Re: [PATCH v5 1/5] ARM: EXYNOS: Add support for mapping PMU base address via DT
From: Tomasz Figa
Date: Mon Jun 30 2014 - 12:12:26 EST
Hi Pankaj,
In general the patch seems quite nice, but please see few comments inline.
On 25.06.2014 16:03, Pankaj Dubey wrote:
> Add support for mapping Samsung Power Management Unit (PMU)
> base address from device tree.
>
> Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
> ---
> arch/arm/mach-exynos/common.h | 1 +
> arch/arm/mach-exynos/exynos.c | 45 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 46 insertions(+)
[snip]
> +static void exynos_map_pmu(void)
> +{
> + struct device_node *np = NULL;
nit: Unnecessary variable initialization.
> +
> + np = of_find_matching_node(NULL, exynos_dt_pmu_match);
> +
nit: Unnecessary blank line.
> + if (!np) {
> + pr_err("Failed to find PMU node\n");
> + return;
Returning here probably doesn't make too much sense, especially when you
just panic if the mapping fails and you remove the static mapping in
patch 2/5, so backwards compatibility isn't provided anyway.
So something like this might be a better idea:
np = of_find_matching_node(NULL, exynos_dt_pmu_match);
if (np)
pmu_base_addr = of_iomap(np, 0);
if (!pmu_base_addr)
panic("failed to find exynos pmu register\n");
> + }
> +
> + pmu_base_addr = of_iomap(np, 0);
> +
> + if (!pmu_base_addr)
> + panic("failed to find exynos pmu register\n");
> +}
> +
> +static void __init exynos_init_time(void)
> +{
> + /* Nothing to do timer specific.
> + * Since platsmp.c needs pmu base address by the time
> + * DT is not unflatten so we can't use DT APIs before
> + * init_time
> + */
> + exynos_map_pmu();
Would moving this to .init_irq() callback work too? There are more
things happening in .init_time() so it seems more fragile and some
platforms (e.g. mach-tegra) do such platform-specific initialization in
.init_irq() instead.
Best regards,
Tomasz
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