diff mbox

memory: omap-gpmc: Make 'bank-width' property optional

Message ID 20171103130909.ug35yc7ovjgkmahs@lenoch (mailing list archive)
State New, archived
Headers show

Commit Message

Ladislav Michl Nov. 3, 2017, 1:09 p.m. UTC
On Fri, Nov 03, 2017 at 02:15:21PM +0200, Roger Quadros wrote:
> On 03/11/17 11:57, Ladislav Michl wrote:
> > Value of device_width is previously read from documented
> > 'gpmc,device-width' property. For now leave 'bank-width'
> > as a fallback for older DT blobs.
> 
> bank-width is mandatory for NOR devices only.
> 
> > 
> > Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
> > ---
> >  drivers/memory/omap-gpmc.c | 9 +++++++--
> >  1 file changed, 7 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
> > index 24b584b74d84..3dc9706e1f15 100644
> > --- a/drivers/memory/omap-gpmc.c
> > +++ b/drivers/memory/omap-gpmc.c
> > @@ -2152,10 +2152,15 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
> >  		gpmc_configure(GPMC_CONFIG_WP, 0);
> >  		gpmc_s.device_nand = true;
> >  	} else {
> > +		/*
> > +		 * Some older DT blobs are missing device-width property,
> > +		 * so try to read bank-width and fail if neither works.
> > +		 */
> 
> I'd get rid of the above comment and rather say, NOR devices use bank-width
> to specify device width.
> 
> >  		ret = of_property_read_u32(child, "bank-width",
> >  					   &gpmc_s.device_width);
> > -		if (ret < 0) {
> > -			dev_err(&pdev->dev, "%pOF has no 'bank-width' property\n",
> > +		if (ret < 0 && !gpmc_s.device_width) {
> > +			dev_err(&pdev->dev,
> > +				"%pOF has no 'gpmc,device-width' property\n",
> >  				child);
> >  			goto err;
> >  		}
> > 
> 
> I'm ok with the approach.
> We could also update the DT binding documentation to say
> "'gpmc,device-width' is mandatory if device is not NOR or NAND type.
> For NOR, bank-width is used and for NAND nand-bus-width is used to figure
> out the device-width"

Will update documentaton in separate patch.

> And update the patch commit log accordingly.

Something like the following?

8<-----------------------
Subject: [PATCH] memory: omap-gpmc: Make 'bank-width' NOR mandatory only

Only NOR devices are using 'bank-width' property to configure device width.
Note that code does not do exactly that - it fails only if 'bank-width' is
missing and device width was not configured previously using
'gpmc,device-width'.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
---
 drivers/memory/omap-gpmc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Ladislav Michl Nov. 3, 2017, 1:16 p.m. UTC | #1
On Fri, Nov 03, 2017 at 02:09:09PM +0100, Ladislav Michl wrote:
> On Fri, Nov 03, 2017 at 02:15:21PM +0200, Roger Quadros wrote:
> > On 03/11/17 11:57, Ladislav Michl wrote:
> > > Value of device_width is previously read from documented
> > > 'gpmc,device-width' property. For now leave 'bank-width'
> > > as a fallback for older DT blobs.
> > 
> > bank-width is mandatory for NOR devices only.
> > 
> > > 
> > > Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
> > > ---
> > >  drivers/memory/omap-gpmc.c | 9 +++++++--
> > >  1 file changed, 7 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
> > > index 24b584b74d84..3dc9706e1f15 100644
> > > --- a/drivers/memory/omap-gpmc.c
> > > +++ b/drivers/memory/omap-gpmc.c
> > > @@ -2152,10 +2152,15 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
> > >  		gpmc_configure(GPMC_CONFIG_WP, 0);
> > >  		gpmc_s.device_nand = true;
> > >  	} else {
> > > +		/*
> > > +		 * Some older DT blobs are missing device-width property,
> > > +		 * so try to read bank-width and fail if neither works.
> > > +		 */
> > 
> > I'd get rid of the above comment and rather say, NOR devices use bank-width
> > to specify device width.
> > 
> > >  		ret = of_property_read_u32(child, "bank-width",
> > >  					   &gpmc_s.device_width);
> > > -		if (ret < 0) {
> > > -			dev_err(&pdev->dev, "%pOF has no 'bank-width' property\n",
> > > +		if (ret < 0 && !gpmc_s.device_width) {
> > > +			dev_err(&pdev->dev,
> > > +				"%pOF has no 'gpmc,device-width' property\n",
> > >  				child);
> > >  			goto err;
> > >  		}
> > > 
> > 
> > I'm ok with the approach.
> > We could also update the DT binding documentation to say
> > "'gpmc,device-width' is mandatory if device is not NOR or NAND type.
> > For NOR, bank-width is used and for NAND nand-bus-width is used to figure
> > out the device-width"
> 
> Will update documentaton in separate patch.
> 
> > And update the patch commit log accordingly.
> 
> Something like the following?
> 
> 8<-----------------------
> Subject: [PATCH] memory: omap-gpmc: Make 'bank-width' NOR mandatory only
> 
> Only NOR devices are using 'bank-width' property to configure device width.
> Note that code does not do exactly that - it fails only if 'bank-width' is
> missing and device width was not configured previously using
> 'gpmc,device-width'.
> 
> Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
> ---
>  drivers/memory/omap-gpmc.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
> index ff73f2ad468c..26cc447662f0 100644
> --- a/drivers/memory/omap-gpmc.c
> +++ b/drivers/memory/omap-gpmc.c
> @@ -2157,9 +2157,10 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
>  		gpmc_configure(GPMC_CONFIG_WP, 0);
>  		gpmc_s.device_nand = true;
>  	} else {
> +		/* NOR devices use bank-width to specify device width */

Actually this comment is still wrong (and thus commit message).
Documentation/devicetree/bindings/net/gpmc-eth.txt
Ethernet is using this as well...

>  		ret = of_property_read_u32(child, "bank-width",
>  					   &gpmc_s.device_width);
> -		if (ret < 0) {
> +		if (ret < 0 && !gpmc_s.device_width) {
>  			dev_err(&pdev->dev, "%pOF has no 'bank-width' property\n",
>  				child);
>  			goto err;
> -- 
> 2.11.0
> 
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Roger Quadros Nov. 3, 2017, 1:30 p.m. UTC | #2
On 03/11/17 15:16, Ladislav Michl wrote:
> On Fri, Nov 03, 2017 at 02:09:09PM +0100, Ladislav Michl wrote:
>> On Fri, Nov 03, 2017 at 02:15:21PM +0200, Roger Quadros wrote:
>>> On 03/11/17 11:57, Ladislav Michl wrote:
>>>> Value of device_width is previously read from documented
>>>> 'gpmc,device-width' property. For now leave 'bank-width'
>>>> as a fallback for older DT blobs.
>>>
>>> bank-width is mandatory for NOR devices only.
>>>
>>>>
>>>> Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
>>>> ---
>>>>  drivers/memory/omap-gpmc.c | 9 +++++++--
>>>>  1 file changed, 7 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
>>>> index 24b584b74d84..3dc9706e1f15 100644
>>>> --- a/drivers/memory/omap-gpmc.c
>>>> +++ b/drivers/memory/omap-gpmc.c
>>>> @@ -2152,10 +2152,15 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
>>>>  		gpmc_configure(GPMC_CONFIG_WP, 0);
>>>>  		gpmc_s.device_nand = true;
>>>>  	} else {
>>>> +		/*
>>>> +		 * Some older DT blobs are missing device-width property,
>>>> +		 * so try to read bank-width and fail if neither works.
>>>> +		 */
>>>
>>> I'd get rid of the above comment and rather say, NOR devices use bank-width
>>> to specify device width.
>>>
>>>>  		ret = of_property_read_u32(child, "bank-width",
>>>>  					   &gpmc_s.device_width);
>>>> -		if (ret < 0) {
>>>> -			dev_err(&pdev->dev, "%pOF has no 'bank-width' property\n",
>>>> +		if (ret < 0 && !gpmc_s.device_width) {
>>>> +			dev_err(&pdev->dev,
>>>> +				"%pOF has no 'gpmc,device-width' property\n",
>>>>  				child);
>>>>  			goto err;
>>>>  		}
>>>>
>>>
>>> I'm ok with the approach.
>>> We could also update the DT binding documentation to say
>>> "'gpmc,device-width' is mandatory if device is not NOR or NAND type.
>>> For NOR, bank-width is used and for NAND nand-bus-width is used to figure
>>> out the device-width"
>>
>> Will update documentaton in separate patch.
>>
>>> And update the patch commit log accordingly.
>>
>> Something like the following?
>>
>> 8<-----------------------
>> Subject: [PATCH] memory: omap-gpmc: Make 'bank-width' NOR mandatory only
>>
>> Only NOR devices are using 'bank-width' property to configure device width.
>> Note that code does not do exactly that - it fails only if 'bank-width' is
>> missing and device width was not configured previously using
>> 'gpmc,device-width'.
>>
>> Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
>> ---
>>  drivers/memory/omap-gpmc.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
>> index ff73f2ad468c..26cc447662f0 100644
>> --- a/drivers/memory/omap-gpmc.c
>> +++ b/drivers/memory/omap-gpmc.c
>> @@ -2157,9 +2157,10 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
>>  		gpmc_configure(GPMC_CONFIG_WP, 0);
>>  		gpmc_s.device_nand = true;
>>  	} else {
>> +		/* NOR devices use bank-width to specify device width */
> 
> Actually this comment is still wrong (and thus commit message).
> Documentation/devicetree/bindings/net/gpmc-eth.txt
> Ethernet is using this as well...

Oh :(. Ideally it shouldn't have been the case. But damage is already done.

I think we should still fix up the gpmc-eth binding document to use gpmc,device-width there.
And continue to support in code anybody already using bank-width for ethernet.

> 
>>  		ret = of_property_read_u32(child, "bank-width",
>>  					   &gpmc_s.device_width);
>> -		if (ret < 0) {
>> +		if (ret < 0 && !gpmc_s.device_width) {
>>  			dev_err(&pdev->dev, "%pOF has no 'bank-width' property\n",
>>  				child);
>>  			goto err;
>> -- 
>> 2.11.0
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
index ff73f2ad468c..26cc447662f0 100644
--- a/drivers/memory/omap-gpmc.c
+++ b/drivers/memory/omap-gpmc.c
@@ -2157,9 +2157,10 @@  static int gpmc_probe_generic_child(struct platform_device *pdev,
 		gpmc_configure(GPMC_CONFIG_WP, 0);
 		gpmc_s.device_nand = true;
 	} else {
+		/* NOR devices use bank-width to specify device width */
 		ret = of_property_read_u32(child, "bank-width",
 					   &gpmc_s.device_width);
-		if (ret < 0) {
+		if (ret < 0 && !gpmc_s.device_width) {
 			dev_err(&pdev->dev, "%pOF has no 'bank-width' property\n",
 				child);
 			goto err;