Re: [PATCH] Add IDT 89HPESx EEPROM/CSR driver

[Serge Semin]

On Sun, Oct 30, 2016 at 09:53:58AM -0400, Greg KH  
wrote:

> On Mon, Oct 03, 2016 at 02:13:45AM +0300, Serge Semin wrote:
> > Hello linux folks,
> > 
> > This driver primarily is developed to give an access to EEPROM of IDT
> > PCIe-switches. Such switches provide a simple SMBus interface to perform
> > IO-operations from/to EEPROM, which is located at private (also called 
> > master)
> > SMBus of the switches. Using that interface this driver creates a simple
> > binary sysfs-file in the device directory:
> > /sys/bus/i2c/devices/-/eeprom
> > In case if read-only flag is specified in the device dts-node, user-space
> > applications won't be able to write to the EEPROM sysfs-node.
> > 
> > Additionally IDT 89HPESx SMBus interface provides an ability to 
> > write/read
> > data of device CSRs. This driver exposes corresponding sysfs-file to perform
> > simple IO operations using that facility for just basic debug purpose.
> 
> If it's for debugging, please put it in debugfs, not in sysfs.  sysfs
> files for one-off drivers is usually discouraged, but at the least, you
> have to document it in a Documentation/ABI/ file.  For debugfs files, we
> don't care, you can do whatever you want in them :)
> 

Undrestood. I'll move it to Debugfs.

> > Particularly next file is created in the device specific sysfs-directory:
> > /sys/bus/i2c/devices/-/csr
> > Format of the sysfs-node is:
> > $ cat /sys/bus/i2c/devices/-/csr;
> > :
> > So reading the content of the sysfs-file gives current CSR address and
> > it value. If user-space application wishes to change current CSR address,
> > it can just write a proper value to the sysfs-file:
> > $ echo "" > /sys/bus/i2c/devices/-/csr
> > If it wants to change the CSR value as well, the format of the write
> > operation is:
> > $ echo ":" > \
> > /sys/bus/i2c/devices/-/csr;
> > CSR address and value can be any of hexadecimal, decimal or octal format.
> 
> Yeah, that all should go into debugfs.
> 

Ok.

> > The driver supports the most of the commonly available SMBus operations:
> > SMBus i2c block, SMBus block, smbus word and byte. The code has been tested
> > to be built for x32/x64 MIPS architecture and tested on the x32 MIPS 
> > machine.
> > The patch was applied on top of commit 
> > c6935931c1894ff857616ff8549b61236a19148f
> > of master branch of repository
> > git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> > 
> > 
> > Thanks,
> > 
> > =
> > Serge V. Semin
> > Leading Programmer
> > Embedded SW development group
> > T-platforms
> > =
> > 
> > Signed-off-by: Serge Semin 
> 
> meta-comment, the "hello", and "thanks" and signature doesn't need to be
> in a changelog text, next time you can drop that.  See the many kernel
> patches on the mailing lists for examples of how to do this.
> 

Understood.

> 
> > 
> > ---
> >  .../devicetree/bindings/misc/idt_89hpesx.txt   |   41 +
> 
> 
> Can you split this out into a separate file and be sure to cc: the patch
> to the devicetree maintainers?
> 
> >  drivers/misc/eeprom/Kconfig|   10 +
> >  drivers/misc/eeprom/Makefile   |1 +
> >  drivers/misc/eeprom/idt_89hpesx.c  | 1483 
> > 
> >  4 files changed, 1535 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> >  create mode 100644 drivers/misc/eeprom/idt_89hpesx.c
> > 
> > diff --git a/Documentation/devicetree/bindings/misc/idt_89hpesx.txt 
> > b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> > new file mode 100644
> > index 000..469cc93
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> > @@ -0,0 +1,41 @@
> > +EEPROM / CSR SMBus-slave interface of IDT 89HPESx devices
> > +
> > +Required properties:
> > +  - compatible : should be ","
> > +Basically there is only one manufacturer: idt, but some
> > +compatible devices may be produced in future. Following devices
> > +are supported: 89hpes8nt2, 89hpes12nt3, 89hpes24nt6ag2,
> > +89hpes32nt8ag2, 89hpes32nt8bg2, 89hpes12nt12g2, 89hpes16nt16g2,
> > +89hpes24nt24g2, 89hpes32nt24ag2, 89hpes32nt24bg2;
> > +89hpes12n3, 89hpes12n3a, 89hpes24n3, 89hpes24n3a;
> > +89hpes32h8, 89hpes32h8g2, 89hpes48h12, 89hpes48h12g2,
> > +89hpes48h12ag2, 89hpes16h16, 89hpes22h16, 89hpes22h16g2,
> > +89hpes34h16, 89hpes34h16g2, 89hpes64h16, 89hpes64h16g2,
> > +89hpes64h16ag2;
> > +89hpes12t3g2, 89hpes24t3g2, 89hpes16t4, 89hpes4t4g2,
> > +89hpes10t4g2, 89hpes16t4g2, 89hpes16t4ag2, 89hpes5t5,
> > +89hpes6t5, 89hpes8t5, 89hpes8t5a, 89hpes24t6, 89hpes6t6g2,
> > +89hpes24t6g2, 89hpes16t7, 89hpes32t8, 89hpes32t8g2,
> > +89hpes48t12, 89hpes48t12g2.
> > +Current 

Re: [PATCH] Add IDT 89HPESx EEPROM/CSR driver

[Serge Semin]

On Sun, Oct 30, 2016 at 09:53:58AM -0400, Greg KH  
wrote:

> On Mon, Oct 03, 2016 at 02:13:45AM +0300, Serge Semin wrote:
> > Hello linux folks,
> > 
> > This driver primarily is developed to give an access to EEPROM of IDT
> > PCIe-switches. Such switches provide a simple SMBus interface to perform
> > IO-operations from/to EEPROM, which is located at private (also called 
> > master)
> > SMBus of the switches. Using that interface this driver creates a simple
> > binary sysfs-file in the device directory:
> > /sys/bus/i2c/devices/-/eeprom
> > In case if read-only flag is specified in the device dts-node, user-space
> > applications won't be able to write to the EEPROM sysfs-node.
> > 
> > Additionally IDT 89HPESx SMBus interface provides an ability to 
> > write/read
> > data of device CSRs. This driver exposes corresponding sysfs-file to perform
> > simple IO operations using that facility for just basic debug purpose.
> 
> If it's for debugging, please put it in debugfs, not in sysfs.  sysfs
> files for one-off drivers is usually discouraged, but at the least, you
> have to document it in a Documentation/ABI/ file.  For debugfs files, we
> don't care, you can do whatever you want in them :)
> 

Undrestood. I'll move it to Debugfs.

> > Particularly next file is created in the device specific sysfs-directory:
> > /sys/bus/i2c/devices/-/csr
> > Format of the sysfs-node is:
> > $ cat /sys/bus/i2c/devices/-/csr;
> > :
> > So reading the content of the sysfs-file gives current CSR address and
> > it value. If user-space application wishes to change current CSR address,
> > it can just write a proper value to the sysfs-file:
> > $ echo "" > /sys/bus/i2c/devices/-/csr
> > If it wants to change the CSR value as well, the format of the write
> > operation is:
> > $ echo ":" > \
> > /sys/bus/i2c/devices/-/csr;
> > CSR address and value can be any of hexadecimal, decimal or octal format.
> 
> Yeah, that all should go into debugfs.
> 

Ok.

> > The driver supports the most of the commonly available SMBus operations:
> > SMBus i2c block, SMBus block, smbus word and byte. The code has been tested
> > to be built for x32/x64 MIPS architecture and tested on the x32 MIPS 
> > machine.
> > The patch was applied on top of commit 
> > c6935931c1894ff857616ff8549b61236a19148f
> > of master branch of repository
> > git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> > 
> > 
> > Thanks,
> > 
> > =
> > Serge V. Semin
> > Leading Programmer
> > Embedded SW development group
> > T-platforms
> > =
> > 
> > Signed-off-by: Serge Semin 
> 
> meta-comment, the "hello", and "thanks" and signature doesn't need to be
> in a changelog text, next time you can drop that.  See the many kernel
> patches on the mailing lists for examples of how to do this.
> 

Understood.

> 
> > 
> > ---
> >  .../devicetree/bindings/misc/idt_89hpesx.txt   |   41 +
> 
> 
> Can you split this out into a separate file and be sure to cc: the patch
> to the devicetree maintainers?
> 
> >  drivers/misc/eeprom/Kconfig|   10 +
> >  drivers/misc/eeprom/Makefile   |1 +
> >  drivers/misc/eeprom/idt_89hpesx.c  | 1483 
> > 
> >  4 files changed, 1535 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> >  create mode 100644 drivers/misc/eeprom/idt_89hpesx.c
> > 
> > diff --git a/Documentation/devicetree/bindings/misc/idt_89hpesx.txt 
> > b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> > new file mode 100644
> > index 000..469cc93
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> > @@ -0,0 +1,41 @@
> > +EEPROM / CSR SMBus-slave interface of IDT 89HPESx devices
> > +
> > +Required properties:
> > +  - compatible : should be ","
> > +Basically there is only one manufacturer: idt, but some
> > +compatible devices may be produced in future. Following devices
> > +are supported: 89hpes8nt2, 89hpes12nt3, 89hpes24nt6ag2,
> > +89hpes32nt8ag2, 89hpes32nt8bg2, 89hpes12nt12g2, 89hpes16nt16g2,
> > +89hpes24nt24g2, 89hpes32nt24ag2, 89hpes32nt24bg2;
> > +89hpes12n3, 89hpes12n3a, 89hpes24n3, 89hpes24n3a;
> > +89hpes32h8, 89hpes32h8g2, 89hpes48h12, 89hpes48h12g2,
> > +89hpes48h12ag2, 89hpes16h16, 89hpes22h16, 89hpes22h16g2,
> > +89hpes34h16, 89hpes34h16g2, 89hpes64h16, 89hpes64h16g2,
> > +89hpes64h16ag2;
> > +89hpes12t3g2, 89hpes24t3g2, 89hpes16t4, 89hpes4t4g2,
> > +89hpes10t4g2, 89hpes16t4g2, 89hpes16t4ag2, 89hpes5t5,
> > +89hpes6t5, 89hpes8t5, 89hpes8t5a, 89hpes24t6, 89hpes6t6g2,
> > +89hpes24t6g2, 89hpes16t7, 89hpes32t8, 89hpes32t8g2,
> > +89hpes48t12, 89hpes48t12g2.
> > +Current implementation of the driver doesn't have any 

Re: [PATCH] Add IDT 89HPESx EEPROM/CSR driver

[Greg KH]

On Mon, Oct 03, 2016 at 02:13:45AM +0300, Serge Semin wrote:
> Hello linux folks,
> 
> This driver primarily is developed to give an access to EEPROM of IDT
> PCIe-switches. Such switches provide a simple SMBus interface to perform
> IO-operations from/to EEPROM, which is located at private (also called master)
> SMBus of the switches. Using that interface this driver creates a simple
> binary sysfs-file in the device directory:
> /sys/bus/i2c/devices/-/eeprom
> In case if read-only flag is specified in the device dts-node, user-space
> applications won't be able to write to the EEPROM sysfs-node.
> 
> Additionally IDT 89HPESx SMBus interface provides an ability to write/read
> data of device CSRs. This driver exposes corresponding sysfs-file to perform
> simple IO operations using that facility for just basic debug purpose.

If it's for debugging, please put it in debugfs, not in sysfs.  sysfs
files for one-off drivers is usually discouraged, but at the least, you
have to document it in a Documentation/ABI/ file.  For debugfs files, we
don't care, you can do whatever you want in them :)

> Particularly next file is created in the device specific sysfs-directory:
> /sys/bus/i2c/devices/-/csr
> Format of the sysfs-node is:
> $ cat /sys/bus/i2c/devices/-/csr;
> :
> So reading the content of the sysfs-file gives current CSR address and
> it value. If user-space application wishes to change current CSR address,
> it can just write a proper value to the sysfs-file:
> $ echo "" > /sys/bus/i2c/devices/-/csr
> If it wants to change the CSR value as well, the format of the write
> operation is:
> $ echo ":" > \
> /sys/bus/i2c/devices/-/csr;
> CSR address and value can be any of hexadecimal, decimal or octal format.

Yeah, that all should go into debugfs.

> The driver supports the most of the commonly available SMBus operations:
> SMBus i2c block, SMBus block, smbus word and byte. The code has been tested
> to be built for x32/x64 MIPS architecture and tested on the x32 MIPS machine.
> The patch was applied on top of commit 
> c6935931c1894ff857616ff8549b61236a19148f
> of master branch of repository
> git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> 
> 
> Thanks,
> 
> =
> Serge V. Semin
> Leading Programmer
> Embedded SW development group
> T-platforms
> =
> 
> Signed-off-by: Serge Semin 

meta-comment, the "hello", and "thanks" and signature doesn't need to be
in a changelog text, next time you can drop that.  See the many kernel
patches on the mailing lists for examples of how to do this.


> 
> ---
>  .../devicetree/bindings/misc/idt_89hpesx.txt   |   41 +


Can you split this out into a separate file and be sure to cc: the patch
to the devicetree maintainers?

>  drivers/misc/eeprom/Kconfig|   10 +
>  drivers/misc/eeprom/Makefile   |1 +
>  drivers/misc/eeprom/idt_89hpesx.c  | 1483 
> 
>  4 files changed, 1535 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/misc/idt_89hpesx.txt
>  create mode 100644 drivers/misc/eeprom/idt_89hpesx.c
> 
> diff --git a/Documentation/devicetree/bindings/misc/idt_89hpesx.txt 
> b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> new file mode 100644
> index 000..469cc93
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> @@ -0,0 +1,41 @@
> +EEPROM / CSR SMBus-slave interface of IDT 89HPESx devices
> +
> +Required properties:
> +  - compatible : should be ","
> +  Basically there is only one manufacturer: idt, but some
> +  compatible devices may be produced in future. Following devices
> +  are supported: 89hpes8nt2, 89hpes12nt3, 89hpes24nt6ag2,
> +  89hpes32nt8ag2, 89hpes32nt8bg2, 89hpes12nt12g2, 89hpes16nt16g2,
> +  89hpes24nt24g2, 89hpes32nt24ag2, 89hpes32nt24bg2;
> +  89hpes12n3, 89hpes12n3a, 89hpes24n3, 89hpes24n3a;
> +  89hpes32h8, 89hpes32h8g2, 89hpes48h12, 89hpes48h12g2,
> +  89hpes48h12ag2, 89hpes16h16, 89hpes22h16, 89hpes22h16g2,
> +  89hpes34h16, 89hpes34h16g2, 89hpes64h16, 89hpes64h16g2,
> +  89hpes64h16ag2;
> +  89hpes12t3g2, 89hpes24t3g2, 89hpes16t4, 89hpes4t4g2,
> +  89hpes10t4g2, 89hpes16t4g2, 89hpes16t4ag2, 89hpes5t5,
> +  89hpes6t5, 89hpes8t5, 89hpes8t5a, 89hpes24t6, 89hpes6t6g2,
> +  89hpes24t6g2, 89hpes16t7, 89hpes32t8, 89hpes32t8g2,
> +  89hpes48t12, 89hpes48t12g2.
> +  Current implementation of the driver doesn't have any device-
> +  specific functionalities. But since each of them differs
> +  by registers mapping, CSRs read/write restrictions can be
> +  added in future.
> +  - reg : I2C address of the IDT 89HPES device.
> +
> +Optional properties:
> +  - read-only :

Re: [PATCH] Add IDT 89HPESx EEPROM/CSR driver

[Greg KH]

On Mon, Oct 03, 2016 at 02:13:45AM +0300, Serge Semin wrote:
> Hello linux folks,
> 
> This driver primarily is developed to give an access to EEPROM of IDT
> PCIe-switches. Such switches provide a simple SMBus interface to perform
> IO-operations from/to EEPROM, which is located at private (also called master)
> SMBus of the switches. Using that interface this driver creates a simple
> binary sysfs-file in the device directory:
> /sys/bus/i2c/devices/-/eeprom
> In case if read-only flag is specified in the device dts-node, user-space
> applications won't be able to write to the EEPROM sysfs-node.
> 
> Additionally IDT 89HPESx SMBus interface provides an ability to write/read
> data of device CSRs. This driver exposes corresponding sysfs-file to perform
> simple IO operations using that facility for just basic debug purpose.

If it's for debugging, please put it in debugfs, not in sysfs.  sysfs
files for one-off drivers is usually discouraged, but at the least, you
have to document it in a Documentation/ABI/ file.  For debugfs files, we
don't care, you can do whatever you want in them :)

> Particularly next file is created in the device specific sysfs-directory:
> /sys/bus/i2c/devices/-/csr
> Format of the sysfs-node is:
> $ cat /sys/bus/i2c/devices/-/csr;
> :
> So reading the content of the sysfs-file gives current CSR address and
> it value. If user-space application wishes to change current CSR address,
> it can just write a proper value to the sysfs-file:
> $ echo "" > /sys/bus/i2c/devices/-/csr
> If it wants to change the CSR value as well, the format of the write
> operation is:
> $ echo ":" > \
> /sys/bus/i2c/devices/-/csr;
> CSR address and value can be any of hexadecimal, decimal or octal format.

Yeah, that all should go into debugfs.

> The driver supports the most of the commonly available SMBus operations:
> SMBus i2c block, SMBus block, smbus word and byte. The code has been tested
> to be built for x32/x64 MIPS architecture and tested on the x32 MIPS machine.
> The patch was applied on top of commit 
> c6935931c1894ff857616ff8549b61236a19148f
> of master branch of repository
> git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
> 
> 
> Thanks,
> 
> =
> Serge V. Semin
> Leading Programmer
> Embedded SW development group
> T-platforms
> =
> 
> Signed-off-by: Serge Semin 

meta-comment, the "hello", and "thanks" and signature doesn't need to be
in a changelog text, next time you can drop that.  See the many kernel
patches on the mailing lists for examples of how to do this.


> 
> ---
>  .../devicetree/bindings/misc/idt_89hpesx.txt   |   41 +


Can you split this out into a separate file and be sure to cc: the patch
to the devicetree maintainers?

>  drivers/misc/eeprom/Kconfig|   10 +
>  drivers/misc/eeprom/Makefile   |1 +
>  drivers/misc/eeprom/idt_89hpesx.c  | 1483 
> 
>  4 files changed, 1535 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/misc/idt_89hpesx.txt
>  create mode 100644 drivers/misc/eeprom/idt_89hpesx.c
> 
> diff --git a/Documentation/devicetree/bindings/misc/idt_89hpesx.txt 
> b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> new file mode 100644
> index 000..469cc93
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
> @@ -0,0 +1,41 @@
> +EEPROM / CSR SMBus-slave interface of IDT 89HPESx devices
> +
> +Required properties:
> +  - compatible : should be ","
> +  Basically there is only one manufacturer: idt, but some
> +  compatible devices may be produced in future. Following devices
> +  are supported: 89hpes8nt2, 89hpes12nt3, 89hpes24nt6ag2,
> +  89hpes32nt8ag2, 89hpes32nt8bg2, 89hpes12nt12g2, 89hpes16nt16g2,
> +  89hpes24nt24g2, 89hpes32nt24ag2, 89hpes32nt24bg2;
> +  89hpes12n3, 89hpes12n3a, 89hpes24n3, 89hpes24n3a;
> +  89hpes32h8, 89hpes32h8g2, 89hpes48h12, 89hpes48h12g2,
> +  89hpes48h12ag2, 89hpes16h16, 89hpes22h16, 89hpes22h16g2,
> +  89hpes34h16, 89hpes34h16g2, 89hpes64h16, 89hpes64h16g2,
> +  89hpes64h16ag2;
> +  89hpes12t3g2, 89hpes24t3g2, 89hpes16t4, 89hpes4t4g2,
> +  89hpes10t4g2, 89hpes16t4g2, 89hpes16t4ag2, 89hpes5t5,
> +  89hpes6t5, 89hpes8t5, 89hpes8t5a, 89hpes24t6, 89hpes6t6g2,
> +  89hpes24t6g2, 89hpes16t7, 89hpes32t8, 89hpes32t8g2,
> +  89hpes48t12, 89hpes48t12g2.
> +  Current implementation of the driver doesn't have any device-
> +  specific functionalities. But since each of them differs
> +  by registers mapping, CSRs read/write restrictions can be
> +  added in future.
> +  - reg : I2C address of the IDT 89HPES device.
> +
> +Optional properties:
> +  - read-only :   Parameterless 

[PATCH] Add IDT 89HPESx EEPROM/CSR driver

[Serge Semin]

Hello linux folks,

This driver primarily is developed to give an access to EEPROM of IDT
PCIe-switches. Such switches provide a simple SMBus interface to perform
IO-operations from/to EEPROM, which is located at private (also called master)
SMBus of the switches. Using that interface this driver creates a simple
binary sysfs-file in the device directory:
/sys/bus/i2c/devices/-/eeprom
In case if read-only flag is specified in the device dts-node, user-space
applications won't be able to write to the EEPROM sysfs-node.

Additionally IDT 89HPESx SMBus interface provides an ability to write/read
data of device CSRs. This driver exposes corresponding sysfs-file to perform
simple IO operations using that facility for just basic debug purpose.
Particularly next file is created in the device specific sysfs-directory:
/sys/bus/i2c/devices/-/csr
Format of the sysfs-node is:
$ cat /sys/bus/i2c/devices/-/csr;
:
So reading the content of the sysfs-file gives current CSR address and
it value. If user-space application wishes to change current CSR address,
it can just write a proper value to the sysfs-file:
$ echo "" > /sys/bus/i2c/devices/-/csr
If it wants to change the CSR value as well, the format of the write
operation is:
$ echo ":" > \
/sys/bus/i2c/devices/-/csr;
CSR address and value can be any of hexadecimal, decimal or octal format.

The driver supports the most of the commonly available SMBus operations:
SMBus i2c block, SMBus block, smbus word and byte. The code has been tested
to be built for x32/x64 MIPS architecture and tested on the x32 MIPS machine.
The patch was applied on top of commit c6935931c1894ff857616ff8549b61236a19148f
of master branch of repository
git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git


Thanks,

=
Serge V. Semin
Leading Programmer
Embedded SW development group
T-platforms
=

Signed-off-by: Serge Semin 

---
 .../devicetree/bindings/misc/idt_89hpesx.txt   |   41 +
 drivers/misc/eeprom/Kconfig|   10 +
 drivers/misc/eeprom/Makefile   |1 +
 drivers/misc/eeprom/idt_89hpesx.c  | 1483 
 4 files changed, 1535 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/idt_89hpesx.txt
 create mode 100644 drivers/misc/eeprom/idt_89hpesx.c

diff --git a/Documentation/devicetree/bindings/misc/idt_89hpesx.txt 
b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
new file mode 100644
index 000..469cc93
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
@@ -0,0 +1,41 @@
+EEPROM / CSR SMBus-slave interface of IDT 89HPESx devices
+
+Required properties:
+  - compatible : should be ","
+Basically there is only one manufacturer: idt, but some
+compatible devices may be produced in future. Following devices
+are supported: 89hpes8nt2, 89hpes12nt3, 89hpes24nt6ag2,
+89hpes32nt8ag2, 89hpes32nt8bg2, 89hpes12nt12g2, 89hpes16nt16g2,
+89hpes24nt24g2, 89hpes32nt24ag2, 89hpes32nt24bg2;
+89hpes12n3, 89hpes12n3a, 89hpes24n3, 89hpes24n3a;
+89hpes32h8, 89hpes32h8g2, 89hpes48h12, 89hpes48h12g2,
+89hpes48h12ag2, 89hpes16h16, 89hpes22h16, 89hpes22h16g2,
+89hpes34h16, 89hpes34h16g2, 89hpes64h16, 89hpes64h16g2,
+89hpes64h16ag2;
+89hpes12t3g2, 89hpes24t3g2, 89hpes16t4, 89hpes4t4g2,
+89hpes10t4g2, 89hpes16t4g2, 89hpes16t4ag2, 89hpes5t5,
+89hpes6t5, 89hpes8t5, 89hpes8t5a, 89hpes24t6, 89hpes6t6g2,
+89hpes24t6g2, 89hpes16t7, 89hpes32t8, 89hpes32t8g2,
+89hpes48t12, 89hpes48t12g2.
+Current implementation of the driver doesn't have any device-
+specific functionalities. But since each of them differs
+by registers mapping, CSRs read/write restrictions can be
+added in future.
+  - reg :   I2C address of the IDT 89HPES device.
+
+Optional properties:
+  - read-only : Parameterless property disables writes to the EEPROM
+  - idt,eesize : Size of EEPROM device connected to IDT 89HPES i2c-master bus
+(default value is 4096 bytes if option isn't specified)
+  - idt,eeaddr : Custom address of EEPROM device
+(If not specified IDT 89HPESx device will try to communicate
+ with EEPROM sited by default address - 0x50)
+
+Example:
+   idt_pcie_sw@60 {
+   compatible = "idt,89hpes12nt3";
+   reg = <0x60>;
+   read-only;
+   idt,eesize = <65536>;
+   idt,eeaddr = <0x50>;
+   };
diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig
index c4e41c2..de58762 100644
--- a/drivers/misc/eeprom/Kconfig
+++ b/drivers/misc/eeprom/Kconfig
@@ -100,4 +100,14 @@ config 

[PATCH] Add IDT 89HPESx EEPROM/CSR driver

[Serge Semin]

Hello linux folks,

This driver primarily is developed to give an access to EEPROM of IDT
PCIe-switches. Such switches provide a simple SMBus interface to perform
IO-operations from/to EEPROM, which is located at private (also called master)
SMBus of the switches. Using that interface this driver creates a simple
binary sysfs-file in the device directory:
/sys/bus/i2c/devices/-/eeprom
In case if read-only flag is specified in the device dts-node, user-space
applications won't be able to write to the EEPROM sysfs-node.

Additionally IDT 89HPESx SMBus interface provides an ability to write/read
data of device CSRs. This driver exposes corresponding sysfs-file to perform
simple IO operations using that facility for just basic debug purpose.
Particularly next file is created in the device specific sysfs-directory:
/sys/bus/i2c/devices/-/csr
Format of the sysfs-node is:
$ cat /sys/bus/i2c/devices/-/csr;
:
So reading the content of the sysfs-file gives current CSR address and
it value. If user-space application wishes to change current CSR address,
it can just write a proper value to the sysfs-file:
$ echo "" > /sys/bus/i2c/devices/-/csr
If it wants to change the CSR value as well, the format of the write
operation is:
$ echo ":" > \
/sys/bus/i2c/devices/-/csr;
CSR address and value can be any of hexadecimal, decimal or octal format.

The driver supports the most of the commonly available SMBus operations:
SMBus i2c block, SMBus block, smbus word and byte. The code has been tested
to be built for x32/x64 MIPS architecture and tested on the x32 MIPS machine.
The patch was applied on top of commit c6935931c1894ff857616ff8549b61236a19148f
of master branch of repository
git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git


Thanks,

=
Serge V. Semin
Leading Programmer
Embedded SW development group
T-platforms
=

Signed-off-by: Serge Semin 

---
 .../devicetree/bindings/misc/idt_89hpesx.txt   |   41 +
 drivers/misc/eeprom/Kconfig|   10 +
 drivers/misc/eeprom/Makefile   |1 +
 drivers/misc/eeprom/idt_89hpesx.c  | 1483 
 4 files changed, 1535 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/idt_89hpesx.txt
 create mode 100644 drivers/misc/eeprom/idt_89hpesx.c

diff --git a/Documentation/devicetree/bindings/misc/idt_89hpesx.txt 
b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
new file mode 100644
index 000..469cc93
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/idt_89hpesx.txt
@@ -0,0 +1,41 @@
+EEPROM / CSR SMBus-slave interface of IDT 89HPESx devices
+
+Required properties:
+  - compatible : should be ","
+Basically there is only one manufacturer: idt, but some
+compatible devices may be produced in future. Following devices
+are supported: 89hpes8nt2, 89hpes12nt3, 89hpes24nt6ag2,
+89hpes32nt8ag2, 89hpes32nt8bg2, 89hpes12nt12g2, 89hpes16nt16g2,
+89hpes24nt24g2, 89hpes32nt24ag2, 89hpes32nt24bg2;
+89hpes12n3, 89hpes12n3a, 89hpes24n3, 89hpes24n3a;
+89hpes32h8, 89hpes32h8g2, 89hpes48h12, 89hpes48h12g2,
+89hpes48h12ag2, 89hpes16h16, 89hpes22h16, 89hpes22h16g2,
+89hpes34h16, 89hpes34h16g2, 89hpes64h16, 89hpes64h16g2,
+89hpes64h16ag2;
+89hpes12t3g2, 89hpes24t3g2, 89hpes16t4, 89hpes4t4g2,
+89hpes10t4g2, 89hpes16t4g2, 89hpes16t4ag2, 89hpes5t5,
+89hpes6t5, 89hpes8t5, 89hpes8t5a, 89hpes24t6, 89hpes6t6g2,
+89hpes24t6g2, 89hpes16t7, 89hpes32t8, 89hpes32t8g2,
+89hpes48t12, 89hpes48t12g2.
+Current implementation of the driver doesn't have any device-
+specific functionalities. But since each of them differs
+by registers mapping, CSRs read/write restrictions can be
+added in future.
+  - reg :   I2C address of the IDT 89HPES device.
+
+Optional properties:
+  - read-only : Parameterless property disables writes to the EEPROM
+  - idt,eesize : Size of EEPROM device connected to IDT 89HPES i2c-master bus
+(default value is 4096 bytes if option isn't specified)
+  - idt,eeaddr : Custom address of EEPROM device
+(If not specified IDT 89HPESx device will try to communicate
+ with EEPROM sited by default address - 0x50)
+
+Example:
+   idt_pcie_sw@60 {
+   compatible = "idt,89hpes12nt3";
+   reg = <0x60>;
+   read-only;
+   idt,eesize = <65536>;
+   idt,eeaddr = <0x50>;
+   };
diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig
index c4e41c2..de58762 100644
--- a/drivers/misc/eeprom/Kconfig
+++ b/drivers/misc/eeprom/Kconfig
@@ -100,4 +100,14 @@ config EEPROM_DIGSY_MTC_CFG