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

From: Felipe Balbi
Date: Fri Oct 16 2015 - 11:41:19 EST



Hi,

Neil Armstrong <narmstrong@xxxxxxxxxxxx> writes:
> Add a function which sets the timer source from the clocks
> binding on dm_timer_prepare call.
>
> In case the clocks property is not valid, it falls back to
> the set_source() with 32_KHZ clock as default.
>
> Suggested-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> ---
> arch/arm/plat-omap/dmtimer.c | 32 ++++++++++++++++++++++++++++++--
> 1 file changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
> index 8ca94d3..5e8aece 100644
> --- a/arch/arm/plat-omap/dmtimer.c
> +++ b/arch/arm/plat-omap/dmtimer.c
> @@ -137,9 +137,33 @@ static int omap_dm_timer_reset(struct omap_dm_timer *timer)
> return 0;
> }
>
> +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.

> + parent = clk_get(&timer->pdev->dev, NULL);

why NULL ? You could use something more descriptive, but no strong
feelings.

> + 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

> + return omap_dm_timer_set_source(timer, OMAP_TIMER_SRC_32_KHZ);
> +
> + return ret;
> }
>
> static inline u32 omap_dm_timer_reserved_systimer(int id)
> --
> 1.9.1
>
> --
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--
balbi

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