RE: [PATCH V6 2/2] iio: accell: mma8452: add vdd/vddio regulator operation support

From: Anson Huang
Date: Tue Jan 08 2019 - 04:17:50 EST


Hi, Jonathan

Best Regards!
Anson Huang

> -----Original Message-----
> From: Jonathan Cameron [mailto:jic23@xxxxxxxxxx]
> Sent: 2019年1月6日 1:30
> To: Anson Huang <anson.huang@xxxxxxx>
> Cc: knaack.h@xxxxxx; lars@xxxxxxxxxx; pmeerw@xxxxxxxxxx;
> robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx; martink@xxxxxxxxx; Leonard
> Crestez <leonard.crestez@xxxxxxx>; gregkh@xxxxxxxxxxxxxxxxxxx;
> gustavo@xxxxxxxxxxxxxx; rtresidd@xxxxxxxxxxxxxxxxx;
> linux-iio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>
> Subject: Re: [PATCH V6 2/2] iio: accell: mma8452: add vdd/vddio regulator
> operation support
>
> On Sun, 23 Dec 2018 09:02:32 +0000
> Anson Huang <anson.huang@xxxxxxx> 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@xxxxxxx>
> > Acked-by: Martin Kepplinger <martink@xxxxxxxxx>
>
> I'm fine with the general approach now, though I would like separate error
> handling for the two different regulators.
>
> Also, this has obviously changed a fair bit since Martin originally gave that Ack.
> Martin, could you confirm you are still happy with the code?
>
> Thanks,
>
> Jonathan
>
>
> > ---
> > ChangeLog since V5:
> > - ONLY enable vdd/vddio regulators after both of them are aquired;
> > - Since the suspend/resume operations are same as runtime
> suspend/resume, so just use the
> > pm_runtime_force_suspend/resume for suspend/resuem callback to
> simply the code.
> > ---
> > drivers/iio/accel/mma8452.c | 99
> > +++++++++++++++++++++++++++++++++++----------
> > 1 file changed, 77 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
> > index 421a0a8..7519ed5 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 +1537,33 @@ 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");
> > + data->vddio_reg = devm_regulator_get(&client->dev, "vddio");
> > + if (IS_ERR(data->vdd_reg) || IS_ERR(data->vddio_reg)) {
> > + if (PTR_ERR(data->vdd_reg) == -EPROBE_DEFER ||
> > + PTR_ERR(data->vddio_reg) == -EPROBE_DEFER)
> > + return -EPROBE_DEFER;
> > +
> > + dev_err(&client->dev, "failed to get VDD/VDDIO regulator!\n");
> > + return IS_ERR(data->vdd_reg) ?
> > + PTR_ERR(data->vdd_reg) : PTR_ERR(data->vddio_reg);
>
> This is overly complex. It'll be more lines of code, but I'd prefer you handle
> the two separately as the result will be more readable / less fragile.

I separated it in V7 patch, please help review, thanks.

Anson.

>
> > + }
> > +
> > + ret = regulator_enable(data->vdd_reg);
> > + if (ret) {
> > + dev_err(&client->dev, "failed to enable VDD regulator!\n");
> > + return ret;
> > + }
> > +
> > + 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 +1576,8 @@ 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 +1594,13 @@ 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 +1609,7 @@ 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 +1623,7 @@ 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 +1632,11 @@ 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 +1689,19
> @@
> > 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);
> >
> > iio_device_unregister(indio_dev);
> >
> > @@ -1678,6 +1713,9 @@ static int 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);
> > +
> > return 0;
> > }
> >
> > @@ -1696,6 +1734,18 @@ 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 +1755,22 @@ 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]; @@ -1717,25 +1780,17
> > @@ static int mma8452_runtime_resume(struct device *dev)
> > msleep_interruptible(sleep_val);
> >
> > return 0;
> > -}
> > -#endif
> >
> > -#ifdef CONFIG_PM_SLEEP
> > -static int mma8452_suspend(struct device *dev) -{
> > - return mma8452_standby(iio_priv(i2c_get_clientdata(
> > - to_i2c_client(dev))));
> > -}
> > +runtime_resume_failed:
> > + regulator_disable(data->vddio_reg);
> > + regulator_disable(data->vdd_reg);
> >
> > -static int mma8452_resume(struct device *dev) -{
> > - return mma8452_active(iio_priv(i2c_get_clientdata(
> > - to_i2c_client(dev))));
> > + return ret;
> > }
> > #endif
> >
> > static const struct dev_pm_ops mma8452_pm_ops = {
> > - SET_SYSTEM_SLEEP_PM_OPS(mma8452_suspend, mma8452_resume)
> > + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > +pm_runtime_force_resume)
> > SET_RUNTIME_PM_OPS(mma8452_runtime_suspend,
> > mma8452_runtime_resume, NULL)
> > };