[+Jonathan] On Tue, Apr 7, 2020 at 10:37 PM Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote: > > When the camera vsync pin is connected to the embedded controller (EC) of > a chromebook, the EC reports a sensor with a counter that increases > at each GPIO rising edge. > > The sensor is presented using the counter subsystem. > In addition, it is also presented via the IIO subsystem with a timestamp, > allowing synchronisation with sensors connected to the same EC, for > image stabilisation or augmented reality applications. > > To enable the counter: > via counter ABI: > echo "rising edge" > counterX/count0/signal_action > via iio ABI > echo 1 > iio:deviceY/en > > To disable the counter: > via counter ABI: > echo "none" > counterX/count0/signal_action > via iio ABI > echo 0 > iio:deviceY/en > > To read the current counter value: > via counter ABI: > cat counterX/count0/count > via iio ABI > cat iio:deviceY/in_count_raw > We can also read the value through the IIO buffer: > echo 1 > iio:deviceY/scan_elements/in_timestamp_en > echo 1 > iio:deviceY/scan_elements/in_count_en > echo 1 > iio:deviceY/buffer/enable > > and each time to counter increase, the following binary blob > will be appended to dev/iio:deviceY: > 000f 0000 0000 0000 dc66 816c 0071 0000 > \ <-- padding -> <-- timestamp ----> > count > > Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx> > --- > An initial version of the driver was presented few month ago at > https://patchwork.kernel.org/patch/11037009/ > > drivers/counter/Kconfig | 11 + > drivers/counter/Makefile | 1 + > drivers/counter/cros_ec_sync.c | 342 ++++++++++++++++++ > .../cros_ec_sensors/cros_ec_sensors_core.c | 15 + > drivers/platform/chrome/cros_ec_sensorhub.c | 3 + > .../linux/iio/common/cros_ec_sensors_core.h | 4 +- > 6 files changed, 375 insertions(+), 1 deletion(-) > create mode 100644 drivers/counter/cros_ec_sync.c > > diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig > index c80fa76bb5311..18fde918ff40b 100644 > --- a/drivers/counter/Kconfig > +++ b/drivers/counter/Kconfig > @@ -29,6 +29,17 @@ config 104_QUAD_8 > The base port addresses for the devices may be configured via the base > array module parameter. > > +config CROS_EC_SYNC > + tristate "ChromeOS EC Counter driver" > + depends on IIO_CROS_EC_SENSORS_CORE > + help > + Module to handle synchronisation sensor presented by the ChromeOS EC > + Sensor hub. > + Synchronisation sensor sends event to the host when the camera > + take a picture. It allows synchronisation with other MEMS sensor, > + like gyroscope for image statbilization or augmented reality > + application (AR). > + > config STM32_TIMER_CNT > tristate "STM32 Timer encoder counter driver" > depends on MFD_STM32_TIMERS || COMPILE_TEST > diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile > index 55142d1f4c436..98378fca50ad6 100644 > --- a/drivers/counter/Makefile > +++ b/drivers/counter/Makefile > @@ -6,6 +6,7 @@ > obj-$(CONFIG_COUNTER) += counter.o > > obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o > +obj-$(CONFIG_CROS_EC_SYNC) += cros_ec_sync.o > obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o > obj-$(CONFIG_STM32_LPTIMER_CNT) += stm32-lptimer-cnt.o > obj-$(CONFIG_TI_EQEP) += ti-eqep.o > diff --git a/drivers/counter/cros_ec_sync.c b/drivers/counter/cros_ec_sync.c > new file mode 100644 > index 0000000000000..94b3ababab4bd > --- /dev/null > +++ b/drivers/counter/cros_ec_sync.c > @@ -0,0 +1,342 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Driver for synchronisation sensor behind CrOS EC. > + * > + * Copyright 2020 Google, Inc > + * > + * This software is licensed under the terms of the GNU General Public > + * License version 2, as published by the Free Software Foundation, and > + * may be copied, distributed, and modified under those terms. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * This driver uses the cros-ec interface to communicate with the Chrome OS > + * EC about counter sensors. Counters are presented through > + * iio sysfs. > + */ > + > +#include <linux/counter.h> > +#include <linux/device.h> > +#include <linux/iio/buffer.h> > +#include <linux/iio/common/cros_ec_sensors_core.h> > +#include <linux/iio/iio.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/platform_data/cros_ec_commands.h> > +#include <linux/platform_data/cros_ec_proto.h> > +#include <linux/platform_device.h> > +#include <linux/slab.h> > + > +/* > + * One channel for counter, the other for timestamp. > + */ > +#define MAX_CHANNELS (1 + 1) > + > +/** > + * struct cros_ec_sync_state - device structure > + * > + * @core: common structure for all cros_ec sensor. > + * Must be at the beggining. > + * @channels: presented iio channels(2). > + * @counter: counter data structure. > + */ > +struct cros_ec_sync_state { > + struct cros_ec_sensors_core_state core; > + struct iio_chan_spec channels[MAX_CHANNELS]; > + struct counter_device counter; > +}; > + > +/** > + * cros_ec_sync_get_enable() - Check if the counter is enabled. > + * > + * @st: core cros_ec sensor > + * @val: status: 0: disabled, 1 enabled. > + * > + * Return: 0 on success, -errno on failure. > + */ > +static int cros_ec_sync_get_enable(struct cros_ec_sensors_core_state *st, > + int *val) > +{ > + int ret; > + > + mutex_lock(&st->cmd_lock); > + st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR; > + st->param.sensor_odr.data = EC_MOTION_SENSE_NO_VALUE; > + > + ret = cros_ec_motion_send_host_cmd(st, 0); > + mutex_unlock(&st->cmd_lock); > + if (ret) > + return ret; > + > + *val = !!st->resp->sensor_odr.ret; > + return 0; > +} > + > +/** > + * cros_ec_sync_set_enable() - Allow the counter to count. > + * > + * When enable, the counter will increase for each VSYNC rising edge > + * and will produce an event in the iio buffer, if enabled. > + * > + * @st: core cros_ec sensor > + * @val: 0: disable, 1 enable. > + * > + * Return: 0 on success, -errno on failure. > + */ > +static int cros_ec_sync_set_enable(struct cros_ec_sensors_core_state *st, > + int val) > +{ > + int ret; > + > + mutex_lock(&st->cmd_lock); > + st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR; > + st->param.sensor_odr.data = val; > + st->param.sensor_odr.roundup = 1; > + > + ret = cros_ec_motion_send_host_cmd(st, 0); > + mutex_unlock(&st->cmd_lock); > + return ret; > +} > + > +static int cros_ec_sync_iio_read(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev); > + u16 data; > + int ret; > + int idx = chan->scan_index; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + mutex_lock(&st->cmd_lock); > + ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx, &data); > + mutex_unlock(&st->cmd_lock); > + if (ret < 0) > + break; > + ret = IIO_VAL_INT; > + *val = data; > + break; > + case IIO_CHAN_INFO_ENABLE: > + ret = cros_ec_sync_get_enable(st, val); > + if (ret < 0) > + break; > + ret = IIO_VAL_INT; > + break; > + default: > + ret = -EINVAL; > + break; > + } > + mutex_unlock(&st->cmd_lock); > + return ret; > +} > + > +static int cros_ec_sync_iio_write(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev); > + > + switch (mask) { > + case IIO_CHAN_INFO_ENABLE: > + if (val < 0 || val > 1) > + return -EINVAL; > + > + return cros_ec_sync_set_enable(st, val); > + > + default: > + return -EINVAL; > + } > +} > + > +static const struct iio_info cros_ec_sync_info = { > + .read_raw = &cros_ec_sync_iio_read, > + .write_raw = &cros_ec_sync_iio_write, > +}; > + > +/* The counter can only increase, so only one function present. */ > +static enum counter_count_function cros_ec_sync_functions[] = { > + COUNTER_COUNT_FUNCTION_INCREASE, > +}; > + > +/* 2 synapse actions allowed: count for each rising edge, or not. */ > +static enum counter_synapse_action cros_ec_sync_synapse_actions[] = { > + COUNTER_SYNAPSE_ACTION_NONE, > + COUNTER_SYNAPSE_ACTION_RISING_EDGE, > +}; > + > +static int cros_ec_sync_read_count(struct counter_device *counter, > + struct counter_count *count, > + unsigned long *val) > +{ > + struct cros_ec_sensors_core_state *st = counter->priv; > + u16 raw; > + int ret; > + > + mutex_lock(&st->cmd_lock); > + ret = cros_ec_sensors_read_cmd(iio_priv_to_dev(st), 1, &raw); > + mutex_unlock(&st->cmd_lock); > + if (ret) > + return ret; > + > + *val = raw; > + return 0; > +} > + > +static int cros_ec_sync_function_get(struct counter_device *counter, > + struct counter_count *count, > + size_t *function) > +{ > + *function = 0; > + return 0; > +} > + > +static int cros_ec_sync_action_get(struct counter_device *counter, > + struct counter_count *count, > + struct counter_synapse *synapse, > + size_t *action) > +{ > + struct cros_ec_sensors_core_state *st = counter->priv; > + int ret; > + int raw; > + > + ret = cros_ec_sync_get_enable(st, &raw); > + if (ret) > + return ret; > + > + *action = !!raw; > + return 0; > +} > + > +static int cros_ec_sync_action_set(struct counter_device *counter, > + struct counter_count *count, > + struct counter_synapse *synapse, > + size_t action) > +{ > + struct cros_ec_sensors_core_state *st = counter->priv; > + > + return cros_ec_sync_set_enable(st, action); > +} > + > +static const struct counter_ops cros_ec_sync_ops = { > + .count_read = cros_ec_sync_read_count, > + .function_get = cros_ec_sync_function_get, > + .action_get = cros_ec_sync_action_get, > + .action_set = cros_ec_sync_action_set, > +}; > + > +static struct counter_signal cros_ec_sync_signals[] = { > + { > + .id = 0, > + .name = "vsync" > + } > +}; > + > +static struct counter_synapse cros_ec_sync_synapses[] = { > + { > + .actions_list = cros_ec_sync_synapse_actions, > + .num_actions = ARRAY_SIZE(cros_ec_sync_synapse_actions), > + .signal = cros_ec_sync_signals > + } > +}; > + > +static struct counter_count cros_ec_sync_counts[] = { > + { > + .id = 0, > + .name = "vsync", > + .functions_list = cros_ec_sync_functions, > + .num_functions = ARRAY_SIZE(cros_ec_sync_functions), > + .synapses = cros_ec_sync_synapses, > + .num_synapses = ARRAY_SIZE(cros_ec_sync_synapses), > + } > +}; > + > +static int cros_ec_sync_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct iio_dev *indio_dev; > + struct cros_ec_sync_state *state; > + struct iio_chan_spec *channel; > + int ret; > + > + indio_dev = devm_iio_device_alloc(dev, sizeof(*state)); > + if (!indio_dev) > + return -ENOMEM; > + > + ret = cros_ec_sensors_core_init(pdev, indio_dev, true, > + cros_ec_sensors_capture, > + cros_ec_sensors_push_data); > + if (ret) > + return ret; > + > + indio_dev->info = &cros_ec_sync_info; > + state = iio_priv(indio_dev); > + > + /* Initialize IIO device */ > + channel = state->channels; > + > + /* Counter channel */ > + channel->type = IIO_COUNT; > + channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); > + channel->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_ENABLE); > + channel->scan_type.realbits = CROS_EC_SENSOR_BITS; > + channel->scan_type.storagebits = CROS_EC_SENSOR_BITS; > + channel->scan_type.shift = 0; > + channel->scan_index = 0; > + channel->ext_info = cros_ec_sensors_limited_info; > + channel->scan_type.sign = 'u'; > + > + /* Timestamp channel */ > + channel++; > + channel->type = IIO_TIMESTAMP; > + channel->channel = -1; > + channel->scan_index = 1; > + channel->scan_type.sign = 's'; > + channel->scan_type.realbits = 64; > + channel->scan_type.storagebits = 64; > + > + indio_dev->channels = state->channels; > + indio_dev->num_channels = MAX_CHANNELS; > + > + state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd; > + > + /* Initialize Counter device */ > + state->counter.name = dev_name(&pdev->dev); > + state->counter.parent = &pdev->dev; > + state->counter.ops = &cros_ec_sync_ops; > + state->counter.counts = cros_ec_sync_counts; > + state->counter.num_counts = ARRAY_SIZE(cros_ec_sync_counts); > + state->counter.signals = cros_ec_sync_signals; > + state->counter.num_signals = ARRAY_SIZE(cros_ec_sync_signals); > + state->counter.priv = state; > + > + ret = devm_iio_device_register(dev, indio_dev); > + if (ret) > + return ret; > + > + return devm_counter_register(dev, &state->counter); > +} > + > +static const struct platform_device_id cros_ec_sync_ids[] = { > + { > + .name = "cros-ec-sync", > + }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(platform, cros_ec_sync_ids); > + > +static struct platform_driver cros_ec_sync_platform_driver = { > + .driver = { > + .name = "cros-ec-sync", > + }, > + .probe = cros_ec_sync_probe, > + .id_table = cros_ec_sync_ids, > +}; > +module_platform_driver(cros_ec_sync_platform_driver); > + > +MODULE_AUTHOR("Gwendal Grignou <gwendal@xxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("ChromeOS EC synchronisation sensor driver"); > +MODULE_LICENSE("GPL v2"); > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c > index c831915ca7e56..3a15094616710 100644 > --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c > @@ -31,6 +31,7 @@ > static char *cros_ec_loc[] = { > [MOTIONSENSE_LOC_BASE] = "base", > [MOTIONSENSE_LOC_LID] = "lid", > + [MOTIONSENSE_LOC_CAMERA] = "camera", > [MOTIONSENSE_LOC_MAX] = "unknown", > }; > > @@ -467,6 +468,20 @@ const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[] = { > }; > EXPORT_SYMBOL_GPL(cros_ec_sensors_ext_info); > > +const struct iio_chan_spec_ext_info cros_ec_sensors_limited_info[] = { > + { > + .name = "id", > + .shared = IIO_SHARED_BY_ALL, > + .read = cros_ec_sensors_id > + }, > + { > + .name = "location", > + .shared = IIO_SHARED_BY_ALL, > + .read = cros_ec_sensors_loc > + }, > + { }, > +}; > +EXPORT_SYMBOL_GPL(cros_ec_sensors_limited_info); > /** > * cros_ec_sensors_idx_to_reg - convert index into offset in shared memory > * @st: pointer to state information for device > diff --git a/drivers/platform/chrome/cros_ec_sensorhub.c b/drivers/platform/chrome/cros_ec_sensorhub.c > index b7f2c00db5e1e..e4ae0868d1e06 100644 > --- a/drivers/platform/chrome/cros_ec_sensorhub.c > +++ b/drivers/platform/chrome/cros_ec_sensorhub.c > @@ -106,6 +106,9 @@ static int cros_ec_sensorhub_register(struct device *dev, > case MOTIONSENSE_TYPE_ACTIVITY: > name = "cros-ec-activity"; > break; > + case MOTIONSENSE_TYPE_SYNC: > + name = "cros-ec-sync"; > + break; > default: > dev_warn(dev, "unknown type %d\n", > sensorhub->resp->info.type); > diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h > index 7bc961defa87e..e416b28cf24c7 100644 > --- a/include/linux/iio/common/cros_ec_sensors_core.h > +++ b/include/linux/iio/common/cros_ec_sensors_core.h > @@ -114,7 +114,9 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st, > struct iio_chan_spec const *chan, > int val, int val2, long mask); > > -/* List of extended channel specification for all sensors */ > +/* List of extended channel specification for all sensors. */ > +extern const struct iio_chan_spec_ext_info cros_ec_sensors_limited_info[]; > +/* Add calibration to set above. */ > extern const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[]; > extern const struct attribute *cros_ec_sensor_fifo_attributes[]; > > -- > 2.26.0.110.g2183baf09c-goog >
