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
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.
9 Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
11 drivers/clocksource/mtk_timer.c | 10 ++++++++++
12 1 file changed, 10 insertions(+)
14 --- a/drivers/clocksource/mtk_timer.c
15 +++ b/drivers/clocksource/mtk_timer.c
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 +#include <linux/sched_clock.h>
21 #include <linux/slab.h>
23 #define GPT_IRQ_EN_REG 0x00
24 @@ -59,6 +60,13 @@ struct mtk_clock_event_device {
25 struct clock_event_device dev;
28 +static void __iomem *gpt_base __read_mostly;
30 +static u64 notrace mtk_read_sched_clock(void)
32 + return readl_relaxed(gpt_base + TIMER_CNT_REG(GPT_CLK_SRC));
35 static inline struct mtk_clock_event_device *to_mtk_clk(
36 struct clock_event_device *c)
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);
45 /* Configure clock event */
46 mtk_timer_setup(evt, GPT_CLK_EVT, TIMER_CTRL_OP_REPEAT);