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
