* [PATCH v2 0/2] Add a property in at24.c
@ 2018-06-26 6:22 alanx.chiang
2018-06-26 6:22 ` [PATCH v2 1/2] dt-bindings: at24: Add address-width property alanx.chiang
` (2 more replies)
0 siblings, 3 replies; 18+ messages in thread
From: alanx.chiang @ 2018-06-26 6:22 UTC (permalink / raw)
To: linux-i2c
Cc: andy.yeh, sakari.ailus, andriy.shevchenko, rajmohan.mani,
andy.shevchenko, brgl, robh+dt, mark.rutland, arnd, gregkh,
linux-kernel, alanx.chiang
From: "alanx.chiang" <alanx.chiang@intel.com>
In at24.c, it uses 8-bit addressing by default. In this patch,
add a property address-width that provides a flexible method to
pass the information to the driver.
alanx.chiang (2):
dt-bindings: at24: Add address-width property
eeprom: at24: Add support for address-width property
Documentation/devicetree/bindings/eeprom/at24.txt | 2 ++
drivers/misc/eeprom/at24.c | 16 ++++++++++++++++
2 files changed, 18 insertions(+)
--
2.7.4
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v2 1/2] dt-bindings: at24: Add address-width property
2018-06-26 6:22 [PATCH v2 0/2] Add a property in at24.c alanx.chiang
@ 2018-06-26 6:22 ` alanx.chiang
2018-06-26 6:49 ` Sakari Ailus
2018-06-26 16:44 ` Rob Herring
2018-06-26 6:22 ` [PATCH v2 2/2] eeprom: at24: Add support for " alanx.chiang
2018-06-26 7:41 ` [PATCH v2 0/2] Add a property in at24.c Bartosz Golaszewski
2 siblings, 2 replies; 18+ messages in thread
From: alanx.chiang @ 2018-06-26 6:22 UTC (permalink / raw)
To: linux-i2c
Cc: andy.yeh, sakari.ailus, andriy.shevchenko, rajmohan.mani,
andy.shevchenko, brgl, robh+dt, mark.rutland, arnd, gregkh,
linux-kernel, alanx.chiang
From: "alanx.chiang" <alanx.chiang@intel.com>
The AT24 series chips use 8-bit address by default. If some
chips would like to support more than 8 bits, should add the compatible
field for specfic chips in the driver.
Provide a flexible way to determine the addressing bits through
address-width in this patch.
Signed-off-by: Alan Chiang <alanx.chiang@intel.com>
Signed-off-by: Andy Yeh <andy.yeh@intel.com>
---
since v1:
-- Remove the address-width field in the example.
---
Documentation/devicetree/bindings/eeprom/at24.txt | 2 ++
1 file changed, 2 insertions(+)
diff --git a/Documentation/devicetree/bindings/eeprom/at24.txt b/Documentation/devicetree/bindings/eeprom/at24.txt
index 61d833a..9467482 100644
--- a/Documentation/devicetree/bindings/eeprom/at24.txt
+++ b/Documentation/devicetree/bindings/eeprom/at24.txt
@@ -72,6 +72,8 @@ Optional properties:
- wp-gpios: GPIO to which the write-protect pin of the chip is connected.
+ - address-width : number of address bits (one of 8, 16).
+
Example:
eeprom@52 {
--
2.7.4
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v2 2/2] eeprom: at24: Add support for address-width property
2018-06-26 6:22 [PATCH v2 0/2] Add a property in at24.c alanx.chiang
2018-06-26 6:22 ` [PATCH v2 1/2] dt-bindings: at24: Add address-width property alanx.chiang
@ 2018-06-26 6:22 ` alanx.chiang
2018-06-26 6:47 ` Sakari Ailus
2018-06-26 7:41 ` [PATCH v2 0/2] Add a property in at24.c Bartosz Golaszewski
2 siblings, 1 reply; 18+ messages in thread
From: alanx.chiang @ 2018-06-26 6:22 UTC (permalink / raw)
To: linux-i2c
Cc: andy.yeh, sakari.ailus, andriy.shevchenko, rajmohan.mani,
andy.shevchenko, brgl, robh+dt, mark.rutland, arnd, gregkh,
linux-kernel, alanx.chiang
From: "alanx.chiang" <alanx.chiang@intel.com>
Provide a flexible way to determine the addressing bits of eeprom.
Pass the addressing bits to driver through address-width property.
Signed-off-by: Alan Chiang <alanx.chiang@intel.com>
Signed-off-by: Andy Yeh <andy.yeh@intel.com>
---
since v1
-- Add a warn message for 8-bit addressing.
---
drivers/misc/eeprom/at24.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 0c125f2..231afcd 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -478,6 +478,22 @@ static void at24_properties_to_pdata(struct device *dev,
if (device_property_present(dev, "no-read-rollover"))
chip->flags |= AT24_FLAG_NO_RDROL;
+ err = device_property_read_u32(dev, "address-width", &val);
+ if (!err) {
+ switch (val) {
+ case 8:
+ chip->flags &= ~AT24_FLAG_ADDR16;
+ dev_warn(dev, "address-width is 8, clear the ADD16 bit\n");
+ break;
+ case 16:
+ chip->flags |= AT24_FLAG_ADDR16;
+ break;
+ default:
+ dev_warn(dev, "Bad \"address-width\" property: %u\n",
+ val);
+ }
+ }
+
err = device_property_read_u32(dev, "size", &val);
if (!err)
chip->byte_len = val;
--
2.7.4
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v2 2/2] eeprom: at24: Add support for address-width property
2018-06-26 6:22 ` [PATCH v2 2/2] eeprom: at24: Add support for " alanx.chiang
@ 2018-06-26 6:47 ` Sakari Ailus
2018-06-26 7:11 ` Chiang, AlanX
0 siblings, 1 reply; 18+ messages in thread
From: Sakari Ailus @ 2018-06-26 6:47 UTC (permalink / raw)
To: alanx.chiang
Cc: linux-i2c, andy.yeh, andriy.shevchenko, rajmohan.mani,
andy.shevchenko, brgl, robh+dt, mark.rutland, arnd, gregkh,
linux-kernel
Hi Alan,
On Tue, Jun 26, 2018 at 02:22:08PM +0800, alanx.chiang@intel.com wrote:
> From: "alanx.chiang" <alanx.chiang@intel.com>
>
> Provide a flexible way to determine the addressing bits of eeprom.
> Pass the addressing bits to driver through address-width property.
>
> Signed-off-by: Alan Chiang <alanx.chiang@intel.com>
> Signed-off-by: Andy Yeh <andy.yeh@intel.com>
>
> ---
> since v1
> -- Add a warn message for 8-bit addressing.
>
> ---
> drivers/misc/eeprom/at24.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index 0c125f2..231afcd 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -478,6 +478,22 @@ static void at24_properties_to_pdata(struct device *dev,
> if (device_property_present(dev, "no-read-rollover"))
> chip->flags |= AT24_FLAG_NO_RDROL;
>
> + err = device_property_read_u32(dev, "address-width", &val);
> + if (!err) {
> + switch (val) {
> + case 8:
> + chip->flags &= ~AT24_FLAG_ADDR16;
> + dev_warn(dev, "address-width is 8, clear the ADD16 bit\n");
Even though the default is 8 address bits, I don't see a need to issue a
warning if the address-width property sets that to 8 explicitly. I.e. only
warn if the flag was set.
> + break;
> + case 16:
> + chip->flags |= AT24_FLAG_ADDR16;
> + break;
> + default:
> + dev_warn(dev, "Bad \"address-width\" property: %u\n",
> + val);
> + }
> + }
> +
> err = device_property_read_u32(dev, "size", &val);
> if (!err)
> chip->byte_len = val;
--
Regards,
Sakari Ailus
sakari.ailus@linux.intel.com
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 1/2] dt-bindings: at24: Add address-width property
2018-06-26 6:22 ` [PATCH v2 1/2] dt-bindings: at24: Add address-width property alanx.chiang
@ 2018-06-26 6:49 ` Sakari Ailus
2018-06-26 16:44 ` Rob Herring
1 sibling, 0 replies; 18+ messages in thread
From: Sakari Ailus @ 2018-06-26 6:49 UTC (permalink / raw)
To: alanx.chiang
Cc: linux-i2c, andy.yeh, andriy.shevchenko, rajmohan.mani,
andy.shevchenko, brgl, robh+dt, mark.rutland, arnd, gregkh,
linux-kernel
Hi Alan,
On Tue, Jun 26, 2018 at 02:22:07PM +0800, alanx.chiang@intel.com wrote:
> From: "alanx.chiang" <alanx.chiang@intel.com>
>
> The AT24 series chips use 8-bit address by default. If some
> chips would like to support more than 8 bits, should add the compatible
> field for specfic chips in the driver.
>
> Provide a flexible way to determine the addressing bits through
> address-width in this patch.
>
> Signed-off-by: Alan Chiang <alanx.chiang@intel.com>
> Signed-off-by: Andy Yeh <andy.yeh@intel.com>
>
> ---
> since v1:
> -- Remove the address-width field in the example.
>
> ---
> Documentation/devicetree/bindings/eeprom/at24.txt | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/eeprom/at24.txt b/Documentation/devicetree/bindings/eeprom/at24.txt
> index 61d833a..9467482 100644
> --- a/Documentation/devicetree/bindings/eeprom/at24.txt
> +++ b/Documentation/devicetree/bindings/eeprom/at24.txt
> @@ -72,6 +72,8 @@ Optional properties:
>
> - wp-gpios: GPIO to which the write-protect pin of the chip is connected.
>
> + - address-width : number of address bits (one of 8, 16).
Please remove the space before the colon; that way it looks the same as the
rest.
> +
> Example:
>
> eeprom@52 {
--
Kind regards,
Sakari Ailus
sakari.ailus@linux.intel.com
^ permalink raw reply [flat|nested] 18+ messages in thread
* RE: [PATCH v2 2/2] eeprom: at24: Add support for address-width property
2018-06-26 6:47 ` Sakari Ailus
@ 2018-06-26 7:11 ` Chiang, AlanX
2018-06-26 7:26 ` Sakari Ailus
2018-06-26 12:11 ` Andy Shevchenko
0 siblings, 2 replies; 18+ messages in thread
From: Chiang, AlanX @ 2018-06-26 7:11 UTC (permalink / raw)
To: Sakari Ailus
Cc: linux-i2c, Yeh, Andy, Shevchenko, Andriy, Mani, Rajmohan,
andy.shevchenko, brgl, robh+dt, mark.rutland, arnd, gregkh,
linux-kernel
Hi Sakari,
> -----Original Message-----
> From: Sakari Ailus [mailto:sakari.ailus@linux.intel.com]
> Sent: Tuesday, June 26, 2018 2:48 PM
> To: Chiang, AlanX <alanx.chiang@intel.com>
> Cc: linux-i2c@vger.kernel.org; Yeh, Andy <andy.yeh@intel.com>;
> Shevchenko, Andriy <andriy.shevchenko@intel.com>; Mani, Rajmohan
> <rajmohan.mani@intel.com>; andy.shevchenko@gmail.com; brgl@bgdev.pl;
> robh+dt@kernel.org; mark.rutland@arm.com; arnd@arndb.de;
> gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v2 2/2] eeprom: at24: Add support for address-width
> property
>
> Hi Alan,
>
> On Tue, Jun 26, 2018 at 02:22:08PM +0800, alanx.chiang@intel.com wrote:
> > From: "alanx.chiang" <alanx.chiang@intel.com>
> >
> > Provide a flexible way to determine the addressing bits of eeprom.
> > Pass the addressing bits to driver through address-width property.
> >
> > Signed-off-by: Alan Chiang <alanx.chiang@intel.com>
> > Signed-off-by: Andy Yeh <andy.yeh@intel.com>
> >
> > ---
> > since v1
> > -- Add a warn message for 8-bit addressing.
> >
> > ---
> > drivers/misc/eeprom/at24.c | 16 ++++++++++++++++
> > 1 file changed, 16 insertions(+)
> >
> > diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> > index 0c125f2..231afcd 100644
> > --- a/drivers/misc/eeprom/at24.c
> > +++ b/drivers/misc/eeprom/at24.c
> > @@ -478,6 +478,22 @@ static void at24_properties_to_pdata(struct device
> *dev,
> > if (device_property_present(dev, "no-read-rollover"))
> > chip->flags |= AT24_FLAG_NO_RDROL;
> >
> > + err = device_property_read_u32(dev, "address-width", &val);
> > + if (!err) {
> > + switch (val) {
> > + case 8:
> > + chip->flags &= ~AT24_FLAG_ADDR16;
> > + dev_warn(dev, "address-width is 8, clear the ADD16
> bit\n");
>
> Even though the default is 8 address bits, I don't see a need to issue a
> warning if the address-width property sets that to 8 explicitly. I.e. only warn
> if the flag was set.
>
Do you mean I have to add a statement for checking if the bit has been set before?
For example:
If (chip->flags & AT24_FLAG_ADDR16)
dev_warn(dev, "address-width is 8, clear the ADD16 bit\n");
If it is, I would like to modify it as below:
case 8:
If (chip->flags & AT24_FLAG_ADDR16) {
chip->flags &= ~AT24_FLAG_ADDR16;
dev_warn(dev, "address-width is 8, clear the ADDR16 bit\n");
}
break;
> > + break;
> > + case 16:
> > + chip->flags |= AT24_FLAG_ADDR16;
> > + break;
> > + default:
> > + dev_warn(dev, "Bad \"address-width\" property:
> %u\n",
> > + val);
> > + }
> > + }
> > +
> > err = device_property_read_u32(dev, "size", &val);
> > if (!err)
> > chip->byte_len = val;
>
> --
> Regards,
>
> Sakari Ailus
> sakari.ailus@linux.intel.com
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 2/2] eeprom: at24: Add support for address-width property
2018-06-26 7:11 ` Chiang, AlanX
@ 2018-06-26 7:26 ` Sakari Ailus
2018-06-26 12:11 ` Andy Shevchenko
1 sibling, 0 replies; 18+ messages in thread
From: Sakari Ailus @ 2018-06-26 7:26 UTC (permalink / raw)
To: Chiang, AlanX
Cc: linux-i2c, Yeh, Andy, Shevchenko, Andriy, Mani, Rajmohan,
andy.shevchenko, brgl, robh+dt, mark.rutland, arnd, gregkh,
linux-kernel
On Tue, Jun 26, 2018 at 07:11:54AM +0000, Chiang, AlanX wrote:
> Hi Sakari,
>
> > -----Original Message-----
> > From: Sakari Ailus [mailto:sakari.ailus@linux.intel.com]
> > Sent: Tuesday, June 26, 2018 2:48 PM
> > To: Chiang, AlanX <alanx.chiang@intel.com>
> > Cc: linux-i2c@vger.kernel.org; Yeh, Andy <andy.yeh@intel.com>;
> > Shevchenko, Andriy <andriy.shevchenko@intel.com>; Mani, Rajmohan
> > <rajmohan.mani@intel.com>; andy.shevchenko@gmail.com; brgl@bgdev.pl;
> > robh+dt@kernel.org; mark.rutland@arm.com; arnd@arndb.de;
> > gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org
> > Subject: Re: [PATCH v2 2/2] eeprom: at24: Add support for address-width
> > property
> >
> > Hi Alan,
> >
> > On Tue, Jun 26, 2018 at 02:22:08PM +0800, alanx.chiang@intel.com wrote:
> > > From: "alanx.chiang" <alanx.chiang@intel.com>
> > >
> > > Provide a flexible way to determine the addressing bits of eeprom.
> > > Pass the addressing bits to driver through address-width property.
> > >
> > > Signed-off-by: Alan Chiang <alanx.chiang@intel.com>
> > > Signed-off-by: Andy Yeh <andy.yeh@intel.com>
> > >
> > > ---
> > > since v1
> > > -- Add a warn message for 8-bit addressing.
> > >
> > > ---
> > > drivers/misc/eeprom/at24.c | 16 ++++++++++++++++
> > > 1 file changed, 16 insertions(+)
> > >
> > > diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> > > index 0c125f2..231afcd 100644
> > > --- a/drivers/misc/eeprom/at24.c
> > > +++ b/drivers/misc/eeprom/at24.c
> > > @@ -478,6 +478,22 @@ static void at24_properties_to_pdata(struct device
> > *dev,
> > > if (device_property_present(dev, "no-read-rollover"))
> > > chip->flags |= AT24_FLAG_NO_RDROL;
> > >
> > > + err = device_property_read_u32(dev, "address-width", &val);
> > > + if (!err) {
> > > + switch (val) {
> > > + case 8:
> > > + chip->flags &= ~AT24_FLAG_ADDR16;
> > > + dev_warn(dev, "address-width is 8, clear the ADD16
> > bit\n");
> >
> > Even though the default is 8 address bits, I don't see a need to issue a
> > warning if the address-width property sets that to 8 explicitly. I.e. only warn
> > if the flag was set.
> >
>
> Do you mean I have to add a statement for checking if the bit has been set before?
> For example:
>
> If (chip->flags & AT24_FLAG_ADDR16)
> dev_warn(dev, "address-width is 8, clear the ADD16 bit\n");
>
> If it is, I would like to modify it as below:
>
> case 8:
> If (chip->flags & AT24_FLAG_ADDR16) {
> chip->flags &= ~AT24_FLAG_ADDR16;
> dev_warn(dev, "address-width is 8, clear the ADDR16 bit\n");
> }
> break;
Seems good to me.
--
Sakari Ailus
sakari.ailus@linux.intel.com
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 0/2] Add a property in at24.c
2018-06-26 6:22 [PATCH v2 0/2] Add a property in at24.c alanx.chiang
2018-06-26 6:22 ` [PATCH v2 1/2] dt-bindings: at24: Add address-width property alanx.chiang
2018-06-26 6:22 ` [PATCH v2 2/2] eeprom: at24: Add support for " alanx.chiang
@ 2018-06-26 7:41 ` Bartosz Golaszewski
2018-06-26 12:14 ` Andy Shevchenko
2 siblings, 1 reply; 18+ messages in thread
From: Bartosz Golaszewski @ 2018-06-26 7:41 UTC (permalink / raw)
To: alanx.chiang
Cc: linux-i2c, andy.yeh, Sakari Ailus, andriy.shevchenko,
rajmohan.mani, Andy Shevchenko, Rob Herring, Mark Rutland,
Arnd Bergmann, Greg Kroah-Hartman, Linux Kernel Mailing List
2018-06-26 8:22 GMT+02:00 <alanx.chiang@intel.com>:
> From: "alanx.chiang" <alanx.chiang@intel.com>
>
> In at24.c, it uses 8-bit addressing by default. In this patch,
> add a property address-width that provides a flexible method to
> pass the information to the driver.
>
> alanx.chiang (2):
> dt-bindings: at24: Add address-width property
> eeprom: at24: Add support for address-width property
>
> Documentation/devicetree/bindings/eeprom/at24.txt | 2 ++
> drivers/misc/eeprom/at24.c | 16 ++++++++++++++++
> 2 files changed, 18 insertions(+)
>
> --
> 2.7.4
>
What is your use case exactly? Do you have an EEPROM model that's not
yet supported explicitly in the driver? Why would you need this
option?
Best regards,
Bartosz Golaszewski
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 2/2] eeprom: at24: Add support for address-width property
2018-06-26 7:11 ` Chiang, AlanX
2018-06-26 7:26 ` Sakari Ailus
@ 2018-06-26 12:11 ` Andy Shevchenko
1 sibling, 0 replies; 18+ messages in thread
From: Andy Shevchenko @ 2018-06-26 12:11 UTC (permalink / raw)
To: Chiang, AlanX, Sakari Ailus
Cc: linux-i2c, Yeh, Andy, Mani, Rajmohan, andy.shevchenko, brgl,
robh+dt, mark.rutland, arnd, gregkh, linux-kernel
On Tue, 2018-06-26 at 15:11 +0800, Chiang, AlanX wrote:
> If it is, I would like to modify it as below:
>
> case 8:
> If (chip->flags & AT24_FLAG_ADDR16) {
> chip->flags &= ~AT24_FLAG_ADDR16;
> dev_warn(dev, "address-width is 8, clear the ADDR16
> bit\n");
> }
> break;
No need to put bit clearing inside the loop, something like below would
be slightly better.
if (chip->flags & AT24_FLAG_ADDR16)
dev_warn(dev, "address-width is 8, clear the ADDR16 bit\n");
chip->flags &= ~AT24_FLAG_ADDR16;
On top of this the message would sound clearer if you put it like
"Override address width to be 8, while default is 16"
--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 0/2] Add a property in at24.c
2018-06-26 7:41 ` [PATCH v2 0/2] Add a property in at24.c Bartosz Golaszewski
@ 2018-06-26 12:14 ` Andy Shevchenko
2018-06-26 12:36 ` Bartosz Golaszewski
0 siblings, 1 reply; 18+ messages in thread
From: Andy Shevchenko @ 2018-06-26 12:14 UTC (permalink / raw)
To: Bartosz Golaszewski, alanx.chiang
Cc: linux-i2c, andy.yeh, Sakari Ailus, rajmohan.mani,
Andy Shevchenko, Rob Herring, Mark Rutland, Arnd Bergmann,
Greg Kroah-Hartman, Linux Kernel Mailing List
On Tue, 2018-06-26 at 09:41 +0200, Bartosz Golaszewski wrote:
> 2018-06-26 8:22 GMT+02:00 <alanx.chiang@intel.com>:
> > From: "alanx.chiang" <alanx.chiang@intel.com>
> >
> > In at24.c, it uses 8-bit addressing by default. In this patch,
> > add a property address-width that provides a flexible method to
> > pass the information to the driver.
> >
> > alanx.chiang (2):
> > dt-bindings: at24: Add address-width property
> > eeprom: at24: Add support for address-width property
> >
> > Documentation/devicetree/bindings/eeprom/at24.txt | 2 ++
> > drivers/misc/eeprom/at24.c | 16
> > ++++++++++++++++
> > 2 files changed, 18 insertions(+)
> >
> > --
> > 2.7.4
> >
>
> What is your use case exactly? Do you have an EEPROM model that's not
> yet supported explicitly in the driver? Why would you need this
> option?
The current at24 driver has no address width support, thus, reusing same
(allocated) IDs (non-DT case) is hard.
--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 0/2] Add a property in at24.c
2018-06-26 12:14 ` Andy Shevchenko
@ 2018-06-26 12:36 ` Bartosz Golaszewski
2018-06-26 13:23 ` Andy Shevchenko
0 siblings, 1 reply; 18+ messages in thread
From: Bartosz Golaszewski @ 2018-06-26 12:36 UTC (permalink / raw)
To: Andy Shevchenko
Cc: alanx.chiang, linux-i2c, andy.yeh, Sakari Ailus, rajmohan.mani,
Andy Shevchenko, Rob Herring, Mark Rutland, Arnd Bergmann,
Greg Kroah-Hartman, Linux Kernel Mailing List
2018-06-26 14:14 GMT+02:00 Andy Shevchenko <andriy.shevchenko@linux.intel.com>:
> On Tue, 2018-06-26 at 09:41 +0200, Bartosz Golaszewski wrote:
>> 2018-06-26 8:22 GMT+02:00 <alanx.chiang@intel.com>:
>> > From: "alanx.chiang" <alanx.chiang@intel.com>
>> >
>> > In at24.c, it uses 8-bit addressing by default. In this patch,
>> > add a property address-width that provides a flexible method to
>> > pass the information to the driver.
>> >
>> > alanx.chiang (2):
>> > dt-bindings: at24: Add address-width property
>> > eeprom: at24: Add support for address-width property
>> >
>> > Documentation/devicetree/bindings/eeprom/at24.txt | 2 ++
>> > drivers/misc/eeprom/at24.c | 16
>> > ++++++++++++++++
>> > 2 files changed, 18 insertions(+)
>> >
>> > --
>> > 2.7.4
>> >
>>
>> What is your use case exactly? Do you have an EEPROM model that's not
>> yet supported explicitly in the driver? Why would you need this
>> option?
>
> The current at24 driver has no address width support, thus, reusing same
> (allocated) IDs (non-DT case) is hard.
>
Every supported compatible has the width already specified in its
corresponding chip data.
Bart
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 0/2] Add a property in at24.c
2018-06-26 12:36 ` Bartosz Golaszewski
@ 2018-06-26 13:23 ` Andy Shevchenko
2018-06-26 13:30 ` Bartosz Golaszewski
0 siblings, 1 reply; 18+ messages in thread
From: Andy Shevchenko @ 2018-06-26 13:23 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: alanx.chiang, linux-i2c, andy.yeh, Sakari Ailus, rajmohan.mani,
Andy Shevchenko, Rob Herring, Mark Rutland, Arnd Bergmann,
Greg Kroah-Hartman, Linux Kernel Mailing List
On Tue, 2018-06-26 at 14:36 +0200, Bartosz Golaszewski wrote:
> 2018-06-26 14:14 GMT+02:00 Andy Shevchenko
> <andriy.shevchenko@linux.intel.com>:
> > On Tue, 2018-06-26 at 09:41 +0200, Bartosz Golaszewski wrote:
> > > What is your use case exactly? Do you have an EEPROM model that's
> > > not
> > > yet supported explicitly in the driver? Why would you need this
> > > option?
> >
> > The current at24 driver has no address width support,
> > thus, reusing same
> > (allocated) IDs (non-DT case) is hard.
^^^^^
> Every supported compatible has the width already specified in its
> corresponding chip data.
Please, read again carefully what I wrote before.
--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 0/2] Add a property in at24.c
2018-06-26 13:23 ` Andy Shevchenko
@ 2018-06-26 13:30 ` Bartosz Golaszewski
2018-06-26 15:48 ` Andy Shevchenko
0 siblings, 1 reply; 18+ messages in thread
From: Bartosz Golaszewski @ 2018-06-26 13:30 UTC (permalink / raw)
To: Andy Shevchenko
Cc: alanx.chiang, linux-i2c, andy.yeh, Sakari Ailus, Rajmohan Mani,
Andy Shevchenko, Rob Herring, Mark Rutland, Arnd Bergmann,
Greg Kroah-Hartman, Linux Kernel Mailing List
2018-06-26 15:23 GMT+02:00 Andy Shevchenko <andriy.shevchenko@linux.intel.com>:
> On Tue, 2018-06-26 at 14:36 +0200, Bartosz Golaszewski wrote:
>> 2018-06-26 14:14 GMT+02:00 Andy Shevchenko
>> <andriy.shevchenko@linux.intel.com>:
>> > On Tue, 2018-06-26 at 09:41 +0200, Bartosz Golaszewski wrote:
>
>> > > What is your use case exactly? Do you have an EEPROM model that's
>> > > not
>> > > yet supported explicitly in the driver? Why would you need this
>> > > option?
>> >
>> > The current at24 driver has no address width support,
>
>> > thus, reusing same
>> > (allocated) IDs (non-DT case) is hard.
>
> ^^^^^
>
>> Every supported compatible has the width already specified in its
>> corresponding chip data.
>
>
> Please, read again carefully what I wrote before.
>
Ok makes sense in that case. Could you just point me towards an
example model which has the address width different than the default
for its type?
Bart
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 0/2] Add a property in at24.c
2018-06-26 13:30 ` Bartosz Golaszewski
@ 2018-06-26 15:48 ` Andy Shevchenko
2018-06-26 16:21 ` Yeh, Andy
0 siblings, 1 reply; 18+ messages in thread
From: Andy Shevchenko @ 2018-06-26 15:48 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: alanx.chiang, linux-i2c, andy.yeh, Sakari Ailus, Rajmohan Mani,
Andy Shevchenko, Rob Herring, Mark Rutland, Arnd Bergmann,
Greg Kroah-Hartman, Linux Kernel Mailing List
On Tue, 2018-06-26 at 15:30 +0200, Bartosz Golaszewski wrote:
> 2018-06-26 15:23 GMT+02:00 Andy Shevchenko <andriy.shevchenko@linux.in
> tel.com>:
> > On Tue, 2018-06-26 at 14:36 +0200, Bartosz Golaszewski wrote:
> > > 2018-06-26 14:14 GMT+02:00 Andy Shevchenko
> > > <andriy.shevchenko@linux.intel.com>:
> > > > On Tue, 2018-06-26 at 09:41 +0200, Bartosz Golaszewski wrote:
> > > > > What is your use case exactly? Do you have an EEPROM model
> > > > > that's
> > > > > not
> > > > > yet supported explicitly in the driver? Why would you need
> > > > > this
> > > > > option?
> > > >
> > > > The current at24 driver has no address width support,
> > > > thus, reusing same
> > > > (allocated) IDs (non-DT case) is hard.
> >
> > ^^^^^
> >
> > > Every supported compatible has the width already specified in its
> > > corresponding chip data.
> >
> >
> > Please, read again carefully what I wrote before.
> >
>
> Ok makes sense in that case. Could you just point me towards an
> example model which has the address width different than the default
> for its type?
AFAIK, it's a companion device inside the camera voice coil IC, i.e.
DONGWOON DW9714.
--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
^ permalink raw reply [flat|nested] 18+ messages in thread
* RE: [PATCH v2 0/2] Add a property in at24.c
2018-06-26 15:48 ` Andy Shevchenko
@ 2018-06-26 16:21 ` Yeh, Andy
2018-06-26 16:31 ` Mani, Rajmohan
2018-06-26 16:38 ` Andy Shevchenko
0 siblings, 2 replies; 18+ messages in thread
From: Yeh, Andy @ 2018-06-26 16:21 UTC (permalink / raw)
To: Andy Shevchenko, Bartosz Golaszewski
Cc: Chiang, AlanX, linux-i2c, Sakari Ailus, Mani, Rajmohan,
Andy Shevchenko, Rob Herring, Mark Rutland, Arnd Bergmann,
Greg Kroah-Hartman, Linux Kernel Mailing List
> -----Original Message-----
> From: Andy Shevchenko [mailto:andriy.shevchenko@linux.intel.com]
> Sent: Tuesday, June 26, 2018 11:48 PM
> To: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Chiang, AlanX <alanx.chiang@intel.com>; linux-i2c <linux-
> i2c@vger.kernel.org>; Yeh, Andy <andy.yeh@intel.com>; Sakari Ailus
> <sakari.ailus@linux.intel.com>; Mani, Rajmohan <rajmohan.mani@intel.com>;
> Andy Shevchenko <andy.shevchenko@gmail.com>; Rob Herring
> <robh+dt@kernel.org>; Mark Rutland <mark.rutland@arm.com>; Arnd
> Bergmann <arnd@arndb.de>; Greg Kroah-Hartman
> <gregkh@linuxfoundation.org>; Linux Kernel Mailing List <linux-
> kernel@vger.kernel.org>
> Subject: Re: [PATCH v2 0/2] Add a property in at24.c
>
> On Tue, 2018-06-26 at 15:30 +0200, Bartosz Golaszewski wrote:
> > 2018-06-26 15:23 GMT+02:00 Andy Shevchenko
> <andriy.shevchenko@linux.in
> > tel.com>:
> > > On Tue, 2018-06-26 at 14:36 +0200, Bartosz Golaszewski wrote:
> > > > 2018-06-26 14:14 GMT+02:00 Andy Shevchenko
> > > > <andriy.shevchenko@linux.intel.com>:
> > > > > On Tue, 2018-06-26 at 09:41 +0200, Bartosz Golaszewski wrote:
> > > > > > What is your use case exactly? Do you have an EEPROM model
> > > > > > that's not yet supported explicitly in the driver? Why would
> > > > > > you need this option?
> > > > >
> > > > > The current at24 driver has no address width support, thus,
> > > > > reusing same
> > > > > (allocated) IDs (non-DT case) is hard.
> > >
> > > ^^^^^
> > >
> > > > Every supported compatible has the width already specified in its
> > > > corresponding chip data.
> > >
> > >
> > > Please, read again carefully what I wrote before.
> > >
> >
> > Ok makes sense in that case. Could you just point me towards an
> > example model which has the address width different than the default
> > for its type?
>
> AFAIK, it's a companion device inside the camera voice coil IC, i.e.
> DONGWOON DW9714.
>
Nope, actually it is DW9807 instead, which is used on a Samsung Chromebook.
> --
> Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Intel Finland Oy
^ permalink raw reply [flat|nested] 18+ messages in thread
* RE: [PATCH v2 0/2] Add a property in at24.c
2018-06-26 16:21 ` Yeh, Andy
@ 2018-06-26 16:31 ` Mani, Rajmohan
2018-06-26 16:38 ` Andy Shevchenko
1 sibling, 0 replies; 18+ messages in thread
From: Mani, Rajmohan @ 2018-06-26 16:31 UTC (permalink / raw)
To: Yeh, Andy, Andy Shevchenko, Bartosz Golaszewski
Cc: Chiang, AlanX, linux-i2c, Sakari Ailus, Andy Shevchenko,
Rob Herring, Mark Rutland, Arnd Bergmann, Greg Kroah-Hartman,
Linux Kernel Mailing List
Hi Bartosz,
> -----Original Message-----
> From: Yeh, Andy
> Sent: Tuesday, June 26, 2018 9:21 AM
> To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>; Bartosz
> Golaszewski <brgl@bgdev.pl>
> Cc: Chiang, AlanX <alanx.chiang@intel.com>; linux-i2c <linux-
> i2c@vger.kernel.org>; Sakari Ailus <sakari.ailus@linux.intel.com>; Mani,
> Rajmohan <rajmohan.mani@intel.com>; Andy Shevchenko
> <andy.shevchenko@gmail.com>; Rob Herring <robh+dt@kernel.org>; Mark
> Rutland <mark.rutland@arm.com>; Arnd Bergmann <arnd@arndb.de>; Greg
> Kroah-Hartman <gregkh@linuxfoundation.org>; Linux Kernel Mailing List
> <linux-kernel@vger.kernel.org>
> Subject: RE: [PATCH v2 0/2] Add a property in at24.c
>
> > -----Original Message-----
> > From: Andy Shevchenko [mailto:andriy.shevchenko@linux.intel.com]
> > Sent: Tuesday, June 26, 2018 11:48 PM
> > To: Bartosz Golaszewski <brgl@bgdev.pl>
> > Cc: Chiang, AlanX <alanx.chiang@intel.com>; linux-i2c <linux-
> > i2c@vger.kernel.org>; Yeh, Andy <andy.yeh@intel.com>; Sakari Ailus
> > <sakari.ailus@linux.intel.com>; Mani, Rajmohan
> > <rajmohan.mani@intel.com>; Andy Shevchenko
> > <andy.shevchenko@gmail.com>; Rob Herring <robh+dt@kernel.org>; Mark
> > Rutland <mark.rutland@arm.com>; Arnd Bergmann <arnd@arndb.de>; Greg
> > Kroah-Hartman <gregkh@linuxfoundation.org>; Linux Kernel Mailing List
> > <linux- kernel@vger.kernel.org>
> > Subject: Re: [PATCH v2 0/2] Add a property in at24.c
> >
> > On Tue, 2018-06-26 at 15:30 +0200, Bartosz Golaszewski wrote:
> > > 2018-06-26 15:23 GMT+02:00 Andy Shevchenko
> > <andriy.shevchenko@linux.in
> > > tel.com>:
> > > > On Tue, 2018-06-26 at 14:36 +0200, Bartosz Golaszewski wrote:
> > > > > 2018-06-26 14:14 GMT+02:00 Andy Shevchenko
> > > > > <andriy.shevchenko@linux.intel.com>:
> > > > > > On Tue, 2018-06-26 at 09:41 +0200, Bartosz Golaszewski wrote:
> > > > > > > What is your use case exactly? Do you have an EEPROM model
> > > > > > > that's not yet supported explicitly in the driver? Why would
> > > > > > > you need this option?
> > > > > >
> > > > > > The current at24 driver has no address width support, thus,
> > > > > > reusing same
> > > > > > (allocated) IDs (non-DT case) is hard.
> > > >
> > > > ^^^^^
> > > >
> > > > > Every supported compatible has the width already specified in
> > > > > its corresponding chip data.
> > > >
> > > >
> > > > Please, read again carefully what I wrote before.
> > > >
> > >
> > > Ok makes sense in that case. Could you just point me towards an
> > > example model which has the address width different than the default
> > > for its type?
> >
> > AFAIK, it's a companion device inside the camera voice coil IC, i.e.
> > DONGWOON DW9714.
> >
>
> Nope, actually it is DW9807 instead, which is used on a Samsung Chromebook.
M24C64S is one example, where reusing same id (non-DT case) is not possible,
since this model uses 16 bits as address width, as the driver supports only
8 bits address width as default.
Thanks
Raj
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 0/2] Add a property in at24.c
2018-06-26 16:21 ` Yeh, Andy
2018-06-26 16:31 ` Mani, Rajmohan
@ 2018-06-26 16:38 ` Andy Shevchenko
1 sibling, 0 replies; 18+ messages in thread
From: Andy Shevchenko @ 2018-06-26 16:38 UTC (permalink / raw)
To: Yeh, Andy, Bartosz Golaszewski
Cc: Chiang, AlanX, linux-i2c, Sakari Ailus, Mani, Rajmohan,
Andy Shevchenko, Rob Herring, Mark Rutland, Arnd Bergmann,
Greg Kroah-Hartman, Linux Kernel Mailing List
On Tue, 2018-06-26 at 16:21 +0000, Yeh, Andy wrote:
> > > Ok makes sense in that case. Could you just point me towards an
> > > example model which has the address width different than the
> > > default
> > > for its type?
> >
> > AFAIK, it's a companion device inside the camera voice coil IC, i.e.
> > DONGWOON DW9714.
> >
>
> Nope, actually it is DW9807 instead, which is used on a Samsung
> Chromebook.
Ah, okay, good to know.
--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 1/2] dt-bindings: at24: Add address-width property
2018-06-26 6:22 ` [PATCH v2 1/2] dt-bindings: at24: Add address-width property alanx.chiang
2018-06-26 6:49 ` Sakari Ailus
@ 2018-06-26 16:44 ` Rob Herring
1 sibling, 0 replies; 18+ messages in thread
From: Rob Herring @ 2018-06-26 16:44 UTC (permalink / raw)
To: Alan Chiang
Cc: Linux I2C, Andy Yeh, Sakari Ailus, Andy Shevchenko,
Rajmohan Mani, Andy Shevchenko, Bartosz Golaszewski,
Mark Rutland, Arnd Bergmann, Greg Kroah-Hartman, linux-kernel
On Tue, Jun 26, 2018 at 12:22 AM <alanx.chiang@intel.com> wrote:
>
> From: "alanx.chiang" <alanx.chiang@intel.com>
Please fix your author name and send bindings to the DT list if you
want them reviewed.
>
> The AT24 series chips use 8-bit address by default. If some
> chips would like to support more than 8 bits, should add the compatible
> field for specfic chips in the driver.
>
> Provide a flexible way to determine the addressing bits through
> address-width in this patch.
>
> Signed-off-by: Alan Chiang <alanx.chiang@intel.com>
> Signed-off-by: Andy Yeh <andy.yeh@intel.com>
>
> ---
> since v1:
> -- Remove the address-width field in the example.
>
> ---
> Documentation/devicetree/bindings/eeprom/at24.txt | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/eeprom/at24.txt b/Documentation/devicetree/bindings/eeprom/at24.txt
> index 61d833a..9467482 100644
> --- a/Documentation/devicetree/bindings/eeprom/at24.txt
> +++ b/Documentation/devicetree/bindings/eeprom/at24.txt
> @@ -72,6 +72,8 @@ Optional properties:
>
> - wp-gpios: GPIO to which the write-protect pin of the chip is connected.
>
> + - address-width : number of address bits (one of 8, 16).
> +
> Example:
>
> eeprom@52 {
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 18+ messages in thread
end of thread, other threads:[~2018-06-26 16:45 UTC | newest]
Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-06-26 6:22 [PATCH v2 0/2] Add a property in at24.c alanx.chiang
2018-06-26 6:22 ` [PATCH v2 1/2] dt-bindings: at24: Add address-width property alanx.chiang
2018-06-26 6:49 ` Sakari Ailus
2018-06-26 16:44 ` Rob Herring
2018-06-26 6:22 ` [PATCH v2 2/2] eeprom: at24: Add support for " alanx.chiang
2018-06-26 6:47 ` Sakari Ailus
2018-06-26 7:11 ` Chiang, AlanX
2018-06-26 7:26 ` Sakari Ailus
2018-06-26 12:11 ` Andy Shevchenko
2018-06-26 7:41 ` [PATCH v2 0/2] Add a property in at24.c Bartosz Golaszewski
2018-06-26 12:14 ` Andy Shevchenko
2018-06-26 12:36 ` Bartosz Golaszewski
2018-06-26 13:23 ` Andy Shevchenko
2018-06-26 13:30 ` Bartosz Golaszewski
2018-06-26 15:48 ` Andy Shevchenko
2018-06-26 16:21 ` Yeh, Andy
2018-06-26 16:31 ` Mani, Rajmohan
2018-06-26 16:38 ` Andy Shevchenko
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