[PATCH v2] media: i2c: dw9714: add optional regulator support

Martin Kepplinger
2021-11-26T09:03:29Z

From: Angus Ainslie <angus@akkea.ca>

Allow the dw9714 to control a regulator and adjust suspend() and resume()
to support both runtime and system pm.

Signed-off-by: Angus Ainslie <angus@akkea.ca>
Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
---

revision history
----------------

v2: (thank you Mark)
* simplify the regulator_get_optional() error path
* fix regulator usage during probe()

v1:
https://lore.kernel.org/linux-media/20211125080922.978583-1-martin.kepplinger@puri.sm/

drivers/media/i2c/dw9714.c | 39 ++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/drivers/media/i2c/dw9714.c b/drivers/media/i2c/dw9714.c
index 3863dfeb8293..e8cc19b89861 100644
--- a/drivers/media/i2c/dw9714.c
+++ b/drivers/media/i2c/dw9714.c
@@ -5,6 +5,7 @@
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
@@ -36,6 +37,7 @@ struct dw9714_device {
struct v4l2_ctrl_handler ctrls_vcm;
struct v4l2_subdev sd;
u16 current_val;
+ struct regulator *vcc;
};

static inline struct dw9714_device *to_dw9714_vcm(struct v4l2_ctrl *ctrl)
@@ -145,6 +147,21 @@ static int dw9714_probe(struct i2c_client *client)
if (dw9714_dev == NULL)
return -ENOMEM;

+ dw9714_dev->vcc = devm_regulator_get_optional(&client->dev, "vcc");
+ if (IS_ERR(dw9714_dev->vcc)) {
+ dev_dbg(&client->dev, "No vcc regulator found: %ld\n",
+ PTR_ERR(dw9714_dev->vcc));
+ dw9714_dev->vcc = NULL;
+ }
+
+ if (dw9714_dev->vcc) {
+ rval = regulator_enable(dw9714_dev->vcc);
+ if (rval < 0) {
+ dev_err(&client->dev, "failed to enable vcc: %d\n", rval);
+ return rval;
+ }
+ }
+
v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops);
dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
V4L2_SUBDEV_FL_HAS_EVENTS;
@@ -200,6 +217,9 @@ static int __maybe_unused dw9714_vcm_suspend(struct device *dev)
struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
int ret, val;

+ if (pm_runtime_suspended(&client->dev))
+ return 0;
+
for (val = dw9714_dev->current_val & ~(DW9714_CTRL_STEPS - 1);
val >= 0; val -= DW9714_CTRL_STEPS) {
ret = dw9714_i2c_write(client,
@@ -208,6 +228,13 @@ static int __maybe_unused dw9714_vcm_suspend(struct device *dev)
dev_err_once(dev, "%s I2C failure: %d", __func__, ret);
usleep_range(DW9714_CTRL_DELAY_US, DW9714_CTRL_DELAY_US + 10);
}
+
+ if (dw9714_dev->vcc) {
+ ret = regulator_disable(dw9714_dev->vcc);
+ if (ret)
+ dev_err(dev, "Failed to disable vcc: %d\n", ret);
+ }
+
return 0;
}

@@ -224,6 +251,18 @@ static int __maybe_unused dw9714_vcm_resume(struct device *dev)
struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd);
int ret, val;

+ if (pm_runtime_suspended(&client->dev))
+ return 0;
+
+ if (dw9714_dev->vcc) {
+ ret = regulator_enable(dw9714_dev->vcc);
+ if (ret) {
+ dev_err(dev, "Failed to enable vcc: %d\n", ret);
+ return ret;
+ }
+ usleep_range(1000, 2000);
+ }
+
for (val = dw9714_dev->current_val % DW9714_CTRL_STEPS;
val < dw9714_dev->current_val + DW9714_CTRL_STEPS - 1;
val += DW9714_CTRL_STEPS) {
--
2.30.2