From: Axel Haslam <ahaslam@baylibre.com>

Simplify probe by using of the devm_regulator_get_enable_read_voltage.

Suggested-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
---
 drivers/iio/dac/ad5791.c | 56 +++++++++-------------------------------
 1 file changed, 12 insertions(+), 44 deletions(-)

diff --git a/drivers/iio/dac/ad5791.c b/drivers/iio/dac/ad5791.c
index a7cf19346cf0..cf3d41a10c20 100644
--- a/drivers/iio/dac/ad5791.c
+++ b/drivers/iio/dac/ad5791.c
@@ -356,32 +356,6 @@ static int ad5791_probe(struct spi_device *spi)
 	if (IS_ERR(st->gpio_ldac))
 		return PTR_ERR(st->gpio_ldac);
 
-	st->reg_vdd = devm_regulator_get(&spi->dev, "vdd");
-	if (!IS_ERR(st->reg_vdd)) {
-		ret = regulator_enable(st->reg_vdd);
-		if (ret)
-			return ret;
-
-		ret = regulator_get_voltage(st->reg_vdd);
-		if (ret < 0)
-			goto error_disable_reg_pos;
-
-		pos_voltage_uv = ret;
-	}
-
-	st->reg_vss = devm_regulator_get(&spi->dev, "vss");
-	if (!IS_ERR(st->reg_vss)) {
-		ret = regulator_enable(st->reg_vss);
-		if (ret)
-			goto error_disable_reg_pos;
-
-		ret = regulator_get_voltage(st->reg_vss);
-		if (ret < 0)
-			goto error_disable_reg_neg;
-
-		neg_voltage_uv = ret;
-	}
-
 	st->pwr_down = true;
 	st->spi = spi;
 
@@ -391,7 +365,15 @@ static int ad5791_probe(struct spi_device *spi)
 		use_rbuf_gain2 = device_property_read_bool(&spi->dev,
 							   "adi,rbuf-gain2-en");
 
-	if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) {
+	pos_voltage_uv = devm_regulator_get_enable_read_voltage(&spi->dev, "vdd");
+	if (pos_voltage_uv < 0 && pos_voltage_uv != -ENODEV)
+		return dev_err_probe(&spi->dev, ret, "failed to get vdd voltage\n");
+
+	neg_voltage_uv = devm_regulator_get_enable_read_voltage(&spi->dev, "vss");
+	if (neg_voltage_uv < 0 && neg_voltage_uv != -ENODEV)
+		return dev_err_probe(&spi->dev, ret, "failed to get vss voltage\n");
+
+	if (neg_voltage_uv >= 0 && pos_voltage_uv >= 0) {
 		st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
 		st->vref_neg_mv = neg_voltage_uv / 1000;
 	} else if (pdata) {
@@ -407,7 +389,7 @@ static int ad5791_probe(struct spi_device *spi)
 	} else {
 		ret = ad5791_spi_write(st, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
 		if (ret)
-			goto error_disable_reg_neg;
+			return dev_err_probe(&spi->dev, ret, "fail to reset\n");
 	}
 
 	st->chip_info = spi_get_device_match_data(spi);
@@ -421,7 +403,7 @@ static int ad5791_probe(struct spi_device *spi)
 	ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl |
 		AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
 	if (ret)
-		goto error_disable_reg_neg;
+		return dev_err_probe(&spi->dev, ret, "fail to write ctrl register\n");
 
 	spi_set_drvdata(spi, indio_dev);
 	indio_dev->info = &ad5791_info;
@@ -431,30 +413,16 @@ static int ad5791_probe(struct spi_device *spi)
 	indio_dev->name = st->chip_info->name;
 	ret = iio_device_register(indio_dev);
 	if (ret)
-		goto error_disable_reg_neg;
+		return dev_err_probe(&spi->dev, ret, "unable to register iio device\n");
 
 	return 0;
-
-error_disable_reg_neg:
-	if (!IS_ERR(st->reg_vss))
-		regulator_disable(st->reg_vss);
-error_disable_reg_pos:
-	if (!IS_ERR(st->reg_vdd))
-		regulator_disable(st->reg_vdd);
-	return ret;
 }
 
 static void ad5791_remove(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
-	struct ad5791_state *st = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
-	if (!IS_ERR(st->reg_vdd))
-		regulator_disable(st->reg_vdd);
-
-	if (!IS_ERR(st->reg_vss))
-		regulator_disable(st->reg_vss);
 }
 
 static const struct of_device_id ad5791_of_match[] = {
-- 
2.34.1

Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on jic23-iio/togreg]
[also build test WARNING on linus/master v6.12-rc5 next-20241028]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/ahaslam-baylibre-com/dt-bindings-iio-dac-ad5791-Add-optional-reset-clr-and-ldac-gpios/20241028-151319
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link:    https://lore.kernel.org/r/20241028071118.699951-6-ahaslam%40baylibre.com
patch subject: [PATCH 5/6] iio: dac: ad5791: Use devm_regulator_get_enable_read_voltage
config: x86_64-buildonly-randconfig-004-20241028 (https://download.01.org/0day-ci/archive/20241029/202410290245.0RC0cDV4-lkp@intel.com/config)
compiler: clang version 19.1.2 (https://github.com/llvm/llvm-project 7ba7d8e2f7b6445b60679da826210cdde29eaf8b)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241029/202410290245.0RC0cDV4-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410290245.0RC0cDV4-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/iio/dac/ad5791.c:14:
   In file included from include/linux/spi/spi.h:17:
   In file included from include/linux/scatterlist.h:8:
   In file included from include/linux/mm.h:2213:
   include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
>> drivers/iio/dac/ad5791.c:370:35: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
     370 |                 return dev_err_probe(&spi->dev, ret, "failed to get vdd voltage\n");
         |                                                 ^~~
   drivers/iio/dac/ad5791.c:336:9: note: initialize the variable 'ret' to silence this warning
     336 |         int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
         |                ^
         |                 = 0
   2 warnings generated.


vim +/ret +370 drivers/iio/dac/ad5791.c

   330	
   331	static int ad5791_probe(struct spi_device *spi)
   332	{
   333		const struct ad5791_platform_data *pdata = dev_get_platdata(&spi->dev);
   334		struct iio_dev *indio_dev;
   335		struct ad5791_state *st;
   336		int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
   337		bool use_rbuf_gain2;
   338	
   339		indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
   340		if (!indio_dev)
   341			return -ENOMEM;
   342		st = iio_priv(indio_dev);
   343	
   344		st->gpio_reset = devm_gpiod_get_optional(&spi->dev, "reset",
   345							 GPIOD_OUT_HIGH);
   346		if (IS_ERR(st->gpio_reset))
   347			return PTR_ERR(st->gpio_reset);
   348	
   349		st->gpio_clear = devm_gpiod_get_optional(&spi->dev, "clear",
   350							 GPIOD_OUT_LOW);
   351		if (IS_ERR(st->gpio_clear))
   352			return PTR_ERR(st->gpio_clear);
   353	
   354		st->gpio_ldac = devm_gpiod_get_optional(&spi->dev, "ldac",
   355							GPIOD_OUT_HIGH);
   356		if (IS_ERR(st->gpio_ldac))
   357			return PTR_ERR(st->gpio_ldac);
   358	
   359		st->pwr_down = true;
   360		st->spi = spi;
   361	
   362		if (pdata)
   363			use_rbuf_gain2 = pdata->use_rbuf_gain2;
   364		else
   365			use_rbuf_gain2 = device_property_read_bool(&spi->dev,
   366								   "adi,rbuf-gain2-en");
   367	
   368		pos_voltage_uv = devm_regulator_get_enable_read_voltage(&spi->dev, "vdd");
   369		if (pos_voltage_uv < 0 && pos_voltage_uv != -ENODEV)
 > 370			return dev_err_probe(&spi->dev, ret, "failed to get vdd voltage\n");
   371	
   372		neg_voltage_uv = devm_regulator_get_enable_read_voltage(&spi->dev, "vss");
   373		if (neg_voltage_uv < 0 && neg_voltage_uv != -ENODEV)
   374			return dev_err_probe(&spi->dev, ret, "failed to get vss voltage\n");
   375	
   376		if (neg_voltage_uv >= 0 && pos_voltage_uv >= 0) {
   377			st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
   378			st->vref_neg_mv = neg_voltage_uv / 1000;
   379		} else if (pdata) {
   380			st->vref_mv = pdata->vref_pos_mv + pdata->vref_neg_mv;
   381			st->vref_neg_mv = pdata->vref_neg_mv;
   382		} else {
   383			dev_warn(&spi->dev, "reference voltage unspecified\n");
   384		}
   385	
   386		if (st->gpio_reset) {
   387			fsleep(20);
   388			gpiod_set_value_cansleep(st->gpio_reset, 0);
   389		} else {
   390			ret = ad5791_spi_write(st, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
   391			if (ret)
   392				return dev_err_probe(&spi->dev, ret, "fail to reset\n");
   393		}
   394	
   395		st->chip_info = spi_get_device_match_data(spi);
   396		if (!st->chip_info)
   397			return dev_err_probe(&spi->dev, -EINVAL, "no chip info\n");
   398	
   399		st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv))
   400			  | (use_rbuf_gain2 ? 0 : AD5791_CTRL_RBUF) |
   401			  AD5791_CTRL_BIN2SC;
   402	
   403		ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl |
   404			AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
   405		if (ret)
   406			return dev_err_probe(&spi->dev, ret, "fail to write ctrl register\n");
   407	
   408		spi_set_drvdata(spi, indio_dev);
   409		indio_dev->info = &ad5791_info;
   410		indio_dev->modes = INDIO_DIRECT_MODE;
   411		indio_dev->channels = &st->chip_info->channel;
   412		indio_dev->num_channels = 1;
   413		indio_dev->name = st->chip_info->name;
   414		ret = iio_device_register(indio_dev);
   415		if (ret)
   416			return dev_err_probe(&spi->dev, ret, "unable to register iio device\n");
   417	
   418		return 0;
   419	}
   420	

-- 
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https://github.com/intel/lkp-tests/wiki