[PATCH v2 4/9] clocksource: mediatek: Use GPT as sched clock source
Matthias Brugger
matthias.bgg at gmail.com
Wed May 20 04:02:21 PDT 2015
2015-05-16 9:58 GMT+02:00 Yingjoe Chen <yingjoe.chen at mediatek.com>:
> When cpu is in deep idle, arch timer will stop counting. Setup GPT as
> sched clock source so it can keep counting in idle.
>
> Signed-off-by: Yingjoe Chen <yingjoe.chen at mediatek.com>
> ---
> drivers/clocksource/mtk_timer.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/clocksource/mtk_timer.c b/drivers/clocksource/mtk_timer.c
> index 91206f9..fe7cf72 100644
> --- a/drivers/clocksource/mtk_timer.c
> +++ b/drivers/clocksource/mtk_timer.c
> @@ -24,6 +24,7 @@
> #include <linux/of.h>
> #include <linux/of_address.h>
> #include <linux/of_irq.h>
> +#include <linux/sched_clock.h>
> #include <linux/slab.h>
>
> #define GPT_IRQ_EN_REG 0x00
> @@ -59,6 +60,13 @@ struct mtk_clock_event_device {
> struct clock_event_device dev;
> };
>
> +static void __iomem *gpt_base __read_mostly;
> +
> +static u64 notrace mtk_read_sched_clock(void)
> +{
> + return readl_relaxed(gpt_base + TIMER_CNT_REG(GPT_CLK_SRC));
> +}
> +
> static inline struct mtk_clock_event_device *to_mtk_clk(
> struct clock_event_device *c)
> {
> @@ -243,6 +251,8 @@ static void __init mtk_timer_init(struct device_node *node)
> mtk_timer_setup(evt, GPT_CLK_SRC, TIMER_CTRL_OP_FREERUN, 1);
> clocksource_mmio_init(evt->gpt_base + TIMER_CNT_REG(GPT_CLK_SRC),
> node->name, rate, 300, 32, clocksource_mmio_readl_up);
> + gpt_base = evt->gpt_base;
This is really hacky. We should clean up the code and provide
mtk_clock_event_device globally.
Please add the patch below, which does exactly this.
---- 8< ---------------- >8 ------
>From 631e7bf4e5d9456d0bb4a29b2dee4b84e8c052bd Mon Sep 17 00:00:00 2001
From: Matthias Brugger <matthias.bgg at gmail.com>
Date: Wed, 20 May 2015 12:43:16 +0200
Subject: [PATCH] clocksource: mediatek: Define mtk_clock_event_device globally
Sched clock code, especially sched_clock_register does not allow to pass a
pointer to actual_read_sched_clock. So if in the driver the register base
address is not globally defined, we are not able to read the scheduler
clock register. This patch sets the mtk_clock_event_device struct globally
for the driver, to be able to read the register.
Signed-off-by: Matthias Brugger <matthias.bgg at gmail.com>
---
drivers/clocksource/mtk_timer.c | 50 +++++++++++++++--------------------------
1 file changed, 18 insertions(+), 32 deletions(-)
diff --git a/drivers/clocksource/mtk_timer.c b/drivers/clocksource/mtk_timer.c
index 68ab423..c5f5b40 100644
--- a/drivers/clocksource/mtk_timer.c
+++ b/drivers/clocksource/mtk_timer.c
@@ -59,13 +59,9 @@ struct mtk_clock_event_device {
struct clock_event_device dev;
};
-static inline struct mtk_clock_event_device *to_mtk_clk(
- struct clock_event_device *c)
-{
- return container_of(c, struct mtk_clock_event_device, dev);
-}
+struct mtk_clock_event_device *evt;
-static void mtk_clkevt_time_stop(struct mtk_clock_event_device *evt, u8 timer)
+static void mtk_clkevt_time_stop(u8 timer)
{
u32 val;
@@ -74,14 +70,12 @@ static void mtk_clkevt_time_stop(struct
mtk_clock_event_device *evt, u8 timer)
TIMER_CTRL_REG(timer));
}
-static void mtk_clkevt_time_setup(struct mtk_clock_event_device *evt,
- unsigned long delay, u8 timer)
+static void mtk_clkevt_time_setup(unsigned long delay, u8 timer)
{
writel(delay, evt->gpt_base + TIMER_CMP_REG(timer));
}
-static void mtk_clkevt_time_start(struct mtk_clock_event_device *evt,
- bool periodic, u8 timer)
+static void mtk_clkevt_time_start(bool periodic, u8 timer)
{
u32 val;
@@ -105,14 +99,12 @@ static void mtk_clkevt_time_start(struct
mtk_clock_event_device *evt,
static void mtk_clkevt_mode(enum clock_event_mode mode,
struct clock_event_device *clk)
{
- struct mtk_clock_event_device *evt = to_mtk_clk(clk);
-
- mtk_clkevt_time_stop(evt, GPT_CLK_EVT);
+ mtk_clkevt_time_stop(GPT_CLK_EVT);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
- mtk_clkevt_time_setup(evt, evt->ticks_per_jiffy, GPT_CLK_EVT);
- mtk_clkevt_time_start(evt, true, GPT_CLK_EVT);
+ mtk_clkevt_time_setup(evt->ticks_per_jiffy, GPT_CLK_EVT);
+ mtk_clkevt_time_start(true, GPT_CLK_EVT);
break;
case CLOCK_EVT_MODE_ONESHOT:
/* Timer is enabled in set_next_event */
@@ -128,19 +120,15 @@ static void mtk_clkevt_mode(enum clock_event_mode mode,
static int mtk_clkevt_next_event(unsigned long event,
struct clock_event_device *clk)
{
- struct mtk_clock_event_device *evt = to_mtk_clk(clk);
-
- mtk_clkevt_time_stop(evt, GPT_CLK_EVT);
- mtk_clkevt_time_setup(evt, event, GPT_CLK_EVT);
- mtk_clkevt_time_start(evt, false, GPT_CLK_EVT);
+ mtk_clkevt_time_stop(GPT_CLK_EVT);
+ mtk_clkevt_time_setup(event, GPT_CLK_EVT);
+ mtk_clkevt_time_start(false, GPT_CLK_EVT);
return 0;
}
static irqreturn_t mtk_timer_interrupt(int irq, void *dev_id)
{
- struct mtk_clock_event_device *evt = dev_id;
-
/* Acknowledge timer0 irq */
writel(GPT_IRQ_ACK(GPT_CLK_EVT), evt->gpt_base + GPT_IRQ_ACK_REG);
evt->dev.event_handler(&evt->dev);
@@ -148,7 +136,7 @@ static irqreturn_t mtk_timer_interrupt(int irq,
void *dev_id)
return IRQ_HANDLED;
}
-static void mtk_timer_global_reset(struct mtk_clock_event_device *evt)
+static inline void mtk_timer_global_reset(void)
{
/* Disable all interrupts */
writel(0x0, evt->gpt_base + GPT_IRQ_EN_REG);
@@ -156,8 +144,7 @@ static void mtk_timer_global_reset(struct
mtk_clock_event_device *evt)
writel(0x3f, evt->gpt_base + GPT_IRQ_ACK_REG);
}
-static void
-mtk_timer_setup(struct mtk_clock_event_device *evt, u8 timer, u8 option)
+static void mtk_timer_setup(u8 timer, u8 option)
{
writel(TIMER_CTRL_CLEAR | TIMER_CTRL_DISABLE,
evt->gpt_base + TIMER_CTRL_REG(timer));
@@ -171,7 +158,7 @@ mtk_timer_setup(struct mtk_clock_event_device
*evt, u8 timer, u8 option)
evt->gpt_base + TIMER_CTRL_REG(timer));
}
-static void mtk_timer_enable_irq(struct mtk_clock_event_device *evt, u8 timer)
+static void mtk_timer_enable_irq(u8 timer)
{
u32 val;
@@ -182,7 +169,6 @@ static void mtk_timer_enable_irq(struct
mtk_clock_event_device *evt, u8 timer)
static void __init mtk_timer_init(struct device_node *node)
{
- struct mtk_clock_event_device *evt;
struct resource res;
unsigned long rate = 0;
struct clk *clk;
@@ -224,10 +210,10 @@ static void __init mtk_timer_init(struct
device_node *node)
}
rate = clk_get_rate(clk);
- mtk_timer_global_reset(evt);
+ mtk_timer_global_reset();
if (request_irq(evt->dev.irq, mtk_timer_interrupt,
- IRQF_TIMER | IRQF_IRQPOLL, "mtk_timer", evt)) {
+ IRQF_TIMER | IRQF_IRQPOLL, "mtk_timer", NULL)) {
pr_warn("failed to setup irq %d\n", evt->dev.irq);
goto err_clk_disable;
}
@@ -235,16 +221,16 @@ static void __init mtk_timer_init(struct
device_node *node)
evt->ticks_per_jiffy = DIV_ROUND_UP(rate, HZ);
/* Configure clock source */
- mtk_timer_setup(evt, GPT_CLK_SRC, TIMER_CTRL_OP_FREERUN);
+ mtk_timer_setup(GPT_CLK_SRC, TIMER_CTRL_OP_FREERUN);
clocksource_mmio_init(evt->gpt_base + TIMER_CNT_REG(GPT_CLK_SRC),
node->name, rate, 300, 32, clocksource_mmio_readl_up);
/* Configure clock event */
- mtk_timer_setup(evt, GPT_CLK_EVT, TIMER_CTRL_OP_REPEAT);
+ mtk_timer_setup(GPT_CLK_EVT, TIMER_CTRL_OP_REPEAT);
clockevents_config_and_register(&evt->dev, rate, 0x3,
0xffffffff);
- mtk_timer_enable_irq(evt, GPT_CLK_EVT);
+ mtk_timer_enable_irq(GPT_CLK_EVT);
return;
--
1.9.1
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