On 2016/2017 MacBook Pro's with a Touch Bar the ALS is attached to, and exposed via the iBridge device. This provides the driver for that sensor. Signed-off-by: Ronald Tschalär <ronald@xxxxxxxxxxxxx> --- drivers/iio/light/Kconfig | 12 + drivers/iio/light/Makefile | 1 + drivers/iio/light/apple-ib-als.c | 694 +++++++++++++++++++++++++++++++ 3 files changed, 707 insertions(+) create mode 100644 drivers/iio/light/apple-ib-als.c diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig index 36f458433480..49159fab1c0e 100644 --- a/drivers/iio/light/Kconfig +++ b/drivers/iio/light/Kconfig @@ -64,6 +64,18 @@ config APDS9960 To compile this driver as a module, choose M here: the module will be called apds9960 +config APPLE_IBRIDGE_ALS + tristate "Apple iBridge ambient light sensor" + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + depends on MFD_APPLE_IBRIDGE + help + Say Y here to build the driver for the Apple iBridge ALS + sensor. + + To compile this driver as a module, choose M here: the + module will be called apple-ib-als. + config BH1750 tristate "ROHM BH1750 ambient light sensor" depends on I2C diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile index 286bf3975372..144d918917f7 100644 --- a/drivers/iio/light/Makefile +++ b/drivers/iio/light/Makefile @@ -9,6 +9,7 @@ obj-$(CONFIG_ADJD_S311) += adjd_s311.o obj-$(CONFIG_AL3320A) += al3320a.o obj-$(CONFIG_APDS9300) += apds9300.o obj-$(CONFIG_APDS9960) += apds9960.o +obj-$(CONFIG_APPLE_IBRIDGE_ALS) += apple-ib-als.o obj-$(CONFIG_BH1750) += bh1750.o obj-$(CONFIG_BH1780) += bh1780.o obj-$(CONFIG_CM32181) += cm32181.o diff --git a/drivers/iio/light/apple-ib-als.c b/drivers/iio/light/apple-ib-als.c new file mode 100644 index 000000000000..1718fcbe304f --- /dev/null +++ b/drivers/iio/light/apple-ib-als.c @@ -0,0 +1,694 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Apple Ambient Light Sensor Driver + * + * Copyright (c) 2017-2018 Ronald Tschalär + */ + +/* + * MacBookPro models with an iBridge chip (13,[23] and 14,[23]) have an + * ambient light sensor that is exposed via one of the USB interfaces on + * the iBridge as a standard HID light sensor. However, we cannot use the + * existing hid-sensor-als driver, for two reasons: + * + * 1. The hid-sensor-als driver is part of the hid-sensor-hub which in turn + * is a hid driver, but you can't have more than one hid driver per hid + * device, which is a problem because the touch bar also needs to + * register as a driver for this hid device. + * + * 2. While the hid-sensors-als driver stores sensor readings received via + * interrupt in an iio buffer, reads on the sysfs + * .../iio:deviceX/in_illuminance_YYY attribute result in a get of the + * feature report; however, in the case of this sensor here the + * illuminance field of that report is always 0. Instead, the input + * report needs to be requested. + */ + +#define dev_fmt(fmt) "als: " fmt + +#include <linux/device.h> +#include <linux/hid.h> +#include <linux/hid-sensor-ids.h> +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger.h> +#include <linux/mfd/apple-ibridge.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#define APPLEALS_DYN_SENS 0 /* our dynamic sensitivity */ +#define APPLEALS_DEF_CHANGE_SENS APPLEALS_DYN_SENS + +struct appleals_device { + struct appleib_device *ib_dev; + struct device *log_dev; + struct hid_device *hid_dev; + struct hid_report *cfg_report; + struct hid_field *illum_field; + struct iio_dev *iio_dev; + struct iio_trigger *iio_trig; + int cur_sensitivity; + int cur_hysteresis; + bool events_enabled; +}; + +static struct hid_driver appleals_hid_driver; + +/* + * This is a primitive way to get a relative sensitivity, one where we get + * notified when the value changes by a certain percentage rather than some + * absolute value. MacOS somehow manages to configure the sensor to work this + * way (with a 15% relative sensitivity), but I haven't been able to figure + * out how so far. So until we do, this provides a less-than-perfect + * simulation. + * + * When the brightness value is within one of the ranges, the sensitivity is + * set to that range's sensitivity. But in order to reduce flapping when the + * brightness is right on the border between two ranges, the ranges overlap + * somewhat (by at least one sensitivity), and sensitivity is only changed if + * the value leaves the current sensitivity's range. + * + * The values chosen for the map are somewhat arbitrary: a compromise of not + * too many ranges (and hence changing the sensitivity) but not too small or + * large of a percentage of the min and max values in the range (currently + * from 7.5% to 30%, i.e. within a factor of 2 of 15%), as well as just plain + * "this feels reasonable to me". + */ +struct appleals_sensitivity_map { + int sensitivity; + int illum_low; + int illum_high; +}; + +static struct appleals_sensitivity_map appleals_sensitivity_map[] = { + { 1, 0, 14 }, + { 3, 10, 40 }, + { 9, 30, 120 }, + { 27, 90, 360 }, + { 81, 270, 1080 }, + { 243, 810, 3240 }, + { 729, 2430, 9720 }, +}; + +static int appleals_compute_sensitivity(int cur_illum, int cur_sens) +{ + struct appleals_sensitivity_map *entry; + int i; + + /* see if we're still in current range */ + for (i = 0; i < ARRAY_SIZE(appleals_sensitivity_map); i++) { + entry = &appleals_sensitivity_map[i]; + + if (entry->sensitivity == cur_sens && + entry->illum_low <= cur_illum && + entry->illum_high >= cur_illum) + return cur_sens; + else if (entry->sensitivity > cur_sens) + break; + } + + /* not in current range, so find new sensitivity */ + for (i = 0; i < ARRAY_SIZE(appleals_sensitivity_map); i++) { + entry = &appleals_sensitivity_map[i]; + + if (entry->illum_low <= cur_illum && + entry->illum_high >= cur_illum) + return entry->sensitivity; + } + + /* hmm, not in table, so assume we are above highest range */ + i = ARRAY_SIZE(appleals_sensitivity_map) - 1; + return appleals_sensitivity_map[i].sensitivity; +} + +static int appleals_get_field_value_for_usage(struct hid_field *field, + unsigned int usage) +{ + int u; + + if (!field) + return -1; + + for (u = 0; u < field->maxusage; u++) { + if (field->usage[u].hid == usage) + return u + field->logical_minimum; + } + + return -1; +} + +static __s32 appleals_get_field_value(struct appleals_device *als_dev, + struct hid_field *field) +{ + hid_hw_request(als_dev->hid_dev, field->report, HID_REQ_GET_REPORT); + hid_hw_wait(als_dev->hid_dev); + + return field->value[0]; +} + +static void appleals_set_field_value(struct appleals_device *als_dev, + struct hid_field *field, __s32 value) +{ + hid_set_field(field, 0, value); + hid_hw_request(als_dev->hid_dev, field->report, HID_REQ_SET_REPORT); +} + +static int appleals_get_config(struct appleals_device *als_dev, + unsigned int field_usage, __s32 *value) +{ + struct hid_field *field; + + field = appleib_find_report_field(als_dev->cfg_report, field_usage); + if (!field) + return -EINVAL; + + *value = appleals_get_field_value(als_dev, field); + + return 0; +} + +static int appleals_set_config(struct appleals_device *als_dev, + unsigned int field_usage, __s32 value) +{ + struct hid_field *field; + + field = appleib_find_report_field(als_dev->cfg_report, field_usage); + if (!field) + return -EINVAL; + + appleals_set_field_value(als_dev, field, value); + + return 0; +} + +static int appleals_set_enum_config(struct appleals_device *als_dev, + unsigned int field_usage, + unsigned int value_usage) +{ + struct hid_field *field; + int value; + + field = appleib_find_report_field(als_dev->cfg_report, field_usage); + if (!field) + return -EINVAL; + + value = appleals_get_field_value_for_usage(field, value_usage); + + appleals_set_field_value(als_dev, field, value); + + return 0; +} + +static void appleals_update_dyn_sensitivity(struct appleals_device *als_dev, + __s32 value) +{ + int new_sens; + int rc; + + new_sens = appleals_compute_sensitivity(value, + als_dev->cur_sensitivity); + if (new_sens != als_dev->cur_sensitivity) { + rc = appleals_set_config(als_dev, + HID_USAGE_SENSOR_LIGHT_ILLUM | + HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS, + new_sens); + if (!rc) + als_dev->cur_sensitivity = new_sens; + } +} + +static void appleals_push_new_value(struct appleals_device *als_dev, + __s32 value) +{ + __s32 buf[2] = { value, value }; + + iio_push_to_buffers(als_dev->iio_dev, buf); + + if (als_dev->cur_hysteresis == APPLEALS_DYN_SENS) + appleals_update_dyn_sensitivity(als_dev, value); +} + +static int appleals_hid_event(struct hid_device *hdev, struct hid_field *field, + struct hid_usage *usage, __s32 value) +{ + struct appleals_device *als_dev = + appleib_get_drvdata(hid_get_drvdata(hdev), + &appleals_hid_driver); + int rc = 0; + + if ((usage->hid & HID_USAGE_PAGE) != HID_UP_SENSOR) + return 0; + + if (usage->hid == HID_USAGE_SENSOR_LIGHT_ILLUM) { + appleals_push_new_value(als_dev, value); + rc = 1; + } + + return rc; +} + +static int appleals_enable_events(struct iio_trigger *trig, bool enable) +{ + struct appleals_device *als_dev = iio_trigger_get_drvdata(trig); + int value; + + /* set the sensor's reporting state */ + appleals_set_enum_config(als_dev, HID_USAGE_SENSOR_PROP_REPORT_STATE, + enable ? HID_USAGE_SENSOR_PROP_REPORTING_STATE_ALL_EVENTS_ENUM : + HID_USAGE_SENSOR_PROP_REPORTING_STATE_NO_EVENTS_ENUM); + als_dev->events_enabled = enable; + + /* if the sensor was enabled, push an initial value */ + if (enable) { + value = appleals_get_field_value(als_dev, als_dev->illum_field); + appleals_push_new_value(als_dev, value); + } + + return 0; +} + +static int appleals_read_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct appleals_device *als_dev = + *(struct appleals_device **)iio_priv(iio_dev); + __s32 value; + int rc; + + *val = 0; + *val2 = 0; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + case IIO_CHAN_INFO_PROCESSED: + *val = appleals_get_field_value(als_dev, als_dev->illum_field); + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SAMP_FREQ: + rc = appleals_get_config(als_dev, + HID_USAGE_SENSOR_PROP_REPORT_INTERVAL, + &value); + if (rc) + return rc; + + /* interval is in ms; val is in HZ, val2 in µHZ */ + value = 1000000000 / value; + *val = value / 1000000; + *val2 = value - (*val * 1000000); + + return IIO_VAL_INT_PLUS_MICRO; + + case IIO_CHAN_INFO_HYSTERESIS: + if (als_dev->cur_hysteresis == APPLEALS_DYN_SENS) { + *val = als_dev->cur_hysteresis; + return IIO_VAL_INT; + } + + rc = appleals_get_config(als_dev, + HID_USAGE_SENSOR_LIGHT_ILLUM | + HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS, + val); + if (!rc) { + als_dev->cur_sensitivity = *val; + als_dev->cur_hysteresis = *val; + } + return rc ? rc : IIO_VAL_INT; + + default: + return -EINVAL; + } +} + +static int appleals_write_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct appleals_device *als_dev = + *(struct appleals_device **)iio_priv(iio_dev); + __s32 illum; + int rc; + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + rc = appleals_set_config(als_dev, + HID_USAGE_SENSOR_PROP_REPORT_INTERVAL, + 1000000000 / (val * 1000000 + val2)); + break; + + case IIO_CHAN_INFO_HYSTERESIS: + if (val == APPLEALS_DYN_SENS) { + if (als_dev->cur_hysteresis != APPLEALS_DYN_SENS) { + als_dev->cur_hysteresis = val; + illum = appleals_get_field_value(als_dev, + als_dev->illum_field); + appleals_update_dyn_sensitivity(als_dev, illum); + } + rc = 0; + break; + } + + rc = appleals_set_config(als_dev, + HID_USAGE_SENSOR_LIGHT_ILLUM | + HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS, + val); + if (!rc) { + als_dev->cur_sensitivity = val; + als_dev->cur_hysteresis = val; + } + break; + + default: + rc = -EINVAL; + } + + return rc; +} + +static const struct iio_chan_spec appleals_channels[] = { + { + .type = IIO_INTENSITY, + .modified = 1, + .channel2 = IIO_MOD_LIGHT_BOTH, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | + BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | + BIT(IIO_CHAN_INFO_HYSTERESIS), + .scan_type = { + .sign = 'u', + .realbits = 32, + .storagebits = 32, + }, + .scan_index = 0, + }, + { + .type = IIO_LIGHT, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | + BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | + BIT(IIO_CHAN_INFO_HYSTERESIS), + .scan_type = { + .sign = 'u', + .realbits = 32, + .storagebits = 32, + }, + .scan_index = 1, + } +}; + +static const struct iio_trigger_ops appleals_trigger_ops = { + .set_trigger_state = &appleals_enable_events, +}; + +static const struct iio_info appleals_info = { + .read_raw = &appleals_read_raw, + .write_raw = &appleals_write_raw, +}; + +static void appleals_config_sensor(struct appleals_device *als_dev, + bool events_enabled, int sensitivity) +{ + struct hid_field *field; + __s32 val; + + /* + * We're (often) in a probe here, so need to enable input processing + * in that case, but only in that case. + */ + if (appleib_in_hid_probe(als_dev->ib_dev)) + hid_device_io_start(als_dev->hid_dev); + + /* power on the sensor */ + field = appleib_find_report_field(als_dev->cfg_report, + HID_USAGE_SENSOR_PROY_POWER_STATE); + val = appleals_get_field_value_for_usage(field, + HID_USAGE_SENSOR_PROP_POWER_STATE_D0_FULL_POWER_ENUM); + hid_set_field(field, 0, val); + + /* configure reporting of change events */ + field = appleib_find_report_field(als_dev->cfg_report, + HID_USAGE_SENSOR_PROP_REPORT_STATE); + val = appleals_get_field_value_for_usage(field, + events_enabled ? + HID_USAGE_SENSOR_PROP_REPORTING_STATE_ALL_EVENTS_ENUM : + HID_USAGE_SENSOR_PROP_REPORTING_STATE_NO_EVENTS_ENUM); + hid_set_field(field, 0, val); + + /* report change events asap */ + field = appleib_find_report_field(als_dev->cfg_report, + HID_USAGE_SENSOR_PROP_REPORT_INTERVAL); + hid_set_field(field, 0, field->logical_minimum); + + /* + * Set initial change sensitivity; if dynamic, enabling trigger will set + * it instead. + */ + if (sensitivity != APPLEALS_DYN_SENS) { + field = appleib_find_report_field(als_dev->cfg_report, + HID_USAGE_SENSOR_LIGHT_ILLUM | + HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS); + + hid_set_field(field, 0, sensitivity); + } + + /* write the new config to the sensor */ + hid_hw_request(als_dev->hid_dev, als_dev->cfg_report, + HID_REQ_SET_REPORT); + + if (appleib_in_hid_probe(als_dev->ib_dev)) + hid_device_io_stop(als_dev->hid_dev); +}; + +static int appleals_config_iio(struct appleals_device *als_dev) +{ + struct iio_dev *iio_dev; + struct iio_trigger *iio_trig; + int rc; + + /* create and register iio device */ + iio_dev = iio_device_alloc(sizeof(als_dev)); + if (!iio_dev) + return -ENOMEM; + + *(struct appleals_device **)iio_priv(iio_dev) = als_dev; + + iio_dev->channels = appleals_channels; + iio_dev->num_channels = ARRAY_SIZE(appleals_channels); + iio_dev->dev.parent = &als_dev->hid_dev->dev; + iio_dev->info = &appleals_info; + iio_dev->name = "als"; + iio_dev->modes = INDIO_DIRECT_MODE; + + rc = iio_triggered_buffer_setup(iio_dev, &iio_pollfunc_store_time, NULL, + NULL); + if (rc) { + dev_err(als_dev->log_dev, "failed to set up iio triggers: %d\n", + rc); + goto free_iio_dev; + } + + iio_trig = iio_trigger_alloc("%s-dev%d", iio_dev->name, iio_dev->id); + if (!iio_trig) { + rc = -ENOMEM; + goto clean_trig_buf; + } + + iio_trig->dev.parent = &als_dev->hid_dev->dev; + iio_trig->ops = &appleals_trigger_ops; + iio_trigger_set_drvdata(iio_trig, als_dev); + + rc = iio_trigger_register(iio_trig); + if (rc) { + dev_err(als_dev->log_dev, "failed to register iio trigger: %d\n", + rc); + goto free_iio_trig; + } + + als_dev->iio_trig = iio_trig; + + rc = iio_device_register(iio_dev); + if (rc) { + dev_err(als_dev->log_dev, "failed to register iio device: %d\n", + rc); + goto unreg_iio_trig; + } + + als_dev->iio_dev = iio_dev; + + return 0; + +unreg_iio_trig: + iio_trigger_unregister(iio_trig); +free_iio_trig: + iio_trigger_free(iio_trig); + als_dev->iio_trig = NULL; +clean_trig_buf: + iio_triggered_buffer_cleanup(iio_dev); +free_iio_dev: + iio_device_free(iio_dev); + + return rc; +} + +static int appleals_probe(struct hid_device *hdev, + const struct hid_device_id *id) +{ + struct appleals_device *als_dev = + appleib_get_drvdata(hid_get_drvdata(hdev), + &appleals_hid_driver); + struct hid_field *state_field; + struct hid_field *illum_field; + int rc; + + /* find als fields and reports */ + state_field = appleib_find_hid_field(hdev, HID_USAGE_SENSOR_ALS, + HID_USAGE_SENSOR_PROP_REPORT_STATE); + illum_field = appleib_find_hid_field(hdev, HID_USAGE_SENSOR_ALS, + HID_USAGE_SENSOR_LIGHT_ILLUM); + if (!state_field || !illum_field) + return -ENODEV; + + if (als_dev->hid_dev) { + dev_warn(als_dev->log_dev, + "Found duplicate ambient light sensor - ignoring\n"); + return -EBUSY; + } + + dev_info(als_dev->log_dev, "Found ambient light sensor\n"); + + /* initialize device */ + als_dev->hid_dev = hdev; + als_dev->cfg_report = state_field->report; + als_dev->illum_field = illum_field; + + als_dev->cur_hysteresis = APPLEALS_DEF_CHANGE_SENS; + als_dev->cur_sensitivity = APPLEALS_DEF_CHANGE_SENS; + appleals_config_sensor(als_dev, false, als_dev->cur_sensitivity); + + rc = appleals_config_iio(als_dev); + if (rc) + return rc; + + return 0; +} + +static void appleals_remove(struct hid_device *hdev) +{ + struct appleals_device *als_dev = + appleib_get_drvdata(hid_get_drvdata(hdev), + &appleals_hid_driver); + + if (als_dev->iio_dev) { + iio_device_unregister(als_dev->iio_dev); + + iio_trigger_unregister(als_dev->iio_trig); + iio_trigger_free(als_dev->iio_trig); + als_dev->iio_trig = NULL; + + iio_triggered_buffer_cleanup(als_dev->iio_dev); + iio_device_free(als_dev->iio_dev); + als_dev->iio_dev = NULL; + } + + als_dev->hid_dev = NULL; +} + +#ifdef CONFIG_PM +static int appleals_reset_resume(struct hid_device *hdev) +{ + struct appleals_device *als_dev = + appleib_get_drvdata(hid_get_drvdata(hdev), + &appleals_hid_driver); + + appleals_config_sensor(als_dev, als_dev->events_enabled, + als_dev->cur_sensitivity); + + return 0; +} +#endif + +static struct hid_driver appleals_hid_driver = { + .name = "apple-ib-als", + .probe = appleals_probe, + .remove = appleals_remove, + .event = appleals_hid_event, +#ifdef CONFIG_PM + .reset_resume = appleals_reset_resume, +#endif +}; + +static int appleals_platform_probe(struct platform_device *pdev) +{ + struct appleib_platform_data *pdata = pdev->dev.platform_data; + struct appleib_device *ib_dev = pdata->ib_dev; + struct appleals_device *als_dev; + int rc; + + als_dev = kzalloc(sizeof(*als_dev), GFP_KERNEL); + if (!als_dev) + return -ENOMEM; + + als_dev->ib_dev = ib_dev; + als_dev->log_dev = pdata->log_dev; + + rc = appleib_register_hid_driver(ib_dev, &appleals_hid_driver, als_dev); + if (rc) { + dev_err(als_dev->log_dev, "Error registering hid driver: %d\n", + rc); + goto error; + } + + platform_set_drvdata(pdev, als_dev); + + return 0; + +error: + kfree(als_dev); + return rc; +} + +static int appleals_platform_remove(struct platform_device *pdev) +{ + struct appleib_platform_data *pdata = pdev->dev.platform_data; + struct appleib_device *ib_dev = pdata->ib_dev; + struct appleals_device *als_dev = platform_get_drvdata(pdev); + int rc; + + rc = appleib_unregister_hid_driver(ib_dev, &appleals_hid_driver); + if (rc) { + dev_err(als_dev->log_dev, + "Error unregistering hid driver: %d\n", rc); + goto error; + } + + kfree(als_dev); + + return 0; + +error: + return rc; +} + +static const struct platform_device_id appleals_platform_ids[] = { + { .name = PLAT_NAME_IB_ALS }, + { } +}; +MODULE_DEVICE_TABLE(platform, appleals_platform_ids); + +static struct platform_driver appleals_platform_driver = { + .id_table = appleals_platform_ids, + .driver = { + .name = "apple-ib-als", + }, + .probe = appleals_platform_probe, + .remove = appleals_platform_remove, +}; + +module_platform_driver(appleals_platform_driver); + +MODULE_AUTHOR("Ronald Tschalär"); +MODULE_DESCRIPTION("Apple iBridge ALS driver"); +MODULE_LICENSE("GPL v2"); -- 2.20.1