use %pe,
> hence should be an exported function. Or dev_err_probe() should be split to
> a version that makes the difference between int and const void * (maybe using
> _Generic()).
> 

I replied a bit in the other patch but I'm of the opinion that's likely just more
complicated than it needs to be (IMO). Why is the PTR_ERR(___err_ptr) that bad? If we
really want to have a version that takes pointer why not just:

#define dev_err_ptr_probe(dev, ___err, fmt, ...) \
	dev_err_probe(dev, PTR_ERR(__err), fmt, ##__VA_ARGS__)


(yes, while _Generic() could be fun I'm trying to avoid it. In this case, I think
having explicit defines is more helpful)

- Nuno Sá

Re: [PATCH v2 1/4] dev_printk: add new dev_err_probe() helpers

[Andy Shevchenko]

On Thu, May 02, 2024 at 01:54:36PM +0200, Nuno Sá wrote:
> On Tue, 2024-04-23 at 18:45 +0300, Andy Shevchenko wrote:
> > On Tue, Apr 23, 2024 at 06:31:20PM +0300, Andy Shevchenko wrote:
> > > On Tue, Apr 23, 2024 at 05:20:30PM +0200, Nuno Sa via B4 Relay wrote:
> > > > From: Nuno Sa <nuno.sa@analog.com>

...

> > > > +#define dev_err_cast_probe(dev, ___err_ptr, fmt,
> > > > ...)	({			\
> > > > +	ERR_PTR(dev_err_probe(dev, PTR_ERR(___err_ptr), fmt,
> > > > ##__VA_ARGS__));	\
> > > > +})
> > 
> > After looking into the next patch I think this should be rewritten to use %pe,
> > hence should be an exported function. Or dev_err_probe() should be split to
> > a version that makes the difference between int and const void * (maybe using
> > _Generic()).
> 
> I replied a bit in the other patch but I'm of the opinion that's likely just more
> complicated than it needs to be (IMO). Why is the PTR_ERR(___err_ptr) that bad? If we
> really want to have a version that takes pointer why not just:
> 
> #define dev_err_ptr_probe(dev, ___err, fmt, ...) \
> 	dev_err_probe(dev, PTR_ERR(__err), fmt, ##__VA_ARGS__)
> 
> 
> (yes, while _Generic() could be fun I'm trying to avoid it. In this case, I think
> having explicit defines is more helpful)

It seems dev_err_probe() already uses %pe, so we are fine.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 1/4] dev_printk: add new dev_err_probe() helpers

[Nuno Sá]

On Tue, 2024-04-23 at 18:31 +0300, Andy Shevchenko wrote:
> On Tue, Apr 23, 2024 at 05:20:30PM +0200, Nuno Sa via B4 Relay wrote:
> > From: Nuno Sa <nuno.sa@analog.com>
> > 
> > This is similar to dev_err_probe() but for cases where an ERR_PTR() or
> > ERR_CAST() is to be returned simplifying patterns like:
> > 
> > 	dev_err_probe(dev, ret, ...);
> > 	return ERR_PTR(ret)
> > or
> > 	dev_err_probe(dev, PTR_ERR(ptr), ...);
> > 	return ERR_CAST(ptr)
> 
> ...
> 
> > +/* Simple helper for dev_err_probe() when ERR_PTR() is to be returned. */
> > +#define dev_err_ptr_probe(dev, ___err, fmt, ...)	({		\
> > +	ERR_PTR(dev_err_probe(dev, ___err, fmt, ##__VA_ARGS__));	\
> > +})
> 
> Why ; and hence why ({}) ?
> 
> I even believe the compiler may warn if you have double ;; in some cases.
> 

Oh yes, no need for any of those...

- Nuno Sá

[PATCH v2 2/4] iio: temperature: ltc2983: convert to dev_err_probe()

[Nuno Sa]

Use dev_err_probe() in the probe() path. While at it, made some simple
improvements:
 * Declare a struct device *dev helper. This also makes the style more
   consistent (some places the helper was used and not in other places);
 * Explicitly included the err.h and errno.h headers;
 * Removed an useless else if();
 * Removed some unnecessary line breaks.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 drivers/iio/temperature/ltc2983.c | 282 +++++++++++++++++---------------------
 1 file changed, 127 insertions(+), 155 deletions(-)

diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c
index 24d19f3c7292..941b3ab5c927 100644
--- a/drivers/iio/temperature/ltc2983.c
+++ b/drivers/iio/temperature/ltc2983.c
@@ -8,6 +8,8 @@
 #include <linux/bitfield.h>
 #include <linux/completion.h>
 #include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/iio/iio.h>
 #include <linux/interrupt.h>
@@ -432,10 +434,9 @@ __ltc2983_custom_sensor_new(struct ltc2983_data *st, const struct fwnode_handle
 	else
 		n_entries = fwnode_property_count_u64(fn, propname);
 	/* n_entries must be an even number */
-	if (!n_entries || (n_entries % 2) != 0) {
-		dev_err(dev, "Number of entries either 0 or not even\n");
-		return ERR_PTR(-EINVAL);
-	}
+	if (!n_entries || (n_entries % 2) != 0)
+		return dev_err_ptr_probe(dev, -EINVAL,
+					 "Number of entries either 0 or not even\n");
 
 	new_custom = devm_kzalloc(dev, sizeof(*new_custom), GFP_KERNEL);
 	if (!new_custom)
@@ -443,19 +444,17 @@ __ltc2983_custom_sensor_new(struct ltc2983_data *st, const struct fwnode_handle
 
 	new_custom->size = n_entries * n_size;
 	/* check Steinhart size */
-	if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE) {
-		dev_err(dev, "Steinhart sensors size(%zu) must be %u\n", new_custom->size,
-			LTC2983_CUSTOM_STEINHART_SIZE);
-		return ERR_PTR(-EINVAL);
-	}
+	if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE)
+		return dev_err_ptr_probe(dev, -EINVAL,
+					 "Steinhart sensors size(%zu) must be %u\n",
+					 new_custom->size, LTC2983_CUSTOM_STEINHART_SIZE);
+
 	/* Check space on the table. */
 	if (st->custom_table_size + new_custom->size >
-	    (LTC2983_CUST_SENS_TBL_END_REG -
-	     LTC2983_CUST_SENS_TBL_START_REG) + 1) {
-		dev_err(dev, "No space left(%d) for new custom sensor(%zu)",
-				st->custom_table_size, new_custom->size);
-		return ERR_PTR(-EINVAL);
-	}
+	    (LTC2983_CUST_SENS_TBL_END_REG - LTC2983_CUST_SENS_TBL_START_REG) + 1)
+		return dev_err_ptr_probe(dev, -EINVAL,
+					 "No space left(%d) for new custom sensor(%zu)",
+					 st->custom_table_size, new_custom->size);
 
 	/* allocate the table */
 	if (is_steinhart)
@@ -658,10 +657,11 @@ ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data
 			 const struct ltc2983_sensor *sensor)
 {
 	struct ltc2983_thermocouple *thermo;
+	struct device *dev = &st->spi->dev;
 	u32 oc_current;
 	int ret;
 
-	thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), GFP_KERNEL);
+	thermo = devm_kzalloc(dev, sizeof(*thermo), GFP_KERNEL);
 	if (!thermo)
 		return ERR_PTR(-ENOMEM);
 
@@ -688,21 +688,19 @@ ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data
 					LTC2983_THERMOCOUPLE_OC_CURR(3);
 			break;
 		default:
-			dev_err(&st->spi->dev,
-				"Invalid open circuit current:%u", oc_current);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid open circuit current:%u",
+					      oc_current);
 		}
 
 		thermo->sensor_config |= LTC2983_THERMOCOUPLE_OC_CHECK(1);
 	}
 	/* validate channel index */
 	if (!(thermo->sensor_config & LTC2983_THERMOCOUPLE_DIFF_MASK) &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev,
-			"Invalid chann:%d for differential thermocouple",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chann:%d for differential thermocouple",
+				      sensor->chan);
 
 	struct fwnode_handle *ref __free(fwnode_handle) =
 		fwnode_find_reference(child, "adi,cold-junction-handle", 0);
@@ -710,14 +708,13 @@ ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data
 		ref = NULL;
 	} else {
 		ret = fwnode_property_read_u32(ref, "reg", &thermo->cold_junction_chan);
-		if (ret) {
+		if (ret)
 			/*
 			 * This would be catched later but we can just return
 			 * the error right away.
 			 */
-			dev_err(&st->spi->dev, "Property reg must be given\n");
-			return ERR_PTR(ret);
-		}
+			return dev_err_ptr_probe(dev, ret,
+					      "Property reg must be given\n");
 	}
 
 	/* check custom sensor */
@@ -753,16 +750,14 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 
 	struct fwnode_handle *ref __free(fwnode_handle) =
 		fwnode_find_reference(child, "adi,rsense-handle", 0);
-	if (IS_ERR(ref)) {
-		dev_err(dev, "Property adi,rsense-handle missing or invalid");
-		return ERR_CAST(ref);
-	}
+	if (IS_ERR(ref))
+		return dev_err_cast_probe(dev, ref,
+					  "Property adi,rsense-handle missing or invalid");
 
 	ret = fwnode_property_read_u32(ref, "reg", &rtd->r_sense_chan);
-	if (ret) {
-		dev_err(dev, "Property reg must be given\n");
-		return ERR_PTR(ret);
-	}
+	if (ret)
+		return dev_err_ptr_probe(dev, ret,
+				      "Property reg must be given\n");
 
 	ret = fwnode_property_read_u32(child, "adi,number-of-wires", &n_wires);
 	if (!ret) {
@@ -781,19 +776,19 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 			rtd->sensor_config = LTC2983_RTD_N_WIRES(3);
 			break;
 		default:
-			dev_err(dev, "Invalid number of wires:%u\n", n_wires);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid number of wires:%u\n",
+					      n_wires);
 		}
 	}
 
 	if (fwnode_property_read_bool(child, "adi,rsense-share")) {
 		/* Current rotation is only available with rsense sharing */
 		if (fwnode_property_read_bool(child, "adi,current-rotate")) {
-			if (n_wires == 2 || n_wires == 3) {
-				dev_err(dev,
-					"Rotation not allowed for 2/3 Wire RTDs");
-				return ERR_PTR(-EINVAL);
-			}
+			if (n_wires == 2 || n_wires == 3)
+				return dev_err_ptr_probe(dev, -EINVAL,
+						      "Rotation not allowed for 2/3 Wire RTDs");
+
 			rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1);
 		} else {
 			rtd->sensor_config |= LTC2983_RTD_R_SHARE(1);
@@ -816,29 +811,22 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 
 		if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK)
 		     == LTC2983_RTD_KELVIN_R_SENSE_MASK) &&
-		    (rtd->r_sense_chan <=  min)) {
+		    (rtd->r_sense_chan <=  min))
 			/* kelvin rsense*/
-			dev_err(dev,
-				"Invalid rsense chann:%d to use in kelvin rsense",
-				rtd->r_sense_chan);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid rsense chann:%d to use in kelvin rsense",
+					      rtd->r_sense_chan);
 
-			return ERR_PTR(-EINVAL);
-		}
-
-		if (sensor->chan < min || sensor->chan > max) {
-			dev_err(dev, "Invalid chann:%d for the rtd config",
-				sensor->chan);
-
-			return ERR_PTR(-EINVAL);
-		}
+		if (sensor->chan < min || sensor->chan > max)
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid chann:%d for the rtd config",
+					      sensor->chan);
 	} else {
 		/* same as differential case */
-		if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-			dev_err(&st->spi->dev,
-				"Invalid chann:%d for RTD", sensor->chan);
-
-			return ERR_PTR(-EINVAL);
-		}
+		if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid chann:%d for RTD",
+					      sensor->chan);
 	}
 
 	/* check custom sensor */
@@ -886,10 +874,9 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 			rtd->excitation_current = 0x08;
 			break;
 		default:
-			dev_err(&st->spi->dev,
-				"Invalid value for excitation current(%u)",
-				excitation_current);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid value for excitation current(%u)",
+					      excitation_current);
 		}
 	}
 
@@ -913,16 +900,14 @@ ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *s
 
 	struct fwnode_handle *ref __free(fwnode_handle) =
 		fwnode_find_reference(child, "adi,rsense-handle", 0);
-	if (IS_ERR(ref)) {
-		dev_err(dev, "Property adi,rsense-handle missing or invalid");
-		return ERR_CAST(ref);
-	}
+	if (IS_ERR(ref))
+		return dev_err_cast_probe(dev, ref,
+					  "Property adi,rsense-handle missing or invalid");
 
 	ret = fwnode_property_read_u32(ref, "reg", &thermistor->r_sense_chan);
-	if (ret) {
-		dev_err(dev, "rsense channel must be configured...\n");
-		return ERR_PTR(ret);
-	}
+	if (ret)
+		return dev_err_ptr_probe(dev, ret,
+					 "rsense channel must be configured...\n");
 
 	if (fwnode_property_read_bool(child, "adi,single-ended")) {
 		thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1);
@@ -937,12 +922,10 @@ ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *s
 	}
 	/* validate channel index */
 	if (!(thermistor->sensor_config & LTC2983_THERMISTOR_DIFF_MASK) &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev,
-			"Invalid chann:%d for differential thermistor",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chann:%d for differential thermistor",
+				      sensor->chan);
 
 	/* check custom sensor */
 	if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) {
@@ -981,12 +964,10 @@ ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *s
 		switch (excitation_current) {
 		case 0:
 			/* auto range */
-			if (sensor->type >=
-			    LTC2983_SENSOR_THERMISTOR_STEINHART) {
-				dev_err(&st->spi->dev,
-					"Auto Range not allowed for custom sensors\n");
-				return ERR_PTR(-EINVAL);
-			}
+			if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART)
+				return dev_err_ptr_probe(dev, -EINVAL,
+						      "Auto Range not allowed for custom sensors\n");
+
 			thermistor->excitation_current = 0x0c;
 			break;
 		case 250:
@@ -1023,10 +1004,9 @@ ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *s
 			thermistor->excitation_current = 0x0b;
 			break;
 		default:
-			dev_err(&st->spi->dev,
-				"Invalid value for excitation current(%u)",
-				excitation_current);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid value for excitation current(%u)",
+					      excitation_current);
 		}
 	}
 
@@ -1037,11 +1017,12 @@ static struct ltc2983_sensor *
 ltc2983_diode_new(const struct fwnode_handle *child, const struct ltc2983_data *st,
 		  const struct ltc2983_sensor *sensor)
 {
+	struct device *dev = &st->spi->dev;
 	struct ltc2983_diode *diode;
 	u32 temp = 0, excitation_current = 0;
 	int ret;
 
-	diode = devm_kzalloc(&st->spi->dev, sizeof(*diode), GFP_KERNEL);
+	diode = devm_kzalloc(dev, sizeof(*diode), GFP_KERNEL);
 	if (!diode)
 		return ERR_PTR(-ENOMEM);
 
@@ -1056,12 +1037,11 @@ ltc2983_diode_new(const struct fwnode_handle *child, const struct ltc2983_data *
 
 	/* validate channel index */
 	if (!(diode->sensor_config & LTC2983_DIODE_DIFF_MASK) &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev,
-			"Invalid chann:%d for differential thermistor",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chann:%d for differential thermistor",
+				      sensor->chan);
+
 	/* set common parameters */
 	diode->sensor.fault_handler = ltc2983_common_fault_handler;
 	diode->sensor.assign_chan = ltc2983_diode_assign_chan;
@@ -1083,10 +1063,9 @@ ltc2983_diode_new(const struct fwnode_handle *child, const struct ltc2983_data *
 			diode->excitation_current = 0x03;
 			break;
 		default:
-			dev_err(&st->spi->dev,
-				"Invalid value for excitation current(%u)",
-				excitation_current);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid value for excitation current(%u)",
+					      excitation_current);
 		}
 	}
 
@@ -1102,26 +1081,26 @@ static struct ltc2983_sensor *ltc2983_r_sense_new(struct fwnode_handle *child,
 					struct ltc2983_data *st,
 					const struct ltc2983_sensor *sensor)
 {
+	struct device *dev = &st->spi->dev;
 	struct ltc2983_rsense *rsense;
 	int ret;
 	u32 temp;
 
-	rsense = devm_kzalloc(&st->spi->dev, sizeof(*rsense), GFP_KERNEL);
+	rsense = devm_kzalloc(dev, sizeof(*rsense), GFP_KERNEL);
 	if (!rsense)
 		return ERR_PTR(-ENOMEM);
 
 	/* validate channel index */
-	if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev, "Invalid chann:%d for r_sense",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chann:%d for r_sense",
+				      sensor->chan);
 
 	ret = fwnode_property_read_u32(child, "adi,rsense-val-milli-ohms", &temp);
-	if (ret) {
-		dev_err(&st->spi->dev, "Property adi,rsense-val-milli-ohms missing\n");
-		return ERR_PTR(-EINVAL);
-	}
+	if (ret)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Property adi,rsense-val-milli-ohms missing\n");
+
 	/*
 	 * Times 1000 because we have milli-ohms and __convert_to_raw
 	 * expects scales of 1000000 which are used for all other
@@ -1140,21 +1119,21 @@ static struct ltc2983_sensor *ltc2983_adc_new(struct fwnode_handle *child,
 					 struct ltc2983_data *st,
 					 const struct ltc2983_sensor *sensor)
 {
+	struct device *dev = &st->spi->dev;
 	struct ltc2983_adc *adc;
 
-	adc = devm_kzalloc(&st->spi->dev, sizeof(*adc), GFP_KERNEL);
+	adc = devm_kzalloc(dev, sizeof(*adc), GFP_KERNEL);
 	if (!adc)
 		return ERR_PTR(-ENOMEM);
 
 	if (fwnode_property_read_bool(child, "adi,single-ended"))
 		adc->single_ended = true;
 
-	if (!adc->single_ended &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev, "Invalid chan:%d for differential adc\n",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	if (!adc->single_ended && sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chan:%d for differential adc\n",
+				      sensor->chan);
+
 	/* set common parameters */
 	adc->sensor.assign_chan = ltc2983_adc_assign_chan;
 	adc->sensor.fault_handler = ltc2983_common_fault_handler;
@@ -1166,21 +1145,20 @@ static struct ltc2983_sensor *ltc2983_temp_new(struct fwnode_handle *child,
 					       struct ltc2983_data *st,
 					       const struct ltc2983_sensor *sensor)
 {
+	struct device *dev = &st->spi->dev;
 	struct ltc2983_temp *temp;
 
-	temp = devm_kzalloc(&st->spi->dev, sizeof(*temp), GFP_KERNEL);
+	temp = devm_kzalloc(dev, sizeof(*temp), GFP_KERNEL);
 	if (!temp)
 		return ERR_PTR(-ENOMEM);
 
 	if (fwnode_property_read_bool(child, "adi,single-ended"))
 		temp->single_ended = true;
 
-	if (!temp->single_ended &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev, "Invalid chan:%d for differential temp\n",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	if (!temp->single_ended && sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chan:%d for differential temp\n",
+				      sensor->chan);
 
 	temp->custom = __ltc2983_custom_sensor_new(st, child, "adi,custom-temp",
 						   false, 4096, true);
@@ -1330,10 +1308,9 @@ static int ltc2983_parse_fw(struct ltc2983_data *st)
 	device_property_read_u32(dev, "adi,filter-notch-freq", &st->filter_notch_freq);
 
 	st->num_channels = device_get_child_node_count(dev);
-	if (!st->num_channels) {
-		dev_err(&st->spi->dev, "At least one channel must be given!");
-		return -EINVAL;
-	}
+	if (!st->num_channels)
+		return dev_err_probe(dev, -EINVAL,
+				     "At least one channel must be given!");
 
 	st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st->sensors),
 				   GFP_KERNEL);
@@ -1420,6 +1397,7 @@ static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
 			      unsigned int wait_time, unsigned int status_reg,
 			      unsigned long status_fail_mask)
 {
+	struct device *dev = &st->spi->dev;
 	unsigned long time;
 	unsigned int val;
 	int ret;
@@ -1438,19 +1416,16 @@ static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
 
 	time = wait_for_completion_timeout(&st->completion,
 					   msecs_to_jiffies(wait_time));
-	if (!time) {
-		dev_err(&st->spi->dev, "EEPROM command timed out\n");
-		return -ETIMEDOUT;
-	}
+	if (!time)
+		return dev_err_probe(dev, -ETIMEDOUT, "EEPROM command timed out\n");
 
 	ret = regmap_read(st->regmap, status_reg, &val);
 	if (ret)
 		return ret;
 
-	if (val & status_fail_mask) {
-		dev_err(&st->spi->dev, "EEPROM command failed: 0x%02X\n", val);
-		return -EINVAL;
-	}
+	if (val & status_fail_mask)
+		return dev_err_probe(dev, -EINVAL,
+				     "EEPROM command failed: 0x%02X\n", val);
 
 	return 0;
 }
@@ -1458,16 +1433,15 @@ static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
 static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
 {
 	u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0, status;
+	struct device *dev = &st->spi->dev;
 	int ret;
 
 	/* make sure the device is up: start bit (7) is 0 and done bit (6) is 1 */
 	ret = regmap_read_poll_timeout(st->regmap, LTC2983_STATUS_REG, status,
 				       LTC2983_STATUS_UP(status) == 1, 25000,
 				       25000 * 10);
-	if (ret) {
-		dev_err(&st->spi->dev, "Device startup timed out\n");
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret, "Device startup timed out\n");
 
 	ret = regmap_update_bits(st->regmap, LTC2983_GLOBAL_CONFIG_REG,
 				 LTC2983_NOTCH_FREQ_MASK,
@@ -1567,12 +1541,13 @@ static const struct  iio_info ltc2983_iio_info = {
 
 static int ltc2983_probe(struct spi_device *spi)
 {
+	struct device *dev = &spi->dev;
 	struct ltc2983_data *st;
 	struct iio_dev *indio_dev;
 	struct gpio_desc *gpio;
 	int ret;
 
-	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 	if (!indio_dev)
 		return -ENOMEM;
 
@@ -1583,10 +1558,9 @@ static int ltc2983_probe(struct spi_device *spi)
 		return -ENODEV;
 
 	st->regmap = devm_regmap_init_spi(spi, &ltc2983_regmap_config);
-	if (IS_ERR(st->regmap)) {
-		dev_err(&spi->dev, "Failed to initialize regmap\n");
-		return PTR_ERR(st->regmap);
-	}
+	if (IS_ERR(st->regmap))
+		return dev_err_probe(dev, PTR_ERR(st->regmap),
+				     "Failed to initialize regmap\n");
 
 	mutex_init(&st->lock);
 	init_completion(&st->completion);
@@ -1602,7 +1576,7 @@ static int ltc2983_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
+	gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(gpio))
 		return PTR_ERR(gpio);
 
@@ -1612,7 +1586,7 @@ static int ltc2983_probe(struct spi_device *spi)
 		gpiod_set_value_cansleep(gpio, 0);
 	}
 
-	st->iio_chan = devm_kzalloc(&spi->dev,
+	st->iio_chan = devm_kzalloc(dev,
 				    st->iio_channels * sizeof(*st->iio_chan),
 				    GFP_KERNEL);
 	if (!st->iio_chan)
@@ -1622,12 +1596,10 @@ static int ltc2983_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	ret = devm_request_irq(&spi->dev, spi->irq, ltc2983_irq_handler,
+	ret = devm_request_irq(dev, spi->irq, ltc2983_irq_handler,
 			       IRQF_TRIGGER_RISING, st->info->name, st);
-	if (ret) {
-		dev_err(&spi->dev, "failed to request an irq, %d", ret);
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to request an irq\n");
 
 	if (st->info->has_eeprom) {
 		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_WRITE_CMD,
@@ -1644,7 +1616,7 @@ static int ltc2983_probe(struct spi_device *spi)
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &ltc2983_iio_info;
 
-	return devm_iio_device_register(&spi->dev, indio_dev);
+	return devm_iio_device_register(dev, indio_dev);
 }
 
 static int ltc2983_resume(struct device *dev)

-- 
2.44.0

[PATCH v2 2/4] iio: temperature: ltc2983: convert to dev_err_probe()

[Nuno Sa via B4 Relay]

From: Nuno Sa <nuno.sa@analog.com>

Use dev_err_probe() in the probe() path. While at it, made some simple
improvements:
 * Declare a struct device *dev helper. This also makes the style more
   consistent (some places the helper was used and not in other places);
 * Explicitly included the err.h and errno.h headers;
 * Removed an useless else if();
 * Removed some unnecessary line breaks.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 drivers/iio/temperature/ltc2983.c | 282 +++++++++++++++++---------------------
 1 file changed, 127 insertions(+), 155 deletions(-)

diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c
index 24d19f3c7292..941b3ab5c927 100644
--- a/drivers/iio/temperature/ltc2983.c
+++ b/drivers/iio/temperature/ltc2983.c
@@ -8,6 +8,8 @@
 #include <linux/bitfield.h>
 #include <linux/completion.h>
 #include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/iio/iio.h>
 #include <linux/interrupt.h>
@@ -432,10 +434,9 @@ __ltc2983_custom_sensor_new(struct ltc2983_data *st, const struct fwnode_handle
 	else
 		n_entries = fwnode_property_count_u64(fn, propname);
 	/* n_entries must be an even number */
-	if (!n_entries || (n_entries % 2) != 0) {
-		dev_err(dev, "Number of entries either 0 or not even\n");
-		return ERR_PTR(-EINVAL);
-	}
+	if (!n_entries || (n_entries % 2) != 0)
+		return dev_err_ptr_probe(dev, -EINVAL,
+					 "Number of entries either 0 or not even\n");
 
 	new_custom = devm_kzalloc(dev, sizeof(*new_custom), GFP_KERNEL);
 	if (!new_custom)
@@ -443,19 +444,17 @@ __ltc2983_custom_sensor_new(struct ltc2983_data *st, const struct fwnode_handle
 
 	new_custom->size = n_entries * n_size;
 	/* check Steinhart size */
-	if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE) {
-		dev_err(dev, "Steinhart sensors size(%zu) must be %u\n", new_custom->size,
-			LTC2983_CUSTOM_STEINHART_SIZE);
-		return ERR_PTR(-EINVAL);
-	}
+	if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE)
+		return dev_err_ptr_probe(dev, -EINVAL,
+					 "Steinhart sensors size(%zu) must be %u\n",
+					 new_custom->size, LTC2983_CUSTOM_STEINHART_SIZE);
+
 	/* Check space on the table. */
 	if (st->custom_table_size + new_custom->size >
-	    (LTC2983_CUST_SENS_TBL_END_REG -
-	     LTC2983_CUST_SENS_TBL_START_REG) + 1) {
-		dev_err(dev, "No space left(%d) for new custom sensor(%zu)",
-				st->custom_table_size, new_custom->size);
-		return ERR_PTR(-EINVAL);
-	}
+	    (LTC2983_CUST_SENS_TBL_END_REG - LTC2983_CUST_SENS_TBL_START_REG) + 1)
+		return dev_err_ptr_probe(dev, -EINVAL,
+					 "No space left(%d) for new custom sensor(%zu)",
+					 st->custom_table_size, new_custom->size);
 
 	/* allocate the table */
 	if (is_steinhart)
@@ -658,10 +657,11 @@ ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data
 			 const struct ltc2983_sensor *sensor)
 {
 	struct ltc2983_thermocouple *thermo;
+	struct device *dev = &st->spi->dev;
 	u32 oc_current;
 	int ret;
 
-	thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), GFP_KERNEL);
+	thermo = devm_kzalloc(dev, sizeof(*thermo), GFP_KERNEL);
 	if (!thermo)
 		return ERR_PTR(-ENOMEM);
 
@@ -688,21 +688,19 @@ ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data
 					LTC2983_THERMOCOUPLE_OC_CURR(3);
 			break;
 		default:
-			dev_err(&st->spi->dev,
-				"Invalid open circuit current:%u", oc_current);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid open circuit current:%u",
+					      oc_current);
 		}
 
 		thermo->sensor_config |= LTC2983_THERMOCOUPLE_OC_CHECK(1);
 	}
 	/* validate channel index */
 	if (!(thermo->sensor_config & LTC2983_THERMOCOUPLE_DIFF_MASK) &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev,
-			"Invalid chann:%d for differential thermocouple",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chann:%d for differential thermocouple",
+				      sensor->chan);
 
 	struct fwnode_handle *ref __free(fwnode_handle) =
 		fwnode_find_reference(child, "adi,cold-junction-handle", 0);
@@ -710,14 +708,13 @@ ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data
 		ref = NULL;
 	} else {
 		ret = fwnode_property_read_u32(ref, "reg", &thermo->cold_junction_chan);
-		if (ret) {
+		if (ret)
 			/*
 			 * This would be catched later but we can just return
 			 * the error right away.
 			 */
-			dev_err(&st->spi->dev, "Property reg must be given\n");
-			return ERR_PTR(ret);
-		}
+			return dev_err_ptr_probe(dev, ret,
+					      "Property reg must be given\n");
 	}
 
 	/* check custom sensor */
@@ -753,16 +750,14 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 
 	struct fwnode_handle *ref __free(fwnode_handle) =
 		fwnode_find_reference(child, "adi,rsense-handle", 0);
-	if (IS_ERR(ref)) {
-		dev_err(dev, "Property adi,rsense-handle missing or invalid");
-		return ERR_CAST(ref);
-	}
+	if (IS_ERR(ref))
+		return dev_err_cast_probe(dev, ref,
+					  "Property adi,rsense-handle missing or invalid");
 
 	ret = fwnode_property_read_u32(ref, "reg", &rtd->r_sense_chan);
-	if (ret) {
-		dev_err(dev, "Property reg must be given\n");
-		return ERR_PTR(ret);
-	}
+	if (ret)
+		return dev_err_ptr_probe(dev, ret,
+				      "Property reg must be given\n");
 
 	ret = fwnode_property_read_u32(child, "adi,number-of-wires", &n_wires);
 	if (!ret) {
@@ -781,19 +776,19 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 			rtd->sensor_config = LTC2983_RTD_N_WIRES(3);
 			break;
 		default:
-			dev_err(dev, "Invalid number of wires:%u\n", n_wires);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid number of wires:%u\n",
+					      n_wires);
 		}
 	}
 
 	if (fwnode_property_read_bool(child, "adi,rsense-share")) {
 		/* Current rotation is only available with rsense sharing */
 		if (fwnode_property_read_bool(child, "adi,current-rotate")) {
-			if (n_wires == 2 || n_wires == 3) {
-				dev_err(dev,
-					"Rotation not allowed for 2/3 Wire RTDs");
-				return ERR_PTR(-EINVAL);
-			}
+			if (n_wires == 2 || n_wires == 3)
+				return dev_err_ptr_probe(dev, -EINVAL,
+						      "Rotation not allowed for 2/3 Wire RTDs");
+
 			rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1);
 		} else {
 			rtd->sensor_config |= LTC2983_RTD_R_SHARE(1);
@@ -816,29 +811,22 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 
 		if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK)
 		     == LTC2983_RTD_KELVIN_R_SENSE_MASK) &&
-		    (rtd->r_sense_chan <=  min)) {
+		    (rtd->r_sense_chan <=  min))
 			/* kelvin rsense*/
-			dev_err(dev,
-				"Invalid rsense chann:%d to use in kelvin rsense",
-				rtd->r_sense_chan);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid rsense chann:%d to use in kelvin rsense",
+					      rtd->r_sense_chan);
 
-			return ERR_PTR(-EINVAL);
-		}
-
-		if (sensor->chan < min || sensor->chan > max) {
-			dev_err(dev, "Invalid chann:%d for the rtd config",
-				sensor->chan);
-
-			return ERR_PTR(-EINVAL);
-		}
+		if (sensor->chan < min || sensor->chan > max)
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid chann:%d for the rtd config",
+					      sensor->chan);
 	} else {
 		/* same as differential case */
-		if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-			dev_err(&st->spi->dev,
-				"Invalid chann:%d for RTD", sensor->chan);
-
-			return ERR_PTR(-EINVAL);
-		}
+		if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid chann:%d for RTD",
+					      sensor->chan);
 	}
 
 	/* check custom sensor */
@@ -886,10 +874,9 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 			rtd->excitation_current = 0x08;
 			break;
 		default:
-			dev_err(&st->spi->dev,
-				"Invalid value for excitation current(%u)",
-				excitation_current);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid value for excitation current(%u)",
+					      excitation_current);
 		}
 	}
 
@@ -913,16 +900,14 @@ ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *s
 
 	struct fwnode_handle *ref __free(fwnode_handle) =
 		fwnode_find_reference(child, "adi,rsense-handle", 0);
-	if (IS_ERR(ref)) {
-		dev_err(dev, "Property adi,rsense-handle missing or invalid");
-		return ERR_CAST(ref);
-	}
+	if (IS_ERR(ref))
+		return dev_err_cast_probe(dev, ref,
+					  "Property adi,rsense-handle missing or invalid");
 
 	ret = fwnode_property_read_u32(ref, "reg", &thermistor->r_sense_chan);
-	if (ret) {
-		dev_err(dev, "rsense channel must be configured...\n");
-		return ERR_PTR(ret);
-	}
+	if (ret)
+		return dev_err_ptr_probe(dev, ret,
+					 "rsense channel must be configured...\n");
 
 	if (fwnode_property_read_bool(child, "adi,single-ended")) {
 		thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1);
@@ -937,12 +922,10 @@ ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *s
 	}
 	/* validate channel index */
 	if (!(thermistor->sensor_config & LTC2983_THERMISTOR_DIFF_MASK) &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev,
-			"Invalid chann:%d for differential thermistor",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chann:%d for differential thermistor",
+				      sensor->chan);
 
 	/* check custom sensor */
 	if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) {
@@ -981,12 +964,10 @@ ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *s
 		switch (excitation_current) {
 		case 0:
 			/* auto range */
-			if (sensor->type >=
-			    LTC2983_SENSOR_THERMISTOR_STEINHART) {
-				dev_err(&st->spi->dev,
-					"Auto Range not allowed for custom sensors\n");
-				return ERR_PTR(-EINVAL);
-			}
+			if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART)
+				return dev_err_ptr_probe(dev, -EINVAL,
+						      "Auto Range not allowed for custom sensors\n");
+
 			thermistor->excitation_current = 0x0c;
 			break;
 		case 250:
@@ -1023,10 +1004,9 @@ ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *s
 			thermistor->excitation_current = 0x0b;
 			break;
 		default:
-			dev_err(&st->spi->dev,
-				"Invalid value for excitation current(%u)",
-				excitation_current);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid value for excitation current(%u)",
+					      excitation_current);
 		}
 	}
 
@@ -1037,11 +1017,12 @@ static struct ltc2983_sensor *
 ltc2983_diode_new(const struct fwnode_handle *child, const struct ltc2983_data *st,
 		  const struct ltc2983_sensor *sensor)
 {
+	struct device *dev = &st->spi->dev;
 	struct ltc2983_diode *diode;
 	u32 temp = 0, excitation_current = 0;
 	int ret;
 
-	diode = devm_kzalloc(&st->spi->dev, sizeof(*diode), GFP_KERNEL);
+	diode = devm_kzalloc(dev, sizeof(*diode), GFP_KERNEL);
 	if (!diode)
 		return ERR_PTR(-ENOMEM);
 
@@ -1056,12 +1037,11 @@ ltc2983_diode_new(const struct fwnode_handle *child, const struct ltc2983_data *
 
 	/* validate channel index */
 	if (!(diode->sensor_config & LTC2983_DIODE_DIFF_MASK) &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev,
-			"Invalid chann:%d for differential thermistor",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chann:%d for differential thermistor",
+				      sensor->chan);
+
 	/* set common parameters */
 	diode->sensor.fault_handler = ltc2983_common_fault_handler;
 	diode->sensor.assign_chan = ltc2983_diode_assign_chan;
@@ -1083,10 +1063,9 @@ ltc2983_diode_new(const struct fwnode_handle *child, const struct ltc2983_data *
 			diode->excitation_current = 0x03;
 			break;
 		default:
-			dev_err(&st->spi->dev,
-				"Invalid value for excitation current(%u)",
-				excitation_current);
-			return ERR_PTR(-EINVAL);
+			return dev_err_ptr_probe(dev, -EINVAL,
+					      "Invalid value for excitation current(%u)",
+					      excitation_current);
 		}
 	}
 
@@ -1102,26 +1081,26 @@ static struct ltc2983_sensor *ltc2983_r_sense_new(struct fwnode_handle *child,
 					struct ltc2983_data *st,
 					const struct ltc2983_sensor *sensor)
 {
+	struct device *dev = &st->spi->dev;
 	struct ltc2983_rsense *rsense;
 	int ret;
 	u32 temp;
 
-	rsense = devm_kzalloc(&st->spi->dev, sizeof(*rsense), GFP_KERNEL);
+	rsense = devm_kzalloc(dev, sizeof(*rsense), GFP_KERNEL);
 	if (!rsense)
 		return ERR_PTR(-ENOMEM);
 
 	/* validate channel index */
-	if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev, "Invalid chann:%d for r_sense",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chann:%d for r_sense",
+				      sensor->chan);
 
 	ret = fwnode_property_read_u32(child, "adi,rsense-val-milli-ohms", &temp);
-	if (ret) {
-		dev_err(&st->spi->dev, "Property adi,rsense-val-milli-ohms missing\n");
-		return ERR_PTR(-EINVAL);
-	}
+	if (ret)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Property adi,rsense-val-milli-ohms missing\n");
+
 	/*
 	 * Times 1000 because we have milli-ohms and __convert_to_raw
 	 * expects scales of 1000000 which are used for all other
@@ -1140,21 +1119,21 @@ static struct ltc2983_sensor *ltc2983_adc_new(struct fwnode_handle *child,
 					 struct ltc2983_data *st,
 					 const struct ltc2983_sensor *sensor)
 {
+	struct device *dev = &st->spi->dev;
 	struct ltc2983_adc *adc;
 
-	adc = devm_kzalloc(&st->spi->dev, sizeof(*adc), GFP_KERNEL);
+	adc = devm_kzalloc(dev, sizeof(*adc), GFP_KERNEL);
 	if (!adc)
 		return ERR_PTR(-ENOMEM);
 
 	if (fwnode_property_read_bool(child, "adi,single-ended"))
 		adc->single_ended = true;
 
-	if (!adc->single_ended &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev, "Invalid chan:%d for differential adc\n",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	if (!adc->single_ended && sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chan:%d for differential adc\n",
+				      sensor->chan);
+
 	/* set common parameters */
 	adc->sensor.assign_chan = ltc2983_adc_assign_chan;
 	adc->sensor.fault_handler = ltc2983_common_fault_handler;
@@ -1166,21 +1145,20 @@ static struct ltc2983_sensor *ltc2983_temp_new(struct fwnode_handle *child,
 					       struct ltc2983_data *st,
 					       const struct ltc2983_sensor *sensor)
 {
+	struct device *dev = &st->spi->dev;
 	struct ltc2983_temp *temp;
 
-	temp = devm_kzalloc(&st->spi->dev, sizeof(*temp), GFP_KERNEL);
+	temp = devm_kzalloc(dev, sizeof(*temp), GFP_KERNEL);
 	if (!temp)
 		return ERR_PTR(-ENOMEM);
 
 	if (fwnode_property_read_bool(child, "adi,single-ended"))
 		temp->single_ended = true;
 
-	if (!temp->single_ended &&
-	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
-		dev_err(&st->spi->dev, "Invalid chan:%d for differential temp\n",
-			sensor->chan);
-		return ERR_PTR(-EINVAL);
-	}
+	if (!temp->single_ended && sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
+		return dev_err_ptr_probe(dev, -EINVAL,
+				      "Invalid chan:%d for differential temp\n",
+				      sensor->chan);
 
 	temp->custom = __ltc2983_custom_sensor_new(st, child, "adi,custom-temp",
 						   false, 4096, true);
@@ -1330,10 +1308,9 @@ static int ltc2983_parse_fw(struct ltc2983_data *st)
 	device_property_read_u32(dev, "adi,filter-notch-freq", &st->filter_notch_freq);
 
 	st->num_channels = device_get_child_node_count(dev);
-	if (!st->num_channels) {
-		dev_err(&st->spi->dev, "At least one channel must be given!");
-		return -EINVAL;
-	}
+	if (!st->num_channels)
+		return dev_err_probe(dev, -EINVAL,
+				     "At least one channel must be given!");
 
 	st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st->sensors),
 				   GFP_KERNEL);
@@ -1420,6 +1397,7 @@ static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
 			      unsigned int wait_time, unsigned int status_reg,
 			      unsigned long status_fail_mask)
 {
+	struct device *dev = &st->spi->dev;
 	unsigned long time;
 	unsigned int val;
 	int ret;
@@ -1438,19 +1416,16 @@ static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
 
 	time = wait_for_completion_timeout(&st->completion,
 					   msecs_to_jiffies(wait_time));
-	if (!time) {
-		dev_err(&st->spi->dev, "EEPROM command timed out\n");
-		return -ETIMEDOUT;
-	}
+	if (!time)
+		return dev_err_probe(dev, -ETIMEDOUT, "EEPROM command timed out\n");
 
 	ret = regmap_read(st->regmap, status_reg, &val);
 	if (ret)
 		return ret;
 
-	if (val & status_fail_mask) {
-		dev_err(&st->spi->dev, "EEPROM command failed: 0x%02X\n", val);
-		return -EINVAL;
-	}
+	if (val & status_fail_mask)
+		return dev_err_probe(dev, -EINVAL,
+				     "EEPROM command failed: 0x%02X\n", val);
 
 	return 0;
 }
@@ -1458,16 +1433,15 @@ static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
 static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
 {
 	u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0, status;
+	struct device *dev = &st->spi->dev;
 	int ret;
 
 	/* make sure the device is up: start bit (7) is 0 and done bit (6) is 1 */
 	ret = regmap_read_poll_timeout(st->regmap, LTC2983_STATUS_REG, status,
 				       LTC2983_STATUS_UP(status) == 1, 25000,
 				       25000 * 10);
-	if (ret) {
-		dev_err(&st->spi->dev, "Device startup timed out\n");
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret, "Device startup timed out\n");
 
 	ret = regmap_update_bits(st->regmap, LTC2983_GLOBAL_CONFIG_REG,
 				 LTC2983_NOTCH_FREQ_MASK,
@@ -1567,12 +1541,13 @@ static const struct  iio_info ltc2983_iio_info = {
 
 static int ltc2983_probe(struct spi_device *spi)
 {
+	struct device *dev = &spi->dev;
 	struct ltc2983_data *st;
 	struct iio_dev *indio_dev;
 	struct gpio_desc *gpio;
 	int ret;
 
-	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 	if (!indio_dev)
 		return -ENOMEM;
 
@@ -1583,10 +1558,9 @@ static int ltc2983_probe(struct spi_device *spi)
 		return -ENODEV;
 
 	st->regmap = devm_regmap_init_spi(spi, &ltc2983_regmap_config);
-	if (IS_ERR(st->regmap)) {
-		dev_err(&spi->dev, "Failed to initialize regmap\n");
-		return PTR_ERR(st->regmap);
-	}
+	if (IS_ERR(st->regmap))
+		return dev_err_probe(dev, PTR_ERR(st->regmap),
+				     "Failed to initialize regmap\n");
 
 	mutex_init(&st->lock);
 	init_completion(&st->completion);
@@ -1602,7 +1576,7 @@ static int ltc2983_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
+	gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(gpio))
 		return PTR_ERR(gpio);
 
@@ -1612,7 +1586,7 @@ static int ltc2983_probe(struct spi_device *spi)
 		gpiod_set_value_cansleep(gpio, 0);
 	}
 
-	st->iio_chan = devm_kzalloc(&spi->dev,
+	st->iio_chan = devm_kzalloc(dev,
 				    st->iio_channels * sizeof(*st->iio_chan),
 				    GFP_KERNEL);
 	if (!st->iio_chan)
@@ -1622,12 +1596,10 @@ static int ltc2983_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	ret = devm_request_irq(&spi->dev, spi->irq, ltc2983_irq_handler,
+	ret = devm_request_irq(dev, spi->irq, ltc2983_irq_handler,
 			       IRQF_TRIGGER_RISING, st->info->name, st);
-	if (ret) {
-		dev_err(&spi->dev, "failed to request an irq, %d", ret);
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to request an irq\n");
 
 	if (st->info->has_eeprom) {
 		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_WRITE_CMD,
@@ -1644,7 +1616,7 @@ static int ltc2983_probe(struct spi_device *spi)
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &ltc2983_iio_info;
 
-	return devm_iio_device_register(&spi->dev, indio_dev);
+	return devm_iio_device_register(dev, indio_dev);
 }
 
 static int ltc2983_resume(struct device *dev)

-- 
2.44.0

Re: [PATCH v2 2/4] iio: temperature: ltc2983: convert to dev_err_probe()

[Andy Shevchenko]

On Tue, Apr 23, 2024 at 05:20:31PM +0200, Nuno Sa via B4 Relay wrote:
> From: Nuno Sa <nuno.sa@analog.com>
> 
> Use dev_err_probe() in the probe() path. While at it, made some simple
> improvements:
>  * Declare a struct device *dev helper. This also makes the style more
>    consistent (some places the helper was used and not in other places);
>  * Explicitly included the err.h and errno.h headers;
>  * Removed an useless else if();
>  * Removed some unnecessary line breaks.

...

>  	/* Check space on the table. */
>  	if (st->custom_table_size + new_custom->size >
> -	    (LTC2983_CUST_SENS_TBL_END_REG -
> -	     LTC2983_CUST_SENS_TBL_START_REG) + 1) {

> +	    (LTC2983_CUST_SENS_TBL_END_REG - LTC2983_CUST_SENS_TBL_START_REG) + 1)

Semi-unrelated change?

...

> +		return dev_err_ptr_probe(dev, -EINVAL,
> +				      "Invalid chann:%d for differential thermocouple",

While at it, add missing \n.

> +				      sensor->chan);

...

> +		return dev_err_cast_probe(dev, ref,
> +					  "Property adi,rsense-handle missing or invalid");

Ditto.

...

> +			return dev_err_ptr_probe(dev, -EINVAL,
> +					      "Invalid number of wires:%u\n",
> +					      n_wires);

Can be compressed in terms of LoCs?

...

> +				return dev_err_ptr_probe(dev, -EINVAL,
> +						      "Rotation not allowed for 2/3 Wire RTDs");

\n

...

> +			return dev_err_ptr_probe(dev, -EINVAL,
> +					      "Invalid rsense chann:%d to use in kelvin rsense",
> +					      rtd->r_sense_chan);

Ditto.

...

> +			return dev_err_ptr_probe(dev, -EINVAL,
> +					      "Invalid chann:%d for the rtd config",

Ditto.

> +					      sensor->chan);

...

> +			return dev_err_ptr_probe(dev, -EINVAL,
> +					      "Invalid chann:%d for RTD",

Ditto.

> +					      sensor->chan);

...

> +			return dev_err_ptr_probe(dev, -EINVAL,
> +					      "Invalid value for excitation current(%u)",

Ditto.

> +					      excitation_current);

...

> +	if (IS_ERR(ref))
> +		return dev_err_cast_probe(dev, ref,
> +					  "Property adi,rsense-handle missing or invalid");

Ditto.

...

> +		return dev_err_ptr_probe(dev, -EINVAL,
> +				      "Invalid chann:%d for differential thermistor",
> +				      sensor->chan);


Ditto.

...

> +			return dev_err_ptr_probe(dev, -EINVAL,
> +					      "Invalid value for excitation current(%u)",
> +					      excitation_current);

Ditto.

...

> +		return dev_err_ptr_probe(dev, -EINVAL,
> +				      "Invalid chann:%d for differential thermistor",
> +				      sensor->chan);

Ditto.

...

> +			return dev_err_ptr_probe(dev, -EINVAL,
> +					      "Invalid value for excitation current(%u)",
> +					      excitation_current);

Ditto.

...

> +		return dev_err_ptr_probe(dev, -EINVAL,
> +				      "Invalid chann:%d for r_sense",
> +				      sensor->chan);

Ditto.

...

> +	if (!st->num_channels)
> +		return dev_err_probe(dev, -EINVAL,
> +				     "At least one channel must be given!");

Ditto.

...

> +		return dev_err_probe(dev, -EINVAL,
> +				     "EEPROM command failed: 0x%02X\n", val);

One line?

...

> +	if (IS_ERR(st->regmap))
> +		return dev_err_probe(dev, PTR_ERR(st->regmap),
> +				     "Failed to initialize regmap\n");

Wondering about Andi's proposal in conjunction with %pe to be in use

		return dev_???(dev, st->regmap, "Failed to initialize regmap\n");

where it returns an int and uses const void * as an error pointer for %pe.



> -	st->iio_chan = devm_kzalloc(&spi->dev,
> +	st->iio_chan = devm_kzalloc(dev,
>  				    st->iio_channels * sizeof(*st->iio_chan),
>  				    GFP_KERNEL);

Separate change to devm_kzalloc() before this patch?
In that patch you may also introduce a temporary struct device *dev.


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 2/4] iio: temperature: ltc2983: convert to dev_err_probe()

[Nuno Sá]

On Tue, 2024-04-23 at 18:42 +0300, Andy Shevchenko wrote:
> On Tue, Apr 23, 2024 at 05:20:31PM +0200, Nuno Sa via B4 Relay wrote:
> > From: Nuno Sa <nuno.sa@analog.com>
> > 
> > Use dev_err_probe() in the probe() path. While at it, made some simple
> > improvements:
> >  * Declare a struct device *dev helper. This also makes the style more
> >    consistent (some places the helper was used and not in other places);
> >  * Explicitly included the err.h and errno.h headers;
> >  * Removed an useless else if();
> >  * Removed some unnecessary line breaks.
> 
> ...
> 
> >  	/* Check space on the table. */
> >  	if (st->custom_table_size + new_custom->size >
> > -	    (LTC2983_CUST_SENS_TBL_END_REG -
> > -	     LTC2983_CUST_SENS_TBL_START_REG) + 1) {
> 
> > +	    (LTC2983_CUST_SENS_TBL_END_REG - LTC2983_CUST_SENS_TBL_START_REG) +
> > 1)
> 
> Semi-unrelated change?


Yeah, indeed. One of those cases where the old limit does hurt readability (IMO)

> 
> ...
> 
> > +		return dev_err_ptr_probe(dev, -EINVAL,
> > +				      "Invalid chann:%d for differential
> > thermocouple",
> 
> While at it, add missing \n.

Will do for all the places...

> 
> > +				      sensor->chan);
> 
> ...
> 
> > +		return dev_err_cast_probe(dev, ref,
> > +					  "Property adi,rsense-handle missing or
> > invalid");
> 
> Ditto.
> 
> ...
> 
> > +			return dev_err_ptr_probe(dev, -EINVAL,
> > +					      "Invalid number of wires:%u\n",
> > +					      n_wires);
> 
> Can be compressed in terms of LoCs?
> 
> ...
> 
> > +				return dev_err_ptr_probe(dev, -EINVAL,
> > +						      "Rotation not allowed for
> > 2/3 Wire RTDs");
> 
> \n
> 
> ...
> 
> > +			return dev_err_ptr_probe(dev, -EINVAL,
> > +					      "Invalid rsense chann:%d to use in
> > kelvin rsense",
> > +					      rtd->r_sense_chan);
> 
> Ditto.
> 
> ...
> 
> > +			return dev_err_ptr_probe(dev, -EINVAL,
> > +					      "Invalid chann:%d for the rtd
> > config",
> 
> Ditto.
> 
> > +					      sensor->chan);
> 
> ...
> 
> > +			return dev_err_ptr_probe(dev, -EINVAL,
> > +					      "Invalid chann:%d for RTD",
> 
> Ditto.
> 
> > +					      sensor->chan);
> 
> ...
> 
> > +			return dev_err_ptr_probe(dev, -EINVAL,
> > +					      "Invalid value for excitation
> > current(%u)",
> 
> Ditto.
> 
> > +					      excitation_current);
> 
> ...
> 
> > +	if (IS_ERR(ref))
> > +		return dev_err_cast_probe(dev, ref,
> > +					  "Property adi,rsense-handle missing or
> > invalid");
> 
> Ditto.
> 
> ...
> 
> > +		return dev_err_ptr_probe(dev, -EINVAL,
> > +				      "Invalid chann:%d for differential
> > thermistor",
> > +				      sensor->chan);
> 
> 
> Ditto.
> 
> ...
> 
> > +			return dev_err_ptr_probe(dev, -EINVAL,
> > +					      "Invalid value for excitation
> > current(%u)",
> > +					      excitation_current);
> 
> Ditto.
> 
> ...
> 
> > +		return dev_err_ptr_probe(dev, -EINVAL,
> > +				      "Invalid chann:%d for differential
> > thermistor",
> > +				      sensor->chan);
> 
> Ditto.
> 
> ...
> 
> > +			return dev_err_ptr_probe(dev, -EINVAL,
> > +					      "Invalid value for excitation
> > current(%u)",
> > +					      excitation_current);
> 
> Ditto.
> 
> ...
> 
> > +		return dev_err_ptr_probe(dev, -EINVAL,
> > +				      "Invalid chann:%d for r_sense",
> > +				      sensor->chan);
> 
> Ditto.
> 
> ...
> 
> > +	if (!st->num_channels)
> > +		return dev_err_probe(dev, -EINVAL,
> > +				     "At least one channel must be given!");
> 
> Ditto.
> 
> ...
> 
> > +		return dev_err_probe(dev, -EINVAL,
> > +				     "EEPROM command failed: 0x%02X\n", val);
> 
> One line?
> 
> ...
> 
> > +	if (IS_ERR(st->regmap))
> > +		return dev_err_probe(dev, PTR_ERR(st->regmap),
> > +				     "Failed to initialize regmap\n");
> 
> Wondering about Andi's proposal in conjunction with %pe to be in use
> 
> 		return dev_???(dev, st->regmap, "Failed to initialize regmap\n");
> 
> where it returns an int and uses const void * as an error pointer for %pe.

Yeah, I would like to avoid including that variation in this series (unless everyone
agrees and requires it now). We already have tons of cases where we do
dev_err_probe(dev, PTR_ERR(), ...). Do we want to change all of them or not having
more? Personally, I'm not seeing as a big deal to have to do the PTR_ERR(). Yes,
internally we will go back to ERR_PTR() but still...

> 
> 
> 
> > -	st->iio_chan = devm_kzalloc(&spi->dev,
> > +	st->iio_chan = devm_kzalloc(dev,
> >  				    st->iio_channels * sizeof(*st->iio_chan),
> >  				    GFP_KERNEL);
> 
> Separate change to devm_kzalloc() before this patch?
> In that patch you may also introduce a temporary struct device *dev.
> 

If the introduction of the temporary struct device *dev is too much to be included in
here I may just remove it and send a patch afterwards.. (note I'm adding more
temporary *dev in other places to be consistent throughout the driver.
> 

[PATCH v2 3/4] iio: backend: make use of dev_err_cast_probe()

[Nuno Sa]

Using dev_err_cast_probe() to simplify the code.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 drivers/iio/industrialio-backend.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c
index f08ed6d70ae5..2cc6459246ce 100644
--- a/drivers/iio/industrialio-backend.c
+++ b/drivers/iio/industrialio-backend.c
@@ -475,11 +475,9 @@ struct iio_backend *devm_iio_backend_get(struct device *dev, const char *name)
 	}
 
 	fwnode = fwnode_find_reference(dev_fwnode(dev), "io-backends", index);
-	if (IS_ERR(fwnode)) {
-		dev_err_probe(dev, PTR_ERR(fwnode),
-			      "Cannot get Firmware reference\n");
-		return ERR_CAST(fwnode);
-	}
+	if (IS_ERR(fwnode))
+		return dev_err_cast_probe(dev, fwnode,
+					  "Cannot get Firmware reference\n");
 
 	guard(mutex)(&iio_back_lock);
 	list_for_each_entry(back, &iio_back_list, entry) {

-- 
2.44.0

[PATCH v2 3/4] iio: backend: make use of dev_err_cast_probe()

[Nuno Sa via B4 Relay]

From: Nuno Sa <nuno.sa@analog.com>

Using dev_err_cast_probe() to simplify the code.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 drivers/iio/industrialio-backend.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c
index f08ed6d70ae5..2cc6459246ce 100644
--- a/drivers/iio/industrialio-backend.c
+++ b/drivers/iio/industrialio-backend.c
@@ -475,11 +475,9 @@ struct iio_backend *devm_iio_backend_get(struct device *dev, const char *name)
 	}
 
 	fwnode = fwnode_find_reference(dev_fwnode(dev), "io-backends", index);
-	if (IS_ERR(fwnode)) {
-		dev_err_probe(dev, PTR_ERR(fwnode),
-			      "Cannot get Firmware reference\n");
-		return ERR_CAST(fwnode);
-	}
+	if (IS_ERR(fwnode))
+		return dev_err_cast_probe(dev, fwnode,
+					  "Cannot get Firmware reference\n");
 
 	guard(mutex)(&iio_back_lock);
 	list_for_each_entry(back, &iio_back_list, entry) {

-- 
2.44.0

[PATCH v2 4/4] iio: common: scmi_iio: convert to dev_err_probe()

[Nuno Sa]

Make use of dev_err_probe() and dev_err_ptr_probe() to simplify error paths
during probe.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 drivers/iio/common/scmi_sensors/scmi_iio.c | 45 +++++++++++++-----------------
 1 file changed, 19 insertions(+), 26 deletions(-)

diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
index 0c2caf3570db..841eda79a8cc 100644
--- a/drivers/iio/common/scmi_sensors/scmi_iio.c
+++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
@@ -626,12 +626,10 @@ scmi_alloc_iiodev(struct scmi_device *sdev,
 				SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
 				&sensor->sensor_info->id,
 				&sensor->sensor_update_nb);
-	if (ret) {
-		dev_err(&iiodev->dev,
-			"Error in registering sensor update notifier for sensor %s err %d",
-			sensor->sensor_info->name, ret);
-		return ERR_PTR(ret);
-	}
+	if (ret)
+		return dev_err_ptr_probe(&iiodev->dev, ret,
+					 "Error in registering sensor update notifier for sensor %s err %d",
+					 sensor->sensor_info->name, ret);
 
 	scmi_iio_set_timestamp_channel(&iio_channels[i], i);
 	iiodev->channels = iio_channels;
@@ -653,10 +651,9 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
 		return -ENODEV;
 
 	sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
-	if (IS_ERR(sensor_ops)) {
-		dev_err(dev, "SCMI device has no sensor interface\n");
-		return PTR_ERR(sensor_ops);
-	}
+	if (IS_ERR(sensor_ops))
+		return dev_err_probe(dev, PTR_ERR(sensor_ops),
+				     "SCMI device has no sensor interface\n");
 
 	nr_sensors = sensor_ops->count_get(ph);
 	if (!nr_sensors) {
@@ -667,8 +664,8 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
 	for (i = 0; i < nr_sensors; i++) {
 		sensor_info = sensor_ops->info_get(ph, i);
 		if (!sensor_info) {
-			dev_err(dev, "SCMI sensor %d has missing info\n", i);
-			return -EINVAL;
+			return dev_err_probe(dev, -EINVAL,
+					     "SCMI sensor %d has missing info\n", i);
 		}
 
 		/* This driver only supports 3-axis accel and gyro, skipping other sensors */
@@ -683,29 +680,25 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
 		scmi_iio_dev = scmi_alloc_iiodev(sdev, sensor_ops, ph,
 						 sensor_info);
 		if (IS_ERR(scmi_iio_dev)) {
-			dev_err(dev,
-				"failed to allocate IIO device for sensor %s: %ld\n",
-				sensor_info->name, PTR_ERR(scmi_iio_dev));
-			return PTR_ERR(scmi_iio_dev);
+			return dev_err_probe(dev, PTR_ERR(scmi_iio_dev),
+					     "failed to allocate IIO device for sensor %s: %ld\n",
+					     sensor_info->name, PTR_ERR(scmi_iio_dev));
 		}
 
 		err = devm_iio_kfifo_buffer_setup(&scmi_iio_dev->dev,
 						  scmi_iio_dev,
 						  &scmi_iio_buffer_ops);
 		if (err < 0) {
-			dev_err(dev,
-				"IIO buffer setup error at sensor %s: %d\n",
-				sensor_info->name, err);
-			return err;
+			return dev_err_probe(dev, err,
+					     "IIO buffer setup error at sensor %s: %d\n",
+					     sensor_info->name, err);
 		}
 
 		err = devm_iio_device_register(dev, scmi_iio_dev);
-		if (err) {
-			dev_err(dev,
-				"IIO device registration failed at sensor %s: %d\n",
-				sensor_info->name, err);
-			return err;
-		}
+		if (err)
+			return dev_err_probe(dev, err,
+					     "IIO device registration failed at sensor %s: %d\n",
+					     sensor_info->name, err);
 	}
 	return err;
 }

-- 
2.44.0

[PATCH v2 4/4] iio: common: scmi_iio: convert to dev_err_probe()

[Nuno Sa via B4 Relay]

From: Nuno Sa <nuno.sa@analog.com>

Make use of dev_err_probe() and dev_err_ptr_probe() to simplify error paths
during probe.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 drivers/iio/common/scmi_sensors/scmi_iio.c | 45 +++++++++++++-----------------
 1 file changed, 19 insertions(+), 26 deletions(-)

diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
index 0c2caf3570db..841eda79a8cc 100644
--- a/drivers/iio/common/scmi_sensors/scmi_iio.c
+++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
@@ -626,12 +626,10 @@ scmi_alloc_iiodev(struct scmi_device *sdev,
 				SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
 				&sensor->sensor_info->id,
 				&sensor->sensor_update_nb);
-	if (ret) {
-		dev_err(&iiodev->dev,
-			"Error in registering sensor update notifier for sensor %s err %d",
-			sensor->sensor_info->name, ret);
-		return ERR_PTR(ret);
-	}
+	if (ret)
+		return dev_err_ptr_probe(&iiodev->dev, ret,
+					 "Error in registering sensor update notifier for sensor %s err %d",
+					 sensor->sensor_info->name, ret);
 
 	scmi_iio_set_timestamp_channel(&iio_channels[i], i);
 	iiodev->channels = iio_channels;
@@ -653,10 +651,9 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
 		return -ENODEV;
 
 	sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
-	if (IS_ERR(sensor_ops)) {
-		dev_err(dev, "SCMI device has no sensor interface\n");
-		return PTR_ERR(sensor_ops);
-	}
+	if (IS_ERR(sensor_ops))
+		return dev_err_probe(dev, PTR_ERR(sensor_ops),
+				     "SCMI device has no sensor interface\n");
 
 	nr_sensors = sensor_ops->count_get(ph);
 	if (!nr_sensors) {
@@ -667,8 +664,8 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
 	for (i = 0; i < nr_sensors; i++) {
 		sensor_info = sensor_ops->info_get(ph, i);
 		if (!sensor_info) {
-			dev_err(dev, "SCMI sensor %d has missing info\n", i);
-			return -EINVAL;
+			return dev_err_probe(dev, -EINVAL,
+					     "SCMI sensor %d has missing info\n", i);
 		}
 
 		/* This driver only supports 3-axis accel and gyro, skipping other sensors */
@@ -683,29 +680,25 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
 		scmi_iio_dev = scmi_alloc_iiodev(sdev, sensor_ops, ph,
 						 sensor_info);
 		if (IS_ERR(scmi_iio_dev)) {
-			dev_err(dev,
-				"failed to allocate IIO device for sensor %s: %ld\n",
-				sensor_info->name, PTR_ERR(scmi_iio_dev));
-			return PTR_ERR(scmi_iio_dev);
+			return dev_err_probe(dev, PTR_ERR(scmi_iio_dev),
+					     "failed to allocate IIO device for sensor %s: %ld\n",
+					     sensor_info->name, PTR_ERR(scmi_iio_dev));
 		}
 
 		err = devm_iio_kfifo_buffer_setup(&scmi_iio_dev->dev,
 						  scmi_iio_dev,
 						  &scmi_iio_buffer_ops);
 		if (err < 0) {
-			dev_err(dev,
-				"IIO buffer setup error at sensor %s: %d\n",
-				sensor_info->name, err);
-			return err;
+			return dev_err_probe(dev, err,
+					     "IIO buffer setup error at sensor %s: %d\n",
+					     sensor_info->name, err);
 		}
 
 		err = devm_iio_device_register(dev, scmi_iio_dev);
-		if (err) {
-			dev_err(dev,
-				"IIO device registration failed at sensor %s: %d\n",
-				sensor_info->name, err);
-			return err;
-		}
+		if (err)
+			return dev_err_probe(dev, err,
+					     "IIO device registration failed at sensor %s: %d\n",
+					     sensor_info->name, err);
 	}
 	return err;
 }

-- 
2.44.0

Re: [PATCH v2 4/4] iio: common: scmi_iio: convert to dev_err_probe()

[Andy Shevchenko]

On Tue, Apr 23, 2024 at 05:20:33PM +0200, Nuno Sa via B4 Relay wrote:
> From: Nuno Sa <nuno.sa@analog.com>
> 
> Make use of dev_err_probe() and dev_err_ptr_probe() to simplify error paths
> during probe.

...

> +		return dev_err_ptr_probe(&iiodev->dev, ret,
> +					 "Error in registering sensor update notifier for sensor %s err %d",

\n

> +					 sensor->sensor_info->name, ret);

...

> +			return dev_err_probe(dev, -EINVAL,
> +					     "SCMI sensor %d has missing info\n", i);

One line? (It's 99 if you use relaxed limit).

...

> +			return dev_err_probe(dev, PTR_ERR(scmi_iio_dev),
> +					     "failed to allocate IIO device for sensor %s: %ld\n",
> +					     sensor_info->name, PTR_ERR(scmi_iio_dev));

Please, be sure you remove double error code printing, dev_err_probe() does it
for you already. (This applies to all places like this, if any, in the entire
series.)

...

> +			return dev_err_probe(dev, err,
> +					     "IIO buffer setup error at sensor %s: %d\n",
> +					     sensor_info->name, err);

Ditto.

...

> +			return dev_err_probe(dev, err,
> +					     "IIO device registration failed at sensor %s: %d\n",
> +					     sensor_info->name, err);

Ditto.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 4/4] iio: common: scmi_iio: convert to dev_err_probe()

[Nuno Sá]

On Tue, 2024-04-23 at 18:50 +0300, Andy Shevchenko wrote:
> On Tue, Apr 23, 2024 at 05:20:33PM +0200, Nuno Sa via B4 Relay wrote:
> > From: Nuno Sa <nuno.sa@analog.com>
> > 
> > Make use of dev_err_probe() and dev_err_ptr_probe() to simplify error paths
> > during probe.
> 
> ...
> 
> > +		return dev_err_ptr_probe(&iiodev->dev, ret,
> > +					 "Error in registering sensor update
> > notifier for sensor %s err %d",
> 
> \n

sure...

> 
> > +					 sensor->sensor_info->name, ret);
> 
> ...
> 
> > +			return dev_err_probe(dev, -EINVAL,
> > +					     "SCMI sensor %d has missing
> > info\n", i);
> 
> One line? (It's 99 if you use relaxed limit).

Being this IIO, Jonathan prefers to stick the old limit unless readability is hurt...
> 
> ...
> 
> > +			return dev_err_probe(dev, PTR_ERR(scmi_iio_dev),
> > +					     "failed to allocate IIO device for
> > sensor %s: %ld\n",
> > +					     sensor_info->name,
> > PTR_ERR(scmi_iio_dev));
> 
> Please, be sure you remove double error code printing, dev_err_probe() does it
> for you already. (This applies to all places like this, if any, in the entire
> series.)

Up... blind conversion. Thanks!

- Nuno Sá