[PATCH v4 1/5] iio: accel: mma8452: convert to bulk regulator usage

[Sanjay Chitroda]

From: Sanjay Chitroda <sanjayembeddedse@xxxxxxxxx>

The "vdd" and "vddio" regulators are always controlled together. Switch
to the regulator bulk API to handle setup, enable, and disable paths in
a single call.

No functional change intended.

Suggested-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Sanjay Chitroda <sanjayembeddedse@xxxxxxxxx>

---
changes in v4:
- added explicit header with input from Joshua Crofts
- validate new member of structure with `pahole` and `bloat-o-meter`
  comment from Andy
  ./scripts/bloat-o-meter mma8452-before.o mma8452-after.o
  add/remove: 0/0 grow/shrink: 0/6 up/down: 0/-1013 (-1013)
  Function                                     old     new   delta
  _entry_ptr                                    72      56     -16
  _entry                                       396     308     -88
  mma8452_remove                               646     548     -98
  mma8452_runtime_suspend                      633     467    -166
  mma8452_runtime_resume                       939     639    -300
  mma8452_probe                               4247    3902    -345
  Total: Before=36561, After=35548, chg -2.77%

  pahole before:
    /* size: 288, cachelines: 5, members: 10 */
    /* sum members: 278, holes: 2, sum holes: 10 */

  pahole after:
    /* size: 320, cachelines: 5, members: 9 */
    /* sum members: 310, holes: 2, sum holes: 10 */
  summary: overall size of driver is optimized and all new member are in same cacheline
- v3 link -> https://lore.kernel.org/all/20260505174640.3998281-7-sanjayembedded@xxxxxxxxx/
---
 drivers/iio/accel/mma8452.c | 60 ++++++++++++---------------------------------
 1 file changed, 16 insertions(+), 44 deletions(-)

diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
index 1403b32e2b21..a44b2138951e 100644
--- a/drivers/iio/accel/mma8452.c
+++ b/drivers/iio/accel/mma8452.c
@@ -18,6 +18,7 @@
  * TODO: orientation events
  */
 
+#include <linux/array_size.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/mod_devicetable.h>
@@ -111,8 +112,7 @@ struct mma8452_data {
 	u8 data_cfg;
 	const struct mma_chip_info *chip_info;
 	int sleep_val;
-	struct regulator *vdd_reg;
-	struct regulator *vddio_reg;
+	struct regulator_bulk_data regs[2];
 
 	/* Ensure correct alignment of time stamp when present */
 	struct {
@@ -1570,25 +1570,15 @@ static int mma8452_probe(struct i2c_client *client)
 	if (ret)
 		return ret;
 
-	data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
-	if (IS_ERR(data->vdd_reg))
-		return dev_err_probe(&client->dev, PTR_ERR(data->vdd_reg),
-				     "failed to get VDD regulator!\n");
-
-	data->vddio_reg = devm_regulator_get(&client->dev, "vddio");
-	if (IS_ERR(data->vddio_reg))
-		return dev_err_probe(&client->dev, PTR_ERR(data->vddio_reg),
-				     "failed to get VDDIO regulator!\n");
-
-	ret = regulator_enable(data->vdd_reg);
+	data->regs[0].supply = "vdd";
+	data->regs[1].supply = "vddio";
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->regs), data->regs);
 	if (ret)
-		return dev_err_probe(dev, ret, "failed to enable VDD regulator!\n");
+		return dev_err_probe(dev, ret, "failed to get regulators\n");
 
-	ret = regulator_enable(data->vddio_reg);
-	if (ret) {
-		dev_err_probe(dev, ret, "failed to enable VDDIO regulator!\n");
-		goto disable_regulator_vdd;
-	}
+	ret = regulator_bulk_enable(ARRAY_SIZE(data->regs), data->regs);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to enable regulators\n");
 
 	ret = i2c_smbus_read_byte_data(client, MMA8452_WHO_AM_I);
 	if (ret < 0)
@@ -1723,10 +1713,7 @@ static int mma8452_probe(struct i2c_client *client)
 	mma8452_trigger_cleanup(indio_dev);
 
 disable_regulators:
-	regulator_disable(data->vddio_reg);
-
-disable_regulator_vdd:
-	regulator_disable(data->vdd_reg);
+	regulator_bulk_disable(ARRAY_SIZE(data->regs), data->regs);
 
 	return ret;
 }
@@ -1748,8 +1735,7 @@ static void mma8452_remove(struct i2c_client *client)
 	mma8452_trigger_cleanup(indio_dev);
 	mma8452_standby(iio_priv(indio_dev));
 
-	regulator_disable(data->vddio_reg);
-	regulator_disable(data->vdd_reg);
+	regulator_bulk_disable(ARRAY_SIZE(data->regs), data->regs);
 }
 
 #ifdef CONFIG_PM
@@ -1767,15 +1753,9 @@ static int mma8452_runtime_suspend(struct device *dev)
 		return -EAGAIN;
 	}
 
-	ret = regulator_disable(data->vddio_reg);
-	if (ret) {
-		dev_err(dev, "failed to disable VDDIO regulator\n");
-		return ret;
-	}
-
-	ret = regulator_disable(data->vdd_reg);
+	ret = regulator_bulk_disable(ARRAY_SIZE(data->regs), data->regs);
 	if (ret) {
-		dev_err(dev, "failed to disable VDD regulator\n");
+		dev_err(dev, "failed to disable regulators\n");
 		return ret;
 	}
 
@@ -1788,16 +1768,9 @@ static int mma8452_runtime_resume(struct device *dev)
 	struct mma8452_data *data = iio_priv(indio_dev);
 	int ret, sleep_val;
 
-	ret = regulator_enable(data->vdd_reg);
-	if (ret) {
-		dev_err(dev, "failed to enable VDD regulator\n");
-		return ret;
-	}
-
-	ret = regulator_enable(data->vddio_reg);
+	ret = regulator_bulk_enable(ARRAY_SIZE(data->regs), data->regs);
 	if (ret) {
-		dev_err(dev, "failed to enable VDDIO regulator\n");
-		regulator_disable(data->vdd_reg);
+		dev_err(dev, "failed to enable regulators\n");
 		return ret;
 	}
 
@@ -1815,8 +1788,7 @@ static int mma8452_runtime_resume(struct device *dev)
 	return 0;
 
 runtime_resume_failed:
-	regulator_disable(data->vddio_reg);
-	regulator_disable(data->vdd_reg);
+	regulator_bulk_disable(ARRAY_SIZE(data->regs), data->regs);
 
 	return ret;
 }

-- 
2.34.1