Hi Jyoti,
just some initial feedback down below.
I'll get back to this series again next days.
On Fri, Nov 13, 2020 at 05:06:11PM +0000, Jyoti Bhayana wrote:
> This change provides ARM SCMI Protocol based IIO device.
> This driver provides support for Accelerometer and Gyroscope using
> new SCMI Sensor Protocol defined by the upcoming SCMIv3.0
> ARM specification
>
> Signed-off-by: Jyoti Bhayana <jbhayana@xxxxxxxxxx>
> ---
> MAINTAINERS | 6 +
> drivers/iio/Kconfig | 1 +
> drivers/iio/Makefile | 1 +
> drivers/iio/scmi/Kconfig | 18 +
> drivers/iio/scmi/Makefile | 5 +
> drivers/iio/scmi/scmi_iio.c | 771 ++++++++++++++++++++++++++++++++++++
> 6 files changed, 802 insertions(+)
> create mode 100644 drivers/iio/scmi/Kconfig
> create mode 100644 drivers/iio/scmi/Makefile
> create mode 100644 drivers/iio/scmi/scmi_iio.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index deaafb617361..11624961b13b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8477,6 +8477,12 @@ S: Maintained
> F: Documentation/devicetree/bindings/iio/multiplexer/io-channel-mux.txt
> F: drivers/iio/multiplexer/iio-mux.c
>
> +IIO SCMI BASED DRIVER
> +M: Jyoti Bhayana <jbhayana@xxxxxxxxxx>
> +L: linux-iio@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/iio/scmi/scmi_iio.c
> +
> IIO SUBSYSTEM AND DRIVERS
> M: Jonathan Cameron <jic23@xxxxxxxxxx>
> R: Hartmut Knaack <knaack.h@xxxxxx>
> diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
> index d5c073a8aa3e..d31e0ceb152e 100644
> --- a/drivers/iio/Kconfig
> +++ b/drivers/iio/Kconfig
> @@ -94,6 +94,7 @@ source "drivers/iio/potentiostat/Kconfig"
> source "drivers/iio/pressure/Kconfig"
> source "drivers/iio/proximity/Kconfig"
> source "drivers/iio/resolver/Kconfig"
> +source "drivers/iio/scmi/Kconfig"
> source "drivers/iio/temperature/Kconfig"
>
> endif # IIO
> diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
> index 1712011c0f4a..2da7907da608 100644
> --- a/drivers/iio/Makefile
> +++ b/drivers/iio/Makefile
> @@ -37,5 +37,6 @@ obj-y += potentiostat/
> obj-y += pressure/
> obj-y += proximity/
> obj-y += resolver/
> +obj-y += scmi/
> obj-y += temperature/
> obj-y += trigger/
> diff --git a/drivers/iio/scmi/Kconfig b/drivers/iio/scmi/Kconfig
> new file mode 100644
> index 000000000000..67e084cbb1ab
> --- /dev/null
> +++ b/drivers/iio/scmi/Kconfig
> @@ -0,0 +1,18 @@
> +#
> +# IIO over SCMI
> +#
> +# When adding new entries keep the list in alphabetical order
> +
> +menu "IIO SCMI Sensors"
> +
> +config IIO_SCMI
> + tristate "IIO SCMI"
> + depends on ARM_SCMI_PROTOCOL
> + select IIO_BUFFER
> + select IIO_KFIFO_BUF
> + help
> + Say yes here to build support for IIO SCMI Driver.
> + This provides ARM SCMI Protocol based IIO device.
> + This driver provides support for accelerometer and gyroscope
> + sensors available on SCMI based platforms.
> +endmenu
> diff --git a/drivers/iio/scmi/Makefile b/drivers/iio/scmi/Makefile
> new file mode 100644
> index 000000000000..f13140a2575a
> --- /dev/null
> +++ b/drivers/iio/scmi/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX - License - Identifier : GPL - 2.0 - only
> +#
> +# Makefile for the IIO over SCMI
> +#
> +obj-$(CONFIG_IIO_SCMI) += scmi_iio.o
> diff --git a/drivers/iio/scmi/scmi_iio.c b/drivers/iio/scmi/scmi_iio.c
> new file mode 100644
> index 000000000000..987c3a56abcf
> --- /dev/null
> +++ b/drivers/iio/scmi/scmi_iio.c
> @@ -0,0 +1,771 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * System Control and Management Interface(SCMI) based IIO sensor driver
> + *
> + * Copyright (C) 2020 Google LLC
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/kfifo_buf.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/kernel.h>
> +#include <linux/kthread.h>
> +#include <linux/module.h>
> +#include <linux/scmi_protocol.h>
> +#include <linux/time.h>
> +#include <linux/types.h>
> +
> +#define NSEC_MULT_POW_10 (const_ilog2(NSEC_PER_SEC) / const_ilog2(10))
> +#define UHZ_PER_HZ 1000000UL
> +#define ODR_EXPAND(odr, uodr) (((odr) * 1000000ULL) + (uodr))
> +#define SCMI_SENS_CFG_SET_TSTAMP_ENABLED(x) ((x) | BIT(1))
> +#define SCMI_SENS_CFG_SET_ENABLE(x) ((x) | BIT(0))
> +#define SCMI_SENS_CFG_SET_DISABLE(x) ((x) & ~BIT(0))
> +#define SCMI_SENS_CFG_SET_UPDATE_SECS(x, v) ((x) | ((u32)(v) << 16))
> +#define SCMI_SENS_CFG_SET_UPDATE_MULTI(x, v) \
> + ((x) | (((s16)(v) << 11) & GENMASK(15, 11)))
> +#define SCMI_SENS_CFG_SET_AUTO_ROUND_UP(x) ((x) | BIT(10))
I removed this kind of SET macros from the last series of SCMIv3.0 Sensors
that you are using because I fully converted to use bitfield.h facilities
and so I tried to stick to the usage pattern described in the comment at
the start of include/linux/bitfield.h:
/*
* Bitfield access macros
*
* FIELD_{GET,PREP} macros take as first parameter shifted mask
* from which they extract the base mask and shift amount.
* Mask must be a compilation time constant.
*
* Example:
*
* #define REG_FIELD_A GENMASK(6, 0)
* #define REG_FIELD_B BIT(7)
* #define REG_FIELD_C GENMASK(15, 8)
* #define REG_FIELD_D GENMASK(31, 16)
*
* Get:
* a = FIELD_GET(REG_FIELD_A, reg);
* b = FIELD_GET(REG_FIELD_B, reg);
*
* Set:
* reg = FIELD_PREP(REG_FIELD_A, 1) |
* FIELD_PREP(REG_FIELD_B, 0) |
* FIELD_PREP(REG_FIELD_C, c) |
* FIELD_PREP(REG_FIELD_D, 0x40);
*
* Modify:
* reg &= ~REG_FIELD_C;
* reg |= FIELD_PREP(REG_FIELD_C, c);
*/
and also because (I could be wrong) it seemed to me that were a bit
ambiguos in fact in their behaviour of modifying one of its argument.
(without clearing multibiot field in advance as you noted below)
Down below I reported a few usage example using just bitfield.h style
and the available MASK fields in scmi_protocol.h.
Let me know what you think about this.
> +
> +//one additional channel for timestamp
This C++ style comment should have been reported by checkpatch.
> +#define SCMI_IIO_EXTRA_CHANNELS 1
> +
> +struct scmi_iio_priv {
> + struct scmi_handle *handle;
> + const struct scmi_sensor_info *sensor_info;
> + struct iio_dev *indio_dev;
> + u8 *iio_buf;
> + struct notifier_block sensor_update_nb;
> +};
> +
> +struct sensor_freq {
> + u64 hz;
> + u64 uhz;
> +};
> +
> +static int scmi_iio_check_valid_sensor(struct scmi_iio_priv *sensor)
> +{
> + if (!sensor || !sensor->handle || !sensor->sensor_info ||
> + !sensor->indio_dev)
> + return -EINVAL;
> + else
> + return 0;
> +}
> +
Maybe inline ?
> +static int sensor_update_cb(struct notifier_block *nb, unsigned long event,
> + void *data)
> +{
> + struct scmi_sensor_update_report *sensor_update = data;
> + u64 time, time_ns;
> + s64 sensor_value;
> + struct scmi_iio_priv *sensor =
> + container_of(nb, struct scmi_iio_priv, sensor_update_nb);
> + struct iio_dev *scmi_iio_dev;
> + s8 tstamp_scale_ns;
> + int i, err;
> +
> + err = scmi_iio_check_valid_sensor(sensor);
> +
> + if (err)
> + return err;
> +
> + scmi_iio_dev = sensor->indio_dev;
> +
> + for (i = 0; i < sensor_update->readings_count; i++) {
> + sensor_value = sensor_update->readings[i].value;
> + time = sensor_update->readings[i].timestamp;
> + memcpy(&sensor->iio_buf[i * sizeof(s64)], &sensor_value,
> + sizeof(s64));
> + }
> +
> + if (!sensor->sensor_info->timestamped) {
> + time_ns = iio_get_time_ns(scmi_iio_dev);
> + } else {
> + tstamp_scale_ns =
> + sensor->sensor_info->tstamp_scale + NSEC_MULT_POW_10;
> + if (tstamp_scale_ns < 0) {
> + tstamp_scale_ns = -1 * tstamp_scale_ns;
> + time_ns = div64_u64(time, int_pow(10, tstamp_scale_ns));
> + } else {
> + time_ns = time * int_pow(10, tstamp_scale_ns);
> + }
> + }
> +
> + iio_push_to_buffers_with_timestamp(scmi_iio_dev, sensor->iio_buf,
> + time_ns);
> +
> + return NOTIFY_OK;
> +}
> +
> +static int scmi_iio_is_scalar_sensor(const struct scmi_sensor_info *sensor_info,
> + bool *scalar)
> +{
> + if (!sensor_info || !scalar)
> + return -EINVAL;
> +
> + if (sensor_info->num_axis > 0)
> + *scalar = false;
> + else
> + *scalar = true;
> +
> + return 0;
> +}
> +
Haven't you checked already in probe() that all the sensor_info that you
process are NON null ?
So that the inner check abpve is not needed and this helper could be simple:
static bool scmi_iio_is_scalar_sensor(const struct scmi_sensor_info *sensor_info)
or better a macro something like:
IS_SCALAR_SENSOR(s) ((s)->num_axis == 0)
but I could have missed something.
> +static int scmi_iio_buffer_preenable(struct iio_dev *dev)
> +{
> + struct scmi_iio_priv *sensor = iio_priv(dev);
> + u32 sensor_config = 0;
> + int err = scmi_iio_check_valid_sensor(sensor);
> + u32 sensor_id = sensor->sensor_info->id;
> +
> + if (err)
> + return err;
> +
> + if (sensor->sensor_info->timestamped)
> + sensor_config = SCMI_SENS_CFG_SET_TSTAMP_ENABLED(sensor_config);
sensor_config |=
FIELD_PREP(SCMI_SENS_CFG_TSTAMP_ENABLED_MASK, 1);
> +
> + sensor_config = SCMI_SENS_CFG_SET_ENABLE(sensor_config);
> +
sensor_config |=
FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK, 1);
> + err = sensor->handle->notify_ops->register_event_notifier(
> + sensor->handle, SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
> + &sensor_id, &sensor->sensor_update_nb);
> +
> + if (err) {
> + pr_err("Error in registering sensor update notifier for sensor %s err %d",
> + sensor->sensor_info->name, err);
> + return err;
> + }
> + err = sensor->handle->sensor_ops->config_set(
> + sensor->handle, sensor->sensor_info->id, sensor_config);
> + if (err)
> + pr_err("Error in enabling sensor %s err %d",
> + sensor->sensor_info->name, err);
> +
> + return err;
> +}
> +
> +static int scmi_iio_buffer_postdisable(struct iio_dev *iio_dev)
> +{
> + struct scmi_iio_priv *sensor = iio_priv(iio_dev);
> + u32 sensor_config = 0;
> + int err = scmi_iio_check_valid_sensor(sensor);
> + u32 sensor_id = sensor_id = sensor->sensor_info->id;
> +
> + if (err)
> + return err;
> +
> + sensor_config = SCMI_SENS_CFG_SET_DISABLE(sensor_config);
sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK, 0);
> +
> + err = sensor->handle->notify_ops->unregister_event_notifier(
> + sensor->handle, SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
> + &sensor_id, &sensor->sensor_update_nb);
> + if (err) {
> + pr_err("Error in unregistering sensor update notifier for sensor %s err %d",
> + sensor->sensor_info->name, err);
> + return err;
> + }
> +
> + err = sensor->handle->sensor_ops->config_set(
> + sensor->handle, sensor->sensor_info->id, sensor_config);
> +
> + if (err)
> + pr_err("Error in disabling sensor %s with err %d",
> + sensor->sensor_info->name, err);
> +
> + return err;
> +}
> +
> +static u64 convert_interval_to_ns(u32 val)
> +{
> + u64 sensor_update_interval, sensor_interval_mult;
> + int mult;
> +
> + mult = SCMI_SENS_INTVL_GET_EXP(val);
> + sensor_update_interval = SCMI_SENS_INTVL_GET_SECS(val) * NSEC_PER_SEC;
> + if (mult < 0) {
> + sensor_interval_mult = int_pow(10, abs(mult));
> + sensor_update_interval =
> + sensor_update_interval / sensor_interval_mult;
> + } else {
> + sensor_interval_mult = int_pow(10, mult);
> + sensor_update_interval =
> + sensor_update_interval * sensor_interval_mult;
> + }
> +
> + return sensor_update_interval;
> +}
> +
> +static int convert_ns_to_freq(u64 interval_ns, struct sensor_freq *freq)
> +{
> + u64 rem;
> +
> + if (!freq)
> + return -EINVAL;
> +
> + freq->hz = div64_u64_rem(NSEC_PER_SEC, interval_ns, &rem);
> + freq->uhz = (rem * 1000000UL) / interval_ns;
> +
> + return 0;
> +}
> +
> +static ssize_t scmi_iio_sysfs_sampling_freq_avail(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct scmi_iio_priv *sensor = iio_priv(dev_get_drvdata(dev));
> + int err = scmi_iio_check_valid_sensor(sensor);
> + struct sensor_freq freq;
> + u64 lowest_interval_ns, highest_interval_ns, cur_interval_ns,
> + step_size_ns;
> + unsigned int lowest_interval, highest_interval, step_size, cur_interval;
> + int i, len = 0;
> +
> + if (err)
> + return err;
> +
> + if (!sensor->sensor_info->intervals.segmented) {
> + for (i = 0; i < sensor->sensor_info->intervals.count; i++) {
> + cur_interval = sensor->sensor_info->intervals.desc[i];
> + cur_interval_ns = convert_interval_to_ns(cur_interval);
> + err = convert_ns_to_freq(cur_interval_ns, &freq);
> + if (err)
> + return 0;
> + len += scnprintf(buf + len, PAGE_SIZE - len,
> + "%llu.%06llu ", freq.hz, freq.uhz);
> + }
> + } else {
> + // If the intervals are segmented, the intervals array is a triplet
> + // which constitues a segment in the form of
> + // [lowest_interval,highest_interval,step_size]
> + if (sensor->sensor_info->intervals.count != 3) {
> + pr_err("SCMI sensor %s has segmented update intervals count %d which is not a triplet",
> + sensor->sensor_info->name,
> + sensor->sensor_info->intervals.count);
> + return len;
> + }
I'm handling this in SCMI Sensors now, so you should not even see any
NON null sensors_info with segmented intervals non in a single triplet.
And it's probably better tp add in scmi_protocol.h trivial common defines
to map LOW, HIGH STEP without using 0,1,2
> + lowest_interval = sensor->sensor_info->intervals.desc[0];
> + highest_interval = sensor->sensor_info->intervals.desc[1];
> + step_size = sensor->sensor_info->intervals.desc[2];
> + lowest_interval_ns = convert_interval_to_ns(lowest_interval);
> + highest_interval_ns = convert_interval_to_ns(highest_interval);
> + step_size_ns = convert_interval_to_ns(step_size);
> + cur_interval_ns = lowest_interval_ns;
> + while (cur_interval_ns <= highest_interval_ns) {
> + err = convert_ns_to_freq(cur_interval_ns, &freq);
> + if (err)
> + return 0;
> + len += scnprintf(buf + len, PAGE_SIZE - len,
> + "%llu.%06llu ", freq.hz, freq.uhz);
> + cur_interval_ns += step_size_ns;
> + }
> + }
> +
> + if (len > 0)
> + buf[len - 1] = '\n';
> + return len;
> +}
> +
> +static int scmi_iio_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
> +{
> + struct scmi_iio_priv *sensor = iio_priv(iio_dev);
> + int err = scmi_iio_check_valid_sensor(sensor);
> + u32 sensor_config = 0, cur_sensor_config;
> + u64 sec, mult, uHz;
> + char buf[32];
> +
> + if (err)
> + return err;
> +
> + err = sensor->handle->sensor_ops->config_get(
> + sensor->handle, sensor->sensor_info->id, &cur_sensor_config);
> +
> + if (err) {
> + pr_err("%s: Error in getting sensor config for sensor %s err %d",
> + __func__, sensor->sensor_info->name, err);
> + return err;
> + }
> +
> + uHz = ODR_EXPAND(val, val2);
> +
> + // The seconds field in the sensor interval in SCMI is 16 bits long
> + // Therefore seconds = 1/Hz <= 0xFFFF. As floating point calculations are
> + // discouraged in the kernel driver code, to calculate the scale factor (sf)
> + // (1* 1000000 * sf)/uHz <= 0xFFFF. Therefore, sf <= (uHz * 0xFFFF)/1000000
> + // To calculate the multiplier,we convert the sf into char string and
> + // count the number of characters
> +
C++ comment
> + mult = scnprintf(buf, 32, "%llu", ((u64)uHz * 0xFFFF) / UHZ_PER_HZ) - 1;
> +
> + sec = div64_u64(int_pow(10, mult) * UHZ_PER_HZ, uHz);
> + if (sec == 0) {
> + pr_err("Trying to set invalid sensor update value for sensor %s",
> + sensor->sensor_info->name);
> + return -EINVAL;
> + }
> +
> + // Not able to use cur_sensor_config to build/modify the sensor config with
> + // new configuration as the SCMI macros below doesn't clear the old values
> + // and executes bitwise operations over them. Therefore, building new sensor config
> + // from scratch.
> + sensor_config = SCMI_SENS_CFG_SET_UPDATE_SECS(sensor_config, sec);
cur_sensor_config &= ~SCMI_SENS_CFG_UPDATE_SECS_MASK;
cur_sensor_config |=
FIELD_PREP(SCMI_SENS_CFG_UPDATE_SECS_MASK, sec);
> + sensor_config = SCMI_SENS_CFG_SET_UPDATE_MULTI(sensor_config, -mult);
cur_sensor_config &= ~SCMI_SENS_CFG_UPDATE_EXP_MASK;
cur_sensor_config |=
FIELD_PREP(SCMI_SENS_CFG_UPDATE_EXP_MASK, -multi);
> + sensor_config = SCMI_SENS_CFG_SET_AUTO_ROUND_UP(sensor_config);
cur_sensor_config &= ~SCMI_SENS_CFG_ROUND_MASK;
cur_sensor_config |=
FIELD_PREP(SCMI_SENS_CFG_ROUND_MASK, SCMI_SENS_CFG_ROUND_AUTO);
> + if (sensor->sensor_info->timestamped)
> + sensor_config = SCMI_SENS_CFG_SET_TSTAMP_ENABLED(sensor_config);
cur_sensor_config |=
FIELD_PREP(SCMI_SENS_CFG_TSTAMP_ENABLED_MASK, 1);
> + if (SCMI_SENS_CFG_IS_ENABLED(cur_sensor_config))
> + sensor_config = SCMI_SENS_CFG_SET_ENABLE(sensor_config);
cur_sensor_config |=
FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK, 1);
> + else
> + sensor_config = SCMI_SENS_CFG_SET_DISABLE(sensor_config);
cur_sensor_config |=
FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK, 0);
> +
> + err = sensor->handle->sensor_ops->config_set(
> + sensor->handle, sensor->sensor_info->id, sensor_config);
> +
> + if (err)
> + pr_err("Error in setting sensor update interval for sensor %s value %u err %d",
> + sensor->sensor_info->name, sensor_config, err);
> + return err;
> +}
> +
> +static int scmi_iio_write_raw(struct iio_dev *iio_dev,
> + struct iio_chan_spec const *chan, int val,
> + int val2, long mask)
> +{
> + int err;
> +
> + mutex_lock(&iio_dev->mlock);
> + switch (mask) {
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + err = scmi_iio_set_odr_val(iio_dev, val, val2);
> + break;
> + default:
> + err = -EINVAL;
> + break;
> + }
> + mutex_unlock(&iio_dev->mlock);
> +
> + return err;
> +}
> +
> +static int scmi_iio_read_raw(struct iio_dev *iio_dev,
> + struct iio_chan_spec const *ch, int *val,
> + int *val2, long mask)
> +{
> + struct scmi_iio_priv *sensor = iio_priv(iio_dev);
> + int ret = scmi_iio_check_valid_sensor(sensor);
> + bool scalar_sensor;
> + s8 scale;
> +
> + if (ret)
> + return ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_SCALE:
> + ret = scmi_iio_is_scalar_sensor(sensor->sensor_info,
> + &scalar_sensor);
> + if (ret)
> + return ret;
> + if (!scalar_sensor) {
> + if (!ch)
> + return -EINVAL;
> + scale = sensor->sensor_info->axis[ch->scan_index].scale;
> + if (scale < 0) {
> + scale = -scale;
> + *val = 1;
> + *val2 = int_pow(10, scale);
> + ret = IIO_VAL_FRACTIONAL;
> + } else {
> + *val = int_pow(10, scale);
> + ret = IIO_VAL_INT;
> + }
> + } else {
> + ret = -EINVAL;
> + }
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + return ret;
> +}
> +
Two things here:
- if you are not going to handle any SCALAR sensor couldn't you just
remove from your list of sensors at probe time ? or fail is NO such
sensor can exist as Accel or Gyro.
- not sure if being a generic SCMI IIODEV driver which supports some set
of Accel and Gyro you can just ignore scalar sensors (if they could
exists)
Thanks
Cristian
> +static ssize_t scmi_iio_get_sensor_power(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct scmi_iio_priv *sensor = iio_priv(dev_get_drvdata(dev));
> + int err = scmi_iio_check_valid_sensor(sensor);
> + int len = 0;
> +
> + if (err)
> + return err;
> +
> + if (sensor->sensor_info->extended_scalar_attrs)
> + len = scnprintf(buf, PAGE_SIZE, "%u\n",
> + sensor->sensor_info->sensor_power);
> +
> + return len;
> +}
> +
> +static ssize_t scmi_iio_get_sensor_max_range(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct scmi_iio_priv *sensor = iio_priv(dev_get_drvdata(dev));
> + int err = scmi_iio_check_valid_sensor(sensor);
> + int i;
> + s64 max_range = S64_MIN, max_range_axis;
> +
> + if (err)
> + return err;
> +
> + for (i = 0; i < sensor->sensor_info->num_axis; i++) {
> + if (sensor->sensor_info->axis[i].extended_attrs) {
> + max_range_axis =
> + sensor->sensor_info->axis[i].attrs.max_range;
> + max_range = max(max_range, max_range_axis);
> + }
> + }
> +
> + return scnprintf(buf, PAGE_SIZE, "%lld\n", max_range);
> +}
> +
> +static ssize_t scmi_iio_get_sensor_resolution(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct scmi_iio_priv *sensor = iio_priv(dev_get_drvdata(dev));
> + bool scalar_sensor;
> + int len = 0;
> + int err = scmi_iio_check_valid_sensor(sensor);
> +
> + if (err)
> + return err;
> +
> + err = scmi_iio_is_scalar_sensor(sensor->sensor_info, &scalar_sensor);
> + if (err)
> + return err;
> +
> + if (!scalar_sensor) {
> + // All the axes are supposed to have the same value for resolution
> + // and exponent. We are just using the values from the Axis 0 here.
> + if (sensor->sensor_info->axis[0].extended_attrs) {
> + u32 resolution =
> + sensor->sensor_info->axis[0].resolution;
> + s8 exponent = sensor->sensor_info->axis[0].exponent;
> + u32 multiplier = int_pow(10, abs(exponent));
> +
> + if (exponent < 0) {
> + int vals[] = { resolution, multiplier };
> +
> + len = iio_format_value(buf, IIO_VAL_FRACTIONAL,
> + ARRAY_SIZE(vals), vals);
> + } else {
> + int vals[] = { resolution * multiplier };
> +
> + len = iio_format_value(buf, IIO_VAL_INT,
> + ARRAY_SIZE(vals), vals);
> + }
> + }
> + }
> +
> + return len;
> +}
> +
> +static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(scmi_iio_sysfs_sampling_freq_avail);
> +static IIO_DEVICE_ATTR(sensor_power, 0444, scmi_iio_get_sensor_power, NULL, 0);
> +static IIO_DEVICE_ATTR(sensor_max_range, 0444, scmi_iio_get_sensor_max_range,
> + NULL, 0);
> +static IIO_DEVICE_ATTR(sensor_resolution, 0444, scmi_iio_get_sensor_resolution,
> + NULL, 0);
> +
> +static struct attribute *scmi_iio_attributes[] = {
> + &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
> + &iio_dev_attr_sensor_power.dev_attr.attr,
> + &iio_dev_attr_sensor_max_range.dev_attr.attr,
> + &iio_dev_attr_sensor_resolution.dev_attr.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group scmi_iio_attribute_group = {
> + .attrs = scmi_iio_attributes,
> +};
> +
> +static const struct iio_info scmi_iio_info = {
> + .read_raw = scmi_iio_read_raw,
> + .write_raw = scmi_iio_write_raw,
> + .attrs = &scmi_iio_attribute_group,
> +};
> +
> +static const struct iio_buffer_setup_ops scmi_iio_buffer_ops = {
> + .preenable = scmi_iio_buffer_preenable,
> + .postdisable = scmi_iio_buffer_postdisable,
> +};
> +
> +static int scmi_iio_get_chan_type(u8 scmi_type, enum iio_chan_type *iio_type)
> +{
> + int ret = 0;
> +
> + if (!iio_type)
> + return -EINVAL;
> +
> + switch (scmi_type) {
> + case METERS_SEC_SQUARED:
> + *iio_type = IIO_ACCEL;
> + break;
> + case RADIANS_SEC:
> + *iio_type = IIO_ANGL_VEL;
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + return ret;
> +}
> +
> +static int scmi_iio_get_chan_modifier(const char *name,
> + enum iio_modifier *modifier)
> +{
> + int ret = 0;
> +
> + if (!name || !modifier)
> + return -EINVAL;
> +
> + if (strcasecmp(name, "X") == 0)
> + *modifier = IIO_MOD_X;
> + else if (strcasecmp(name, "Y") == 0)
> + *modifier = IIO_MOD_Y;
> + else if (strcasecmp(name, "Z") == 0)
> + *modifier = IIO_MOD_Z;
> + else
> + ret = -EINVAL;
> +
> + return ret;
> +}
> +
> +static void scmi_iio_set_data_channel(struct iio_chan_spec *iio_chan,
> + enum iio_chan_type type,
> + enum iio_modifier mod, int scan_index)
> +{
> + if (!iio_chan)
> + return;
> +
> + iio_chan->type = type;
> + iio_chan->modified = 1;
> + iio_chan->channel2 = mod;
> + iio_chan->info_mask_separate =
> + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE);
> + iio_chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ);
> + iio_chan->scan_index = scan_index;
> + iio_chan->scan_type.sign = 's';
> + iio_chan->scan_type.realbits = 64;
> + iio_chan->scan_type.storagebits = 64;
> + iio_chan->scan_type.endianness = IIO_LE;
> +}
> +
> +static void scmi_iio_set_timestamp_channel(struct iio_chan_spec *iio_chan,
> + int scan_index)
> +{
> + if (!iio_chan)
> + return;
> +
> + iio_chan->type = IIO_TIMESTAMP;
> + iio_chan->channel = -1;
> + iio_chan->scan_index = scan_index;
> + iio_chan->scan_type.sign = 'u';
> + iio_chan->scan_type.realbits = 64;
> + iio_chan->scan_type.storagebits = 64;
> +}
> +
> +static int
> +scmi_iio_alloc_nonscalar_sensor(struct device *dev, struct scmi_handle *handle,
> + const struct scmi_sensor_info *sensor_info,
> + struct iio_dev **scmi_iio_dev)
> +{
> + struct scmi_iio_priv *sensor;
> + struct iio_chan_spec *iio_channels;
> + enum iio_chan_type type;
> + enum iio_modifier modifier;
> + struct iio_dev *iio_dev_temp;
> + int i, ret = 0;
> +
> + if (!scmi_iio_dev)
> + return -EINVAL;
> +
> + iio_dev_temp = devm_iio_device_alloc(dev, sizeof(struct scmi_iio_priv));
> + if (!iio_dev_temp)
> + return -ENOMEM;
> + iio_dev_temp->modes = INDIO_DIRECT_MODE;
> + iio_dev_temp->dev.parent = dev;
> + sensor = iio_priv(iio_dev_temp);
> + sensor->handle = handle;
> + sensor->sensor_info = sensor_info;
> + sensor->sensor_update_nb.notifier_call = sensor_update_cb;
> + sensor->indio_dev = iio_dev_temp;
> + iio_dev_temp->num_channels =
> + sensor_info->num_axis + SCMI_IIO_EXTRA_CHANNELS;
> + iio_dev_temp->name = sensor_info->name;
> + iio_dev_temp->info = &scmi_iio_info;
> + iio_channels = devm_kzalloc(dev,
> + sizeof(struct iio_chan_spec) *
> + (iio_dev_temp->num_channels),
> + GFP_KERNEL);
> + if (!iio_channels)
> + return -ENOMEM;
> + for (i = 0; i < sensor_info->num_axis; i++) {
> + ret = scmi_iio_get_chan_type(sensor_info->axis[i].type, &type);
> + if (ret < 0)
> + return ret;
> + ret = scmi_iio_get_chan_modifier(sensor_info->axis[i].name,
> + &modifier);
> + if (ret < 0)
> + return ret;
> + scmi_iio_set_data_channel(&iio_channels[i], type, modifier,
> + sensor_info->axis[i].id);
> + }
> + scmi_iio_set_timestamp_channel(&iio_channels[i], i);
> + iio_dev_temp->channels = iio_channels;
> + *scmi_iio_dev = iio_dev_temp;
> + return ret;
> +}
> +
> +static int scmi_alloc_iiodev(struct device *dev, struct scmi_handle *handle,
> + const struct scmi_sensor_info *sensor_info,
> + struct iio_dev **scmi_iio_dev)
> +{
> + int ret = 0;
> + bool scalar_sensor;
> +
> + ret = scmi_iio_is_scalar_sensor(sensor_info, &scalar_sensor);
> +
> + if (ret)
> + return ret;
> +
> + if (!scalar_sensor)
> + ret = scmi_iio_alloc_nonscalar_sensor(dev, handle, sensor_info,
> + scmi_iio_dev);
> + else
> + ret = -EINVAL;
> +
> + return ret;
> +}
> +
> +static int scmi_iio_buffers_setup(struct iio_dev *scmi_iiodev)
> +{
> + struct iio_buffer *buffer = devm_iio_kfifo_allocate(&scmi_iiodev->dev);
> + struct scmi_iio_priv *sensor = iio_priv(scmi_iiodev);
> + int err = scmi_iio_check_valid_sensor(sensor);
> +
> + if (!buffer)
> + return -ENOMEM;
> +
> + if (err)
> + return err;
> +
> + iio_device_attach_buffer(scmi_iiodev, buffer);
> + scmi_iiodev->modes |= INDIO_BUFFER_SOFTWARE;
> + scmi_iiodev->setup_ops = &scmi_iio_buffer_ops;
> + sensor->iio_buf =
> + devm_kzalloc(&scmi_iiodev->dev,
> + sizeof(s64) * (scmi_iiodev->num_channels),
> + GFP_KERNEL);
> + if (!sensor->iio_buf)
> + return -ENOMEM;
> + return 0;
> +}
> +
> +static int scmi_iio_dev_probe(struct scmi_device *sdev)
> +{
> + struct scmi_handle *handle;
> + u16 nr_sensors;
> + struct iio_dev *scmi_iio_dev;
> + const struct scmi_sensor_info *sensor_info;
> + int err = 0, i;
> + struct device *dev;
> +
> + if (!sdev) {
> + pr_err("scmi_iio_dev: missing SCMI device\n");
> + return -ENODEV;
> + }
> +
> + dev = &sdev->dev;
> +
> + handle = sdev->handle;
> + if (!handle || !handle->sensor_ops) {
> + dev_err(dev, "SCMI device has no sensor interface\n");
> + return -EINVAL;
> + }
> +
> + nr_sensors = handle->sensor_ops->count_get(handle);
> + if (!nr_sensors) {
> + dev_warn(dev, "0 sensors found via SCMI bus\n");
> + return -EINVAL;
> + }
> +
> + dev_info(dev, "%d sensors found via SCMI bus\n", nr_sensors);
> +
> + for (i = 0; i < nr_sensors; i++) {
> + sensor_info = handle->sensor_ops->info_get(handle, i);
> + if (!sensor_info) {
> + dev_err(dev, "SCMI sensor %d has missing info\n", i);
> + return -EINVAL;
> + }
> + err = scmi_alloc_iiodev(dev, handle, sensor_info,
> + &scmi_iio_dev);
> + if (err < 0) {
> + dev_err(dev,
> + "memory allocation error at sensor %s: %d\n",
> + sensor_info->name, err);
> + return err;
> + }
> + if (!scmi_iio_dev) {
> + dev_err(dev, "memory allocation failed at sensor %s\n",
> + sensor_info->name);
> + return -ENOMEM;
> + }
> + err = scmi_iio_buffers_setup(scmi_iio_dev);
> + if (err < 0) {
> + dev_err(dev,
> + "IIO buffer setup error at sensor %s: %d\n",
> + sensor_info->name, err);
> + return err;
> + }
> + err = devm_iio_device_register(dev, scmi_iio_dev);
> + if (err) {
> + dev_err(dev,
> + "IIO device registration failed at sensor %s: %d\n",
> + sensor_info->name, err);
> + return err;
> + }
> + }
> +
> + return err;
> +}
> +
> +static void scmi_iio_dev_remove(struct scmi_device *sdev)
> +{
> + pr_debug("scmi_iio_drv_remove\n");
> +}
> +
> +static const struct scmi_device_id scmi_id_table[] = {
> + { SCMI_PROTOCOL_SENSOR, "iiodev" },
> + {},
> +};
> +
> +MODULE_DEVICE_TABLE(scmi, scmi_id_table);
> +
> +static struct scmi_driver scmi_iiodev_driver = {
> + .name = "scmi-sensor-iiodev",
> + .probe = scmi_iio_dev_probe,
> + .remove = scmi_iio_dev_remove,
> + .id_table = scmi_id_table,
> +};
> +
> +module_scmi_driver(scmi_iiodev_driver);
> +
> +MODULE_AUTHOR("Jyoti Bhayana <jbhayana@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("SCMI IIO Driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.29.2.299.gdc1121823c-goog
>
