Re: [PATCH v2 5/7] iio: tsl2772: add support for regulator framework

Jonathan Cameron
2018-07-21T17:45:55Z

On Tue, 17 Jul 2018 04:41:56 -0400
Brian Masney <masneyb@onstation.org> wrote:

> This patch adds support for the regulator framework to the tsl2772
> driver. Driver was tested using a LG Nexus 5 (hammerhead) phone with
> the two regulators and on a Raspberry Pi 2 without any regulators
> controlling the power to the sensor.
>
> Signed-off-by: Brian Masney <masneyb@onstation.org>
There is an ordering issue in probe and hence the tear down. Fixing
it is unfortunately going to make the rest of the handling more complex...

Jonathan

> ---
> .../devicetree/bindings/iio/light/tsl2772.txt | 4 +
> drivers/iio/light/tsl2772.c | 82 ++++++++++++++++++-
> 2 files changed, 85 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/iio/light/tsl2772.txt b/Documentation/devicetree/bindings/iio/light/tsl2772.txt
> index ab553d52b9fc..bfde8b2c8790 100644
> --- a/Documentation/devicetree/bindings/iio/light/tsl2772.txt
> +++ b/Documentation/devicetree/bindings/iio/light/tsl2772.txt
> @@ -21,6 +21,8 @@ Optional properties:
> TSL2772_DIODE_BOTH.
> - amstaos,prox_power - must be TSL2772_100_mA, TSL2772_50_mA, TSL2772_25_mA,
> or TSL2772_13_mA.
> + - vdd-supply: phandle to the regulator that provides power to the sensor.
> + - vddio-supply: phandle to the regulator that provides power to the bus.
> - interrupt-parent: should be the phandle for the interrupt controller
> - interrupts: the sole interrupt generated by the device
>
> @@ -35,5 +37,7 @@ tsl2772@39 {
> compatible = "amstaos,tsl2772";
> reg = <0x39>;
> interrupts-extended = <&msmgpio 61 IRQ_TYPE_EDGE_FALLING>;
> + vdd-supply = <&pm8941_l17>;
> + vddio-supply = <&pm8941_lvs1>;
> amstaos,prox_diode = <TSL2772_DIODE0>;
> };
> diff --git a/drivers/iio/light/tsl2772.c b/drivers/iio/light/tsl2772.c
> index 0be57f2ecb02..f6a27f8b3ca7 100644
> --- a/drivers/iio/light/tsl2772.c
> +++ b/drivers/iio/light/tsl2772.c
> @@ -20,6 +20,7 @@
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> #include <linux/platform_data/tsl2772.h>
> +#include <linux/regulator/consumer.h>
>
> /* Cal defs */
> #define PROX_STAT_CAL 0
> @@ -146,6 +147,9 @@ struct tsl2772_chip {
> struct mutex prox_mutex;
> struct mutex als_mutex;
> struct i2c_client *client;
> + struct regulator *vdd_supply;
> + struct regulator *vddio_supply;
> + bool regulators_enabled;
> u16 prox_data;
> struct tsl2772_als_info als_cur_info;
> struct tsl2772_settings settings;
> @@ -609,6 +613,46 @@ static int tsl2772_als_calibrate(struct iio_dev *indio_dev)
> return ret;
> }
>
> +static int tsl2772_enable_regulators(struct tsl2772_chip *chip)
> +{
> + int ret;
> +
> + ret = regulator_enable(chip->vddio_supply);
> + if (ret < 0) {
> + dev_err(&chip->client->dev, "Failed to enable regulator: %d\n",
> + ret);
> + return ret;
> + }
> +
> + ret = regulator_enable(chip->vdd_supply);
> + if (ret < 0) {
> + regulator_disable(chip->vddio_supply);
> + dev_err(&chip->client->dev, "Failed to enable regulator: %d\n",
> + ret);
> + return ret;
> + }
> +
> + chip->regulators_enabled = true;
> +
> + return 0;
> +}
> +
> +static void tsl2772_disable_regulators(struct tsl2772_chip *chip)
> +{
> + if (!chip->regulators_enabled)
> + return;
> +
> + regulator_disable(chip->vdd_supply);
> + regulator_disable(chip->vddio_supply);
> +
> + chip->regulators_enabled = false;

hmm. this gets fiddly so I can see why you are using
this flag to avoid missbalanced enables / disables.

> +}
> +
> +static void tsl2772_disable_regulators_action(void *_data)
> +{
> + tsl2772_disable_regulators(_data);
> +}
> +
> static int tsl2772_chip_on(struct iio_dev *indio_dev)
> {
> struct tsl2772_chip *chip = iio_priv(indio_dev);
> @@ -666,6 +710,10 @@ static int tsl2772_chip_on(struct iio_dev *indio_dev)
> chip->als_gain_time_scale = als_time_us *
> tsl2772_als_gain[chip->settings.als_gain];
>
> + ret = tsl2772_enable_regulators(chip);
> + if (ret < 0)
> + return ret;
> +
> /*
> * TSL2772 Specific power-on / adc enable sequence
> * Power on the device 1st.
> @@ -724,10 +772,13 @@ static int tsl2772_chip_on(struct iio_dev *indio_dev)
> static int tsl2772_chip_off(struct iio_dev *indio_dev)
> {
> struct tsl2772_chip *chip = iio_priv(indio_dev);
> + int ret;
>
> /* turn device off */
> chip->tsl2772_chip_status = TSL2772_CHIP_SUSPENDED;
> - return tsl2772_write_control_reg(chip, 0x00);
> + ret = tsl2772_write_control_reg(chip, 0x00);
> + tsl2772_disable_regulators(chip);

Blank line here would be nice.

> + return ret;
> }
>
> /**
> @@ -1666,6 +1717,35 @@ static int tsl2772_probe(struct i2c_client *clientp,
> chip->client = clientp;
> i2c_set_clientdata(clientp, indio_dev);
>
> + chip->vddio_supply = devm_regulator_get(&clientp->dev, "vddio");
> + if (IS_ERR(chip->vddio_supply)) {
> + if (PTR_ERR(chip->vddio_supply) != -EPROBE_DEFER)
> + dev_err(&clientp->dev,
> + "Failed to get vddio regulator %d\n",
> + (int)PTR_ERR(chip->vddio_supply));
> +
> + return PTR_ERR(chip->vddio_supply);
> + }
> +
> + chip->vdd_supply = devm_regulator_get(&clientp->dev, "vdd");
> + if (IS_ERR(chip->vdd_supply)) {
> + if (PTR_ERR(chip->vdd_supply) != -EPROBE_DEFER)
> + dev_err(&clientp->dev,
> + "Failed to get vdd regulator %d\n",
> + (int)PTR_ERR(chip->vdd_supply));
> +
> + return PTR_ERR(chip->vdd_supply);
> + }
> +
> + ret = devm_add_action(&clientp->dev, tsl2772_disable_regulators_action,
> + chip);

Can't do them together. you need to think about where you might
get a failure. What if it is after the first enable but before the
second? In that case you've just left a regulator on as we haven't done this
setup yet.

> + if (ret < 0) {
> + tsl2772_disable_regulators_action(chip);
> + dev_err(&clientp->dev, "Failed to setup regulator cleanup action %d\n",
> + ret);
> + return ret;
> + }
> +
> ret = i2c_smbus_read_byte_data(chip->client,
> TSL2772_CMD_REG | TSL2772_CHIPID);
> if (ret < 0)