Subject: [PATCHv4 16/33] CLK: OMAP: DPLL: do not of_iomap NULL autoidle register

From: [email-masked] (Nishanth Menon)
Date: Tue, 30 Jul 2013 14:49:31 -0500

On 07/23/2013 02:20 AM, Tero Kristo wrote:
> AM33xx series SoCs do not have autoidle support, and for these the
> autoidle register is marked as NULL. Check against a NULL pointer and
> do not attempt to of_iomap in this case, as this just creates a bogus
> pointer and causes a kernel crash during boot.
>
> Signed-off-by: Tero Kristo <[email-masked]>
> ---
>   drivers/clk/omap/dpll.c |   10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/omap/dpll.c b/drivers/clk/omap/dpll.c
> index 1d24feada..d8a958a 100644
> --- a/drivers/clk/omap/dpll.c
> +++ b/drivers/clk/omap/dpll.c
> @@ -162,6 +162,7 @@ static void __init of_omap_dpll_setup(struct device_node *node,
>   	u32 max_multiplier = 2047;
>   	u32 max_divider = 128;
>   	u32 min_divider = 1;
> +	u32 val;
>   	int i;
>
>   	dd = kzalloc(sizeof(struct dpll_data), GFP_KERNEL);
> @@ -210,7 +211,14 @@ static void __init of_omap_dpll_setup(struct device_node *node,
>
>   	dd->control_reg = of_iomap(node, 0);
>   	dd->idlest_reg = of_iomap(node, 1);
> -	dd->autoidle_reg = of_iomap(node, 2);
> +	/*
> +	 * AM33xx DPLLs have no autoidle support, and the autoidle reg
> +	 * for these is NULL. Do not attempt to of_iomap in this case,
> +	 * as this just creates a bogus pointer and crashes the kernel.
> +	 */
> +	of_property_read_u32_index(node, "reg", 2 * 2, &val);
> +	if (val)
> +		dd->autoidle_reg = of_iomap(node, 2);
should we not do that for all the parameters?
OR:
move this as index 3 which is optional and is not defined for am33xx?

>   	dd->mult_div1_reg = of_iomap(node, 3);

>
>   	dd->idlest_mask = idlest_mask;
>
we could probably squash this in original dpll.c as a result?

-- 
Regards,
Nishanth Menon