From: Alexandre Belloni <alexandre.belloni@bootlin.com> To: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de>, Nicolas Ferre <nicolas.ferre@microchip.com>, Alexander Dahl <ada@thorsis.com>, Sebastian Andrzej Siewior <bigeasy@linutronix.de>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Alexandre Belloni <alexandre.belloni@bootlin.com> Subject: [PATCH v2 3/9] clocksource/drivers/tcb_clksrc: Use tcb as sched_clock Date: Mon, 15 Apr 2019 17:08:50 +0200 [thread overview] Message-ID: <20190415150856.9384-4-alexandre.belloni@bootlin.com> (raw) In-Reply-To: <20190415150856.9384-1-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> --- 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: -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Alexandre Belloni <alexandre.belloni@bootlin.com> To: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>, Alexander Dahl <ada@thorsis.com>, Sebastian Andrzej Siewior <bigeasy@linutronix.de>, linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 3/9] clocksource/drivers/tcb_clksrc: Use tcb as sched_clock Date: Mon, 15 Apr 2019 17:08:50 +0200 [thread overview] Message-ID: <20190415150856.9384-4-alexandre.belloni@bootlin.com> (raw) In-Reply-To: <20190415150856.9384-1-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> --- 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: -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-04-15 15:09 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-04-15 15:08 [PATCH v2 0/9] clocksource: improve Atmel TCB timer driver Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni 2019-04-15 15:08 ` [PATCH v2 1/9] ARM: at91: move SoC specific definitions to SoC folder Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni 2019-04-15 15:08 ` [PATCH v2 2/9] clocksource/drivers/tcb_clksrc: stop depending on atmel_tclib Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni [this message] 2019-04-15 15:08 ` [PATCH v2 3/9] clocksource/drivers/tcb_clksrc: Use tcb as sched_clock Alexandre Belloni 2019-04-15 15:08 ` [PATCH v2 4/9] ARM: at91: Implement clocksource selection Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni 2019-04-15 15:08 ` [PATCH v2 5/9] clocksource/drivers/tcb_clksrc: move Kconfig option Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni 2019-04-16 13:55 ` Daniel Lezcano 2019-04-16 13:55 ` Daniel Lezcano 2019-04-15 15:08 ` [PATCH v2 6/9] clocksource/drivers/timer-atmel-pit: rework " Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni 2019-04-15 15:08 ` [PATCH v2 7/9] clocksource/drivers/tcb_clksrc: Rename the file for consistency Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni 2019-04-15 15:08 ` [PATCH v2 8/9] clocksource/drivers/timer-atmel-tcb: tc_clksrc_suspend() can be static Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni 2019-04-15 15:08 ` [PATCH v2 9/9] misc: atmel_tclib: do not probe already used TCBs Alexandre Belloni 2019-04-15 15:08 ` Alexandre Belloni 2019-04-17 11:50 ` Romain Izard 2019-04-17 11:50 ` Romain Izard 2019-04-17 12:00 ` Alexandre Belloni 2019-04-17 12:00 ` Alexandre Belloni
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20190415150856.9384-4-alexandre.belloni@bootlin.com \ --to=alexandre.belloni@bootlin.com \ --cc=ada@thorsis.com \ --cc=bigeasy@linutronix.de \ --cc=daniel.lezcano@linaro.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=nicolas.ferre@microchip.com \ --cc=tglx@linutronix.de \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.