Re: [PATCH 1/1] drivers/misc: Add Intel System ID driver

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Feb 15, 2017 at 07:09:41PM +0800, thloh wrote:
> From: "Loh, Tien Hock" <tien.hock.loh@intel.com>
> 
> This patch is to add Altera System ID driver.
> User can obtain the system ID and timestamp of the system by
> reading the sysfs entry.
> 
> Usage:
> cat /sys/bus/platform/devices/[addr].sysid/sysid/id
> cat /sys/bus/platform/devices/[addr].sysid/sysid/timestamp

If you add new sysfs attributes, you need to also add a
Documentation/ABI/ description as well.

> 
> Signed-off-by: Loh, Tien Hock <tien.hock.loh@intel.com>
> ---
>  drivers/misc/Kconfig       |    5 ++
>  drivers/misc/Makefile      |    1 +
>  drivers/misc/intel_sysid.c |  142 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 148 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/misc/intel_sysid.c
> 
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index b4d6aac..e5552fa 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -139,6 +139,11 @@ config INTEL_MID_PTI
>  	  an Intel Atom (non-netbook) mobile device containing a MIPI
>  	  P1149.7 standard implementation.
>  
> +config INTEL_SYSID
> +        tristate "Intel System ID"
> +        help
> +        This enables Intel System ID soft core driver.
> +
>  config SGI_IOC4
>  	tristate "SGI IOC4 Base IO support"
>  	depends on PCI
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> index 7a3ea89..24fe724 100644
> --- a/drivers/misc/Makefile
> +++ b/drivers/misc/Makefile
> @@ -43,6 +43,7 @@ obj-y				+= ti-st/
>  obj-y				+= lis3lv02d/
>  obj-$(CONFIG_USB_SWITCH_FSA9480) += fsa9480.o
>  obj-$(CONFIG_ALTERA_STAPL)	+=altera-stapl/
> +obj-$(CONFIG_INTEL_SYSID)       += intel_sysid.o
>  obj-$(CONFIG_INTEL_MEI)		+= mei/
>  obj-$(CONFIG_VMWARE_VMCI)	+= vmw_vmci/
>  obj-$(CONFIG_LATTICE_ECP3_CONFIG)	+= lattice-ecp3-config.o
> diff --git a/drivers/misc/intel_sysid.c b/drivers/misc/intel_sysid.c
> new file mode 100644
> index 0000000..1ef72b8
> --- /dev/null
> +++ b/drivers/misc/intel_sysid.c
> @@ -0,0 +1,142 @@
> +/*
> + * Copyright Intel Corporation (C) 2017.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
> + *
> + * Credit:
> + * Walter Goossens
> + */
> +
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#define DRV_NAME	"intel_sysid"
> +
> +struct intel_sysid {
> +	void __iomem		*regs;
> +};
> +
> +/* System ID Registers*/
> +#define SYSID_REG_ID		(0x0)
> +#define SYSID_REG_TIMESTAMP	(0x4)
> +
> +static ssize_t intel_sysid_show_id(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct intel_sysid *sysid = dev_get_drvdata(dev);
> +
> +	return sprintf(buf, "%u\n", readl(sysid->regs + SYSID_REG_ID));
> +}
> +
> +static ssize_t intel_sysid_show_timestamp(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	unsigned int reg;
> +	struct tm timestamp;
> +	struct intel_sysid *sysid = dev_get_drvdata(dev);
> +
> +	reg = readl(sysid->regs + SYSID_REG_TIMESTAMP);
> +
> +	time_to_tm(reg, 0, &timestamp);
> +
> +	return sprintf(buf, "%u (%u-%u-%u %u:%u:%u UTC)\n", reg,
> +		(unsigned int)(timestamp.tm_year + 1900),
> +		timestamp.tm_mon + 1, timestamp.tm_mday, timestamp.tm_hour,
> +		timestamp.tm_min, timestamp.tm_sec);
> +}
> +
> +static DEVICE_ATTR(id, S_IRUGO, intel_sysid_show_id, NULL);
> +static DEVICE_ATTR(timestamp, S_IRUGO, intel_sysid_show_timestamp, NULL);

DEVICE_ATTR_RO()?

> +static struct attribute *intel_sysid_attrs[] = {
> +	&dev_attr_id.attr,
> +	&dev_attr_timestamp.attr,
> +	NULL,
> +};
> +
> +struct attribute_group intel_sysid_attr_group = {
> +	.name = "sysid",
> +	.attrs = intel_sysid_attrs,
> +};

ATTRIBUTE_GROUP()?

thanks,

greg k-h