Re: [PATCH 5/6] clk: tegra114: implement wait_for_reset and disable_clock for tegra_cpu_car_ops

[Mike Turquette <mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>]

Quoting Joseph Lo (2013-05-15 03:27:23)
> The conventional CPU hotplug sequence on the other Tegra chips, we will also
> clock gate the CPU in tegra_cpu_kill() after the CPU was power gated. For
> Tegra114, the flow controller will clock gate the CPU after the power down
> sequence. But we still need to implement a empty function for disable_clock
> to avoid kernel warning message.
> 
> Cc: Mike Turquette <mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> Signed-off-by: Joseph Lo <josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

Acked-by: Mike Turquette <mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

> ---
>  drivers/clk/tegra/clk-tegra114.c | 23 ++++++++++++++++++++++-
>  1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/tegra/clk-tegra114.c b/drivers/clk/tegra/clk-tegra114.c
> index d78e16e..40d939d 100644
> --- a/drivers/clk/tegra/clk-tegra114.c
> +++ b/drivers/clk/tegra/clk-tegra114.c
> @@ -250,6 +250,9 @@
>  #define CLK_SOURCE_XUSB_DEV_SRC 0x60c
>  #define CLK_SOURCE_EMC 0x19c
>  
> +/* Tegra CPU clock and reset control regs */
> +#define CLK_RST_CONTROLLER_CPU_CMPLX_STATUS    0x470
> +
>  static int periph_clk_enb_refcnt[CLK_OUT_ENB_NUM * 32];
>  
>  static void __iomem *clk_base;
> @@ -2000,7 +2003,25 @@ static __init void tegra114_periph_clk_init(void __iomem *clk_base)
>         }
>  }
>  
> -static struct tegra_cpu_car_ops tegra114_cpu_car_ops;
> +/* Tegra114 CPU clock and reset control functions */
> +static void tegra114_wait_cpu_in_reset(u32 cpu)
> +{
> +       unsigned int reg;
> +
> +       do {
> +               reg = readl(clk_base + CLK_RST_CONTROLLER_CPU_CMPLX_STATUS);
> +               cpu_relax();
> +       } while (!(reg & (1 << cpu)));  /* check CPU been reset or not */
> +}
> +static void tegra114_disable_cpu_clock(u32 cpu)
> +{
> +       /* flow controller would take care in the power sequence. */
> +}
> +
> +static struct tegra_cpu_car_ops tegra114_cpu_car_ops = {
> +       .wait_for_reset = tegra114_wait_cpu_in_reset,
> +       .disable_clock  = tegra114_disable_cpu_clock,
> +};
>  
>  static const struct of_device_id pmc_match[] __initconst = {
>         { .compatible = "nvidia,tegra114-pmc" },
> -- 
> 1.8.2.2