diff mbox series

[v7,08/12] mfd: intel-peci-client: Add PECI client MFD driver

Message ID 20180723214751.1733-9-jae.hyun.yoo@linux.intel.com
State Not Applicable, archived
Headers show
Series PECI device driver introduction | expand

Commit Message

Jae Hyun Yoo July 23, 2018, 9:47 p.m. UTC
This commit adds PECI client MFD driver.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: James Feist <james.feist@linux.intel.com>
Cc: Jason M Biils <jason.m.bills@linux.intel.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Vernon Mauery <vernon.mauery@linux.intel.com>
---
 drivers/mfd/Kconfig                   |  14 ++
 drivers/mfd/Makefile                  |   1 +
 drivers/mfd/intel-peci-client.c       | 182 ++++++++++++++++++++++++++
 include/linux/mfd/intel-peci-client.h |  81 ++++++++++++
 4 files changed, 278 insertions(+)
 create mode 100644 drivers/mfd/intel-peci-client.c
 create mode 100644 include/linux/mfd/intel-peci-client.h

Comments

Randy Dunlap July 23, 2018, 10:21 p.m. UTC | #1
On 07/23/2018 02:47 PM, Jae Hyun Yoo wrote:
> This commit adds PECI client MFD driver.
> 
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Andrew Jeffery <andrew@aj.id.au>
> Cc: James Feist <james.feist@linux.intel.com>
> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
> Cc: Joel Stanley <joel@jms.id.au>
> Cc: Vernon Mauery <vernon.mauery@linux.intel.com>
> ---
>  drivers/mfd/Kconfig                   |  14 ++
>  drivers/mfd/Makefile                  |   1 +
>  drivers/mfd/intel-peci-client.c       | 182 ++++++++++++++++++++++++++
>  include/linux/mfd/intel-peci-client.h |  81 ++++++++++++
>  4 files changed, 278 insertions(+)
>  create mode 100644 drivers/mfd/intel-peci-client.c
>  create mode 100644 include/linux/mfd/intel-peci-client.h
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index f3fa516011ec..e38b591479d4 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -595,6 +595,20 @@ config MFD_INTEL_MSIC
>  	  Passage) chip. This chip embeds audio, battery, GPIO, etc.
>  	  devices used in Intel Medfield platforms.
>  
> +config MFD_INTEL_PECI_CLIENT
> +	bool "Intel PECI client"
> +	depends on (PECI || COMPILE_TEST)
> +	select MFD_CORE
> +	help
> +	  If you say yes to this option, support will be included for the
> +	  multi-funtional Intel PECI (Platform Environment Control Interface)

	  multi-functional

> +	  client. PECI is a one-wire bus interface that provides a communication
> +	  channel from PECI clients in Intel processors and chipset components
> +	  to external monitoring or control devices.
> +
> +	  Additional drivers must be enabled in order to use the functionality
> +	  of the device.
> +
>  config MFD_IPAQ_MICRO
>  	bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
>  	depends on SA1100_H3100 || SA1100_H3600
Jae Hyun Yoo July 23, 2018, 10:36 p.m. UTC | #2
Hi Randy,

On 7/23/2018 3:21 PM, Randy Dunlap wrote:
> On 07/23/2018 02:47 PM, Jae Hyun Yoo wrote:
>> This commit adds PECI client MFD driver.
>>
>> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
>> Cc: Lee Jones <lee.jones@linaro.org>
>> Cc: Rob Herring <robh+dt@kernel.org>
>> Cc: Andrew Jeffery <andrew@aj.id.au>
>> Cc: James Feist <james.feist@linux.intel.com>
>> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
>> Cc: Joel Stanley <joel@jms.id.au>
>> Cc: Vernon Mauery <vernon.mauery@linux.intel.com>
>> ---
>>   drivers/mfd/Kconfig                   |  14 ++
>>   drivers/mfd/Makefile                  |   1 +
>>   drivers/mfd/intel-peci-client.c       | 182 ++++++++++++++++++++++++++
>>   include/linux/mfd/intel-peci-client.h |  81 ++++++++++++
>>   4 files changed, 278 insertions(+)
>>   create mode 100644 drivers/mfd/intel-peci-client.c
>>   create mode 100644 include/linux/mfd/intel-peci-client.h
>>
>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index f3fa516011ec..e38b591479d4 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -595,6 +595,20 @@ config MFD_INTEL_MSIC
>>   	  Passage) chip. This chip embeds audio, battery, GPIO, etc.
>>   	  devices used in Intel Medfield platforms.
>>   
>> +config MFD_INTEL_PECI_CLIENT
>> +	bool "Intel PECI client"
>> +	depends on (PECI || COMPILE_TEST)
>> +	select MFD_CORE
>> +	help
>> +	  If you say yes to this option, support will be included for the
>> +	  multi-funtional Intel PECI (Platform Environment Control Interface)
> 
> 	  multi-functional
> 

Thanks for your pointing it out. Will fix it.

Thanks,

Jae

>> +	  client. PECI is a one-wire bus interface that provides a communication
>> +	  channel from PECI clients in Intel processors and chipset components
>> +	  to external monitoring or control devices.
>> +
>> +	  Additional drivers must be enabled in order to use the functionality
>> +	  of the device.
>> +
>>   config MFD_IPAQ_MICRO
>>   	bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
>>   	depends on SA1100_H3100 || SA1100_H3600
> 
>
Lee Jones July 27, 2018, 8:26 a.m. UTC | #3
On Mon, 23 Jul 2018, Jae Hyun Yoo wrote:

> This commit adds PECI client MFD driver.
> 
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Andrew Jeffery <andrew@aj.id.au>
> Cc: James Feist <james.feist@linux.intel.com>
> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
> Cc: Joel Stanley <joel@jms.id.au>
> Cc: Vernon Mauery <vernon.mauery@linux.intel.com>
> ---
>  drivers/mfd/Kconfig                   |  14 ++
>  drivers/mfd/Makefile                  |   1 +
>  drivers/mfd/intel-peci-client.c       | 182 ++++++++++++++++++++++++++
>  include/linux/mfd/intel-peci-client.h |  81 ++++++++++++
>  4 files changed, 278 insertions(+)
>  create mode 100644 drivers/mfd/intel-peci-client.c
>  create mode 100644 include/linux/mfd/intel-peci-client.h
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index f3fa516011ec..e38b591479d4 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -595,6 +595,20 @@ config MFD_INTEL_MSIC
>  	  Passage) chip. This chip embeds audio, battery, GPIO, etc.
>  	  devices used in Intel Medfield platforms.
>  
> +config MFD_INTEL_PECI_CLIENT
> +	bool "Intel PECI client"
> +	depends on (PECI || COMPILE_TEST)
> +	select MFD_CORE
> +	help
> +	  If you say yes to this option, support will be included for the
> +	  multi-funtional Intel PECI (Platform Environment Control Interface)
> +	  client. PECI is a one-wire bus interface that provides a communication
> +	  channel from PECI clients in Intel processors and chipset components
> +	  to external monitoring or control devices.
> +
> +	  Additional drivers must be enabled in order to use the functionality
> +	  of the device.
> +
>  config MFD_IPAQ_MICRO
>  	bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
>  	depends on SA1100_H3100 || SA1100_H3600
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 2852a6042ecf..29e2cacc58bd 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -203,6 +203,7 @@ obj-$(CONFIG_MFD_INTEL_LPSS)	+= intel-lpss.o
>  obj-$(CONFIG_MFD_INTEL_LPSS_PCI)	+= intel-lpss-pci.o
>  obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)	+= intel-lpss-acpi.o
>  obj-$(CONFIG_MFD_INTEL_MSIC)	+= intel_msic.o
> +obj-$(CONFIG_MFD_INTEL_PECI_CLIENT)	+= intel-peci-client.o
>  obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
>  obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
>  obj-$(CONFIG_MFD_RC5T583)	+= rc5t583.o rc5t583-irq.o
> diff --git a/drivers/mfd/intel-peci-client.c b/drivers/mfd/intel-peci-client.c
> new file mode 100644
> index 000000000000..d7702cf1ea50
> --- /dev/null
> +++ b/drivers/mfd/intel-peci-client.c
> @@ -0,0 +1,182 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2018 Intel Corporation
> +
> +#include <linux/bitfield.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/intel-peci-client.h>
> +#include <linux/module.h>
> +#include <linux/peci.h>
> +#include <linux/of_device.h>
> +
> +enum cpu_gens {
> +	CPU_GEN_HSX = 0, /* Haswell Xeon */
> +	CPU_GEN_BRX,     /* Broadwell Xeon */
> +	CPU_GEN_SKX,     /* Skylake Xeon */
> +};
> +
> +static struct mfd_cell peci_functions[] = {
> +	{
> +		.name = "peci-cputemp",
> +		.of_compatible = "intel,peci-cputemp",
> +	},
> +	{
> +		.name = "peci-dimmtemp",
> +		.of_compatible = "intel,peci-dimmtemp",
> +	},
> +};

The more I look at this driver, the less I think it fits into MFD.

What's stopping you from registering these devices directly from DT?
Jae Hyun Yoo July 27, 2018, 5:36 p.m. UTC | #4
Hi Lee,

On 7/27/2018 1:26 AM, Lee Jones wrote:
> On Mon, 23 Jul 2018, Jae Hyun Yoo wrote:
> 
>> This commit adds PECI client MFD driver.
>>
>> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
>> Cc: Lee Jones <lee.jones@linaro.org>
>> Cc: Rob Herring <robh+dt@kernel.org>
>> Cc: Andrew Jeffery <andrew@aj.id.au>
>> Cc: James Feist <james.feist@linux.intel.com>
>> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
>> Cc: Joel Stanley <joel@jms.id.au>
>> Cc: Vernon Mauery <vernon.mauery@linux.intel.com>
>> ---
>>   drivers/mfd/Kconfig                   |  14 ++
>>   drivers/mfd/Makefile                  |   1 +
>>   drivers/mfd/intel-peci-client.c       | 182 ++++++++++++++++++++++++++
>>   include/linux/mfd/intel-peci-client.h |  81 ++++++++++++
>>   4 files changed, 278 insertions(+)
>>   create mode 100644 drivers/mfd/intel-peci-client.c
>>   create mode 100644 include/linux/mfd/intel-peci-client.h
>>
>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index f3fa516011ec..e38b591479d4 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -595,6 +595,20 @@ config MFD_INTEL_MSIC
>>   	  Passage) chip. This chip embeds audio, battery, GPIO, etc.
>>   	  devices used in Intel Medfield platforms.
>>   
>> +config MFD_INTEL_PECI_CLIENT
>> +	bool "Intel PECI client"
>> +	depends on (PECI || COMPILE_TEST)
>> +	select MFD_CORE
>> +	help
>> +	  If you say yes to this option, support will be included for the
>> +	  multi-funtional Intel PECI (Platform Environment Control Interface)
>> +	  client. PECI is a one-wire bus interface that provides a communication
>> +	  channel from PECI clients in Intel processors and chipset components
>> +	  to external monitoring or control devices.
>> +
>> +	  Additional drivers must be enabled in order to use the functionality
>> +	  of the device.
>> +
>>   config MFD_IPAQ_MICRO
>>   	bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
>>   	depends on SA1100_H3100 || SA1100_H3600
>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>> index 2852a6042ecf..29e2cacc58bd 100644
>> --- a/drivers/mfd/Makefile
>> +++ b/drivers/mfd/Makefile
>> @@ -203,6 +203,7 @@ obj-$(CONFIG_MFD_INTEL_LPSS)	+= intel-lpss.o
>>   obj-$(CONFIG_MFD_INTEL_LPSS_PCI)	+= intel-lpss-pci.o
>>   obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)	+= intel-lpss-acpi.o
>>   obj-$(CONFIG_MFD_INTEL_MSIC)	+= intel_msic.o
>> +obj-$(CONFIG_MFD_INTEL_PECI_CLIENT)	+= intel-peci-client.o
>>   obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
>>   obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
>>   obj-$(CONFIG_MFD_RC5T583)	+= rc5t583.o rc5t583-irq.o
>> diff --git a/drivers/mfd/intel-peci-client.c b/drivers/mfd/intel-peci-client.c
>> new file mode 100644
>> index 000000000000..d7702cf1ea50
>> --- /dev/null
>> +++ b/drivers/mfd/intel-peci-client.c
>> @@ -0,0 +1,182 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Copyright (c) 2018 Intel Corporation
>> +
>> +#include <linux/bitfield.h>
>> +#include <linux/mfd/core.h>
>> +#include <linux/mfd/intel-peci-client.h>
>> +#include <linux/module.h>
>> +#include <linux/peci.h>
>> +#include <linux/of_device.h>
>> +
>> +enum cpu_gens {
>> +	CPU_GEN_HSX = 0, /* Haswell Xeon */
>> +	CPU_GEN_BRX,     /* Broadwell Xeon */
>> +	CPU_GEN_SKX,     /* Skylake Xeon */
>> +};
>> +
>> +static struct mfd_cell peci_functions[] = {
>> +	{
>> +		.name = "peci-cputemp",
>> +		.of_compatible = "intel,peci-cputemp",
>> +	},
>> +	{
>> +		.name = "peci-dimmtemp",
>> +		.of_compatible = "intel,peci-dimmtemp",
>> +	},
>> +};
> 
> The more I look at this driver, the less I think it fits into MFD.
> 
> What's stopping you from registering these devices directly from DT?
> 

Because DT doesn't allow 2 nodes at the same address so Rob suggested
MFD for this case.

Thanks,

Jae
Rob Herring July 30, 2018, 10:10 p.m. UTC | #5
On Fri, Jul 27, 2018 at 11:36 AM Jae Hyun Yoo
<jae.hyun.yoo@linux.intel.com> wrote:
>
> Hi Lee,
>
> On 7/27/2018 1:26 AM, Lee Jones wrote:
> > On Mon, 23 Jul 2018, Jae Hyun Yoo wrote:
> >
> >> This commit adds PECI client MFD driver.
> >>
> >> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> >> Cc: Lee Jones <lee.jones@linaro.org>
> >> Cc: Rob Herring <robh+dt@kernel.org>
> >> Cc: Andrew Jeffery <andrew@aj.id.au>
> >> Cc: James Feist <james.feist@linux.intel.com>
> >> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
> >> Cc: Joel Stanley <joel@jms.id.au>
> >> Cc: Vernon Mauery <vernon.mauery@linux.intel.com>
> >> ---
> >>   drivers/mfd/Kconfig                   |  14 ++
> >>   drivers/mfd/Makefile                  |   1 +
> >>   drivers/mfd/intel-peci-client.c       | 182 ++++++++++++++++++++++++++
> >>   include/linux/mfd/intel-peci-client.h |  81 ++++++++++++
> >>   4 files changed, 278 insertions(+)
> >>   create mode 100644 drivers/mfd/intel-peci-client.c
> >>   create mode 100644 include/linux/mfd/intel-peci-client.h
> >>
> >> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> >> index f3fa516011ec..e38b591479d4 100644
> >> --- a/drivers/mfd/Kconfig
> >> +++ b/drivers/mfd/Kconfig
> >> @@ -595,6 +595,20 @@ config MFD_INTEL_MSIC
> >>        Passage) chip. This chip embeds audio, battery, GPIO, etc.
> >>        devices used in Intel Medfield platforms.
> >>
> >> +config MFD_INTEL_PECI_CLIENT
> >> +    bool "Intel PECI client"
> >> +    depends on (PECI || COMPILE_TEST)
> >> +    select MFD_CORE
> >> +    help
> >> +      If you say yes to this option, support will be included for the
> >> +      multi-funtional Intel PECI (Platform Environment Control Interface)
> >> +      client. PECI is a one-wire bus interface that provides a communication
> >> +      channel from PECI clients in Intel processors and chipset components
> >> +      to external monitoring or control devices.
> >> +
> >> +      Additional drivers must be enabled in order to use the functionality
> >> +      of the device.
> >> +
> >>   config MFD_IPAQ_MICRO
> >>      bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
> >>      depends on SA1100_H3100 || SA1100_H3600
> >> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> >> index 2852a6042ecf..29e2cacc58bd 100644
> >> --- a/drivers/mfd/Makefile
> >> +++ b/drivers/mfd/Makefile
> >> @@ -203,6 +203,7 @@ obj-$(CONFIG_MFD_INTEL_LPSS)     += intel-lpss.o
> >>   obj-$(CONFIG_MFD_INTEL_LPSS_PCI)   += intel-lpss-pci.o
> >>   obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)  += intel-lpss-acpi.o
> >>   obj-$(CONFIG_MFD_INTEL_MSIC)       += intel_msic.o
> >> +obj-$(CONFIG_MFD_INTEL_PECI_CLIENT) += intel-peci-client.o
> >>   obj-$(CONFIG_MFD_PALMAS)   += palmas.o
> >>   obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
> >>   obj-$(CONFIG_MFD_RC5T583)  += rc5t583.o rc5t583-irq.o
> >> diff --git a/drivers/mfd/intel-peci-client.c b/drivers/mfd/intel-peci-client.c
> >> new file mode 100644
> >> index 000000000000..d7702cf1ea50
> >> --- /dev/null
> >> +++ b/drivers/mfd/intel-peci-client.c
> >> @@ -0,0 +1,182 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +// Copyright (c) 2018 Intel Corporation
> >> +
> >> +#include <linux/bitfield.h>
> >> +#include <linux/mfd/core.h>
> >> +#include <linux/mfd/intel-peci-client.h>
> >> +#include <linux/module.h>
> >> +#include <linux/peci.h>
> >> +#include <linux/of_device.h>
> >> +
> >> +enum cpu_gens {
> >> +    CPU_GEN_HSX = 0, /* Haswell Xeon */
> >> +    CPU_GEN_BRX,     /* Broadwell Xeon */
> >> +    CPU_GEN_SKX,     /* Skylake Xeon */
> >> +};
> >> +
> >> +static struct mfd_cell peci_functions[] = {
> >> +    {
> >> +            .name = "peci-cputemp",
> >> +            .of_compatible = "intel,peci-cputemp",
> >> +    },
> >> +    {
> >> +            .name = "peci-dimmtemp",
> >> +            .of_compatible = "intel,peci-dimmtemp",
> >> +    },
> >> +};
> >
> > The more I look at this driver, the less I think it fits into MFD.
> >
> > What's stopping you from registering these devices directly from DT?
> >
>
> Because DT doesn't allow 2 nodes at the same address so Rob suggested
> MFD for this case.

Only after I first suggested you create cpu and dimm sensors from a
single hwmon driver. Perhaps you should figure out how to fix the
problem with delayed registration. Perhaps you can register the
sensor, but just delay returning actual data until it is ready.

Rob
Jae Hyun Yoo July 30, 2018, 11:15 p.m. UTC | #6
Hi Rob,

On 7/30/2018 3:10 PM, Rob Herring wrote:
> On Fri, Jul 27, 2018 at 11:36 AM Jae Hyun Yoo
> <jae.hyun.yoo@linux.intel.com> wrote:
>>
>> Hi Lee,
>>
>> On 7/27/2018 1:26 AM, Lee Jones wrote:
>>> On Mon, 23 Jul 2018, Jae Hyun Yoo wrote:
>>>
>>>> This commit adds PECI client MFD driver.
>>>>
>>>> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
>>>> Cc: Lee Jones <lee.jones@linaro.org>
>>>> Cc: Rob Herring <robh+dt@kernel.org>
>>>> Cc: Andrew Jeffery <andrew@aj.id.au>
>>>> Cc: James Feist <james.feist@linux.intel.com>
>>>> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
>>>> Cc: Joel Stanley <joel@jms.id.au>
>>>> Cc: Vernon Mauery <vernon.mauery@linux.intel.com>
>>>> ---
>>>>    drivers/mfd/Kconfig                   |  14 ++
>>>>    drivers/mfd/Makefile                  |   1 +
>>>>    drivers/mfd/intel-peci-client.c       | 182 ++++++++++++++++++++++++++
>>>>    include/linux/mfd/intel-peci-client.h |  81 ++++++++++++
>>>>    4 files changed, 278 insertions(+)
>>>>    create mode 100644 drivers/mfd/intel-peci-client.c
>>>>    create mode 100644 include/linux/mfd/intel-peci-client.h
>>>>
>>>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>>>> index f3fa516011ec..e38b591479d4 100644
>>>> --- a/drivers/mfd/Kconfig
>>>> +++ b/drivers/mfd/Kconfig
>>>> @@ -595,6 +595,20 @@ config MFD_INTEL_MSIC
>>>>         Passage) chip. This chip embeds audio, battery, GPIO, etc.
>>>>         devices used in Intel Medfield platforms.
>>>>
>>>> +config MFD_INTEL_PECI_CLIENT
>>>> +    bool "Intel PECI client"
>>>> +    depends on (PECI || COMPILE_TEST)
>>>> +    select MFD_CORE
>>>> +    help
>>>> +      If you say yes to this option, support will be included for the
>>>> +      multi-funtional Intel PECI (Platform Environment Control Interface)
>>>> +      client. PECI is a one-wire bus interface that provides a communication
>>>> +      channel from PECI clients in Intel processors and chipset components
>>>> +      to external monitoring or control devices.
>>>> +
>>>> +      Additional drivers must be enabled in order to use the functionality
>>>> +      of the device.
>>>> +
>>>>    config MFD_IPAQ_MICRO
>>>>       bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
>>>>       depends on SA1100_H3100 || SA1100_H3600
>>>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>>>> index 2852a6042ecf..29e2cacc58bd 100644
>>>> --- a/drivers/mfd/Makefile
>>>> +++ b/drivers/mfd/Makefile
>>>> @@ -203,6 +203,7 @@ obj-$(CONFIG_MFD_INTEL_LPSS)     += intel-lpss.o
>>>>    obj-$(CONFIG_MFD_INTEL_LPSS_PCI)   += intel-lpss-pci.o
>>>>    obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)  += intel-lpss-acpi.o
>>>>    obj-$(CONFIG_MFD_INTEL_MSIC)       += intel_msic.o
>>>> +obj-$(CONFIG_MFD_INTEL_PECI_CLIENT) += intel-peci-client.o
>>>>    obj-$(CONFIG_MFD_PALMAS)   += palmas.o
>>>>    obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
>>>>    obj-$(CONFIG_MFD_RC5T583)  += rc5t583.o rc5t583-irq.o
>>>> diff --git a/drivers/mfd/intel-peci-client.c b/drivers/mfd/intel-peci-client.c
>>>> new file mode 100644
>>>> index 000000000000..d7702cf1ea50
>>>> --- /dev/null
>>>> +++ b/drivers/mfd/intel-peci-client.c
>>>> @@ -0,0 +1,182 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +// Copyright (c) 2018 Intel Corporation
>>>> +
>>>> +#include <linux/bitfield.h>
>>>> +#include <linux/mfd/core.h>
>>>> +#include <linux/mfd/intel-peci-client.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/peci.h>
>>>> +#include <linux/of_device.h>
>>>> +
>>>> +enum cpu_gens {
>>>> +    CPU_GEN_HSX = 0, /* Haswell Xeon */
>>>> +    CPU_GEN_BRX,     /* Broadwell Xeon */
>>>> +    CPU_GEN_SKX,     /* Skylake Xeon */
>>>> +};
>>>> +
>>>> +static struct mfd_cell peci_functions[] = {
>>>> +    {
>>>> +            .name = "peci-cputemp",
>>>> +            .of_compatible = "intel,peci-cputemp",
>>>> +    },
>>>> +    {
>>>> +            .name = "peci-dimmtemp",
>>>> +            .of_compatible = "intel,peci-dimmtemp",
>>>> +    },
>>>> +};
>>>
>>> The more I look at this driver, the less I think it fits into MFD.
>>>
>>> What's stopping you from registering these devices directly from DT?
>>>
>>
>> Because DT doesn't allow 2 nodes at the same address so Rob suggested
>> MFD for this case.
> 
> Only after I first suggested you create cpu and dimm sensors from a
> single hwmon driver. Perhaps you should figure out how to fix the
> problem with delayed registration. Perhaps you can register the
> sensor, but just delay returning actual data until it is ready.
> 

The actual reason why I divided the single hwmon driver into two is for
using recommended hwmon API set which doesn't allow incremental
creation of sysfs attributes at run time - using of
'devm_hwmon_device_register_with_info' is suggested by Guenter instead
of using other deprecated APIs.

The reason why the delayed registration is needed is, BMC kernel cannot
know how many DIMM are installed in remote machine before the machine
completing memory training and testing in POST. So dimm temp driver
cannot create hwmon attributes in advance.

My thought is, this way is the best to address these requirements.

Thanks,

Jae

> Rob
>
Lee Jones July 31, 2018, 7:01 a.m. UTC | #7
On Mon, 30 Jul 2018, Jae Hyun Yoo wrote:

> Hi Rob,
> 
> On 7/30/2018 3:10 PM, Rob Herring wrote:
> > On Fri, Jul 27, 2018 at 11:36 AM Jae Hyun Yoo
> > <jae.hyun.yoo@linux.intel.com> wrote:
> > > 
> > > Hi Lee,
> > > 
> > > On 7/27/2018 1:26 AM, Lee Jones wrote:
> > > > On Mon, 23 Jul 2018, Jae Hyun Yoo wrote:
> > > > 
> > > > > This commit adds PECI client MFD driver.
> > > > > 
> > > > > Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> > > > > Cc: Lee Jones <lee.jones@linaro.org>
> > > > > Cc: Rob Herring <robh+dt@kernel.org>
> > > > > Cc: Andrew Jeffery <andrew@aj.id.au>
> > > > > Cc: James Feist <james.feist@linux.intel.com>
> > > > > Cc: Jason M Biils <jason.m.bills@linux.intel.com>
> > > > > Cc: Joel Stanley <joel@jms.id.au>
> > > > > Cc: Vernon Mauery <vernon.mauery@linux.intel.com>
> > > > > ---
> > > > >    drivers/mfd/Kconfig                   |  14 ++
> > > > >    drivers/mfd/Makefile                  |   1 +
> > > > >    drivers/mfd/intel-peci-client.c       | 182 ++++++++++++++++++++++++++
> > > > >    include/linux/mfd/intel-peci-client.h |  81 ++++++++++++
> > > > >    4 files changed, 278 insertions(+)
> > > > >    create mode 100644 drivers/mfd/intel-peci-client.c
> > > > >    create mode 100644 include/linux/mfd/intel-peci-client.h
> > > > > 
> > > > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > > > > index f3fa516011ec..e38b591479d4 100644
> > > > > --- a/drivers/mfd/Kconfig
> > > > > +++ b/drivers/mfd/Kconfig
> > > > > @@ -595,6 +595,20 @@ config MFD_INTEL_MSIC
> > > > >         Passage) chip. This chip embeds audio, battery, GPIO, etc.
> > > > >         devices used in Intel Medfield platforms.
> > > > > 
> > > > > +config MFD_INTEL_PECI_CLIENT
> > > > > +    bool "Intel PECI client"
> > > > > +    depends on (PECI || COMPILE_TEST)
> > > > > +    select MFD_CORE
> > > > > +    help
> > > > > +      If you say yes to this option, support will be included for the
> > > > > +      multi-funtional Intel PECI (Platform Environment Control Interface)
> > > > > +      client. PECI is a one-wire bus interface that provides a communication
> > > > > +      channel from PECI clients in Intel processors and chipset components
> > > > > +      to external monitoring or control devices.
> > > > > +
> > > > > +      Additional drivers must be enabled in order to use the functionality
> > > > > +      of the device.
> > > > > +
> > > > >    config MFD_IPAQ_MICRO
> > > > >       bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
> > > > >       depends on SA1100_H3100 || SA1100_H3600
> > > > > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> > > > > index 2852a6042ecf..29e2cacc58bd 100644
> > > > > --- a/drivers/mfd/Makefile
> > > > > +++ b/drivers/mfd/Makefile
> > > > > @@ -203,6 +203,7 @@ obj-$(CONFIG_MFD_INTEL_LPSS)     += intel-lpss.o
> > > > >    obj-$(CONFIG_MFD_INTEL_LPSS_PCI)   += intel-lpss-pci.o
> > > > >    obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)  += intel-lpss-acpi.o
> > > > >    obj-$(CONFIG_MFD_INTEL_MSIC)       += intel_msic.o
> > > > > +obj-$(CONFIG_MFD_INTEL_PECI_CLIENT) += intel-peci-client.o
> > > > >    obj-$(CONFIG_MFD_PALMAS)   += palmas.o
> > > > >    obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
> > > > >    obj-$(CONFIG_MFD_RC5T583)  += rc5t583.o rc5t583-irq.o
> > > > > diff --git a/drivers/mfd/intel-peci-client.c b/drivers/mfd/intel-peci-client.c
> > > > > new file mode 100644
> > > > > index 000000000000..d7702cf1ea50
> > > > > --- /dev/null
> > > > > +++ b/drivers/mfd/intel-peci-client.c
> > > > > @@ -0,0 +1,182 @@
> > > > > +// SPDX-License-Identifier: GPL-2.0
> > > > > +// Copyright (c) 2018 Intel Corporation
> > > > > +
> > > > > +#include <linux/bitfield.h>
> > > > > +#include <linux/mfd/core.h>
> > > > > +#include <linux/mfd/intel-peci-client.h>
> > > > > +#include <linux/module.h>
> > > > > +#include <linux/peci.h>
> > > > > +#include <linux/of_device.h>
> > > > > +
> > > > > +enum cpu_gens {
> > > > > +    CPU_GEN_HSX = 0, /* Haswell Xeon */
> > > > > +    CPU_GEN_BRX,     /* Broadwell Xeon */
> > > > > +    CPU_GEN_SKX,     /* Skylake Xeon */
> > > > > +};
> > > > > +
> > > > > +static struct mfd_cell peci_functions[] = {
> > > > > +    {
> > > > > +            .name = "peci-cputemp",
> > > > > +            .of_compatible = "intel,peci-cputemp",
> > > > > +    },
> > > > > +    {
> > > > > +            .name = "peci-dimmtemp",
> > > > > +            .of_compatible = "intel,peci-dimmtemp",
> > > > > +    },
> > > > > +};
> > > > 
> > > > The more I look at this driver, the less I think it fits into MFD.
> > > > 
> > > > What's stopping you from registering these devices directly from DT?
> > > > 
> > > 
> > > Because DT doesn't allow 2 nodes at the same address so Rob suggested
> > > MFD for this case.
> > 
> > Only after I first suggested you create cpu and dimm sensors from a
> > single hwmon driver. Perhaps you should figure out how to fix the
> > problem with delayed registration. Perhaps you can register the
> > sensor, but just delay returning actual data until it is ready.
> > 
> 
> The actual reason why I divided the single hwmon driver into two is for
> using recommended hwmon API set which doesn't allow incremental
> creation of sysfs attributes at run time - using of
> 'devm_hwmon_device_register_with_info' is suggested by Guenter instead
> of using other deprecated APIs.
> 
> The reason why the delayed registration is needed is, BMC kernel cannot
> know how many DIMM are installed in remote machine before the machine
> completing memory training and testing in POST. So dimm temp driver
> cannot create hwmon attributes in advance.
> 
> My thought is, this way is the best to address these requirements.

As I've previously explained, I do not think this is a good fit for
MFD.  Since this whole PECI piece is a bit, let's say 'niche', perhaps
it's better to contain the client within the PECI subsystem too.  You
can then use the platform_device_add() API to register devices as and
when required.
Jae Hyun Yoo July 31, 2018, 6:56 p.m. UTC | #8
Hi Lee,

On 7/31/2018 12:01 AM, Lee Jones wrote:
> On Mon, 30 Jul 2018, Jae Hyun Yoo wrote:
> 
>> Hi Rob,
>>
>> On 7/30/2018 3:10 PM, Rob Herring wrote:
>>> On Fri, Jul 27, 2018 at 11:36 AM Jae Hyun Yoo
>>> <jae.hyun.yoo@linux.intel.com> wrote:
>>>>
>>>> Hi Lee,
>>>>
>>>> On 7/27/2018 1:26 AM, Lee Jones wrote:
>>>>> On Mon, 23 Jul 2018, Jae Hyun Yoo wrote:
>>>>>
>>>>>> This commit adds PECI client MFD driver.
>>>>>>
>>>>>> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
>>>>>> Cc: Lee Jones <lee.jones@linaro.org>
>>>>>> Cc: Rob Herring <robh+dt@kernel.org>
>>>>>> Cc: Andrew Jeffery <andrew@aj.id.au>
>>>>>> Cc: James Feist <james.feist@linux.intel.com>
>>>>>> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
>>>>>> Cc: Joel Stanley <joel@jms.id.au>
>>>>>> Cc: Vernon Mauery <vernon.mauery@linux.intel.com>
>>>>>> ---
>>>>>>     drivers/mfd/Kconfig                   |  14 ++
>>>>>>     drivers/mfd/Makefile                  |   1 +
>>>>>>     drivers/mfd/intel-peci-client.c       | 182 ++++++++++++++++++++++++++
>>>>>>     include/linux/mfd/intel-peci-client.h |  81 ++++++++++++
>>>>>>     4 files changed, 278 insertions(+)
>>>>>>     create mode 100644 drivers/mfd/intel-peci-client.c
>>>>>>     create mode 100644 include/linux/mfd/intel-peci-client.h
>>>>>>
>>>>>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>>>>>> index f3fa516011ec..e38b591479d4 100644
>>>>>> --- a/drivers/mfd/Kconfig
>>>>>> +++ b/drivers/mfd/Kconfig
>>>>>> @@ -595,6 +595,20 @@ config MFD_INTEL_MSIC
>>>>>>          Passage) chip. This chip embeds audio, battery, GPIO, etc.
>>>>>>          devices used in Intel Medfield platforms.
>>>>>>
>>>>>> +config MFD_INTEL_PECI_CLIENT
>>>>>> +    bool "Intel PECI client"
>>>>>> +    depends on (PECI || COMPILE_TEST)
>>>>>> +    select MFD_CORE
>>>>>> +    help
>>>>>> +      If you say yes to this option, support will be included for the
>>>>>> +      multi-funtional Intel PECI (Platform Environment Control Interface)
>>>>>> +      client. PECI is a one-wire bus interface that provides a communication
>>>>>> +      channel from PECI clients in Intel processors and chipset components
>>>>>> +      to external monitoring or control devices.
>>>>>> +
>>>>>> +      Additional drivers must be enabled in order to use the functionality
>>>>>> +      of the device.
>>>>>> +
>>>>>>     config MFD_IPAQ_MICRO
>>>>>>        bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
>>>>>>        depends on SA1100_H3100 || SA1100_H3600
>>>>>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>>>>>> index 2852a6042ecf..29e2cacc58bd 100644
>>>>>> --- a/drivers/mfd/Makefile
>>>>>> +++ b/drivers/mfd/Makefile
>>>>>> @@ -203,6 +203,7 @@ obj-$(CONFIG_MFD_INTEL_LPSS)     += intel-lpss.o
>>>>>>     obj-$(CONFIG_MFD_INTEL_LPSS_PCI)   += intel-lpss-pci.o
>>>>>>     obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)  += intel-lpss-acpi.o
>>>>>>     obj-$(CONFIG_MFD_INTEL_MSIC)       += intel_msic.o
>>>>>> +obj-$(CONFIG_MFD_INTEL_PECI_CLIENT) += intel-peci-client.o
>>>>>>     obj-$(CONFIG_MFD_PALMAS)   += palmas.o
>>>>>>     obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
>>>>>>     obj-$(CONFIG_MFD_RC5T583)  += rc5t583.o rc5t583-irq.o
>>>>>> diff --git a/drivers/mfd/intel-peci-client.c b/drivers/mfd/intel-peci-client.c
>>>>>> new file mode 100644
>>>>>> index 000000000000..d7702cf1ea50
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/mfd/intel-peci-client.c
>>>>>> @@ -0,0 +1,182 @@
>>>>>> +// SPDX-License-Identifier: GPL-2.0
>>>>>> +// Copyright (c) 2018 Intel Corporation
>>>>>> +
>>>>>> +#include <linux/bitfield.h>
>>>>>> +#include <linux/mfd/core.h>
>>>>>> +#include <linux/mfd/intel-peci-client.h>
>>>>>> +#include <linux/module.h>
>>>>>> +#include <linux/peci.h>
>>>>>> +#include <linux/of_device.h>
>>>>>> +
>>>>>> +enum cpu_gens {
>>>>>> +    CPU_GEN_HSX = 0, /* Haswell Xeon */
>>>>>> +    CPU_GEN_BRX,     /* Broadwell Xeon */
>>>>>> +    CPU_GEN_SKX,     /* Skylake Xeon */
>>>>>> +};
>>>>>> +
>>>>>> +static struct mfd_cell peci_functions[] = {
>>>>>> +    {
>>>>>> +            .name = "peci-cputemp",
>>>>>> +            .of_compatible = "intel,peci-cputemp",
>>>>>> +    },
>>>>>> +    {
>>>>>> +            .name = "peci-dimmtemp",
>>>>>> +            .of_compatible = "intel,peci-dimmtemp",
>>>>>> +    },
>>>>>> +};
>>>>>
>>>>> The more I look at this driver, the less I think it fits into MFD.
>>>>>
>>>>> What's stopping you from registering these devices directly from DT?
>>>>>
>>>>
>>>> Because DT doesn't allow 2 nodes at the same address so Rob suggested
>>>> MFD for this case.
>>>
>>> Only after I first suggested you create cpu and dimm sensors from a
>>> single hwmon driver. Perhaps you should figure out how to fix the
>>> problem with delayed registration. Perhaps you can register the
>>> sensor, but just delay returning actual data until it is ready.
>>>
>>
>> The actual reason why I divided the single hwmon driver into two is for
>> using recommended hwmon API set which doesn't allow incremental
>> creation of sysfs attributes at run time - using of
>> 'devm_hwmon_device_register_with_info' is suggested by Guenter instead
>> of using other deprecated APIs.
>>
>> The reason why the delayed registration is needed is, BMC kernel cannot
>> know how many DIMM are installed in remote machine before the machine
>> completing memory training and testing in POST. So dimm temp driver
>> cannot create hwmon attributes in advance.
>>
>> My thought is, this way is the best to address these requirements.
> 
> As I've previously explained, I do not think this is a good fit for
> MFD.  Since this whole PECI piece is a bit, let's say 'niche', perhaps
> it's better to contain the client within the PECI subsystem too.  You
> can then use the platform_device_add() API to register devices as and
> when required.
> 

If I do like that, I would face the 'DT doesn't allow 2 nodes at the
same address' issue again. Also, as I previously explained, additional
PECI sideband function drivers should be added later through this MFD
driver. For an example, remote CPU crash dump driver which would be an
misc char type driver that are sharing the same unit address also needs
to be added later, and it's definitely not an additional hwmon subsystem
driver. I'm still thinking that an MFD driver is more suitable to
support these mixed-type function drivers that are sharing a single
device unit.

Thanks,

Jae
diff mbox series

Patch

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index f3fa516011ec..e38b591479d4 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -595,6 +595,20 @@  config MFD_INTEL_MSIC
 	  Passage) chip. This chip embeds audio, battery, GPIO, etc.
 	  devices used in Intel Medfield platforms.
 
+config MFD_INTEL_PECI_CLIENT
+	bool "Intel PECI client"
+	depends on (PECI || COMPILE_TEST)
+	select MFD_CORE
+	help
+	  If you say yes to this option, support will be included for the
+	  multi-funtional Intel PECI (Platform Environment Control Interface)
+	  client. PECI is a one-wire bus interface that provides a communication
+	  channel from PECI clients in Intel processors and chipset components
+	  to external monitoring or control devices.
+
+	  Additional drivers must be enabled in order to use the functionality
+	  of the device.
+
 config MFD_IPAQ_MICRO
 	bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
 	depends on SA1100_H3100 || SA1100_H3600
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 2852a6042ecf..29e2cacc58bd 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -203,6 +203,7 @@  obj-$(CONFIG_MFD_INTEL_LPSS)	+= intel-lpss.o
 obj-$(CONFIG_MFD_INTEL_LPSS_PCI)	+= intel-lpss-pci.o
 obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)	+= intel-lpss-acpi.o
 obj-$(CONFIG_MFD_INTEL_MSIC)	+= intel_msic.o
+obj-$(CONFIG_MFD_INTEL_PECI_CLIENT)	+= intel-peci-client.o
 obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
 obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
 obj-$(CONFIG_MFD_RC5T583)	+= rc5t583.o rc5t583-irq.o
diff --git a/drivers/mfd/intel-peci-client.c b/drivers/mfd/intel-peci-client.c
new file mode 100644
index 000000000000..d7702cf1ea50
--- /dev/null
+++ b/drivers/mfd/intel-peci-client.c
@@ -0,0 +1,182 @@ 
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Intel Corporation
+
+#include <linux/bitfield.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/intel-peci-client.h>
+#include <linux/module.h>
+#include <linux/peci.h>
+#include <linux/of_device.h>
+
+enum cpu_gens {
+	CPU_GEN_HSX = 0, /* Haswell Xeon */
+	CPU_GEN_BRX,     /* Broadwell Xeon */
+	CPU_GEN_SKX,     /* Skylake Xeon */
+};
+
+static struct mfd_cell peci_functions[] = {
+	{
+		.name = "peci-cputemp",
+		.of_compatible = "intel,peci-cputemp",
+	},
+	{
+		.name = "peci-dimmtemp",
+		.of_compatible = "intel,peci-dimmtemp",
+	},
+};
+
+static const struct cpu_gen_info cpu_gen_info_table[] = {
+	[CPU_GEN_HSX] = {
+		.family        = 6, /* Family code */
+		.model         = INTEL_FAM6_HASWELL_X,
+		.core_max      = CORE_MAX_ON_HSX,
+		.chan_rank_max = CHAN_RANK_MAX_ON_HSX,
+		.dimm_idx_max  = DIMM_IDX_MAX_ON_HSX },
+	[CPU_GEN_BRX] = {
+		.family        = 6, /* Family code */
+		.model         = INTEL_FAM6_BROADWELL_X,
+		.core_max      = CORE_MAX_ON_BDX,
+		.chan_rank_max = CHAN_RANK_MAX_ON_BDX,
+		.dimm_idx_max  = DIMM_IDX_MAX_ON_BDX },
+	[CPU_GEN_SKX] = {
+		.family        = 6, /* Family code */
+		.model         = INTEL_FAM6_SKYLAKE_X,
+		.core_max      = CORE_MAX_ON_SKX,
+		.chan_rank_max = CHAN_RANK_MAX_ON_SKX,
+		.dimm_idx_max  = DIMM_IDX_MAX_ON_SKX },
+};
+
+static int peci_client_get_cpu_gen_info(struct peci_mfd *priv)
+{
+	u32 cpu_id;
+	int i, rc;
+
+	rc = peci_get_cpu_id(priv->adapter, priv->addr, &cpu_id);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < ARRAY_SIZE(cpu_gen_info_table); i++) {
+		if (FIELD_GET(CPU_ID_FAMILY_MASK, cpu_id) +
+			FIELD_GET(CPU_ID_EXT_FAMILY_MASK, cpu_id) ==
+				cpu_gen_info_table[i].family &&
+		    FIELD_GET(CPU_ID_MODEL_MASK, cpu_id) ==
+			FIELD_GET(LOWER_NIBBLE_MASK,
+				  cpu_gen_info_table[i].model) &&
+		    FIELD_GET(CPU_ID_EXT_MODEL_MASK, cpu_id) ==
+			FIELD_GET(UPPER_NIBBLE_MASK,
+				  cpu_gen_info_table[i].model)) {
+			break;
+		}
+	}
+
+	if (i >= ARRAY_SIZE(cpu_gen_info_table))
+		return -ENODEV;
+
+	priv->gen_info = &cpu_gen_info_table[i];
+
+	return 0;
+}
+
+bool peci_temp_need_update(struct temp_data *temp)
+{
+	if (temp->valid &&
+	    time_before(jiffies, temp->last_updated + UPDATE_INTERVAL))
+		return false;
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(peci_temp_need_update);
+
+void peci_temp_mark_updated(struct temp_data *temp)
+{
+	temp->valid = 1;
+	temp->last_updated = jiffies;
+}
+EXPORT_SYMBOL_GPL(peci_temp_mark_updated);
+
+int peci_client_command(struct peci_mfd *priv, enum peci_cmd cmd, void *vmsg)
+{
+	return peci_command(priv->adapter, cmd, vmsg);
+}
+EXPORT_SYMBOL_GPL(peci_client_command);
+
+int peci_client_rd_pkg_cfg_cmd(struct peci_mfd *priv, u8 mbx_idx,
+			       u16 param, u8 *data)
+{
+	struct peci_rd_pkg_cfg_msg msg;
+	int rc;
+
+	msg.addr = priv->addr;
+	msg.index = mbx_idx;
+	msg.param = param;
+	msg.rx_len = 4;
+
+	rc = peci_command(priv->adapter, PECI_CMD_RD_PKG_CFG, &msg);
+	if (!rc)
+		memcpy(data, msg.pkg_config, 4);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(peci_client_rd_pkg_cfg_cmd);
+
+static int peci_client_probe(struct peci_client *client)
+{
+	struct device *dev = &client->dev;
+	struct peci_mfd *priv;
+	int rc;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, priv);
+	priv->client = client;
+	priv->dev = dev;
+	priv->adapter = client->adapter;
+	priv->addr = client->addr;
+	priv->cpu_no = client->addr - PECI_BASE_ADDR;
+
+	snprintf(priv->name, PECI_NAME_SIZE, "peci_client.cpu%d", priv->cpu_no);
+
+	rc = peci_client_get_cpu_gen_info(priv);
+	if (rc)
+		return rc;
+
+	rc = devm_mfd_add_devices(priv->dev, priv->cpu_no, peci_functions,
+				  ARRAY_SIZE(peci_functions), NULL, 0, NULL);
+	if (rc < 0) {
+		dev_err(priv->dev, "devm_mfd_add_devices failed: %d\n", rc);
+		return rc;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id peci_client_of_table[] = {
+	{ .compatible = "intel,peci-client" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, peci_client_of_table);
+#endif
+
+static const struct peci_device_id peci_client_ids[] = {
+	{ .name = "peci-client", .driver_data = 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(peci, peci_client_ids);
+
+static struct peci_driver peci_client_driver = {
+	.probe    = peci_client_probe,
+	.id_table = peci_client_ids,
+	.driver   = {
+			.name           = "peci-client",
+			.of_match_table =
+				of_match_ptr(peci_client_of_table),
+	},
+};
+module_peci_driver(peci_client_driver);
+
+MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
+MODULE_DESCRIPTION("PECI client MFD driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/intel-peci-client.h b/include/linux/mfd/intel-peci-client.h
new file mode 100644
index 000000000000..7ec272cddceb
--- /dev/null
+++ b/include/linux/mfd/intel-peci-client.h
@@ -0,0 +1,81 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018 Intel Corporation */
+
+#ifndef __LINUX_MFD_PECI_CLIENT_H
+#define __LINUX_MFD_PECI_CLIENT_H
+
+#include <linux/peci.h>
+
+#if IS_ENABLED(CONFIG_X86)
+#include <asm/intel-family.h>
+#else
+/**
+ * Architectures other than x86 cannot include the header file so define these
+ * at here. These are needed for detecting type of client x86 CPUs behind a PECI
+ * connection.
+ */
+#define INTEL_FAM6_HASWELL_X   0x3F
+#define INTEL_FAM6_BROADWELL_X 0x4F
+#define INTEL_FAM6_SKYLAKE_X   0x55
+#endif
+
+#define LOWER_NIBBLE_MASK      GENMASK(3, 0)
+#define UPPER_NIBBLE_MASK      GENMASK(7, 4)
+
+#define CPU_ID_MODEL_MASK      GENMASK(7, 4)
+#define CPU_ID_FAMILY_MASK     GENMASK(11, 8)
+#define CPU_ID_EXT_MODEL_MASK  GENMASK(19, 16)
+#define CPU_ID_EXT_FAMILY_MASK GENMASK(27, 20)
+
+#define CORE_MAX_ON_HSX        18 /* Max number of cores on Haswell */
+#define CHAN_RANK_MAX_ON_HSX   8  /* Max number of channel ranks on Haswell */
+#define DIMM_IDX_MAX_ON_HSX    3  /* Max DIMM index per channel on Haswell */
+
+#define CORE_MAX_ON_BDX        24 /* Max number of cores on Broadwell */
+#define CHAN_RANK_MAX_ON_BDX   4  /* Max number of channel ranks on Broadwell */
+#define DIMM_IDX_MAX_ON_BDX    3  /* Max DIMM index per channel on Broadwell */
+
+#define CORE_MAX_ON_SKX        28 /* Max number of cores on Skylake */
+#define CHAN_RANK_MAX_ON_SKX   6  /* Max number of channel ranks on Skylake */
+#define DIMM_IDX_MAX_ON_SKX    2  /* Max DIMM index per channel on Skylake */
+
+#define CORE_NUMS_MAX          CORE_MAX_ON_SKX
+#define CHAN_RANK_MAX          CHAN_RANK_MAX_ON_HSX
+#define DIMM_IDX_MAX           DIMM_IDX_MAX_ON_HSX
+#define DIMM_NUMS_MAX          (CHAN_RANK_MAX * DIMM_IDX_MAX)
+
+#define TEMP_TYPE_PECI         6 /* Sensor type 6: Intel PECI */
+
+#define UPDATE_INTERVAL        HZ
+
+struct temp_data {
+	uint  valid;
+	s32   value;
+	ulong last_updated;
+};
+
+struct cpu_gen_info {
+	u16  family;
+	u8   model;
+	uint core_max;
+	uint chan_rank_max;
+	uint dimm_idx_max;
+};
+
+struct peci_mfd {
+	struct peci_client *client;
+	struct device *dev;
+	struct peci_adapter *adapter;
+	char name[PECI_NAME_SIZE];
+	u8 addr;
+	uint cpu_no;
+	const struct cpu_gen_info *gen_info;
+};
+
+bool peci_temp_need_update(struct temp_data *temp);
+void peci_temp_mark_updated(struct temp_data *temp);
+int  peci_client_command(struct peci_mfd *mfd, enum peci_cmd cmd, void *vmsg);
+int  peci_client_rd_pkg_cfg_cmd(struct peci_mfd *mfd, u8 mbx_idx,
+				u16 param, u8 *data);
+
+#endif /* __LINUX_MFD_PECI_CLIENT_H */