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 <jbhay...@google.com>
---
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 <jbhay...@google.com>
+L: linux-...@vger.kernel.org
+S: Maintained
+F: drivers/iio/scmi/scmi_iio.c
+
IIO SUBSYSTEM AND DRIVERS
M: Jonathan Cameron <ji...@kernel.org>
R: Hartmut Knaack <knaac...@gmx.de>
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))
+
+//one additional channel for timestamp
+#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;
+}
+
+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;
+}
+
+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 = SCMI_SENS_CFG_SET_ENABLE(sensor_config);
+
+ 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);
+
+ 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;
+ }
+ 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
+
+ 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);
+ sensor_config = SCMI_SENS_CFG_SET_UPDATE_MULTI(sensor_config, -mult);
+ sensor_config = SCMI_SENS_CFG_SET_AUTO_ROUND_UP(sensor_config);
+ if (sensor->sensor_info->timestamped)
+ sensor_config = SCMI_SENS_CFG_SET_TSTAMP_ENABLED(sensor_config);
+ if (SCMI_SENS_CFG_IS_ENABLED(cur_sensor_config))
+ sensor_config = SCMI_SENS_CFG_SET_ENABLE(sensor_config);
+ else
+ sensor_config = SCMI_SENS_CFG_SET_DISABLE(sensor_config);
+
+ 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;
+}
+
+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 <jbhay...@google.com>");
+MODULE_DESCRIPTION("SCMI IIO Driver");
+MODULE_LICENSE("GPL v2");
--
2.29.2.299.gdc1121823c-goog
