Re: [PATCH V7 2/2] iio: accell: mma8452: add vdd/vddio regulator operation support

From: Martin Kepplinger
Date: Tue Jan 08 2019 - 06:41:24 EST


On 08.01.19 10:14, Anson Huang 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>
> ---
> ChangeLog Since V6:
> - separate the error handling of regulators get to make code easy to read.
> ---
> drivers/iio/accel/mma8452.c | 105 ++++++++++++++++++++++++++++++++++----------
> 1 file changed, 83 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
> index 421a0a8..3027811 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 +1537,39 @@ 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)) {
> + if (PTR_ERR(data->vdd_reg) == -EPROBE_DEFER)
> + return -EPROBE_DEFER;
> +
> + dev_err(&client->dev, "failed to get VDD regulator!\n");
> + return PTR_ERR(data->vdd_reg);
> + }
> +
> + data->vddio_reg = devm_regulator_get(&client->dev, "vddio");
> + if (IS_ERR(data->vddio_reg)) {
> + if (PTR_ERR(data->vddio_reg) == -EPROBE_DEFER)
> + return -EPROBE_DEFER;
> +
> + dev_err(&client->dev, "failed to get VDDIO regulator!\n");
> + return PTR_ERR(data->vddio_reg);
> + }
> +
> + 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 +1582,8 @@ 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 +1600,13 @@ 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 +1615,7 @@ 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 +1629,7 @@ 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 +1638,11 @@ 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 +1695,19 @@ 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 +1719,9 @@ 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 +1740,18 @@ 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 +1761,22 @@ 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 +1786,17 @@ 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)

Just a quesion: Isn't it semantically a different change to replace
mma8452_suspend() and mma8452_resume()? If not, why is it needed here?

other than that, lgtm.

> SET_RUNTIME_PM_OPS(mma8452_runtime_suspend,
> mma8452_runtime_resume, NULL)
> };
>