Re: [PATCH v2 2/2] iio: adc: adding support for pac193x

Krzysztof Kozlowski
2023-10-27T12:20:19Z

On 25/10/2023 15:44, marius.cristea@microchip.com wrote:
> From: Marius Cristea <marius.cristea@microchip.com>
>
> This is the iio driver for Microchip
> PAC193X series of Power Monitor with Accumulator chip family.
>
> Signed-off-by: Marius Cristea <marius.cristea@microchip.com>
> ---

...

> +
> +static ssize_t reset_accumulators_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct pac1934_chip_info *info = iio_priv(indio_dev);
> + int ret, i;
> + u8 refresh_cmd = PAC1934_REFRESH_REG_ADDR;
> +
> + ret = i2c_smbus_write_byte(info->client, refresh_cmd);
> + if (ret) {
> + dev_err(&indio_dev->dev,
> + "%s - cannot send 0x%02X\n",
> + __func__, refresh_cmd);
> + }
> +
> + for (i = 0 ; i < info->phys_channels; i++)
> + info->chip_reg_data.energy_sec_acc[i] = 0;
> +
> + return count;
> +}
> +
> +static IIO_DEVICE_ATTR(in_shunt_resistor_1, 0644, shunt_value_show, shunt_value_store, 0);
> +static IIO_DEVICE_ATTR(in_shunt_resistor_2, 0644, shunt_value_show, shunt_value_store, 0);
> +static IIO_DEVICE_ATTR(in_shunt_resistor_3, 0644, shunt_value_show, shunt_value_store, 0);
> +static IIO_DEVICE_ATTR(in_shunt_resistor_4, 0644, shunt_value_show, shunt_value_store, 0);
> +static IIO_DEVICE_ATTR(reset_accumulators, 0200, NULL, reset_accumulators_store, 0);
> +
> +static struct attribute *pac1934_all_attributes[] = {
> + PAC1934_DEV_ATTR(in_shunt_resistor_1),
> + PAC1934_DEV_ATTR(in_shunt_resistor_2),
> + PAC1934_DEV_ATTR(in_shunt_resistor_3),
> + PAC1934_DEV_ATTR(in_shunt_resistor_4),
> + PAC1934_DEV_ATTR(reset_accumulators),
> + NULL
> +};
> +
> +static int pac1934_prep_custom_attributes(struct pac1934_chip_info *info,
> + struct iio_dev *indio_dev)
> +{
> + int i, j, active_channels_count = 0;
> + struct attribute **pac1934_custom_attributes;
> + struct attribute_group *pac1934_group;
> + struct i2c_client *client = info->client;
> +
> + for (i = 0 ; i < info->phys_channels; i++)
> + if (info->active_channels[i])
> + active_channels_count++;
> +
> + pac1934_group = devm_kzalloc(&client->dev, sizeof(*pac1934_group), GFP_KERNEL);
> +
> + pac1934_custom_attributes = devm_kzalloc(&client->dev,
> + (PAC1934_CUSTOM_ATTR_FOR_CHANNEL *
> + active_channels_count +
> + PAC1934_SHARED_DEVATTRS_COUNT)
> + * sizeof(*pac1934_group) + 1,
> + GFP_KERNEL);
> + j = 0;
> +
> + for (i = 0 ; i < info->phys_channels; i++) {
> + if (info->active_channels[i]) {
> + pac1934_custom_attributes[PAC1934_CUSTOM_ATTR_FOR_CHANNEL * j] =
> + pac1934_all_attributes[PAC1934_CUSTOM_ATTR_FOR_CHANNEL * i];
> + pac1934_custom_attributes[PAC1934_CUSTOM_ATTR_FOR_CHANNEL * j + 1] =
> + pac1934_all_attributes[PAC1934_CUSTOM_ATTR_FOR_CHANNEL * i + 1];
> + j++;
> + }
> + }
> +
> + for (i = 0; i < PAC1934_SHARED_DEVATTRS_COUNT; i++)
> + pac1934_custom_attributes[PAC1934_CUSTOM_ATTR_FOR_CHANNEL *
> + active_channels_count + i] =
> + pac1934_all_attributes[PAC1934_CUSTOM_ATTR_FOR_CHANNEL *
> + info->phys_channels + i];
> +
> + pac1934_group->attrs = pac1934_custom_attributes;
> + info->pac1934_info.attrs = pac1934_group;
> +
> + return 0;
> +}
> +
> +static void pac1934_remove(struct i2c_client *client)

Remove functions goes always after probe.

> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(&client->dev);
> + struct pac1934_chip_info *info = iio_priv(indio_dev);
> +
> + cancel_delayed_work_sync(&info->work_chip_rfsh);
> +}
> +
> +static int pac1934_probe(struct i2c_client *client)
> +{
> + struct pac1934_chip_info *info;
> + struct iio_dev *indio_dev;
> + const char *name = NULL;
> + int cnt, ret;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*info));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + info = iio_priv(indio_dev);
> +
> + i2c_set_clientdata(client, indio_dev);
> + info->client = client;
> +
> + /*
> + * load default settings - all channels disabled,
> + * uni directional flow
> + */
> + for (cnt = 0; cnt < PAC1934_MAX_NUM_CHANNELS; cnt++) {
> + info->active_channels[cnt] = false;
> + info->bi_dir[cnt] = false;
> + }
> +
> + info->crt_samp_spd_bitfield = PAC1934_SAMP_1024SPS;
> +
> + ret = pac1934_chip_identify(info);
> + if (ret)
> + return -EINVAL;
> +
> + if (ACPI_HANDLE(&client->dev)) {
> + if (!info->phys_channels)
> + /* failed to identify part number, unknown number of channels available */
> + return -EINVAL;
> +
> + name = pac1934_match_acpi_device(client, info);
> + } else {
> + name = pac1934_match_of_device(client, info);
> + }
> +
> + if (!name) {
> + dev_dbg(&client->dev, "parameter parsing returned an error\n");
> + return -EINVAL;
> + }
> +
> + mutex_init(&info->lock);
> +
> + /*
> + * do now any chip specific initialization (e.g. read/write
> + * some registers), enable/disable certain channels, change the sampling
> + * rate to the requested value
> + */
> + ret = pac1934_chip_configure(info);
> + if (ret < 0)
> + goto fail;

Why do you need to go to fail here? Is the work scheduled in error cases?

> +
> + /* prepare the channel information */
> + ret = pac1934_prep_iio_channels(info, indio_dev);
> + if (ret < 0)
> + goto fail;
> +
> + ret = pac1934_prep_custom_attributes(info, indio_dev);
> + if (ret < 0) {
> + dev_err_probe(&indio_dev->dev, ret,
> + "Can't configure custom attributes for PAC1934 device\n");
> + goto fail;
> + }
> +
> + info->pac1934_info.read_raw = pac1934_read_raw;
> + info->pac1934_info.read_avail = pac1934_read_avail;
> + info->pac1934_info.write_raw = pac1934_write_raw;
> + info->pac1934_info.read_label = pac1934_read_label;
> +
> + indio_dev->info = &info->pac1934_info;
> + indio_dev->name = name;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + /*
> + * read whatever has been accumulated in the chip so far
> + * and reset the accumulators
> + */
> + ret = pac1934_reg_snapshot(info, true, PAC1934_REFRESH_REG_ADDR,
> + PAC1934_MIN_UPDATE_WAIT_TIME_US);
> + if (ret < 0)
> + goto fail;
> +
> + ret = devm_iio_device_register(&client->dev, indio_dev);
> + if (ret < 0) {
> + dev_err_probe(&indio_dev->dev, ret,
> + "Can't register IIO device\n");
> + goto fail;
> + }
> +
> + return 0;
> +
> +fail:
> + cancel_delayed_work_sync(&info->work_chip_rfsh);
> +
> + return ret;
> +}
> +
> +static const struct i2c_device_id pac1934_id[] = {
> + { .name = "pac1931", .driver_data = (kernel_ulong_t)&pac1934_chip_config[PAC1931] },
> + { .name = "pac1932", .driver_data = (kernel_ulong_t)&pac1934_chip_config[PAC1932] },
> + { .name = "pac1933", .driver_data = (kernel_ulong_t)&pac1934_chip_config[PAC1933] },
> + { .name = "pac1934", .driver_data = (kernel_ulong_t)&pac1934_chip_config[PAC1934] },
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, pac1934_id);
> +
> +static const struct of_device_id pac1934_of_match[] = {
> + {
> + .compatible = "microchip,pac1931",
> + .data = &pac1934_chip_config[PAC1931]
> + },
> + {
> + .compatible = "microchip,pac1932",
> + .data = &pac1934_chip_config[PAC1932]
> + },
> + {
> + .compatible = "microchip,pac1933",
> + .data = &pac1934_chip_config[PAC1933]
> + },
> + {
> + .compatible = "microchip,pac1934",
> + .data = &pac1934_chip_config[PAC1934]
> + },
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(of, pac1934_of_match);
> +
> +/* using MCHP1930 to be compatible with WINDOWS ACPI */
> +static const struct acpi_device_id pac1934_acpi_match[] = {
> + {"MCHP1930", 0},
> + { }
> +};
> +
> +MODULE_DEVICE_TABLE(acpi, pac1934_acpi_match);
> +
> +static struct i2c_driver pac1934_driver = {
> + .driver = {
> + .name = "pac1934",
> + .of_match_table = pac1934_of_match,
> + .acpi_match_table = ACPI_PTR(pac1934_acpi_match)

Drop ACPI_PTR, causes warnings.

Best regards,
Krzysztof