Subject: Re: [PATCH v2 2/2] powerpc/mpic: add global timer support

From: Scott Wood <[email-masked]>
Date: Fri, 10 Aug 2012 15:37:42 -0500

On 08/10/2012 12:54 AM, [email-masked] wrote:
> +static int group_get_freq(struct group_priv *priv)
> +{
> +	if (priv->flags & FSL_GLOBAL_TIMER) {
> +		ccbfreq = fsl_get_sys_freq();
> +		priv->timerfreq = ccbfreq;
> +	} else {
> +		priv->timerfreq = in_be32(priv->group_tfrr);
> +	}

FSL MPICs have TFRR too.  I'm not sure that the lack of fsl,mpic is a
good indication that TFRR is being set (e.g. we have old device trees
for FSL chips with U-Boot that are labelled as ordinary openpics).

> +
> +	if (priv->timerfreq <= 0)
> +		return -EINVAL;
> +
> +	return 0;
> +}

timerfreq is unsigned.  It can never be < 0.

> +
> +static int group_init_regmap(struct device_node *np, struct group_priv *priv)
> +{
> +	priv->group_tfrr = of_iomap(np, 0);
> +	if (!priv->group_tfrr) {
> +		pr_err("%s: cannot ioremap tfrr address.\n",
> +				np->full_name);
> +		return -EINVAL;
> +	}
> +
> +	priv->regs = of_iomap(np, 1);
> +	if (!priv->regs) {
> +		pr_err("%s: cannot ioremap timer register address.\n",
> +				np->full_name);
> +		return -EINVAL;
> +	}
> +
> +	if (!(priv->flags & FSL_GLOBAL_TIMER))
> +		return 0;
> +
> +	priv->group_tcr = of_iomap(np, 2);
> +	if (!priv->group_tcr) {
> +		pr_err("%s: cannot ioremap tcr address.\n", np->full_name);
> +		return -EINVAL;
> +	}

This is not compatible with existing mpic timer nodes.

> +	p = of_get_property(np, "available-ranges", &len);
> +	if (p && len % (2 * sizeof(u32)) != 0) {
> +		pr_err("%s: malformed fsl,available-ranges property.\n",
> +				np->full_name);
> +		return -EINVAL;
> +	}

You need to support fsl,available-ranges since that's in an accepted
binding and people could have partitioned setups already using it.

You also have a mismatch between the property you check and the error
string.

-Scott