Re: [PATCH v7 1/5] clk: rockchip: RK3288: add suspend and resume

[Mike Turquette]

Quoting Chris Zhong (2014-11-07 05:49:33)
> save and restore some clks, which might be changed in suspend.
> 
> Signed-off-by: Tony Xie <xxx@xxxxxxxxxxxxxx>
> Signed-off-by: Chris Zhong <zyw@xxxxxxxxxxxxxx>
> Reviewed-by: Doug Anderson <dianders@xxxxxxxxxxxx>
> Tested-by: Doug Anderson <dianders@xxxxxxxxxxxx>

Looks good to me.

Regards,
Mike

> 
> ---
> 
> Changes in v7: None
> Changes in v6:
> - modify comments
> 
> Changes in v5:
> - modify comments
> 
> Changes in v4: None
> Changes in v3: None
> Changes in v2:
> - __raw_readl/__raw_writel replaced by readl_relaxed/writel_relaxed
> 
>  drivers/clk/rockchip/clk-rk3288.c | 60 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
> 
> diff --git a/drivers/clk/rockchip/clk-rk3288.c b/drivers/clk/rockchip/clk-rk3288.c
> index 2327829..66a9cb0 100644
> --- a/drivers/clk/rockchip/clk-rk3288.c
> +++ b/drivers/clk/rockchip/clk-rk3288.c
> @@ -16,6 +16,7 @@
>  #include <linux/clk-provider.h>
>  #include <linux/of.h>
>  #include <linux/of_address.h>
> +#include <linux/syscore_ops.h>
>  #include <dt-bindings/clock/rk3288-cru.h>
>  #include "clk.h"
>  
> @@ -762,6 +763,64 @@ static const char *rk3288_critical_clocks[] __initconst = {
>         "hclk_peri",
>  };
>  
> +#ifdef CONFIG_PM_SLEEP
> +static void __iomem *rk3288_cru_base;
> +
> +/* Some CRU registers will be reset in maskrom when the system
> + * wakes up from fastboot.
> + * So save them before suspend, restore them after resume.
> + */
> +static const int rk3288_saved_cru_reg_ids[] = {
> +       RK3288_MODE_CON,
> +       RK3288_CLKSEL_CON(0),
> +       RK3288_CLKSEL_CON(1),
> +       RK3288_CLKSEL_CON(10),
> +       RK3288_CLKSEL_CON(33),
> +       RK3288_CLKSEL_CON(37),
> +};
> +
> +static u32 rk3288_saved_cru_regs[ARRAY_SIZE(rk3288_saved_cru_reg_ids)];
> +
> +static int rk3288_clk_suspend(void)
> +{
> +       int i, reg_id;
> +
> +       for (i = 0; i < ARRAY_SIZE(rk3288_saved_cru_reg_ids); i++) {
> +               reg_id = rk3288_saved_cru_reg_ids[i];
> +
> +               rk3288_saved_cru_regs[i] =
> +                               readl_relaxed(rk3288_cru_base + reg_id);
> +       }
> +       return 0;
> +}
> +
> +static void rk3288_clk_resume(void)
> +{
> +       int i, reg_id;
> +
> +       for (i = ARRAY_SIZE(rk3288_saved_cru_reg_ids) - 1; i >= 0; i--) {
> +               reg_id = rk3288_saved_cru_reg_ids[i];
> +
> +               writel_relaxed(rk3288_saved_cru_regs[i] | 0xffff0000,
> +                              rk3288_cru_base + reg_id);
> +       }
> +}
> +
> +static struct syscore_ops rk3288_clk_syscore_ops = {
> +       .suspend = rk3288_clk_suspend,
> +       .resume = rk3288_clk_resume,
> +};
> +
> +static void rk3288_clk_sleep_init(void __iomem *reg_base)
> +{
> +       rk3288_cru_base = reg_base;
> +       register_syscore_ops(&rk3288_clk_syscore_ops);
> +}
> +
> +#else /* CONFIG_PM_SLEEP */
> +static void rk3288_clk_sleep_init(void __iomem *reg_base) {}
> +#endif
> +
>  static void __init rk3288_clk_init(struct device_node *np)
>  {
>         void __iomem *reg_base;
> @@ -810,5 +869,6 @@ static void __init rk3288_clk_init(struct device_node *np)
>                                   ROCKCHIP_SOFTRST_HIWORD_MASK);
>  
>         rockchip_register_restart_notifier(RK3288_GLB_SRST_FST);
> +       rk3288_clk_sleep_init(reg_base);
>  }
>  CLK_OF_DECLARE(rk3288_cru, "rockchip,rk3288-cru", rk3288_clk_init);
> -- 
> 1.9.1
> 
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