On Wed, 10 Feb 2021 21:46:19 +0000 Cristian Marussi <cristian.marussi@xxxxxxx> wrote: > Hi Jyoti, > > On Wed, Feb 10, 2021 at 11:19:35AM -0800, Jyoti Bhayana wrote: > > Hi Cristian, > > > > Thanks for the feedback. Regarding registering callbacks at the probe time > > instead of .preenable, I have tried it before but I think due to some > > issues(don't remember it now maybe on the platform side) I kept it at the > > .preenable level. > > > > But you are right, that it will be nice to move it at the probe level > > instead. I will try again and test if it works and would move it at the > > probe level. Regarding the unregistering of the notifier, is it required at > > the remove of iio driver or scmi driver will take care of it? > > Because if I add unregister at the iio driver remove level, I would have to > > iterate all the sensors again and unregister them. > > Yes you are right if you move callbacks registration once for all to the > .probe step you'll have to unregister them all in a .remove. > > BUT I think instead you should stick with your current solution given > it's working fine anyway and it's supported by the notification > framework and also for another reason I'm going to explain down below > (which is also the reason why I asked you this at first :D) > > As you may remember I'm refactoring all the SCMI internals in a separate > series to ease modularization and vendor protocols support, and that will > lead also to some changes in the SCMI driver interface that you use: > amongst other things one interesting addition will be a new devres managed > notification registration method, something like: > > handle->notify_ops->devm_register_notifier(sdev, ...); > > With such method you could just move your registration to the .probe > step and just forget about it, without the need to add any unregistration > in the .remove step, since the core will take care to remove all the > callbacks at driver unloading time. > > Now, this series, which is here if you want to have a look: > > https://lore.kernel.org/linux-arm-kernel/20210202221555.41167-1-cristian.marussi@xxxxxxx/ > > is already taking care to port any existent SCMI driver to the new interface, > so when your IIODEV SCMI driver will be finally queued somewhere for merge, I > can in turn rebase my series on yours and take care to port your driver too to > the new interface applying the changes above in the context of my series. > (and ask you to review of course :D) I'm guessing you probably want this driver in an immutable branch then rather than having to wait another cycle for it to tick through to a a sensible upstream? Jonathan > > I'm saying that is better if you keep your series as it is for now > (old interface + .preenable/.postdisable regs/unregs) because, as said, > with the new interface the devm_ methods will ease the registration > @probe time, and also especially because the new interface is not (and > most probably won't) be part of the v5.4 backport that you are testing > against: so if you stick with your current solution you'll have a > working patch easily backportable now, and once queued I'll port it to > the interface using devm_ (so simplifying it) > > In this context, it would be indeed important to know if in general moving > registration to the probe phase (which should be fine by the spec) poses > any kind of problem. (and that's reason why asked it) > > Hope to have been clear despite the flood of words :D > > Thanks > > Cristian > > > > > Thanks, > > Jyoti > > > > On Tue, Feb 9, 2021 at 3:56 AM Cristian Marussi <cristian.marussi@xxxxxxx> > > wrote: > > > > > Hi Jyoti > > > > > > some minor things down below. > > > > > > Other than that, FWIW about the SCMI side of this: > > > > > > Reviewed-by: Cristian Marussi <cristian.marussi@xxxxxxx> > > > > > > Thanks > > > > > > Cristian > > > > > > On Mon, Feb 08, 2021 at 09:19:18PM +0000, Jyoti Bhayana wrote: > > > > 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 > > > > > > > > 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 | 673 +++++++++++++++++++++ > > > > 7 files changed, 705 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..093b1fc24e27 > > > > --- /dev/null > > > > +++ b/drivers/iio/common/scmi_sensors/scmi_iio.c > > > > @@ -0,0 +1,673 @@ > > > > +// 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, > > > > +}; > > > > > > This is just a question, I'm not suggesting to change anything here at > > > this point to be clear, since it works just fine as it is. > > > > > > Following up a previous email, given these are called on enable/disable > > > by sysfs, is there a specific reason why you configure here, inside > > > these ops, also timestamping and callbacks i.e. each time the sensor is > > > turned on/off by sysfs ? ... instead of just, as an example, enabling > > > in _preenable the sensor while registering callbacks and enabling > > > timestamping once for all earlier during probe phase ? > > > (likewise for _postdisable -> remove) > > > > > > AFAIU the spec says notifications are emitted for sensors which has > > > requested them (via SENSOR_CONTINUOUS_UPDATE_NOTIFY) BUT only if the > > > sensor is enabled as a whole (via proper CONFIG_SET as you do), so > > > that enabling/disabling the sensor as a whole should result in starting/ > > > stopping the notification flow without the need of unregistering the > > > callbacks everytime. (same goes with the timestamping) > > > > > > In other words, I would expect the sensor to maintain its state (on the > > > platform side) even when going through enable/disable cycles, so that > > > it 'remembers' that timestamping/notifications were enabled across an > > > on/off. > > > > > > This would reduce the number of SCMI messages exchanges between the > > > kernel and the platform and should be supported by both, but as said, > > > it's more of a question for the future, not necessarily for this series. > > > > > > > + > > > > > > [snip] > > > > > > > +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; > > > > +} > > > > + > > > > +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); > > > > + > > > > + scmi_iio_set_sampling_freq_avail(iiodev); > > > > > > You don't check this for retval, and it could fail with -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 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; > > > > +} > > > > + > > >
