On Sat, Jun 20, 2020 at 3:37 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> Many Bay Trail and Cherry Trail devices come with a camera attached to
> Intel's Image Signal Processor. Linux currently does not have a driver for
> these, so they do not work as a camera.
>
> Some of these camera's have a status LED which is controlled through a GPIO
> in some cases, e.g. on the Asus T100TA and Asus T200TA, there is a firmware
> issue where the LED gets turned on at boot.
>
> This commit adds a Linux LED driver for the camera LED on these devices.
> This driver will turn the LED off at boot and also allows controlling the
> LED (so the user can repurpose it) through the sysfs LED interface.
>
> Which GPIO is attached to the LED is usually not described in the ACPI
> tables, so this driver contains per-system info about the GPIO inside the
> driver. This means that this driver only works on systems the driver knows
> about.
>
Pushed to my review and testing queue, thanks!
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> Changes in v2:
> - Rebase on top of v5.8-rc1
> - Use PTR_ERR_OR_ZERO
> ---
> MAINTAINERS | 6 ++
> drivers/platform/x86/Kconfig | 21 ++++
> drivers/platform/x86/Makefile | 1 +
> drivers/platform/x86/intel_atomisp2_led.c | 116 ++++++++++++++++++++++
> 4 files changed, 144 insertions(+)
> create mode 100644 drivers/platform/x86/intel_atomisp2_led.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 301330e02bca..5535761f2b54 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8600,6 +8600,12 @@ L: platform-driver-x86@xxxxxxxxxxxxxxx
> S: Maintained
> F: drivers/platform/x86/intel_atomisp2_pm.c
>
> +INTEL ATOMISP2 LED DRIVER
> +M: Hans de Goede <hdegoede@xxxxxxxxxx>
> +L: platform-driver-x86@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/platform/x86/intel_atomisp2_led.c
> +
> INTEL BROXTON PMC DRIVER
> M: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> M: Zha Qipeng <qipeng.zha@xxxxxxxxx>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 0581a54cf562..318e083f38b3 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -761,6 +761,27 @@ config INTEL_ATOMISP2_PM
> To compile this driver as a module, choose M here: the module
> will be called intel_atomisp2_pm.
>
> +config INTEL_ATOMISP2_LED
> + tristate "Intel AtomISP2 camera LED driver"
> + depends on GPIOLIB && LEDS_GPIO
> + help
> + Many Bay Trail and Cherry Trail devices come with a camera attached
> + to Intel's Image Signal Processor. Linux currently does not have a
> + driver for these, so they do not work as a camera. Some of these
> + camera's have a LED which is controlled through a GPIO.
> +
> + Some of these devices have a firmware issue where the LED gets turned
> + on at boot. This driver will turn the LED off at boot and also allows
> + controlling the LED (repurposing it) through the sysfs LED interface.
> +
> + Which GPIO is attached to the LED is usually not described in the
> + ACPI tables, so this driver contains per-system info about the GPIO
> + inside the driver, this means that this driver only works on systems
> + the driver knows about.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called intel_atomisp2_led.
> +
> config INTEL_CHT_INT33FE
> tristate "Intel Cherry Trail ACPI INT33FE Driver"
> depends on X86 && ACPI && I2C && REGULATOR
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 2b85852a1a87..7a78cc0bb249 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -70,6 +70,7 @@ obj-$(CONFIG_THINKPAD_ACPI) += thinkpad_acpi.o
>
> # Intel
> obj-$(CONFIG_INTEL_ATOMISP2_PM) += intel_atomisp2_pm.o
> +obj-$(CONFIG_INTEL_ATOMISP2_LED) += intel_atomisp2_led.o
> obj-$(CONFIG_INTEL_CHT_INT33FE) += intel_cht_int33fe.o
> intel_cht_int33fe-objs := intel_cht_int33fe_common.o \
> intel_cht_int33fe_typec.o \
> diff --git a/drivers/platform/x86/intel_atomisp2_led.c b/drivers/platform/x86/intel_atomisp2_led.c
> new file mode 100644
> index 000000000000..5935dfca166f
> --- /dev/null
> +++ b/drivers/platform/x86/intel_atomisp2_led.c
> @@ -0,0 +1,116 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Driver for controlling LEDs for cameras connected to the Intel atomisp2
> + * The main purpose of this driver is to turn off LEDs which are on at boot.
> + *
> + * Copyright (C) 2020 Hans de Goede <hdegoede@xxxxxxxxxx>
> + */
> +
> +#include <linux/dmi.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/gpio/machine.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +#include <linux/workqueue.h>
> +
> +/* This must be leds-gpio as the leds-gpio driver binds to the name */
> +#define DEV_NAME "leds-gpio"
> +
> +static const struct gpio_led atomisp2_leds[] = {
> + {
> + .name = "atomisp2::camera",
> + .default_state = LEDS_GPIO_DEFSTATE_OFF,
> + },
> +};
> +
> +static const struct gpio_led_platform_data atomisp2_leds_pdata = {
> + .num_leds = ARRAY_SIZE(atomisp2_leds),
> + .leds = atomisp2_leds,
> +};
> +
> +static struct gpiod_lookup_table asus_t100ta_lookup = {
> + .dev_id = DEV_NAME,
> + .table = {
> + GPIO_LOOKUP_IDX("INT33FC:02", 8, NULL, 0, GPIO_ACTIVE_HIGH),
> + { }
> + }
> +};
> +
> +static struct gpiod_lookup_table asus_t100chi_lookup = {
> + .dev_id = DEV_NAME,
> + .table = {
> + GPIO_LOOKUP_IDX("INT33FC:01", 24, NULL, 0, GPIO_ACTIVE_HIGH),
> + { }
> + }
> +};
> +
> +static const struct dmi_system_id atomisp2_led_systems[] __initconst = {
> + {
> + .matches = {
> + DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
> + DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T100TA"),
> + },
> + .driver_data = &asus_t100ta_lookup,
> + },
> + {
> + .matches = {
> + DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
> + DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T200TA"),
> + },
> + .driver_data = &asus_t100ta_lookup,
> + },
> + {
> + .matches = {
> + DMI_EXACT_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
> + DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T100CHI"),
> + },
> + .driver_data = &asus_t100chi_lookup,
> + },
> + {} /* Terminating entry */
> +};
> +MODULE_DEVICE_TABLE(dmi, atomisp2_led_systems);
> +
> +static struct gpiod_lookup_table *gpio_lookup;
> +static struct platform_device *pdev;
> +
> +static int __init atomisp2_led_init(void)
> +{
> + const struct dmi_system_id *system;
> +
> + system = dmi_first_match(atomisp2_led_systems);
> + if (!system)
> + return -ENODEV;
> +
> + gpio_lookup = system->driver_data;
> + gpiod_add_lookup_table(gpio_lookup);
> +
> + pdev = platform_device_register_resndata(NULL,
> + DEV_NAME, PLATFORM_DEVID_NONE,
> + NULL, 0, &atomisp2_leds_pdata,
> + sizeof(atomisp2_leds_pdata));
> + if (IS_ERR(pdev))
> + gpiod_remove_lookup_table(gpio_lookup);
> +
> + return PTR_ERR_OR_ZERO(pdev);
> +}
> +
> +static void __exit atomisp2_led_cleanup(void)
> +{
> + platform_device_unregister(pdev);
> + gpiod_remove_lookup_table(gpio_lookup);
> +}
> +
> +module_init(atomisp2_led_init);
> +module_exit(atomisp2_led_cleanup);
> +
> +/*
> + * The ACPI INIT method from Asus WMI's code on the T100TA and T200TA turns the
> + * LED on (without the WMI interface allowing further control over the LED).
> + * Ensure we are loaded after asus-nb-wmi so that we turn the LED off again.
> + */
> +MODULE_SOFTDEP("pre: asus_nb_wmi");
> +MODULE_AUTHOR("Hans de Goede <hdegoede@xxxxxxxxxx");
> +MODULE_DESCRIPTION("Intel atomisp2 camera LED driver");
> +MODULE_LICENSE("GPL");
> --
> 2.26.2
>
--
With Best Regards,
Andy Shevchenko
