Re: [PATCH v2 3/3] iio: light: as73211: add support for as7331

From: Christian Eggers
Date: Fri Jan 12 2024 - 04:51:43 EST

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Hi Javier,

after being back from my extended Christmas holidays, I took a look
onto your changes:

On Wednesday, 3 January 2024, 13:08:53 CET, Javier Carrasco wrote:
> The AMS AS7331 is a UV light sensor with three channels: UVA, UVB and
> UVC (also known as deep UV and referenced as DUV in the iio core).
> Its internal structure and forming blocks are practically identical to
> the ones the AS73211 contains: API, internal DAC, I2C interface and
> registers, measurement modes, number of channels and pinout.
>
> The only difference between them is the photodiodes used to acquire
> light, which means that only some modifications are required to add
> support for the AS7331 in the existing driver.
>
> The temperature channel is identical for both devices and only the
> channel modifiers of the IIO_INTENSITY channels need to account for the
> device type.
>
> The scale values have been obtained from the chapter "7.5 Transfer
> Function" of the official datasheet[1] for the configuration chosen as
> basis (Nclk = 1024 and GAIN = 1). Those values keep the units from the
> datasheet (nW/cm^2), as opposed to the units used for the AS73211
> (nW/m^2).
>
> Add a new device-specific data structure to account for the device
> differences: channel types and scale of LSB per channel.
>
> [1] https://ams.com/documents/20143/9106314/AS7331_DS001047_4-00.pdf
>
> Tested-by: Christian Eggers <ceggers@xxxxxxx>
> Signed-off-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>
> ---
> drivers/iio/light/Kconfig | 5 +-
> drivers/iio/light/as73211.c | 141 ++++++++++++++++++++++++++++++++++++--------
> 2 files changed, 118 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index 143003232d1c..fd5a9879a582 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -87,13 +87,14 @@ config APDS9960
> module will be called apds9960
>
> config AS73211
> - tristate "AMS AS73211 XYZ color sensor"
> + tristate "AMS AS73211 XYZ color sensor and AMS AS7331 UV sensor"
> depends on I2C
> select IIO_BUFFER
> select IIO_TRIGGERED_BUFFER
> help
> If you say yes here you get support for the AMS AS73211
> - JENCOLOR(R) Digital XYZ Sensor.
> + JENCOLOR(R) Digital XYZ and the AMS AS7331 UVA, UVB and UVC
> + ultraviolet sensors.
>
> For triggered measurements, you will need an additional trigger driver
> like IIO_HRTIMER_TRIGGER or IIO_SYSFS_TRIGGER.
> diff --git a/drivers/iio/light/as73211.c b/drivers/iio/light/as73211.c
> index b4c6f389a292..44daf816ae57 100644
> --- a/drivers/iio/light/as73211.c
> +++ b/drivers/iio/light/as73211.c
> @@ -1,6 +1,7 @@
> // SPDX-License-Identifier: GPL-2.0-only
> /*
> - * Support for AMS AS73211 JENCOLOR(R) Digital XYZ Sensor
> + * Support for AMS AS73211 JENCOLOR(R) Digital XYZ Sensor and AMS AS7331
> + * UVA, UVB and UVC (DUV) Ultraviolet Sensor
> *
> * Author: Christian Eggers <ceggers@xxxxxxx>
> *
> @@ -9,7 +10,9 @@
> * Color light sensor with 16-bit channels for x, y, z and temperature);
> * 7-bit I2C slave address 0x74 .. 0x77.
> *
> - * Datasheet: https://ams.com/documents/20143/36005/AS73211_DS000556_3-01.pdf
> + * Datasheets:
> + * AS73211: https://ams.com/documents/20143/36005/AS73211_DS000556_3-01.pdf
> + * AS7331: https://ams.com/documents/20143/9106314/AS7331_DS001047_4-00.pdf
> */
>
> #include <linux/bitfield.h>
> @@ -84,6 +87,20 @@ static const int as73211_hardwaregain_avail[] = {
> 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048,
> };
>
> +struct as73211_data;
> +
> +/**
> + * struct spec_dev_data - device-specific data
> + * @intensity_scale: Function to retrieve intensity scale values.
> + * @channel: Device channels.
> + * @num_channels: Number of channels of the device.
> + */
> +struct spec_dev_data {

I would call it as73211_spec_dev_data (is the C++ One Definition Rule relevant for
the kernel?)

> + int (*intensity_scale)(struct as73211_data *data, int chan, int *val, int *val2);
> + struct iio_chan_spec const *channel;
s/channel/channels/

> + int num_channels;
> +};
> +
> /**
> * struct as73211_data - Instance data for one AS73211
> * @client: I2C client.
> @@ -94,6 +111,7 @@ static const int as73211_hardwaregain_avail[] = {
> * @mutex: Keeps cached registers in sync with the device.
> * @completion: Completion to wait for interrupt.
> * @int_time_avail: Available integration times (depend on sampling frequency).
> + * @spec_dev: device-specific configuration.
> */
> struct as73211_data {
> struct i2c_client *client;
> @@ -104,6 +122,7 @@ struct as73211_data {
> struct mutex mutex;
> struct completion completion;
> int int_time_avail[AS73211_SAMPLE_TIME_NUM * 2];
> + const struct spec_dev_data *spec_dev;
> };
>
> #define AS73211_COLOR_CHANNEL(_color, _si, _addr) { \
> @@ -138,6 +157,10 @@ struct as73211_data {
> #define AS73211_SCALE_Y 298384270 /* nW/m^2 */
> #define AS73211_SCALE_Z 160241927 /* nW/m^2 */
>
> +#define AS7331_SCALE_UVA 340000 /* nW/cm^2 */
> +#define AS7331_SCALE_UVB 378000 /* nW/cm^2 */
> +#define AS7331_SCALE_UVC 166000 /* nW/cm^2 */
> +
> /* Channel order MUST match devices result register order */
> #define AS73211_SCAN_INDEX_TEMP 0
> #define AS73211_SCAN_INDEX_X 1
> @@ -176,6 +199,28 @@ static const struct iio_chan_spec as73211_channels[] = {
> IIO_CHAN_SOFT_TIMESTAMP(AS73211_SCAN_INDEX_TS),
> };
>
> +static const struct iio_chan_spec as7331_channels[] = {
> + {
> + .type = IIO_TEMP,
> + .info_mask_separate =
> + BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_OFFSET) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + .address = AS73211_OUT_TEMP,
> + .scan_index = AS73211_SCAN_INDEX_TEMP,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 16,
> + .storagebits = 16,
> + .endianness = IIO_LE,
> + }
> + },
> + AS73211_COLOR_CHANNEL(LIGHT_UVA, AS73211_SCAN_INDEX_X, AS73211_OUT_MRES1),
> + AS73211_COLOR_CHANNEL(LIGHT_UVB, AS73211_SCAN_INDEX_Y, AS73211_OUT_MRES2),
> + AS73211_COLOR_CHANNEL(LIGHT_DUV, AS73211_SCAN_INDEX_Z, AS73211_OUT_MRES3),
> + IIO_CHAN_SOFT_TIMESTAMP(AS73211_SCAN_INDEX_TS),
> +};
> +
> static unsigned int as73211_integration_time_1024cyc(struct as73211_data *data)
> {
> /*
> @@ -316,6 +361,48 @@ static int as73211_req_data(struct as73211_data *data)
> return 0;
> }
>
> +static int as73211_intensity_scale(struct as73211_data *data, int chan,
> + int *val, int *val2)
> +{
> + switch (chan) {
> + case IIO_MOD_X:
> + *val = AS73211_SCALE_X;
> + break;
> + case IIO_MOD_Y:
> + *val = AS73211_SCALE_Y;
> + break;
> + case IIO_MOD_Z:
> + *val = AS73211_SCALE_Z;
> + break;
> + default:
> + return -EINVAL;
> + }
> + *val2 = as73211_integration_time_1024cyc(data) * as73211_gain(data);
> +
> + return IIO_VAL_FRACTIONAL;
> +}
> +
> +static int as7331_intensity_scale(struct as73211_data *data, int chan,
> + int *val, int *val2)
> +{
> + switch (chan) {
> + case IIO_MOD_LIGHT_UVA:
> + *val = AS7331_SCALE_UVA;
> + break;
> + case IIO_MOD_LIGHT_UVB:
> + *val = AS7331_SCALE_UVB;
> + break;
> + case IIO_MOD_LIGHT_DUV:
> + *val = AS7331_SCALE_UVC;
> + break;
> + default:
> + return -EINVAL;
> + }
> + *val2 = as73211_integration_time_1024cyc(data) * as73211_gain(data);
> +
> + return IIO_VAL_FRACTIONAL;
> +}
> +
> static int as73211_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
> int *val, int *val2, long mask)
> {
> @@ -355,29 +442,13 @@ static int as73211_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec cons
> *val2 = AS73211_SCALE_TEMP_MICRO;
> return IIO_VAL_INT_PLUS_MICRO;
>
> - case IIO_INTENSITY: {
> -
> - switch (chan->channel2) {
> - case IIO_MOD_X:
> - *val = AS73211_SCALE_X;
> - break;
> - case IIO_MOD_Y:
> - *val = AS73211_SCALE_Y;
> - break;
> - case IIO_MOD_Z:
> - *val = AS73211_SCALE_Z;
> - break;
> - default:
> - return -EINVAL;
> - }
> - *val2 = as73211_integration_time_1024cyc(data) *
> - as73211_gain(data);
> -
> - return IIO_VAL_FRACTIONAL;
> + case IIO_INTENSITY:
> + return data->spec_dev->intensity_scale(data, chan->channel2,
> + val, val2);
>
> default:
> return -EINVAL;
> - }}
> + }
>
> case IIO_CHAN_INFO_SAMP_FREQ:
> /* f_samp is configured in CREG3 in powers of 2 (x 1.024 MHz) */
> @@ -675,13 +746,17 @@ static int as73211_probe(struct i2c_client *client)
> i2c_set_clientdata(client, indio_dev);
> data->client = client;
>
> + data->spec_dev = i2c_get_match_data(client);
> + if (!data->spec_dev)
> + return -EINVAL;
> +
> mutex_init(&data->mutex);
> init_completion(&data->completion);
>
> indio_dev->info = &as73211_info;
> indio_dev->name = AS73211_DRV_NAME;
> - indio_dev->channels = as73211_channels;
> - indio_dev->num_channels = ARRAY_SIZE(as73211_channels);
> + indio_dev->channels = data->spec_dev->channel;
> + indio_dev->num_channels = data->spec_dev->num_channels;
> indio_dev->modes = INDIO_DIRECT_MODE;
>
> ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_OSR);
> @@ -771,14 +846,28 @@ static int as73211_resume(struct device *dev)
> static DEFINE_SIMPLE_DEV_PM_OPS(as73211_pm_ops, as73211_suspend,
> as73211_resume);
>
> +static const struct spec_dev_data as73211_spec = {
> + .intensity_scale = as73211_intensity_scale,
> + .channel = as73211_channels,
> + .num_channels = ARRAY_SIZE(as73211_channels),
> +};
> +
> +static const struct spec_dev_data as7331_spec = {
> + .intensity_scale = as7331_intensity_scale,
> + .channel = as7331_channels,
> + .num_channels = ARRAY_SIZE(as7331_channels),
> +};
> +
> static const struct of_device_id as73211_of_match[] = {
> - { .compatible = "ams,as73211" },
> + { .compatible = "ams,as73211", &as73211_spec },
> + { .compatible = "ams,as7331", &as7331_spec },
> { }
> };
> MODULE_DEVICE_TABLE(of, as73211_of_match);
>
> static const struct i2c_device_id as73211_id[] = {
> - { "as73211", 0 },
> + { "as73211", (kernel_ulong_t)&as73211_spec },
> + { "as7331", (kernel_ulong_t)&as7331_spec },
> { }
> };
> MODULE_DEVICE_TABLE(i2c, as73211_id);
>
>

Tested-by: Christian Eggers <ceggers@xxxxxxx>

Next message: Daniel Vetter: "Re: [PATCH v4 4/7] dma-buf: heaps: restricted_heap: Add dma_ops"
Previous message: neil . armstrong: "Re: [PATCH v2] power: supply: qcom_battmgr: Ignore notifications before initialization"
Next in thread: Jonathan Cameron: "Re: [PATCH v2 3/3] iio: light: as73211: add support for as7331"
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