[PATCH 2/9] clocksource/drivers/rockchip: Add err handle for rk_timer_init

[PATCH 2/9] clocksource/drivers/rockchip: Add err handle for rk_timer_init

[Daniel Lezcano]

From: Shawn Lin <shawn.lin@rock-chips.com>

Currently rockchip_timer doesn't do some basic cleanup work when
failing to init the timer. Let's add err handle routine to deal
with all the err cases.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/clocksource/rockchip_timer.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/clocksource/rockchip_timer.c b/drivers/clocksource/rockchip_timer.c
index 8c77a52..b991b28 100644
--- a/drivers/clocksource/rockchip_timer.c
+++ b/drivers/clocksource/rockchip_timer.c
@@ -122,23 +122,23 @@ static void __init rk_timer_init(struct device_node *np)
 	pclk = of_clk_get_by_name(np, "pclk");
 	if (IS_ERR(pclk)) {
 		pr_err("Failed to get pclk for '%s'\n", TIMER_NAME);
-		return;
+		goto out_unmap;
 	}
 
 	if (clk_prepare_enable(pclk)) {
 		pr_err("Failed to enable pclk for '%s'\n", TIMER_NAME);
-		return;
+		goto out_unmap;
 	}
 
 	timer_clk = of_clk_get_by_name(np, "timer");
 	if (IS_ERR(timer_clk)) {
 		pr_err("Failed to get timer clock for '%s'\n", TIMER_NAME);
-		return;
+		goto out_timer_clk;
 	}
 
 	if (clk_prepare_enable(timer_clk)) {
 		pr_err("Failed to enable timer clock\n");
-		return;
+		goto out_timer_clk;
 	}
 
 	bc_timer.freq = clk_get_rate(timer_clk);
@@ -146,7 +146,7 @@ static void __init rk_timer_init(struct device_node *np)
 	irq = irq_of_parse_and_map(np, 0);
 	if (!irq) {
 		pr_err("Failed to map interrupts for '%s'\n", TIMER_NAME);
-		return;
+		goto out_irq;
 	}
 
 	ce->name = TIMER_NAME;
@@ -164,10 +164,19 @@ static void __init rk_timer_init(struct device_node *np)
 	ret = request_irq(irq, rk_timer_interrupt, IRQF_TIMER, TIMER_NAME, ce);
 	if (ret) {
 		pr_err("Failed to initialize '%s': %d\n", TIMER_NAME, ret);
-		return;
+		goto out_irq;
 	}
 
 	clockevents_config_and_register(ce, bc_timer.freq, 1, UINT_MAX);
+
+	return;
+
+out_irq:
+	clk_disable_unprepare(timer_clk);
+out_timer_clk:
+	clk_disable_unprepare(pclk);
+out_unmap:
+	iounmap(bc_timer.base);
 }
 
 CLOCKSOURCE_OF_DECLARE(rk_timer, "rockchip,rk3288-timer", rk_timer_init);
-- 
1.9.1

[PATCH 3/9] clocksource/drivers/lpc32xx: Don't use the prescaler counter for clockevents

[Daniel Lezcano]

From: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

This commit switches the clockevents one-shot current implementation
to avoid using the prescaler counter. The clockevents timer currently
uses MR0=1, PR=ticks; and after this commit is uses MR0=ticks, PR=0.

While using the prescaler with PR=1 works fine in one-shot mode,
it seems it doesn't work as expected in periodic mode.

By using the only match channel register (MR0) for the timer we make
the periodic mode introduction easier, and consistent with one-shot mode.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Joachim Eastwood <manabian@gmail.com>
---
 drivers/clocksource/time-lpc32xx.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/clocksource/time-lpc32xx.c b/drivers/clocksource/time-lpc32xx.c
index 1316876..50d1a63 100644
--- a/drivers/clocksource/time-lpc32xx.c
+++ b/drivers/clocksource/time-lpc32xx.c
@@ -60,14 +60,13 @@ static int lpc32xx_clkevt_next_event(unsigned long delta,
 		container_of(evtdev, struct lpc32xx_clock_event_ddata, evtdev);
 
 	/*
-	 * Place timer in reset and program the delta in the prescale
-	 * register (PR). When the prescale counter matches the value
-	 * in PR the counter register is incremented and the compare
-	 * match will trigger. After setup the timer is released from
-	 * reset and enabled.
+	 * Place timer in reset and program the delta in the match
+	 * channel 0 (MR0). When the timer counter matches the value
+	 * in MR0 register the match will trigger an interrupt.
+	 * After setup the timer is released from reset and enabled.
 	 */
 	writel_relaxed(LPC32XX_TIMER_TCR_CRST, ddata->base + LPC32XX_TIMER_TCR);
-	writel_relaxed(delta, ddata->base + LPC32XX_TIMER_PR);
+	writel_relaxed(delta, ddata->base + LPC32XX_TIMER_MR0);
 	writel_relaxed(LPC32XX_TIMER_TCR_CEN, ddata->base + LPC32XX_TIMER_TCR);
 
 	return 0;
@@ -210,13 +209,13 @@ static int __init lpc32xx_clockevent_init(struct device_node *np)
 
 	/*
 	 * Disable timer and clear any pending interrupt (IR) on match
-	 * channel 0 (MR0). Configure a compare match value of 1 on MR0
-	 * and enable interrupt, reset on match and stop on match (MCR).
+	 * channel 0 (MR0). Clear the prescaler as it's not used.
+	 * Enable interrupt, reset on match and stop on match (MCR).
 	 */
 	writel_relaxed(0, base + LPC32XX_TIMER_TCR);
+	writel_relaxed(0, base + LPC32XX_TIMER_PR);
 	writel_relaxed(0, base + LPC32XX_TIMER_CTCR);
 	writel_relaxed(LPC32XX_TIMER_IR_MR0INT, base + LPC32XX_TIMER_IR);
-	writel_relaxed(1, base + LPC32XX_TIMER_MR0);
 	writel_relaxed(LPC32XX_TIMER_MCR_MR0I | LPC32XX_TIMER_MCR_MR0R |
 		       LPC32XX_TIMER_MCR_MR0S, base + LPC32XX_TIMER_MCR);
 
-- 
1.9.1

[PATCH 4/9] clocksource/drivers/lpc32xx: Support periodic mode

[Daniel Lezcano]

From: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

This commit adds the support for periodic mode. This is done by not
setting the MR0S (Stop on TnMR0) bit on MCR, thus allowing
interrupts to be periodically generated on MR0 matches.

In order to do this, move the initial configuration that is specific to
the one-shot mode to set_state_oneshot().

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Joachim Eastwood <manabian@gmail.com>
---
 drivers/clocksource/time-lpc32xx.c | 39 +++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/time-lpc32xx.c b/drivers/clocksource/time-lpc32xx.c
index 50d1a63..5694edd 100644
--- a/drivers/clocksource/time-lpc32xx.c
+++ b/drivers/clocksource/time-lpc32xx.c
@@ -43,6 +43,7 @@
 struct lpc32xx_clock_event_ddata {
 	struct clock_event_device evtdev;
 	void __iomem *base;
+	u32 ticks_per_jiffy;
 };
 
 /* Needed for the sched clock */
@@ -85,11 +86,39 @@ static int lpc32xx_clkevt_shutdown(struct clock_event_device *evtdev)
 
 static int lpc32xx_clkevt_oneshot(struct clock_event_device *evtdev)
 {
+	struct lpc32xx_clock_event_ddata *ddata =
+		container_of(evtdev, struct lpc32xx_clock_event_ddata, evtdev);
+
 	/*
 	 * When using oneshot, we must also disable the timer
 	 * to wait for the first call to set_next_event().
 	 */
-	return lpc32xx_clkevt_shutdown(evtdev);
+	writel_relaxed(0, ddata->base + LPC32XX_TIMER_TCR);
+
+	/* Enable interrupt, reset on match and stop on match (MCR). */
+	writel_relaxed(LPC32XX_TIMER_MCR_MR0I | LPC32XX_TIMER_MCR_MR0R |
+		       LPC32XX_TIMER_MCR_MR0S, ddata->base + LPC32XX_TIMER_MCR);
+	return 0;
+}
+
+static int lpc32xx_clkevt_periodic(struct clock_event_device *evtdev)
+{
+	struct lpc32xx_clock_event_ddata *ddata =
+		container_of(evtdev, struct lpc32xx_clock_event_ddata, evtdev);
+
+	/* Enable interrupt and reset on match. */
+	writel_relaxed(LPC32XX_TIMER_MCR_MR0I | LPC32XX_TIMER_MCR_MR0R,
+		       ddata->base + LPC32XX_TIMER_MCR);
+
+	/*
+	 * Place timer in reset and program the delta in the match
+	 * channel 0 (MR0).
+	 */
+	writel_relaxed(LPC32XX_TIMER_TCR_CRST, ddata->base + LPC32XX_TIMER_TCR);
+	writel_relaxed(ddata->ticks_per_jiffy, ddata->base + LPC32XX_TIMER_MR0);
+	writel_relaxed(LPC32XX_TIMER_TCR_CEN, ddata->base + LPC32XX_TIMER_TCR);
+
+	return 0;
 }
 
 static irqreturn_t lpc32xx_clock_event_handler(int irq, void *dev_id)
@@ -107,11 +136,13 @@ static irqreturn_t lpc32xx_clock_event_handler(int irq, void *dev_id)
 static struct lpc32xx_clock_event_ddata lpc32xx_clk_event_ddata = {
 	.evtdev = {
 		.name			= "lpc3220 clockevent",
-		.features		= CLOCK_EVT_FEAT_ONESHOT,
+		.features		= CLOCK_EVT_FEAT_ONESHOT |
+					  CLOCK_EVT_FEAT_PERIODIC,
 		.rating			= 300,
 		.set_next_event		= lpc32xx_clkevt_next_event,
 		.set_state_shutdown	= lpc32xx_clkevt_shutdown,
 		.set_state_oneshot	= lpc32xx_clkevt_oneshot,
+		.set_state_periodic	= lpc32xx_clkevt_periodic,
 	},
 };
 
@@ -210,17 +241,15 @@ static int __init lpc32xx_clockevent_init(struct device_node *np)
 	/*
 	 * Disable timer and clear any pending interrupt (IR) on match
 	 * channel 0 (MR0). Clear the prescaler as it's not used.
-	 * Enable interrupt, reset on match and stop on match (MCR).
 	 */
 	writel_relaxed(0, base + LPC32XX_TIMER_TCR);
 	writel_relaxed(0, base + LPC32XX_TIMER_PR);
 	writel_relaxed(0, base + LPC32XX_TIMER_CTCR);
 	writel_relaxed(LPC32XX_TIMER_IR_MR0INT, base + LPC32XX_TIMER_IR);
-	writel_relaxed(LPC32XX_TIMER_MCR_MR0I | LPC32XX_TIMER_MCR_MR0R |
-		       LPC32XX_TIMER_MCR_MR0S, base + LPC32XX_TIMER_MCR);
 
 	rate = clk_get_rate(clk);
 	lpc32xx_clk_event_ddata.base = base;
+	lpc32xx_clk_event_ddata.ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
 	clockevents_config_and_register(&lpc32xx_clk_event_ddata.evtdev,
 					rate, 1, -1);
 
-- 
1.9.1

[PATCH 5/9] clocksource/drivers/lpc32xx: Support timer-based ARM delay

[Daniel Lezcano]

From: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

This commit implements the ARM timer-based delay timer for the
LPC32xx, LPC18xx, LPC43xx family of SoCs.

Also, add a dependency to restrict compiling this driver for
the ARM architecture.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Joachim Eastwood <manabian@gmail.com>
---
 drivers/clocksource/Kconfig        |  1 +
 drivers/clocksource/time-lpc32xx.c | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 56777f0..c9c4db6 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -153,6 +153,7 @@ config CLKSRC_EFM32
 config CLKSRC_LPC32XX
 	bool "Clocksource for LPC32XX" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS && HAS_IOMEM
+	depends on ARM
 	select CLKSRC_MMIO
 	select CLKSRC_OF
 	help
diff --git a/drivers/clocksource/time-lpc32xx.c b/drivers/clocksource/time-lpc32xx.c
index 5694edd..daae61e 100644
--- a/drivers/clocksource/time-lpc32xx.c
+++ b/drivers/clocksource/time-lpc32xx.c
@@ -18,6 +18,7 @@
 #include <linux/clk.h>
 #include <linux/clockchips.h>
 #include <linux/clocksource.h>
+#include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/kernel.h>
@@ -54,6 +55,15 @@ static u64 notrace lpc32xx_read_sched_clock(void)
 	return readl(clocksource_timer_counter);
 }
 
+static unsigned long lpc32xx_delay_timer_read(void)
+{
+	return readl(clocksource_timer_counter);
+}
+
+static struct delay_timer lpc32xx_delay_timer = {
+	.read_current_timer = lpc32xx_delay_timer_read,
+};
+
 static int lpc32xx_clkevt_next_event(unsigned long delta,
 				     struct clock_event_device *evtdev)
 {
@@ -192,6 +202,8 @@ static int __init lpc32xx_clocksource_init(struct device_node *np)
 	}
 
 	clocksource_timer_counter = base + LPC32XX_TIMER_TC;
+	lpc32xx_delay_timer.freq = rate;
+	register_current_timer_delay(&lpc32xx_delay_timer);
 	sched_clock_register(lpc32xx_read_sched_clock, 32, rate);
 
 	return 0;
-- 
1.9.1

[PATCH 6/9] clocksource/drivers/arm_global_timer: Register delay timer

[Daniel Lezcano]

From: Rabin Vincent <rabin.vincent@axis.com>

Provide a delay timer using the lower 32-bits of the global timer so
that we can use that instead of having to calibrating delays.

Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/clocksource/arm_global_timer.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
index d189d8c..36998fa 100644
--- a/drivers/clocksource/arm_global_timer.c
+++ b/drivers/clocksource/arm_global_timer.c
@@ -16,6 +16,7 @@
 #include <linux/clockchips.h>
 #include <linux/cpu.h>
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/of.h>
@@ -221,6 +222,21 @@ static u64 notrace gt_sched_clock_read(void)
 }
 #endif
 
+static unsigned long gt_read_long(void)
+{
+	return readl_relaxed(gt_base + GT_COUNTER0);
+}
+
+static struct delay_timer gt_delay_timer = {
+	.read_current_timer = gt_read_long,
+};
+
+static void __init gt_delay_timer_init(void)
+{
+	gt_delay_timer.freq = gt_clk_rate;
+	register_current_timer_delay(&gt_delay_timer);
+}
+
 static void __init gt_clocksource_init(void)
 {
 	writel(0, gt_base + GT_CONTROL);
@@ -317,6 +333,7 @@ static void __init global_timer_of_register(struct device_node *np)
 	/* Immediately configure the timer on the boot CPU */
 	gt_clocksource_init();
 	gt_clockevents_init(this_cpu_ptr(gt_evt));
+	gt_delay_timer_init();
 
 	return;
 
-- 
1.9.1

[PATCH 8/9] clockevents/drivers/arm_global_timer: Implement ->set_state_oneshot_stopped()

[Daniel Lezcano]

From: Viresh Kumar <viresh.kumar@linaro.org>

set_state_oneshot_stopped() is called by the clkevt core, when the next
event is required at an expiry time of 'KTIME_MAX'. This normally
happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes.

This patch makes the clockevent device to stop on such an event, to
avoid spurious interrupts, as explained by: commit 8fff52fd5093
("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state").

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/clocksource/arm_global_timer.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
index 36998fa..9df0d16 100644
--- a/drivers/clocksource/arm_global_timer.c
+++ b/drivers/clocksource/arm_global_timer.c
@@ -175,6 +175,7 @@ static int gt_clockevents_init(struct clock_event_device *clk)
 	clk->set_state_shutdown = gt_clockevent_shutdown;
 	clk->set_state_periodic = gt_clockevent_set_periodic;
 	clk->set_state_oneshot = gt_clockevent_shutdown;
+	clk->set_state_oneshot_stopped = gt_clockevent_shutdown;
 	clk->set_next_event = gt_clockevent_set_next_event;
 	clk->cpumask = cpumask_of(cpu);
 	clk->rating = 300;
-- 
1.9.1

[PATCH 9/9] clockevents/drivers/exynos_mct: Implement ->set_state_oneshot_stopped()

[Daniel Lezcano]

From: Viresh Kumar <viresh.kumar@linaro.org>

set_state_oneshot_stopped() is called by the clkevt core, when the next
event is required at an expiry time of 'KTIME_MAX'. This normally
happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes.

This patch makes the clockevent device to stop on such an event, to
avoid spurious interrupts, as explained by: commit 8fff52fd5093
("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state").

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/clocksource/exynos_mct.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index ff44082..be09bc0 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -313,6 +313,7 @@ static struct clock_event_device mct_comp_device = {
 	.set_state_periodic	= mct_set_state_periodic,
 	.set_state_shutdown	= mct_set_state_shutdown,
 	.set_state_oneshot	= mct_set_state_shutdown,
+	.set_state_oneshot_stopped = mct_set_state_shutdown,
 	.tick_resume		= mct_set_state_shutdown,
 };
 
@@ -452,6 +453,7 @@ static int exynos4_local_timer_setup(struct mct_clock_event_device *mevt)
 	evt->set_state_periodic = set_state_periodic;
 	evt->set_state_shutdown = set_state_shutdown;
 	evt->set_state_oneshot = set_state_shutdown;
+	evt->set_state_oneshot_stopped = set_state_shutdown;
 	evt->tick_resume = set_state_shutdown;
 	evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
 	evt->rating = 450;
-- 
1.9.1

[PATCH 8/9] clockevents/drivers/arm_global_timer: Implement ->set_state_oneshot_stopped()

[Jisheng Zhang]

Dear Daniel, Viresh,

On Thu, 25 Feb 2016 14:37:16 +0100 Daniel Lezcano wrote:

> From: Viresh Kumar <viresh.kumar@linaro.org>
> 
> set_state_oneshot_stopped() is called by the clkevt core, when the next
> event is required at an expiry time of 'KTIME_MAX'. This normally
> happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes.
> 
> This patch makes the clockevent device to stop on such an event, to
> avoid spurious interrupts, as explained by: commit 8fff52fd5093
> ("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state").

Inspired by this commit, I think dw_apb_timer also needs similar patch because
it only supports PERIODIC mode and the driver emulate ONESHOT over that" as
described in commit 8fff52fd5093. What do you think?

I'm cooking one patch for this purpose.

Thanks for the inspiration,
Jisheng

> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
>  drivers/clocksource/arm_global_timer.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
> index 36998fa..9df0d16 100644
> --- a/drivers/clocksource/arm_global_timer.c
> +++ b/drivers/clocksource/arm_global_timer.c
> @@ -175,6 +175,7 @@ static int gt_clockevents_init(struct clock_event_device *clk)
>  	clk->set_state_shutdown = gt_clockevent_shutdown;
>  	clk->set_state_periodic = gt_clockevent_set_periodic;
>  	clk->set_state_oneshot = gt_clockevent_shutdown;
> +	clk->set_state_oneshot_stopped = gt_clockevent_shutdown;
>  	clk->set_next_event = gt_clockevent_set_next_event;
>  	clk->cpumask = cpumask_of(cpu);
>  	clk->rating = 300;