Re: [PATCH 1/2] powerpc: i2c-mpc: preserve I2C clocking

Re: [PATCH 1/2] powerpc: i2c-mpc: preserve I2C clocking

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 2674 bytes --]

On Tue, Mar 31, 2009 at 02:50:29PM +0200, Wolfgang Grandegger wrote:
> The I2c node property "fsl,preserve-clocking" allows to overtake the
> clock settings from the boot loader and avoids the hard-coded setting.
> 
> Signed-off-by: Wolfgang Grandegger <wg-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
> ---
>  drivers/i2c/busses/i2c-mpc.c |   24 ++++++++++++++++--------
>  1 file changed, 16 insertions(+), 8 deletions(-)
> 
> Index: linux-2.6/drivers/i2c/busses/i2c-mpc.c
> ===================================================================
> --- linux-2.6.orig/drivers/i2c/busses/i2c-mpc.c	2009-03-31 13:25:08.000000000 +0200
> +++ linux-2.6/drivers/i2c/busses/i2c-mpc.c	2009-03-31 13:28:03.000000000 +0200
> @@ -318,17 +318,24 @@
>  {
>  	int result = 0;
>  	struct mpc_i2c *i2c;
> +	int set_clock;
>  
>  	i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
>  	if (!i2c)
>  		return -ENOMEM;
>  
> -	if (of_get_property(op->node, "dfsrr", NULL))
> -		i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
> -
> -	if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
> -			of_device_is_compatible(op->node, "mpc5200-i2c"))
> -		i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
> +	if (of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
> +		set_clock = 0;
> +	} else {
> +		set_clock = 1;
> +
> +		if (of_get_property(op->node, "dfsrr", NULL))
> +			i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
> +
> +		if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
> +		    of_device_is_compatible(op->node, "mpc5200-i2c"))
> +			i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
> +	}
>  
>  	init_waitqueue_head(&i2c->queue);
>  
> @@ -348,8 +355,9 @@
>  			goto fail_request;
>  		}
>  	}
> -	
> -	mpc_i2c_setclock(i2c);
> +
> +	if (set_clock)
> +		mpc_i2c_setclock(i2c);

Can't we drop 'set_clock' with something like this here?

+	if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
+
+		if (of_get_property(op->node, "dfsrr", NULL))
+			i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
+
+		if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
+		    of_device_is_compatible(op->node, "mpc5200-i2c"))
+			i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
+
+		mpc_i2c_setclock(i2c);
+	}

>  
>  	dev_set_drvdata(&op->dev, i2c);
>  
> 
> _______________________________________________
> devicetree-discuss mailing list
> devicetree-discuss-mnsaURCQ41sdnm+yROfE0A@public.gmane.org
> https://ozlabs.org/mailman/listinfo/devicetree-discuss

Regards,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 197 bytes --]

Re: [PATCH 1/2] powerpc: i2c-mpc: preserve I2C clocking

[Wolfgang Grandegger]

Wolfram Sang wrote:
> On Tue, Mar 31, 2009 at 02:50:29PM +0200, Wolfgang Grandegger wrote:
>> The I2c node property "fsl,preserve-clocking" allows to overtake the
>> clock settings from the boot loader and avoids the hard-coded setting.
>>
>> Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
>> ---
>>  drivers/i2c/busses/i2c-mpc.c |   24 ++++++++++++++++--------
>>  1 file changed, 16 insertions(+), 8 deletions(-)
>>
>> Index: linux-2.6/drivers/i2c/busses/i2c-mpc.c
>> ===================================================================
>> --- linux-2.6.orig/drivers/i2c/busses/i2c-mpc.c	2009-03-31 13:25:08.000000000 +0200
>> +++ linux-2.6/drivers/i2c/busses/i2c-mpc.c	2009-03-31 13:28:03.000000000 +0200
>> @@ -318,17 +318,24 @@
>>  {
>>  	int result = 0;
>>  	struct mpc_i2c *i2c;
>> +	int set_clock;
>>  
>>  	i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
>>  	if (!i2c)
>>  		return -ENOMEM;
>>  
>> -	if (of_get_property(op->node, "dfsrr", NULL))
>> -		i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
>> -
>> -	if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
>> -			of_device_is_compatible(op->node, "mpc5200-i2c"))
>> -		i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
>> +	if (of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
>> +		set_clock = 0;
>> +	} else {
>> +		set_clock = 1;
>> +
>> +		if (of_get_property(op->node, "dfsrr", NULL))
>> +			i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
>> +
>> +		if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
>> +		    of_device_is_compatible(op->node, "mpc5200-i2c"))
>> +			i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
>> +	}
>>  
>>  	init_waitqueue_head(&i2c->queue);
>>  
>> @@ -348,8 +355,9 @@
>>  			goto fail_request;
>>  		}
>>  	}
>> -	
>> -	mpc_i2c_setclock(i2c);
>> +
>> +	if (set_clock)
>> +		mpc_i2c_setclock(i2c);
> 
> Can't we drop 'set_clock' with something like this here?
> 
> +	if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
> +
> +		if (of_get_property(op->node, "dfsrr", NULL))
> +			i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
> +
> +		if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
> +		    of_device_is_compatible(op->node, "mpc5200-i2c"))
> +			i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
> +
> +		mpc_i2c_setclock(i2c);
> +	}

No, because the I2C registers are not yet mapped.

Wolfgang.

Re: [PATCH 1/2] powerpc: i2c-mpc: preserve I2C clocking

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 956 bytes --]


> >> -	
> >> -	mpc_i2c_setclock(i2c);
> >> +
> >> +	if (set_clock)
> >> +		mpc_i2c_setclock(i2c);
> > 
> > Can't we drop 'set_clock' with something like this here?
> > 
> > +	if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
> > +
> > +		if (of_get_property(op->node, "dfsrr", NULL))
> > +			i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
> > +
> > +		if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
> > +		    of_device_is_compatible(op->node, "mpc5200-i2c"))
> > +			i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
> > +
> > +		mpc_i2c_setclock(i2c);
> > +	}
> 
> No, because the I2C registers are not yet mapped.

Sorry, I used misleading words :) With 'here' I meant 'at this
position', i.e. insert my above block where mpc_i2c_setclock was used
anyway.

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 197 bytes --]

Re: [PATCH 1/2] powerpc: i2c-mpc: preserve I2C clocking

[Grant Likely]

2009/3/31 Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>:
>
>> >> -
>> >> -  mpc_i2c_setclock(i2c);
>> >> +
>> >> +  if (set_clock)
>> >> +          mpc_i2c_setclock(i2c);
>> >
>> > Can't we drop 'set_clock' with something like this here?
>> >
>> > +   if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
>> > +
>> > +           if (of_get_property(op->node, "dfsrr", NULL))
>> > +                   i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
>> > +
>> > +           if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
>> > +               of_device_is_compatible(op->node, "mpc5200-i2c"))
>> > +                   i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
>> > +
>> > +           mpc_i2c_setclock(i2c);
>> > +   }
>>
>> No, because the I2C registers are not yet mapped.
>
> Sorry, I used misleading words :) With 'here' I meant 'at this
> position', i.e. insert my above block where mpc_i2c_setclock was used
> anyway.

I agree.  The extra flag makes the flow more complex.  The code block
should be moved down.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

Re: [PATCH 1/2] powerpc: i2c-mpc: preserve I2C clocking

[Wolfgang Grandegger]

Grant Likely wrote:
> 2009/3/31 Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>:
>>>>> -
>>>>> -  mpc_i2c_setclock(i2c);
>>>>> +
>>>>> +  if (set_clock)
>>>>> +          mpc_i2c_setclock(i2c);
>>>> Can't we drop 'set_clock' with something like this here?
>>>>
>>>> +   if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
>>>> +
>>>> +           if (of_get_property(op->node, "dfsrr", NULL))
>>>> +                   i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
>>>> +
>>>> +           if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
>>>> +               of_device_is_compatible(op->node, "mpc5200-i2c"))
>>>> +                   i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
>>>> +
>>>> +           mpc_i2c_setclock(i2c);
>>>> +   }
>>> No, because the I2C registers are not yet mapped.
>> Sorry, I used misleading words :) With 'here' I meant 'at this
>> position', i.e. insert my above block where mpc_i2c_setclock was used
>> anyway.
> 
> I agree.  The extra flag makes the flow more complex.  The code block
> should be moved down.

OK, I just resent the patch standalone also including documentation. I
think it can go in immediately without waiting for the full clock
setting patch.

Wolfgang.