target/linux/mediatek/patches/0040-clocksource-mediatek-Use-GPT-as-sched-clock-source.patch

   1 From 3b3c2406dd9797bc806e0ce756142a33d209c4e8 Mon Sep 17 00:00:00 2001
   2 From: "Joe.C" <yingjoe.chen@mediatek.com>
   3 Date: Fri, 1 May 2015 15:43:25 +0800
   4 Subject: [PATCH 40/76] clocksource: mediatek: Use GPT as sched clock source
   5
   6 When cpu is in deep idle, arch timer will stop counting. Setup GPT as
   7 sched clock source so it can keep counting in idle.
   8
   9 Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
  10 ---
  11  drivers/clocksource/mtk_timer.c |   10 ++++++++++
  12  1 file changed, 10 insertions(+)
  13
  14 --- a/drivers/clocksource/mtk_timer.c
  15 +++ b/drivers/clocksource/mtk_timer.c
  16 @@ -24,6 +24,7 @@
  17  #include <linux/of.h>
  18  #include <linux/of_address.h>
  19  #include <linux/of_irq.h>
  20 +#include <linux/sched_clock.h>
  21  #include <linux/slab.h>
  22
  23  #define GPT_IRQ_EN_REG         0x00
  24 @@ -59,6 +60,13 @@ struct mtk_clock_event_device {
  25         struct clock_event_device dev;
  26  };
  27
  28 +static void __iomem *gpt_base __read_mostly;
  29 +
  30 +static u64 notrace mtk_read_sched_clock(void)
  31 +{
  32 +       return readl_relaxed(gpt_base + TIMER_CNT_REG(GPT_CLK_SRC));
  33 +}
  34 +
  35  static inline struct mtk_clock_event_device *to_mtk_clk(
  36                                 struct clock_event_device *c)
  37  {
  38 @@ -239,6 +247,8 @@ static void __init mtk_timer_init(struct
  39         mtk_timer_setup(evt, GPT_CLK_SRC, TIMER_CTRL_OP_FREERUN);
  40         clocksource_mmio_init(evt->gpt_base + TIMER_CNT_REG(GPT_CLK_SRC),
  41                         node->name, rate, 300, 32, clocksource_mmio_readl_up);
  42 +       gpt_base = evt->gpt_base;
  43 +       sched_clock_register(mtk_read_sched_clock, 32, rate);
  44
  45         /* Configure clock event */
  46         mtk_timer_setup(evt, GPT_CLK_EVT, TIMER_CTRL_OP_REPEAT);