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

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

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