[PATCH v3 07/10] mfd: wm831x: support software nodes for DCDC regulators

From: Dmitry Torokhov

Date: Sat Jul 11 2026 - 22:13:33 EST


Allow passing software nodes to wm831x DCDC regulators via PMIC platform
data. This is useful for non-DT/non-ACPI platforms that want to
associate device properties (like DVS GPIOs) with the regulator devices
using software nodes.

We add 'dcdc_swnodes' to the PMIC platform data 'struct wm831x_pdata' and
have the MFD core assign these software nodes to the buckv cells.

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/mfd/wm831x-core.c | 47 ++++++++++++++++++++++++++++++----------
include/linux/mfd/wm831x/pdata.h | 2 ++
2 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/drivers/mfd/wm831x-core.c b/drivers/mfd/wm831x-core.c
index df8e76e000cc..c4793be419ba 100644
--- a/drivers/mfd/wm831x-core.c
+++ b/drivers/mfd/wm831x-core.c
@@ -14,6 +14,7 @@
#include <linux/delay.h>
#include <linux/mfd/core.h>
#include <linux/slab.h>
+#include <linux/string.h>
#include <linux/err.h>

#include <linux/mfd/wm831x/core.h>
@@ -1449,6 +1450,32 @@ const struct of_device_id wm831x_of_match[] = {
};
EXPORT_SYMBOL_GPL(wm831x_of_match);

+static int wm831x_add_devices(struct wm831x *wm831x, int wm831x_num,
+ const struct mfd_cell *cells, int num_cells)
+{
+ struct wm831x_pdata *pdata = &wm831x->pdata;
+ int i;
+
+ struct mfd_cell *local_cells __free(kfree) =
+ kmemdup_array(cells, num_cells, sizeof(*cells), GFP_KERNEL);
+ if (!local_cells)
+ return -ENOMEM;
+
+ for (i = 0; i < num_cells; i++) {
+ struct mfd_cell *cell = &local_cells[i];
+
+ if (strcmp(cell->name, "wm831x-buckv") == 0) {
+ int id = cell->id - 1;
+
+ if (id >= 0 && id < WM831X_MAX_DCDC)
+ cell->swnode = pdata->dcdc_swnodes[id];
+ }
+ }
+
+ return mfd_add_devices(wm831x->dev, wm831x_num, local_cells, num_cells,
+ NULL, 0, NULL);
+}
+
/*
* Instantiate the generic non-control parts of the device.
*/
@@ -1620,15 +1647,13 @@ int wm831x_device_init(struct wm831x *wm831x, int irq)
/* The core device is up, instantiate the subdevices. */
switch (parent) {
case WM8310:
- ret = mfd_add_devices(wm831x->dev, wm831x_num,
- wm8310_devs, ARRAY_SIZE(wm8310_devs),
- NULL, 0, NULL);
+ ret = wm831x_add_devices(wm831x, wm831x_num,
+ wm8310_devs, ARRAY_SIZE(wm8310_devs));
break;

case WM8311:
- ret = mfd_add_devices(wm831x->dev, wm831x_num,
- wm8311_devs, ARRAY_SIZE(wm8311_devs),
- NULL, 0, NULL);
+ ret = wm831x_add_devices(wm831x, wm831x_num,
+ wm8311_devs, ARRAY_SIZE(wm8311_devs));
if (!pdata->disable_touch)
mfd_add_devices(wm831x->dev, wm831x_num,
touch_devs, ARRAY_SIZE(touch_devs),
@@ -1636,9 +1661,8 @@ int wm831x_device_init(struct wm831x *wm831x, int irq)
break;

case WM8312:
- ret = mfd_add_devices(wm831x->dev, wm831x_num,
- wm8312_devs, ARRAY_SIZE(wm8312_devs),
- NULL, 0, NULL);
+ ret = wm831x_add_devices(wm831x, wm831x_num,
+ wm8312_devs, ARRAY_SIZE(wm8312_devs));
if (!pdata->disable_touch)
mfd_add_devices(wm831x->dev, wm831x_num,
touch_devs, ARRAY_SIZE(touch_devs),
@@ -1649,9 +1673,8 @@ int wm831x_device_init(struct wm831x *wm831x, int irq)
case WM8321:
case WM8325:
case WM8326:
- ret = mfd_add_devices(wm831x->dev, wm831x_num,
- wm8320_devs, ARRAY_SIZE(wm8320_devs),
- NULL, 0, NULL);
+ ret = wm831x_add_devices(wm831x, wm831x_num,
+ wm8320_devs, ARRAY_SIZE(wm8320_devs));
break;

default:
diff --git a/include/linux/mfd/wm831x/pdata.h b/include/linux/mfd/wm831x/pdata.h
index 75aa94dadf1c..d5d9d9600756 100644
--- a/include/linux/mfd/wm831x/pdata.h
+++ b/include/linux/mfd/wm831x/pdata.h
@@ -12,6 +12,7 @@

struct wm831x;
struct regulator_init_data;
+struct software_node;

struct wm831x_backlight_pdata {
int isink; /** ISINK to use, 1 or 2 */
@@ -132,6 +133,7 @@ struct wm831x_pdata {
struct wm831x_status_pdata *status[WM831X_MAX_STATUS];
/** DCDC1 = 0 and so on */
struct regulator_init_data *dcdc[WM831X_MAX_DCDC];
+ const struct software_node *dcdc_swnodes[WM831X_MAX_DCDC];
/** EPE1 = 0 and so on */
struct regulator_init_data *epe[WM831X_MAX_EPE];
/** LDO1 = 0 and so on */

--
2.55.0.795.g602f6c329a-goog