From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: tglx@linutronix.de
Cc: linux-kernel@vger.kernel.org,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
Nicolas Ferre <nicolas.ferre@microchip.com>,
linux-arm-kernel@lists.infradead.org (moderated list:MICROCHIP
TIMER COUNTER (TC) AND CLOCKSOURCE DR...)
Subject: [PATCH 09/15] clocksource/drivers/tcb_clksrc: Use tcb as sched_clock
Date: Thu, 9 May 2019 13:10:42 +0200 [thread overview]
Message-ID: <20190509111048.11151-9-daniel.lezcano@linaro.org> (raw)
In-Reply-To: <20190509111048.11151-1-daniel.lezcano@linaro.org>
From: Alexandre Belloni <alexandre.belloni@bootlin.com>
Now that the driver is registered early enough, use the TCB as the
sched_clock which is much more accurate than the jiffies implementation.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
drivers/clocksource/tcb_clksrc.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index bf68504da94a..9de8c10ab546 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -11,6 +11,7 @@
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
#include <linux/syscore_ops.h>
#include <soc/at91/atmel_tcb.h>
@@ -114,6 +115,16 @@ static struct clocksource clksrc = {
.resume = tc_clksrc_resume,
};
+static u64 notrace tc_sched_clock_read(void)
+{
+ return tc_get_cycles(&clksrc);
+}
+
+static u64 notrace tc_sched_clock_read32(void)
+{
+ return tc_get_cycles32(&clksrc);
+}
+
#ifdef CONFIG_GENERIC_CLOCKEVENTS
struct tc_clkevt_device {
@@ -335,6 +346,7 @@ static int __init tcb_clksrc_init(struct device_node *node)
struct atmel_tc tc;
struct clk *t0_clk;
const struct of_device_id *match;
+ u64 (*tc_sched_clock)(void);
u32 rate, divided_rate = 0;
int best_divisor_idx = -1;
int clk32k_divisor_idx = -1;
@@ -419,6 +431,7 @@ static int __init tcb_clksrc_init(struct device_node *node)
clksrc.read = tc_get_cycles32;
/* setup ony channel 0 */
tcb_setup_single_chan(&tc, best_divisor_idx);
+ tc_sched_clock = tc_sched_clock_read32;
} else {
/* we have three clocks no matter what the
* underlying platform supports.
@@ -430,6 +443,7 @@ static int __init tcb_clksrc_init(struct device_node *node)
}
/* setup both channel 0 & 1 */
tcb_setup_dual_chan(&tc, best_divisor_idx);
+ tc_sched_clock = tc_sched_clock_read;
}
/* and away we go! */
@@ -442,6 +456,8 @@ static int __init tcb_clksrc_init(struct device_node *node)
if (ret)
goto err_unregister_clksrc;
+ sched_clock_register(tc_sched_clock, 32, divided_rate);
+
return 0;
err_unregister_clksrc:
--
2.17.1
next prev parent reply other threads:[~2019-05-09 11:11 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-09 11:08 [GIT PULL] timer drivers for 5.2 Daniel Lezcano
2019-05-09 11:10 ` [PATCH 01/15] clocksource/drivers/sun4i: Add a compatible for suniv Daniel Lezcano
2019-05-09 11:10 ` [PATCH 02/15] clocksource/drivers/sp804: Add COMPILE_TEST to CONFIG_ARM_TIMER_SP804 Daniel Lezcano
2019-06-18 12:07 ` Helmut Grohne
2019-05-09 11:10 ` [PATCH 03/15] clocksource/drivers/tegra: Rework for compensation of suspend time Daniel Lezcano
2019-05-09 11:10 ` [PATCH 04/15] clocksource/drivers/timer-milbeaut: Fix to enable one-shot timer Daniel Lezcano
2019-05-09 11:10 ` [PATCH 05/15] clocksource/drivers/timer-milbeaut: Add shutdown function Daniel Lezcano
2019-05-09 11:10 ` [PATCH 06/15] clocksource/drivers/timer-milbeaut: Cleanup common register accesses Daniel Lezcano
2019-05-09 11:10 ` [PATCH 07/15] ARM: at91: move SoC specific definitions to SoC folder Daniel Lezcano
2019-05-09 11:10 ` [PATCH 08/15] clocksource/drivers/tcb_clksrc: Stop depending on atmel_tclib Daniel Lezcano
2019-05-09 11:10 ` Daniel Lezcano [this message]
2019-05-09 11:10 ` [PATCH 10/15] ARM: at91: Implement clocksource selection Daniel Lezcano
2019-05-09 11:10 ` [PATCH 11/15] clocksource/drivers/tcb_clksrc: Move Kconfig option Daniel Lezcano
2019-05-09 11:10 ` [PATCH 12/15] clocksource/drivers/timer-atmel-pit: Rework " Daniel Lezcano
2019-05-09 11:10 ` [PATCH 13/15] clocksource/drivers/tcb_clksrc: Rename the file for consistency Daniel Lezcano
2019-05-09 11:10 ` [PATCH 14/15] clocksource/drivers/timer-atmel-tcb: Convert tc_clksrc_suspend|resume() to static Daniel Lezcano
2019-05-09 11:10 ` [PATCH 15/15] misc: atmel_tclib: Do not probe already used TCBs Daniel Lezcano
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