Re: [PATCH] clk: samsung: exynos7: Enable clocks for CMU_CCORE and CMU_FSYS0 blocks

Tomasz Figa
2016-04-13T06:26:20Z

2016-04-12 14:07 GMT+03:00 Alim Akhtar <alim.akhtar@samsung.com>:
> This patch enables clocks for CMU_CCORE and CMU_FSYS0 blocks. This is
> required before accessing registers of these blocks.
>
> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
> ---
> drivers/clk/samsung/clk-exynos7.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/clk/samsung/clk-exynos7.c b/drivers/clk/samsung/clk-exynos7.c
> index ad68d46..7013aa7 100644
> --- a/drivers/clk/samsung/clk-exynos7.c
> +++ b/drivers/clk/samsung/clk-exynos7.c
> @@ -8,6 +8,7 @@
> *
> */
>
> +#include <linux/clk.h>
> #include <linux/clk-provider.h>
> #include <linux/of.h>
>
> @@ -205,7 +206,11 @@ static struct samsung_cmu_info topc_cmu_info __initdata = {
>
> static void __init exynos7_clk_topc_init(struct device_node *np)
> {
> + struct clk *clk;
> +
> samsung_cmu_register_one(np, &topc_cmu_info);
> + clk = __clk_lookup("aclk_ccore_133");
> + clk_prepare_enable(clk);

Shouldn't this be rather done before calling
samsung_cmu_register_one()? I don't remember exactly, but wouldn't
clock registration trigger reading back current (mux, div) values from
registers?

Also, do we have any guarantees on order of initialization of
particular CMUs? I believe this will happen in order of DT nodes and
so would be not any kind of guarantee at all.

Best regards,
Tomasz