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SubjectRe: [PATCH v7 1/2] Added AMS tsl2591 driver implementation
On Fri, Apr 2, 2021 at 3:45 AM Joe Sandom <joe.g.sandom@gmail.com> wrote:
>
> Driver implementation for AMS/TAOS tsl2591 ambient light sensor.
>
> This driver supports configuration via device tree and sysfs.
> Supported channels for raw infrared light intensity,
> raw combined light intensity and illuminance in lux.
> The driver additionally supports iio events on lower and
> upper thresholds.
>
> This is a very-high sensitivity light-to-digital converter that
> transforms light intensity into a digital signal.

> Datasheet: https://ams.com/tsl25911#tab/documents
>

Shouldn't be blank lines in the tag block.

> Signed-off-by: Joe Sandom <joe.g.sandom@gmail.com>

...

> +#include <asm/unaligned.h>

Better to put this in a separate group after linux/* , but before linux/iio*

> +#include <linux/bitfield.h>
> +#include <linux/debugfs.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/iopoll.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/pm_runtime.h>
> +
> +#include <linux/iio/events.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>

...

> +/* ADC integration time, field value to time in ms*/

Missed space.

> +#define TSL2591_FVAL_TO_ATIME(x) (((x) + 1) * 100)
> +/* ADC integration time, time in ms to field value */
> +#define TSL2591_ATIME_TO_FVAL(x) (((x) / 100) - 1)

Taking comments into consideration I would simply rename

ATIME -> MSEC

...

> +#define TSL2591_CTRL_ALS_INTEGRATION_100MS 0x00
> +#define TSL2591_CTRL_ALS_INTEGRATION_200MS 0x01
> +#define TSL2591_CTRL_ALS_INTEGRATION_300MS 0x02
> +#define TSL2591_CTRL_ALS_INTEGRATION_400MS 0x03
> +#define TSL2591_CTRL_ALS_INTEGRATION_500MS 0x04
> +#define TSL2591_CTRL_ALS_INTEGRATION_600MS 0x05
> +#define TSL2591_CTRL_ALS_LOW_GAIN 0x00
> +#define TSL2591_CTRL_ALS_MED_GAIN 0x10
> +#define TSL2591_CTRL_ALS_HIGH_GAIN 0x20
> +#define TSL2591_CTRL_ALS_MAX_GAIN 0x30
> +#define TSL2591_CTRL_SYS_RESET 0x80

I would do it differently, since they are bit fields, e.g. for GAIN
(0 << 4)
(1 << 4)
(2 << 4)
(3 << 4)

and so on for the rest.

But there are pros and cons for yours and proposed variants, so I
leave it for you and maintainers.

...

> +#define TSL2591_PRST_ALS_INT_CYCLE_MAX TSL2591_PRST_ALS_INT_CYCLE_60

I guess it's a bitfield, so instead of using value from the list, show
explicitly the size in bits of the field

(BIT(x) - 1), or here looks like (BIT(4) - 1)

...

> +/* TSL2591 status register masks */
> +#define TSL2591_STS_ALS_VALID_MASK BIT(0)
> +#define TSL2591_STS_ALS_INT_MASK 0x10
> +#define TSL2591_STS_NPERS_INT_MASK 0x20
> +#define TSL2591_STS_VAL_HIGH_MASK 0x01

Why inconsistent ? Use BIT() for all here, or switch to left shifts or
plain numbers.

...

> +/*
> + * LUX calculations;
> + * AGAIN values from Adafruits TSL2591 Arduino library

Adafruit's

> + * https://github.com/adafruit/Adafruit_TSL2591_Library
> + */

...

> +static int tsl2591_set_als_lower_threshold(struct tsl2591_chip *chip,
> + u16 als_lower_threshold);
> +static int tsl2591_set_als_upper_threshold(struct tsl2591_chip *chip,
> + u16 als_upper_threshold);

Why forward declarations? Do you have recursion in use?
Otherwise, rearrange functions to be ordered and drop these.

...

> +static int tsl2591_check_als_valid(struct i2c_client *client)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_byte_data(client,
> + TSL2591_CMD_NOP | TSL2591_STATUS);

One line?

> + if (ret < 0) {
> + dev_err(&client->dev, "Failed to read register\n");
> + return -EINVAL;
> + }

> + ret = FIELD_GET(TSL2591_STS_ALS_VALID_MASK, ret);
> +
> + return ret;

return FIELD_GET(...);

> +}

...

> + struct tsl2591_chip *chip = iio_priv(indio_dev);
> + struct tsl2591_als_settings *settings = &chip->als_settings;
> + struct i2c_client *client = chip->client;

> +

Extra unneeded blank line.

> + u8 als_data[TSL2591_NUM_DATA_REGISTERS];
> + int counts_per_lux, int_time_fval, gain_multi, lux;
> + u16 als_ch0, als_ch1;
> + int ret;

...

> + struct tsl2591_als_settings als_settings = chip->als_settings;
> + struct i2c_client *client = chip->client;

> +

Ditto.

> + u16 als_upper_threshold;
> + u8 als_lower_l;
> + u8 als_lower_h;
> + int ret;

...

> + struct tsl2591_als_settings als_settings = chip->als_settings;
> + struct i2c_client *client = chip->client;

> +

Ditto.

> + u16 als_lower_threshold;
> + u8 als_upper_l;
> + u8 als_upper_h;
> + int ret;

...

> +static ssize_t tsl2591_in_illuminance_period_available_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct tsl2591_chip *chip = iio_priv(indio_dev);

> + return snprintf(buf, PAGE_SIZE, "%s\n",
> + tsl2591_als_period_list[chip->als_settings.als_int_time]);

sysfs_emit()

> +}

> +

Unneeded blank line.

> +static IIO_DEVICE_ATTR_RO(tsl2591_in_illuminance_period_available, 0);

...

> +static int tsl2591_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct tsl2591_chip *chip = iio_priv(indio_dev);
> + struct i2c_client *client = chip->client;
> + int ret;
> +
> + pm_runtime_get_sync(&client->dev);
> +
> + mutex_lock(&chip->als_mutex);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + if (chan->type != IIO_INTENSITY) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + ret = tsl2591_read_channel_data(indio_dev, chan, val, val2);
> + if (ret < 0)
> + break;
> +
> + ret = IIO_VAL_INT;
> + break;
> + case IIO_CHAN_INFO_PROCESSED:
> + if (chan->type != IIO_LIGHT) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + ret = tsl2591_read_channel_data(indio_dev, chan, val, val2);
> + if (ret < 0)
> + break;
> +
> + ret = IIO_VAL_INT_PLUS_MICRO;
> + break;
> + case IIO_CHAN_INFO_INT_TIME:
> + if (chan->type != IIO_INTENSITY) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + *val = TSL2591_FVAL_TO_ATIME(chip->als_settings.als_int_time);
> + ret = IIO_VAL_INT;
> + break;
> + case IIO_CHAN_INFO_CALIBSCALE:
> + if (chan->type != IIO_INTENSITY) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + *val = tsl2591_gain_to_multiplier(chip->als_settings.als_gain);
> + ret = IIO_VAL_INT;
> + break;
> + default:

> + ret = -EINVAL;

Missed break; statement.

> + }
> +
> + mutex_unlock(&chip->als_mutex);
> +
> + pm_runtime_mark_last_busy(&client->dev);
> + pm_runtime_put_autosuspend(&client->dev);
> +
> + return ret;
> +}

...

> +err:

err_unlock:

> + mutex_unlock(&chip->als_mutex);
> + return ret;
> +}

It's interesting why in one case full of break statements and another
is goto style. Can you be consistent, please?

...

> +err:
> + mutex_unlock(&chip->als_mutex);
> + return ret;
> +}

Ditto.

...

> +err:
> + mutex_unlock(&chip->als_mutex);
> + return ret;
> +}

Ditto.

...

> + if (!i2c_check_functionality(client->adapter,
> + I2C_FUNC_SMBUS_BYTE_DATA)) {

One line?

> + dev_err(&client->dev,
> + "I2C smbus byte data functionality is not supported\n");
> + return -EOPNOTSUPP;
> + }

...

> + /*
> + * Add chip off to automatically managed path and disable runtime
> + * power management. This ensures that the chip power management
> + * is handled correctly on driver remove. tsl2591_chip_off must be

tsl2591_chip_off()

> + * added to the managed path after pm runtime is enabled and before
> + * any error exit paths are met to ensure we're not left in a state
> + * of pm runtime not being disabled properly.
> + */

--
With Best Regards,
Andy Shevchenko

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