RE: [PATCH V5 2/2] iio: accell: mma8452: add vdd/vddio regulator operation support

Anson Huang
2018-12-23T09:05:27Z

Hi, Jonathan

Best Regards!
Anson Huang

> -----Original Message-----
> From: Jonathan Cameron [mailto:jic23@kernel.org]
> Sent: 2018年12月23日 1:20
> To: Anson Huang <anson.huang@nxp.com>
> Cc: knaack.h@gmx.de; lars@metafoo.de; pmeerw@pmeerw.net;
> robh+dt@kernel.org; mark.rutland@arm.com; martink@posteo.de;
> gregkh@linuxfoundation.org; gustavo@embeddedor.com; Leonard Crestez
> <leonard.crestez@nxp.com>; rtresidd@electromag.com.au;
> linux-iio@vger.kernel.org; devicetree@vger.kernel.org;
> linux-kernel@vger.kernel.org; festevam@gmail.com;
> preid@electromag.com.au; dl-linux-imx <linux-imx@nxp.com>
> Subject: Re: [PATCH V5 2/2] iio: accell: mma8452: add vdd/vddio regulator
> operation support
>
> On Mon, 17 Dec 2018 05:22:55 +0000
> Anson Huang <anson.huang@nxp.com> wrote:
>
> > The accelerometer's power supply could be controllable on some
> > platforms, such as i.MX6Q-SABRESD board, the mma8451's power supplies
> > are controlled by a GPIO fixed regulator, need to make sure the
> > regulators are enabled before any communication with mma8451, this
> > patch adds vdd/vddio regulator operation support.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > Acked-by: Martin Kepplinger <martink@posteo.de>
>
> There is a lot of manual handling in the suspend and resume I would not
> expect to see. That should be using the runtime pm calls to take control of
> pm rather than making assumptions about what runtime pm state we are in...

Yes, but I found we can just use pm_runtime_force_suspend/resume for suspend/resume
operations, since the operations are same, it will simply the code and I tested it, it works.

Anson.

>
> Jonathan
>
> > ---
> > ChangeLog since V4:
> > - using devm_regulator_get() instead of devm_regulator_get_optional()
> since the regulator is
> > there always, if dtb does NOT specify one, regulator framework will
> assign dummy regulator for it.
> > ---
> > drivers/iio/accel/mma8452.c | 183
> > +++++++++++++++++++++++++++++++++++++++++---
> > 1 file changed, 172 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
> > index 421a0a8..9a52426 100644
> > --- a/drivers/iio/accel/mma8452.c
> > +++ b/drivers/iio/accel/mma8452.c
> > @@ -31,6 +31,7 @@
> > #include <linux/of_device.h>
> > #include <linux/of_irq.h>
> > #include <linux/pm_runtime.h>
> > +#include <linux/regulator/consumer.h>
> >
> > #define MMA8452_STATUS 0x00
> > #define MMA8452_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
> > @@ -107,6 +108,8 @@ struct mma8452_data {
> > u8 data_cfg;
> > const struct mma_chip_info *chip_info;
> > int sleep_val;
> > + struct regulator *vdd_reg;
> > + struct regulator *vddio_reg;
> > };
> >
> > /**
> > @@ -1534,9 +1537,37 @@ static int mma8452_probe(struct i2c_client
> *client,
> > mutex_init(&data->lock);
> > data->chip_info = match->data;
> >
> > + data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
> > + if (IS_ERR(data->vdd_reg)) {
> > + ret = PTR_ERR(data->vdd_reg);
> > + if (ret != -EPROBE_DEFER)
> > + dev_err(&client->dev, "failed to get VDD regulator!\n");
> > + return ret;
> > + }
> > +
> > + ret = regulator_enable(data->vdd_reg);
> > + if (ret) {
> > + dev_err(&client->dev, "failed to enable VDD regulator!\n");
> > + return ret;
> > + }
>
> Please reorder so the unwind order in remove and devm cleanup is the
> opposite of setup order. I suspect that is just a case of doing the two gets
> before enabling either regulator, but I haven't checked.
>
> > +
> > + data->vddio_reg = devm_regulator_get(&client->dev, "vddio");
> > + if (IS_ERR(data->vddio_reg)) {
> > + ret = PTR_ERR(data->vddio_reg);
> > + if (ret != -EPROBE_DEFER)
> > + dev_err(&client->dev, "failed to get VDDIO regulator!\n");
> > + goto disable_regulator_vdd;
> > + }
> > +
> > + ret = regulator_enable(data->vddio_reg);
> > + if (ret) {
> > + dev_err(&client->dev, "failed to enable VDDIO regulator!\n");
> > + goto disable_regulator_vdd;
> > + }
> > +
> > ret = i2c_smbus_read_byte_data(client, MMA8452_WHO_AM_I);
> > if (ret < 0)
> > - return ret;
> > + goto disable_regulators;
> >
> > switch (ret) {
> > case MMA8451_DEVICE_ID:
> > @@ -1549,7 +1580,8 @@ static int mma8452_probe(struct i2c_client
> *client,
> > break;
> > /* else: fall through */
> > default:
> > - return -ENODEV;
> > + ret = -ENODEV;
> > + goto disable_regulators;
> > }
> >
> > dev_info(&client->dev, "registering %s accelerometer; ID 0x%x\n", @@
> > -1566,13 +1598,13 @@ static int mma8452_probe(struct i2c_client
> > *client,
> >
> > ret = mma8452_reset(client);
> > if (ret < 0)
> > - return ret;
> > + goto disable_regulators;
> >
> > data->data_cfg = MMA8452_DATA_CFG_FS_2G;
> > ret = i2c_smbus_write_byte_data(client, MMA8452_DATA_CFG,
> > data->data_cfg);
> > if (ret < 0)
> > - return ret;
> > + goto disable_regulators;
> >
> > /*
> > * By default set transient threshold to max to avoid events if @@
> > -1581,7 +1613,7 @@ static int mma8452_probe(struct i2c_client *client,
> > ret = i2c_smbus_write_byte_data(client, MMA8452_TRANSIENT_THS,
> > MMA8452_TRANSIENT_THS_MASK);
> > if (ret < 0)
> > - return ret;
> > + goto disable_regulators;
> >
> > if (client->irq) {
> > int irq2;
> > @@ -1595,7 +1627,7 @@ static int mma8452_probe(struct i2c_client
> *client,
> > MMA8452_CTRL_REG5,
> > data->chip_info->all_events);
> > if (ret < 0)
> > - return ret;
> > + goto disable_regulators;
> >
> > dev_dbg(&client->dev, "using interrupt line INT1\n");
> > }
> > @@ -1604,11 +1636,11 @@ static int mma8452_probe(struct i2c_client
> *client,
> > MMA8452_CTRL_REG4,
> > data->chip_info->enabled_events);
> > if (ret < 0)
> > - return ret;
> > + goto disable_regulators;
> >
> > ret = mma8452_trigger_setup(indio_dev);
> > if (ret < 0)
> > - return ret;
> > + goto disable_regulators;
> > }
> >
> > data->ctrl_reg1 = MMA8452_CTRL_ACTIVE | @@ -1661,12 +1693,20
> @@
> > static int mma8452_probe(struct i2c_client *client,
> > trigger_cleanup:
> > mma8452_trigger_cleanup(indio_dev);
> >
> > +disable_regulators:
> > + regulator_disable(data->vddio_reg);
> > +
> > +disable_regulator_vdd:
> > + regulator_disable(data->vdd_reg);
> > +
> > return ret;
> > }
> >
> > static int mma8452_remove(struct i2c_client *client) {
> > struct iio_dev *indio_dev = i2c_get_clientdata(client);
> > + struct mma8452_data *data = iio_priv(indio_dev);
> > + int ret;
> >
> > iio_device_unregister(indio_dev);
> >
> > @@ -1678,6 +1718,18 @@ static int mma8452_remove(struct i2c_client
> *client)
> > mma8452_trigger_cleanup(indio_dev);
> > mma8452_standby(iio_priv(indio_dev));
> >
> > + ret = regulator_disable(data->vddio_reg);
> > + if (ret) {
> > + dev_err(&client->dev, "failed to disable VDDIO regulator\n");
> > + return ret;
> > + }
> > +
> > + ret = regulator_disable(data->vdd_reg);
> > + if (ret) {
> > + dev_err(&client->dev, "failed to disable VDD regulator\n");
> > + return ret;
> > + }
> > +
> > return 0;
> > }
> >
> > @@ -1696,6 +1748,18 @@ 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);
> > + if (ret) {
> > + dev_err(dev, "failed to disable VDD regulator\n");
> > + return ret;
> > + }
> > +
> > return 0;
> > }
> >
> > @@ -1705,9 +1769,22 @@ 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);
> > + if (ret) {
> > + dev_err(dev, "failed to enable VDDIO regulator\n");
> > + regulator_disable(data->vdd_reg);
> > + return ret;
> > + }
> > +
> > ret = mma8452_active(data);
> > if (ret < 0)
> > - return ret;
> > + goto runtime_resume_failed;
> >
> > ret = mma8452_get_odr_index(data);
> > sleep_val = 1000 / mma8452_samp_freq[ret][0]; @@ -1717,20
> +1794,104
> > @@ static int mma8452_runtime_resume(struct device *dev)
> > msleep_interruptible(sleep_val);
> >
> > return 0;
> > +
> > +runtime_resume_failed:
> > + regulator_disable(data->vddio_reg);
> > + regulator_disable(data->vdd_reg);
> > +
> > + return ret;
> > }
> > #endif
> >
> > #ifdef CONFIG_PM_SLEEP
> > static int mma8452_suspend(struct device *dev) {
> > - return mma8452_standby(iio_priv(i2c_get_clientdata(
> > + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> > + struct mma8452_data *data = iio_priv(indio_dev);
> > + int ret;
> > +
>
> I'd rather see the runtime pm calls done than doing this directly.
> So you should let the runtime pm know it needs to power the device on, then
> take over control (disable runtime pm) and power down.
>
> > + 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);
> > + if (ret) {
> > + dev_err(dev, "failed to enable VDDIO regulator\n");
> > + regulator_disable(data->vdd_reg);
> > + return ret;
> > + }
> > +
> > + ret = mma8452_standby(iio_priv(i2c_get_clientdata(
> > to_i2c_client(dev))));
> > + if (ret)
> > + goto suspend_failed;
> > +
> > + 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);
> > + if (ret) {
> > + dev_err(dev, "failed to disable VDD regulator\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +
> > +suspend_failed:
> > + regulator_disable(data->vddio_reg);
> > + regulator_disable(data->vdd_reg);
> > +
> > + return ret;
> > }
> >
> > static int mma8452_resume(struct device *dev) {
> > - return mma8452_active(iio_priv(i2c_get_clientdata(
> > + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> > + struct mma8452_data *data = iio_priv(indio_dev);
> > + int ret;
> > +
> > + 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);
> > + if (ret) {
> > + dev_err(dev, "failed to enable VDDIO regulator\n");
> > + regulator_disable(data->vdd_reg);
> > + return ret;
> > + }
> > +
> > + ret = mma8452_active(iio_priv(i2c_get_clientdata(
> > to_i2c_client(dev))));
> > + if (ret)
> > + goto resume_failed;
> > +
> > + ret = regulator_disable(data->vddio_reg);
> > + if (ret) {
> > + dev_err(dev, "failed to disable VDDIO regulator\n");
> > + return ret;
>
> This is odd in a resume path to turn it off. Normally you just hand off to the
> runtime pm again to autosuspend as necessary.
>
> > + }
> > +
> > + ret = regulator_disable(data->vdd_reg);
> > + if (ret) {
> > + dev_err(dev, "failed to disable VDD regulator\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +
> > +resume_failed:
> > + regulator_disable(data->vddio_reg);
> > + regulator_disable(data->vdd_reg);
> > +
> > + return ret;
> > }
> > #endif
> >