Re: [PATCH v2] media: i2c: dw9714: add optional regulator support
From: Sakari Ailus <sakari.ailus@linux.intel.com>
Date: 2021-11-26 10:48:14
Also in:
linux-media, lkml
Hi Martin, On Fri, Nov 26, 2021 at 10:01:07AM +0100, Martin Kepplinger wrote:
quoted hunk ↗ jump to hunk
From: Angus Ainslie <redacted> Allow the dw9714 to control a regulator and adjust suspend() and resume() to support both runtime and system pm. Signed-off-by: Angus Ainslie <redacted> Signed-off-by: Martin Kepplinger <redacted> --- 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/ (local) 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");
You you used regular devm_regulator_get(), you could remove the error handling below. If there's no regulator, you'll simply get a dummy one.
+ 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) {With (dummy) regulators, these checks become unnecessary.
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+ 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;
This can't take place in a runtime PM suspend callback. You'll need to add system suspend callback for this.
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+ 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))
Same for this one.
+ 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) {-- Kind regards, Sakari Ailus