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

Wolfram Sang w.sang at pengutronix.de
Wed Apr 1 00:39:53 EST 2009


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 at 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);
+	}

>  
>  	dev_set_drvdata(&op->dev, i2c);
>  
> 
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Regards,

   Wolfram

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