[PATCH v6 1/1] iio/scmi: Adding support for IIO SCMI Based Sensors
From: Jyoti Bhayana
Date: Fri Feb 12 2021 - 12:24:13 EST
This change provides ARM SCMI Protocol based IIO device.
This driver provides support for Accelerometer and Gyroscope using
SCMI Sensor Protocol extensions added in the SCMIv3.0 ARM specification
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Jyoti Bhayana <jbhayana@xxxxxxxxxx>
---
MAINTAINERS | 6 +
drivers/firmware/arm_scmi/driver.c | 2 +-
drivers/iio/common/Kconfig | 1 +
drivers/iio/common/Makefile | 1 +
drivers/iio/common/scmi_sensors/Kconfig | 18 +
drivers/iio/common/scmi_sensors/Makefile | 5 +
drivers/iio/common/scmi_sensors/scmi_iio.c | 678 +++++++++++++++++++++
7 files changed, 710 insertions(+), 1 deletion(-)
create mode 100644 drivers/iio/common/scmi_sensors/Kconfig
create mode 100644 drivers/iio/common/scmi_sensors/Makefile
create mode 100644 drivers/iio/common/scmi_sensors/scmi_iio.c
diff --git a/MAINTAINERS b/MAINTAINERS
index b516bb34a8d5..ccf37d43ab41 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8567,6 +8567,12 @@ 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/common/scmi_sensors/scmi_iio.c
+
IIO SUBSYSTEM AND DRIVERS
M: Jonathan Cameron <jic23@xxxxxxxxxx>
R: Lars-Peter Clausen <lars@xxxxxxxxxx>
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 5392e1fc6b4e..248313bbd473 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -741,7 +741,7 @@ static struct scmi_prot_devnames devnames[] = {
{ SCMI_PROTOCOL_SYSTEM, { "syspower" },},
{ SCMI_PROTOCOL_PERF, { "cpufreq" },},
{ SCMI_PROTOCOL_CLOCK, { "clocks" },},
- { SCMI_PROTOCOL_SENSOR, { "hwmon" },},
+ { SCMI_PROTOCOL_SENSOR, { "hwmon", "iiodev" },},
{ SCMI_PROTOCOL_RESET, { "reset" },},
{ SCMI_PROTOCOL_VOLTAGE, { "regulator" },},
};
diff --git a/drivers/iio/common/Kconfig b/drivers/iio/common/Kconfig
index 2b9ee9161abd..0334b4954773 100644
--- a/drivers/iio/common/Kconfig
+++ b/drivers/iio/common/Kconfig
@@ -6,5 +6,6 @@
source "drivers/iio/common/cros_ec_sensors/Kconfig"
source "drivers/iio/common/hid-sensors/Kconfig"
source "drivers/iio/common/ms_sensors/Kconfig"
+source "drivers/iio/common/scmi_sensors/Kconfig"
source "drivers/iio/common/ssp_sensors/Kconfig"
source "drivers/iio/common/st_sensors/Kconfig"
diff --git a/drivers/iio/common/Makefile b/drivers/iio/common/Makefile
index 4bc30bb548e2..fad40e1e1718 100644
--- a/drivers/iio/common/Makefile
+++ b/drivers/iio/common/Makefile
@@ -11,5 +11,6 @@
obj-y += cros_ec_sensors/
obj-y += hid-sensors/
obj-y += ms_sensors/
+obj-y += scmi_sensors/
obj-y += ssp_sensors/
obj-y += st_sensors/
diff --git a/drivers/iio/common/scmi_sensors/Kconfig b/drivers/iio/common/scmi_sensors/Kconfig
new file mode 100644
index 000000000000..67e084cbb1ab
--- /dev/null
+++ b/drivers/iio/common/scmi_sensors/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/common/scmi_sensors/Makefile b/drivers/iio/common/scmi_sensors/Makefile
new file mode 100644
index 000000000000..f13140a2575a
--- /dev/null
+++ b/drivers/iio/common/scmi_sensors/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/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
new file mode 100644
index 000000000000..31977c3bc600
--- /dev/null
+++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
@@ -0,0 +1,678 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * System Control and Management Interface(SCMI) based IIO sensor driver
+ *
+ * Copyright (C) 2021 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 SCMI_IIO_NUM_OF_AXIS 3
+
+struct scmi_iio_priv {
+ struct scmi_handle *handle;
+ const struct scmi_sensor_info *sensor_info;
+ struct iio_dev *indio_dev;
+ /* adding one additional channel for timestamp */
+ long long iio_buf[SCMI_IIO_NUM_OF_AXIS + 1];
+ struct notifier_block sensor_update_nb;
+ u32 *freq_avail;
+};
+
+static int scmi_iio_sensor_update_cb(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct scmi_sensor_update_report *sensor_update = data;
+ struct iio_dev *scmi_iio_dev;
+ struct scmi_iio_priv *sensor;
+ s8 tstamp_scale;
+ u64 time, time_ns;
+ int i;
+
+ if (sensor_update->readings_count == 0)
+ return NOTIFY_DONE;
+
+ sensor = container_of(nb, struct scmi_iio_priv, sensor_update_nb);
+
+ for (i = 0; i < sensor_update->readings_count; i++)
+ sensor->iio_buf[i] = sensor_update->readings[i].value;
+
+ if (!sensor->sensor_info->timestamped) {
+ time_ns = ktime_to_ns(sensor_update->timestamp);
+ } else {
+ /*
+ * All the axes are supposed to have the same value for timestamp.
+ * We are just using the values from the Axis 0 here.
+ */
+ time = sensor_update->readings[0].timestamp;
+
+ /*
+ * Timestamp returned by SCMI is in seconds and is equal to
+ * time * power-of-10 multiplier(tstamp_scale) seconds.
+ * Converting the timestamp to nanoseconds below.
+ */
+ tstamp_scale = sensor->sensor_info->tstamp_scale +
+ const_ilog2(NSEC_PER_SEC) / const_ilog2(10);
+ if (tstamp_scale < 0)
+ time_ns =
+ div64_u64(time, int_pow(10, abs(tstamp_scale)));
+ else
+ time_ns = time * int_pow(10, tstamp_scale);
+ }
+
+ scmi_iio_dev = sensor->indio_dev;
+ iio_push_to_buffers_with_timestamp(scmi_iio_dev, sensor->iio_buf,
+ time_ns);
+ return NOTIFY_OK;
+}
+
+static int scmi_iio_buffer_preenable(struct iio_dev *iio_dev)
+{
+ struct scmi_iio_priv *sensor = iio_priv(iio_dev);
+ u32 sensor_id = sensor->sensor_info->id;
+ u32 sensor_config = 0;
+ int err;
+
+ if (sensor->sensor_info->timestamped)
+ sensor_config |= FIELD_PREP(SCMI_SENS_CFG_TSTAMP_ENABLED_MASK,
+ SCMI_SENS_CFG_TSTAMP_ENABLE);
+
+ sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
+ SCMI_SENS_CFG_SENSOR_ENABLE);
+
+ 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) {
+ dev_err(&iio_dev->dev,
+ "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) {
+ sensor->handle->notify_ops->unregister_event_notifier(sensor->handle,
+ SCMI_PROTOCOL_SENSOR,
+ SCMI_EVENT_SENSOR_UPDATE, &sensor_id,
+ &sensor->sensor_update_nb);
+ dev_err(&iio_dev->dev, "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_id = sensor->sensor_info->id;
+ u32 sensor_config = 0;
+ int err;
+
+ sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
+ SCMI_SENS_CFG_SENSOR_DISABLE);
+
+ 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) {
+ dev_err(&iio_dev->dev,
+ "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_id,
+ sensor_config);
+ if (err) {
+ dev_err(&iio_dev->dev,
+ "Error in disabling sensor %s with err %d",
+ sensor->sensor_info->name, err);
+ }
+
+ return err;
+}
+
+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_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
+{
+ struct scmi_iio_priv *sensor = iio_priv(iio_dev);
+ const unsigned long UHZ_PER_HZ = 1000000UL;
+ u64 sec, mult, uHz;
+ u32 sensor_config;
+ char buf[32];
+
+ int err = sensor->handle->sensor_ops->config_get(sensor->handle,
+ sensor->sensor_info->id, &sensor_config);
+ if (err) {
+ dev_err(&iio_dev->dev,
+ "Error in getting sensor config for sensor %s err %d",
+ sensor->sensor_info->name, err);
+ return err;
+ }
+
+ uHz = val * UHZ_PER_HZ + 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
+ */
+ mult = scnprintf(buf, sizeof(buf), "%llu", ((u64)uHz * 0xFFFF) / UHZ_PER_HZ) - 1;
+
+ sec = div64_u64(int_pow(10, mult) * UHZ_PER_HZ, uHz);
+ if (sec == 0) {
+ dev_err(&iio_dev->dev,
+ "Trying to set invalid sensor update value for sensor %s",
+ sensor->sensor_info->name);
+ return -EINVAL;
+ }
+
+ sensor_config &= ~SCMI_SENS_CFG_UPDATE_SECS_MASK;
+ sensor_config |= FIELD_PREP(SCMI_SENS_CFG_UPDATE_SECS_MASK, sec);
+ sensor_config &= ~SCMI_SENS_CFG_UPDATE_EXP_MASK;
+ sensor_config |= FIELD_PREP(SCMI_SENS_CFG_UPDATE_EXP_MASK, -mult);
+
+ if (sensor->sensor_info->timestamped) {
+ sensor_config &= ~SCMI_SENS_CFG_TSTAMP_ENABLED_MASK;
+ sensor_config |= FIELD_PREP(SCMI_SENS_CFG_TSTAMP_ENABLED_MASK,
+ SCMI_SENS_CFG_TSTAMP_ENABLE);
+ }
+
+ sensor_config &= ~SCMI_SENS_CFG_ROUND_MASK;
+ sensor_config |=
+ FIELD_PREP(SCMI_SENS_CFG_ROUND_MASK, SCMI_SENS_CFG_ROUND_AUTO);
+
+ err = sensor->handle->sensor_ops->config_set(sensor->handle,
+ sensor->sensor_info->id, sensor_config);
+ if (err)
+ dev_err(&iio_dev->dev,
+ "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;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ mutex_lock(&iio_dev->mlock);
+ err = scmi_iio_set_odr_val(iio_dev, val, val2);
+ mutex_unlock(&iio_dev->mlock);
+ return err;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int scmi_iio_read_avail(struct iio_dev *iio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long mask)
+{
+ struct scmi_iio_priv *sensor = iio_priv(iio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *vals = sensor->freq_avail;
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ *length = sensor->sensor_info->intervals.count * 2;
+ if (sensor->sensor_info->intervals.segmented)
+ return IIO_AVAIL_RANGE;
+ else
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
+static void convert_ns_to_freq(u64 interval_ns, u64 *hz, u64 *uhz)
+{
+ u64 rem;
+
+ *hz = div64_u64_rem(NSEC_PER_SEC, interval_ns, &rem);
+ *uhz = (rem * 1000000UL) / interval_ns;
+}
+
+static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
+{
+ u64 sensor_update_interval, sensor_interval_mult, hz, uhz;
+ struct scmi_iio_priv *sensor = iio_priv(iio_dev);
+ u32 sensor_config;
+ int mult;
+
+ int err = sensor->handle->sensor_ops->config_get(sensor->handle,
+ sensor->sensor_info->id, &sensor_config);
+ if (err) {
+ dev_err(&iio_dev->dev,
+ "Error in getting sensor config for sensor %s err %d",
+ sensor->sensor_info->name, err);
+ return err;
+ }
+
+ sensor_update_interval =
+ SCMI_SENS_CFG_GET_UPDATE_SECS(sensor_config) * NSEC_PER_SEC;
+
+ mult = SCMI_SENS_CFG_GET_UPDATE_EXP(sensor_config);
+ 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;
+ }
+
+ convert_ns_to_freq(sensor_update_interval, &hz, &uhz);
+ *val = hz;
+ *val2 = uhz;
+ return 0;
+}
+
+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);
+ s8 scale;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ scale = sensor->sensor_info->axis[ch->scan_index].scale;
+ if (scale < 0) {
+ *val = 1;
+ *val2 = int_pow(10, abs(scale));
+ return IIO_VAL_FRACTIONAL;
+ }
+ *val = int_pow(10, scale);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ ret = scmi_iio_get_odr_val(iio_dev, val, val2);
+ return ret ? ret : IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info scmi_iio_info = {
+ .read_raw = scmi_iio_read_raw,
+ .read_avail = scmi_iio_read_avail,
+ .write_raw = scmi_iio_write_raw,
+};
+
+static ssize_t scmi_iio_get_raw_available(struct iio_dev *iio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ char *buf)
+{
+ struct scmi_iio_priv *sensor = iio_priv(iio_dev);
+ unsigned long long resolution, rem;
+ long long min_range, max_range;
+ s8 exponent, scale;
+ int len = 0;
+
+ /*
+ * All the axes are supposed to have the same value for range and resolution.
+ * We are just using the values from the Axis 0 here.
+ */
+ if (sensor->sensor_info->axis[0].extended_attrs) {
+ min_range = sensor->sensor_info->axis[0].attrs.min_range;
+ max_range = sensor->sensor_info->axis[0].attrs.max_range;
+ resolution = sensor->sensor_info->axis[0].resolution;
+ exponent = sensor->sensor_info->axis[0].exponent;
+ scale = sensor->sensor_info->axis[0].scale;
+
+ /*
+ * To provide the raw value for the resolution to the userspace,
+ * need to divide the resolution exponent by the sensor scale
+ */
+ exponent = exponent - scale;
+ if (exponent < 0) {
+ resolution = div64_u64_rem(resolution,
+ int_pow(10, abs(exponent)),
+ &rem);
+ len = scnprintf(buf, PAGE_SIZE,
+ "[%lld %llu.%llu %lld]\n", min_range,
+ resolution, rem, max_range);
+ } else {
+ resolution = resolution * int_pow(10, exponent);
+ len = scnprintf(buf, PAGE_SIZE, "[%lld %llu %lld]\n",
+ min_range, resolution, max_range);
+ }
+ }
+ return len;
+}
+
+static const struct iio_chan_spec_ext_info scmi_iio_ext_info[] = {
+ {
+ .name = "raw_available",
+ .read = scmi_iio_get_raw_available,
+ .shared = IIO_SHARED_BY_TYPE,
+ },
+ {},
+};
+
+static void scmi_iio_set_timestamp_channel(struct iio_chan_spec *iio_chan,
+ int scan_index)
+{
+ 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 void scmi_iio_set_data_channel(struct iio_chan_spec *iio_chan,
+ enum iio_chan_type type,
+ enum iio_modifier mod, int scan_index)
+{
+ iio_chan->type = type;
+ iio_chan->modified = 1;
+ iio_chan->channel2 = mod;
+ iio_chan->info_mask_separate = BIT(IIO_CHAN_INFO_SCALE);
+ iio_chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ);
+ iio_chan->info_mask_shared_by_type_available =
+ 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;
+ iio_chan->ext_info = scmi_iio_ext_info;
+}
+
+static int scmi_iio_get_chan_modifier(const char *name,
+ enum iio_modifier *modifier)
+{
+ char *pch, mod;
+
+ if (!name)
+ return -EINVAL;
+
+ pch = strrchr(name, '_');
+ if (!pch)
+ return -EINVAL;
+
+ mod = *(pch + 1);
+ switch (mod) {
+ case 'X':
+ *modifier = IIO_MOD_X;
+ return 0;
+ case 'Y':
+ *modifier = IIO_MOD_Y;
+ return 0;
+ case 'Z':
+ *modifier = IIO_MOD_Z;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int scmi_iio_get_chan_type(u8 scmi_type, enum iio_chan_type *iio_type)
+{
+ switch (scmi_type) {
+ case METERS_SEC_SQUARED:
+ *iio_type = IIO_ACCEL;
+ return 0;
+ case RADIANS_SEC:
+ *iio_type = IIO_ANGL_VEL;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static u64 scmi_iio_convert_interval_to_ns(u32 val)
+{
+ u64 sensor_update_interval =
+ SCMI_SENS_INTVL_GET_SECS(val) * NSEC_PER_SEC;
+ u64 sensor_interval_mult;
+ int mult;
+
+ mult = SCMI_SENS_INTVL_GET_EXP(val);
+ 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 scmi_iio_set_sampling_freq_avail(struct iio_dev *iio_dev)
+{
+ u64 cur_interval_ns, low_interval_ns, high_interval_ns, step_size_ns,
+ hz, uhz;
+ unsigned int cur_interval, low_interval, high_interval, step_size;
+ struct scmi_iio_priv *sensor = iio_priv(iio_dev);
+ int i;
+
+ sensor->freq_avail =
+ devm_kzalloc(&iio_dev->dev,
+ sizeof(*sensor->freq_avail) *
+ (sensor->sensor_info->intervals.count * 2),
+ GFP_KERNEL);
+ if (!sensor->freq_avail)
+ return -ENOMEM;
+
+ if (sensor->sensor_info->intervals.segmented) {
+ low_interval = sensor->sensor_info->intervals
+ .desc[SCMI_SENS_INTVL_SEGMENT_LOW];
+ low_interval_ns = scmi_iio_convert_interval_to_ns(low_interval);
+ convert_ns_to_freq(low_interval_ns, &hz, &uhz);
+ sensor->freq_avail[0] = hz;
+ sensor->freq_avail[1] = uhz;
+
+ step_size = sensor->sensor_info->intervals
+ .desc[SCMI_SENS_INTVL_SEGMENT_STEP];
+ step_size_ns = scmi_iio_convert_interval_to_ns(step_size);
+ convert_ns_to_freq(step_size_ns, &hz, &uhz);
+ sensor->freq_avail[2] = hz;
+ sensor->freq_avail[3] = uhz;
+
+ high_interval = sensor->sensor_info->intervals
+ .desc[SCMI_SENS_INTVL_SEGMENT_HIGH];
+ high_interval_ns =
+ scmi_iio_convert_interval_to_ns(high_interval);
+ convert_ns_to_freq(high_interval_ns, &hz, &uhz);
+ sensor->freq_avail[4] = hz;
+ sensor->freq_avail[5] = uhz;
+ } else {
+ for (i = 0; i < sensor->sensor_info->intervals.count; i++) {
+ cur_interval = sensor->sensor_info->intervals.desc[i];
+ cur_interval_ns =
+ scmi_iio_convert_interval_to_ns(cur_interval);
+ convert_ns_to_freq(cur_interval_ns, &hz, &uhz);
+ sensor->freq_avail[i * 2] = hz;
+ sensor->freq_avail[i * 2 + 1] = uhz;
+ }
+ }
+ return 0;
+}
+
+static int scmi_iio_buffers_setup(struct iio_dev *scmi_iiodev)
+{
+ struct iio_buffer *buffer;
+
+ buffer = devm_iio_kfifo_allocate(&scmi_iiodev->dev);
+ if (!buffer)
+ return -ENOMEM;
+
+ iio_device_attach_buffer(scmi_iiodev, buffer);
+ scmi_iiodev->modes |= INDIO_BUFFER_SOFTWARE;
+ scmi_iiodev->setup_ops = &scmi_iio_buffer_ops;
+ return 0;
+}
+
+static struct iio_dev *scmi_alloc_iiodev(struct device *dev,
+ struct scmi_handle *handle,
+ const struct scmi_sensor_info *sensor_info)
+{
+ struct iio_chan_spec *iio_channels;
+ struct scmi_iio_priv *sensor;
+ enum iio_modifier modifier;
+ enum iio_chan_type type;
+ struct iio_dev *iiodev;
+ int i, ret;
+
+ iiodev = devm_iio_device_alloc(dev, sizeof(*sensor));
+ if (!iiodev)
+ return ERR_PTR(-ENOMEM);
+
+ iiodev->modes = INDIO_DIRECT_MODE;
+ iiodev->dev.parent = dev;
+ sensor = iio_priv(iiodev);
+ sensor->handle = handle;
+ sensor->sensor_info = sensor_info;
+ sensor->sensor_update_nb.notifier_call = scmi_iio_sensor_update_cb;
+ sensor->indio_dev = iiodev;
+
+ /* adding one additional channel for timestamp */
+ iiodev->num_channels = sensor_info->num_axis + 1;
+ iiodev->name = sensor_info->name;
+ iiodev->info = &scmi_iio_info;
+
+ iio_channels =
+ devm_kzalloc(dev,
+ sizeof(*iio_channels) * (iiodev->num_channels),
+ GFP_KERNEL);
+ if (!iio_channels)
+ return ERR_PTR(-ENOMEM);
+
+ ret = scmi_iio_set_sampling_freq_avail(iiodev);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ 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 ERR_PTR(ret);
+
+ ret = scmi_iio_get_chan_modifier(sensor_info->axis[i].name,
+ &modifier);
+ if (ret < 0)
+ return ERR_PTR(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);
+ iiodev->channels = iio_channels;
+ return iiodev;
+}
+
+static int scmi_iio_dev_probe(struct scmi_device *sdev)
+{
+ const struct scmi_sensor_info *sensor_info;
+ struct scmi_handle *handle = sdev->handle;
+ struct device *dev = &sdev->dev;
+ struct iio_dev *scmi_iio_dev;
+ u16 nr_sensors;
+ int err = -ENODEV, i;
+
+ 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_dbg(dev, "0 sensors found via SCMI bus\n");
+ return -ENODEV;
+ }
+
+ 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;
+ }
+
+ /* This driver only supports 3-axis accel and gyro, skipping other sensors */
+ if (sensor_info->num_axis != SCMI_IIO_NUM_OF_AXIS)
+ continue;
+
+ /* This driver only supports 3-axis accel and gyro, skipping other sensors */
+ if (sensor_info->axis[0].type != METERS_SEC_SQUARED &&
+ sensor_info->axis[0].type != RADIANS_SEC)
+ continue;
+
+ scmi_iio_dev = scmi_alloc_iiodev(dev, handle, sensor_info);
+ if (IS_ERR(scmi_iio_dev)) {
+ dev_err(dev,
+ "failed to allocate IIO device for sensor %s: %ld\n",
+ sensor_info->name, PTR_ERR(scmi_iio_dev));
+ return PTR_ERR(scmi_iio_dev);
+ }
+
+ 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 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,
+ .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");
--
2.30.0.478.g8a0d178c01-goog