Add a driver for the ambient light sensors, exposed through the standard IIO interface with left and right channels.
This replaces the light sensor support in applesmc. Signed-off-by: Atharva Tiwari <[email protected]> --- drivers/iio/light/Kconfig | 11 ++ drivers/iio/light/Makefile | 1 + drivers/iio/light/macsmc-light.c | 189 +++++++++++++++++++++++++++++++ drivers/mfd/macsmc-core.c | 11 ++ 4 files changed, 212 insertions(+) create mode 100644 drivers/iio/light/macsmc-light.c diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig index 462fff1dd..f84707edc 100644 --- a/drivers/iio/light/Kconfig +++ b/drivers/iio/light/Kconfig @@ -457,6 +457,17 @@ config LV0104CS To compile this driver as a module, choose M here: the module will be called lv0104cs. +config MACSMC_LIGHT + tristate "Apple SMC Light Sensor" + depends on MACSMC_ACPI + help + Say Y here if you have a Intel-based Mac. and you + want support for light sensors. + + To compile this driver as a module, choose M here: + the module will be called macsmc_light + + config MAX44000 tristate "MAX44000 Ambient and Infrared Proximity Sensor" depends on I2C diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile index 6672ed01a..2ef4c054d 100644 --- a/drivers/iio/light/Makefile +++ b/drivers/iio/light/Makefile @@ -40,6 +40,7 @@ obj-$(CONFIG_LTR390) += ltr390.o obj-$(CONFIG_LTR501) += ltr501.o obj-$(CONFIG_LTRF216A) += ltrf216a.o obj-$(CONFIG_LV0104CS) += lv0104cs.o +obj-$(CONFIG_MACSMC_LIGHT) += macsmc-light.o obj-$(CONFIG_MAX44000) += max44000.o obj-$(CONFIG_MAX44009) += max44009.o obj-$(CONFIG_NOA1305) += noa1305.o diff --git a/drivers/iio/light/macsmc-light.c b/drivers/iio/light/macsmc-light.c new file mode 100644 index 000000000..9d4532b34 --- /dev/null +++ b/drivers/iio/light/macsmc-light.c @@ -0,0 +1,189 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Apple SMC Light Sensor Driver + * + * Copyright (C) 2026 Atharva Tiwari <[email protected]> + * + * Based on drivers/hwmom/applesmc.c: + * Copyright (C) 2007 Nicolas Boichat <[email protected]> + * Copyright (C) 2010 Henrik Rydberg <[email protected]> + */ + +#include <linux/iio/events.h> +#include <linux/iio/iio.h> +#include <linux/byteorder/generic.h> +#include <linux/mfd/macsmc.h> +#include <linux/platform_device.h> +#include <linux/unaligned.h> + +enum { + LEFT_LIGHT = 0, + RIGHT_LIGHT +}; + +struct macsmc_light { + struct apple_smc *smc; + struct notifier_block nb; + struct iio_dev *indio_dev; + u8 size; +}; + +static int macsmc_light_read_raw(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + int *val, int *val2, long mask) + +{ + struct macsmc_light *drv = iio_priv(indio_dev); + u8 buffer[10]; + int ret; + + if (mask != IIO_CHAN_INFO_RAW) + return -EINVAL; + + switch (chan->channel) { + case LEFT_LIGHT: + ret = apple_smc_read(drv->smc, SMC_KEY(ALV0), buffer, drv->size); + if (ret < 0) + return ret; + + if (drv->size == 10) + *val = be16_to_cpu(get_unaligned_be16(buffer + 6)) >> 10; + else + *val = buffer[2]; + + break; + case RIGHT_LIGHT: + if (drv->size == 10) { + *val = 0; + break; + } + ret = apple_smc_read(drv->smc, SMC_KEY(ALV1), buffer, drv->size); + if (ret < 0) + return ret; + + *val = buffer[2]; + break; + default: + return -EINVAL; + } + + return IIO_VAL_INT; +} + +static int macsmc_light_event(struct notifier_block *nb, unsigned long event, void *data) +{ + struct macsmc_light *drv = container_of(nb, struct macsmc_light, nb); + s64 timestamp = iio_get_time_ns(drv->indio_dev); + + /* check if event is for us */ + if (event != 0x2A) + return NOTIFY_DONE; + + iio_push_event(drv->indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_LIGHT, + LEFT_LIGHT, + IIO_EV_TYPE_CHANGE, + IIO_EV_DIR_EITHER), + timestamp); + + if (drv->size != 10) { + iio_push_event(drv->indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_LIGHT, + RIGHT_LIGHT, + IIO_EV_TYPE_CHANGE, + IIO_EV_DIR_EITHER), + timestamp); + } + + return NOTIFY_OK; +} + +static void macsmc_light_unregister_notifier(void *data) +{ + struct macsmc_light *drv = data; + + blocking_notifier_chain_unregister(drv->smc->event_handlers, + &drv->nb); +} + +static const struct iio_event_spec macsmc_light_events[] = { + { + .type = IIO_EV_TYPE_CHANGE, + .dir = IIO_EV_DIR_EITHER, + .mask_separate = BIT(IIO_EV_INFO_ENABLE), + }, +}; + +static const struct iio_chan_spec macsmc_light_channels[] = { + { + .type = IIO_LIGHT, + .channel = LEFT_LIGHT, + .extend_name = "left", + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .event_spec = macsmc_light_events, + .num_event_specs = ARRAY_SIZE(macsmc_light_events), + }, + { + .type = IIO_LIGHT, + .channel = RIGHT_LIGHT, + .extend_name = "right", + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .event_spec = macsmc_light_events, + .num_event_specs = ARRAY_SIZE(macsmc_light_events), + }, +}; + +static const struct iio_info macsmc_light_info = { + .read_raw = macsmc_light_read_raw, +}; + +static int macsmc_light_probe(struct platform_device *pdev) +{ + struct iio_dev *indio_dev; + struct macsmc_light *drv; + struct apple_smc_key_info info; + int ret; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*drv)); + if (!indio_dev) + return -ENOMEM; + + drv = iio_priv(indio_dev); + drv->smc = dev_get_drvdata(pdev->dev.parent); + + ret = apple_smc_get_key_info(drv->smc, SMC_KEY(ALV0), &info); + if (ret < 0) + return -ENODEV; + + drv->size = info.size; + drv->indio_dev = indio_dev; + drv->nb.notifier_call = macsmc_light_event; + ret = blocking_notifier_chain_register(drv->smc->event_handlers, &drv->nb); + if (ret) + return ret; + + ret = devm_add_action_or_reset(&pdev->dev, macsmc_light_unregister_notifier, drv); + if (ret) + return ret; + + indio_dev->name = "macsmc-light"; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &macsmc_light_info; + indio_dev->channels = macsmc_light_channels; + indio_dev->num_channels = ARRAY_SIZE(macsmc_light_channels); + + return devm_iio_device_register(&pdev->dev, indio_dev); +} + +static struct platform_driver macsmc_light_driver = { + .probe = macsmc_light_probe, + .driver = { + .name = "macsmc-light", + }, +}; +module_platform_driver(macsmc_light_driver); + +MODULE_AUTHOR("Atharva Tiwari <[email protected]>"); +MODULE_LICENSE("Dual MIT/GPL"); +MODULE_DESCRIPTION("Apple SMC Light Sensor Driver"); +MODULE_ALIAS("platform:macsmc-light"); diff --git a/drivers/mfd/macsmc-core.c b/drivers/mfd/macsmc-core.c index 1c1469828..6014df4fe 100644 --- a/drivers/mfd/macsmc-core.c +++ b/drivers/mfd/macsmc-core.c @@ -29,6 +29,10 @@ static const struct mfd_cell apple_smc_acpi_common[] = { MFD_CELL_NAME("macsmc-power"), }; +static const struct mfd_cell apple_smc_acpi_light[] = { + MFD_CELL_NAME("macsmc-light"), +}; + static const struct mfd_cell apple_smc_acpi_rtc[] = { MFD_CELL_NAME("macsmc-rtc"), }; @@ -158,6 +162,13 @@ int apple_smc_probe(struct device *dev, const struct apple_smc_backend_ops *ops, return ret; } + if (apple_smc_key_exists(smc, SMC_KEY(ALV0))) { + ret = devm_mfd_add_devices(dev, -1, apple_smc_acpi_light, + ARRAY_SIZE(apple_smc_acpi_light), NULL, 0, NULL); + if (ret < 0) + return ret; + } + } else ret = devm_mfd_add_devices(dev, -1, apple_smc_rtkit_devs, ARRAY_SIZE(apple_smc_rtkit_devs), NULL, 0, NULL); -- 2.55.0
