Re: [PATCH 1/2] introduce ALS sysfs class

[Jonathan Cameron <jic23@cam.ac.uk>]

Hi Amit,

Sorry, NAK from me for this. We still need to get the registration
code switched to handling allocation of numbers etc in here rather
than in the drivers. If needed I can propose a patch to do that but
it will Saturday at the earliest before I get to it.

For references on this see for example Jean's comments on the tsl2550
port http://lkml.org/lkml/2009/10/10/127
and also the thread leading to
http://lkml.org/lkml/2009/11/10/63

Everything else is fine.

Jonathan
> 
> This is a refresh of the ALS sysfs class driver.
> 
> ALS sysfs class device provides a standard sysfs interface
> for Ambient Light Sensor devices.
> 
> Only one sysfs I/F is introduced currently.
> /sys/class/als/xxx/illuminance:
> 	indicates the amount of light incident upon a specified surface area.
> 
> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
> Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
> Acked-by: Amit Kucheria <amit.kucheria@verdurent.com>
> ---
>  Documentation/ABI/testing/sysfs-class-als |    9 ++++
>  MAINTAINERS                               |    6 ++
>  drivers/Kconfig                           |    2 +
>  drivers/Makefile                          |    1 +
>  drivers/als/Kconfig                       |   10 ++++
>  drivers/als/Makefile                      |    5 ++
>  drivers/als/als_sys.c                     |   74 +++++++++++++++++++++++++++++
>  include/linux/als_sys.h                   |   35 ++++++++++++++
>  8 files changed, 142 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-class-als
>  create mode 100644 drivers/als/Kconfig
>  create mode 100644 drivers/als/Makefile
>  create mode 100644 drivers/als/als_sys.c
>  create mode 100644 include/linux/als_sys.h
> 
> diff --git a/Documentation/ABI/testing/sysfs-class-als b/Documentation/ABI/testing/sysfs-class-als
> new file mode 100644
> index 0000000..d3b33f3
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-als
> @@ -0,0 +1,9 @@
> +What:		/sys/class/als/.../illuminance
> +Date:		Sep. 2009
> +KernelVersion:	2.6.32
> +Contact:	Zhang Rui <rui.zhang@intel.com>
> +Description:	Current Ambient Light Illuminance reported by
> +		native ALS driver
> +		Unit: lux (lumens per square meter)
> +		RO
> +
> diff --git a/MAINTAINERS b/MAINTAINERS
> index c824b4d..0894a1c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -409,6 +409,12 @@ S:	Maintained for 2.4; PCI support for 2.6.
>  L:	linux-alpha@vger.kernel.org
>  F:	arch/alpha/
>  
> +AMBIENT LIGHT SENSOR
> +M:	Zhang Rui <rui.zhang@intel.com>
> +S:	Supported
> +F:	include/linux/als_sys.h
> +F:	drivers/als/
> +
>  AMD GEODE CS5536 USB DEVICE CONTROLLER DRIVER
>  M:	Thomas Dahlmann <dahlmann.thomas@arcor.de>
>  L:	linux-geode@lists.infradead.org (moderated for non-subscribers)
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 48bbdbe..67cf884 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -62,6 +62,8 @@ source "drivers/power/Kconfig"
>  
>  source "drivers/hwmon/Kconfig"
>  
> +source "drivers/als/Kconfig"
> +
>  source "drivers/thermal/Kconfig"
>  
>  source "drivers/watchdog/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 6ee53c7..ecb6d5d 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -77,6 +77,7 @@ obj-$(CONFIG_PPS)		+= pps/
>  obj-$(CONFIG_W1)		+= w1/
>  obj-$(CONFIG_POWER_SUPPLY)	+= power/
>  obj-$(CONFIG_HWMON)		+= hwmon/
> +obj-$(CONFIG_ALS)		+= als/
>  obj-$(CONFIG_THERMAL)		+= thermal/
>  obj-$(CONFIG_WATCHDOG)		+= watchdog/
>  obj-$(CONFIG_PHONE)		+= telephony/
> diff --git a/drivers/als/Kconfig b/drivers/als/Kconfig
> new file mode 100644
> index 0000000..200c52b
> --- /dev/null
> +++ b/drivers/als/Kconfig
> @@ -0,0 +1,10 @@
> +#
> +# Ambient Light Sensor sysfs device configuration
> +#
> +
> +menuconfig ALS
> +	tristate "Ambient Light Sensor sysfs device"
> +	help
> +	  This framework provides a generic sysfs I/F for Ambient Light
> +	  Sensor devices.
> +	  If you want this support, you should say Y or M here.
> diff --git a/drivers/als/Makefile b/drivers/als/Makefile
> new file mode 100644
> index 0000000..a527197
> --- /dev/null
> +++ b/drivers/als/Makefile
> @@ -0,0 +1,5 @@
> +#
> +# Makefile for sensor chip drivers.
> +#
> +
> +obj-$(CONFIG_ALS)		+= als_sys.o
> diff --git a/drivers/als/als_sys.c b/drivers/als/als_sys.c
> new file mode 100644
> index 0000000..e1d6395
> --- /dev/null
> +++ b/drivers/als/als_sys.c
> @@ -0,0 +1,74 @@
> +/*
> + *  als_sys.c - Ambient Light Sensor Sysfs support.
> + *
> + *  Copyright (C) 2009 Intel Corp
> + *  Copyright (C) 2009 Zhang Rui <rui.zhang@intel.com>
> + *
> + *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; version 2 of the License.
> + *
> + *  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.
> + *
> + *  You should have received a copy of the GNU General Public License along
> + *  with this program; if not, write to the Free Software Foundation, Inc.,
> + *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + */
> +
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/kdev_t.h>
> +
> +MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
> +MODULE_DESCRIPTION("Ambient Light Sensor sysfs/class support");
> +MODULE_LICENSE("GPL");
> +
> +static struct class *als_class;
> +
> +/**
> + * als_device_register - register a new Ambient Light Sensor class device
> + * @parent:	the device to register.
> + *
> + * Returns the pointer to the new device
> + */
> +struct device *als_device_register(struct device *dev, char *name)
> +{
> +	return device_create(als_class, dev, MKDEV(0, 0), NULL, name);
> +}
> +EXPORT_SYMBOL(als_device_register);
> +
> +/**
> + * als_device_unregister - removes the registered ALS class device
> + * @dev:	the class device to destroy.
> + */
> +void als_device_unregister(struct device *dev)
> +{
> +	device_unregister(dev);
> +}
> +EXPORT_SYMBOL(als_device_unregister);
> +
> +static int __init als_init(void)
> +{
> +	als_class = class_create(THIS_MODULE, "als");
> +	if (IS_ERR(als_class)) {
> +		printk(KERN_ERR "als_sys.c: couldn't create sysfs class\n");
> +		return PTR_ERR(als_class);
> +	}
> +	return 0;
> +}
> +
> +static void __exit als_exit(void)
> +{
> +	class_destroy(als_class);
> +}
> +
> +subsys_initcall(als_init);
> +module_exit(als_exit);
> diff --git a/include/linux/als_sys.h b/include/linux/als_sys.h
> new file mode 100644
> index 0000000..500f300
> --- /dev/null
> +++ b/include/linux/als_sys.h
> @@ -0,0 +1,35 @@
> +/*
> + *  als_sys.h
> + *
> + *  Copyright (C) 2009  Intel Corp
> + *  Copyright (C) 2009  Zhang Rui <rui.zhang@intel.com>
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; version 2 of the License.
> + *
> + *  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.
> + *
> + *  You should have received a copy of the GNU General Public License along
> + *  with this program; if not, write to the Free Software Foundation, Inc.,
> + *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + */
> +
> +#ifndef __ALS_SYS_H__
> +#define __ALS_SYS_H__
> +
> +#include <linux/device.h>
> +
> +#define ALS_ILLUMINANCE_MIN 0
> +#define ALS_ILLUMINANCE_MAX -1
> +
> +struct device *als_device_register(struct device *dev, char *name);
> +void als_device_unregister(struct device *dev);
> +
> +#endif /* __ALS_SYS_H__ */