Re: [RFC PATCH 1/3] arm: plat-omap: dmtimer: Add clock source from DT

From: Neil Armstrong
Date: Mon Oct 19 2015 - 08:41:42 EST


Hi,

On 10/16/2015 05:40 PM, Felipe Balbi wrote:
>> +static int omap_dm_timer_of_set_source(struct omap_dm_timer *timer)
>> +{
>> + int ret;
>> + struct clk *parent;
>> +
>> + if (unlikely(!timer))
>> + return -EINVAL;
>
> IMO, let this crash. If this happens we have bigger problems.
>
>> + if (IS_ERR(timer->fclk))
>> + return -EINVAL;
>
> We bail out if we can't get fclk, this check is unnecessary.

Sure, I will remove the checks.
This was also breaking OMAP1, fclk must be checked against NULL here to detect OMAP1 and return -ENODEV;

>
>> + parent = clk_get(&timer->pdev->dev, NULL);
>
> why NULL ? You could use something more descriptive, but no strong
> feelings.


Actually, I just wanted the "default" clock for this device, NULL will select the first OF clock found.
If we specify a name, we should also specify it in the DT as clock-names, is it desired ?
If you feel I should name it somehow... I don't want it to conflict all the HWMOD clk namings actually.

>
>> + if (IS_ERR(parent))
>> + return -ENODEV;
>> +
>> + ret = clk_set_parent(timer->fclk, parent);
>> + if (ret < 0)
>> + pr_err("%s: failed to set parent\n", __func__);
>> +
>> + clk_put(parent);
>> +
>> + return ret;
>> +}
>> +
>> static int omap_dm_timer_prepare(struct omap_dm_timer *timer)
>> {
>> - int rc;
>> + int rc, ret;
>
> doesn't seem like you need this extra 'ret' variable. Just use 'rc'.
>
>> @@ -166,7 +190,11 @@ static int omap_dm_timer_prepare(struct omap_dm_timer *timer)
>> __omap_dm_timer_enable_posted(timer);
>> omap_dm_timer_disable(timer);
>>
>> - return omap_dm_timer_set_source(timer, OMAP_TIMER_SRC_32_KHZ);
>> + ret = omap_dm_timer_of_set_source(timer);
>> + if (ret < 0 && ret == -ENODEV)
>
> this < 0 check is pointless if you're going to check for equality to -ENODEV

Sure, I was certainly tired, this was a so stupid mistake...

Neil
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