target/linux/ramips/patches-4.3/0006-MIPS-ralink-add-cpu-frequency-scaling.patch

   1 From bd30f19a006fb52bac80c6463c49dd2f4159f4ac Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Sun, 28 Jul 2013 16:26:41 +0200
   4 Subject: [PATCH 06/53] MIPS: ralink: add cpu frequency scaling
   5
   6 This feature will break udelay() and cause the delay loop to have longer delays
   7 when the frequency is scaled causing a performance hit.
   8
   9 Signed-off-by: John Crispin <blogic@openwrt.org>
  10 ---
  11  arch/mips/ralink/cevt-rt3352.c |   38 ++++++++++++++++++++++++++++++++++++++
  12  1 file changed, 38 insertions(+)
  13
  14 diff --git a/arch/mips/ralink/cevt-rt3352.c b/arch/mips/ralink/cevt-rt3352.c
  15 index a8e70a9..b36888c 100644
  16 --- a/arch/mips/ralink/cevt-rt3352.c
  17 +++ b/arch/mips/ralink/cevt-rt3352.c
  18 @@ -29,6 +29,10 @@
  19  /* enable the counter */
  20  #define CFG_CNT_EN             0x1
  21
  22 +/* mt7620 frequency scaling defines */
  23 +#define CLK_LUT_CFG    0x40
  24 +#define SLEEP_EN       BIT(31)
  25 +
  26  struct systick_device {
  27         void __iomem *membase;
  28         struct clock_event_device dev;
  29 @@ -36,9 +40,26 @@ struct systick_device {
  30         int freq_scale;
  31  };
  32
  33 +static void (*systick_freq_scaling)(struct systick_device *sdev, int status);
  34 +
  35  static int systick_set_oneshot(struct clock_event_device *evt);
  36  static int systick_shutdown(struct clock_event_device *evt);
  37
  38 +static inline void mt7620_freq_scaling(struct systick_device *sdev, int status)
  39 +{
  40 +       if (sdev->freq_scale == status)
  41 +               return;
  42 +
  43 +       sdev->freq_scale = status;
  44 +
  45 +       pr_info("%s: %s autosleep mode\n", systick.dev.name,
  46 +                       (status) ? ("enable") : ("disable"));
  47 +       if (status)
  48 +               rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) | SLEEP_EN, CLK_LUT_CFG);
  49 +       else
  50 +               rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) & ~SLEEP_EN, CLK_LUT_CFG);
  51 +}
  52 +
  53  static int systick_next_event(unsigned long delta,
  54                                 struct clock_event_device *evt)
  55  {
  56 @@ -99,6 +120,9 @@ static int systick_shutdown(struct clock_event_device *evt)
  57         sdev->irq_requested = 0;
  58         iowrite32(0, systick.membase + SYSTICK_CONFIG);
  59
  60 +       if (systick_freq_scaling)
  61 +               systick_freq_scaling(sdev, 0);
  62 +
  63         return 0;
  64  }
  65
  66 @@ -114,15 +138,29 @@ static int systick_set_oneshot(struct clock_event_device *evt)
  67         iowrite32(CFG_EXT_STK_EN | CFG_CNT_EN,
  68                   systick.membase + SYSTICK_CONFIG);
  69
  70 +       if (systick_freq_scaling)
  71 +               systick_freq_scaling(sdev, 1);
  72 +
  73         return 0;
  74  }
  75
  76 +static const struct of_device_id systick_match[] = {
  77 +       { .compatible = "ralink,mt7620-systick", .data = mt7620_freq_scaling},
  78 +       {},
  79 +};
  80 +
  81  static void __init ralink_systick_init(struct device_node *np)
  82  {
  83 +       const struct of_device_id *match;
  84 +
  85         systick.membase = of_iomap(np, 0);
  86         if (!systick.membase)
  87                 return;
  88
  89 +       match = of_match_node(systick_match, np);
  90 +       if (match)
  91 +               systick_freq_scaling = match->data;
  92 +
  93         systick_irqaction.name = np->name;
  94         systick.dev.name = np->name;
  95         clockevents_calc_mult_shift(&systick.dev, SYSTICK_FREQ, 60);
  96 --
  97 1.7.10.4
  98