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Groups > linux.kernel > #1561808
| From | fu.wei@linaro.org |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. |
| Date | 2017-01-18 14:40 +0100 |
| Message-ID | <t0YD1-4Gk-45@gated-at.bofh.it> (permalink) |
| References | <t0Ytk-4D1-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Fu Wei <fu.wei@linaro.org>
The counter frequency detection call(arch_timer_detect_rate) combines two
ways to get counter frequency: system coprocessor register and MMIO timer.
But in a specific timer init code, we only need one way to try:
getting frequency from MMIO timer register will be needed only when we
init MMIO timer; getting frequency from system coprocessor register will
be needed only when we init arch timer.
This patch separates paths to determine frequency:
Separate out the MMIO frequency and the sysreg frequency detection call,
and use the appropriate one for the counter.
Signed-off-by: Fu Wei <fu.wei@linaro.org>
---
drivers/clocksource/arm_arch_timer.c | 40 ++++++++++++++++++++++--------------
1 file changed, 25 insertions(+), 15 deletions(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 6484f84..9482481 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -488,23 +488,33 @@ static int arch_timer_starting_cpu(unsigned int cpu)
return 0;
}
-static void arch_timer_detect_rate(void __iomem *cntbase)
+static void __arch_timer_determine_rate(u32 rate)
{
- /* Who has more than one independent system counter? */
- if (arch_timer_rate)
- return;
+ /* Check the timer frequency. */
+ if (!arch_timer_rate) {
+ if (rate)
+ arch_timer_rate = rate;
+ else
+ pr_warn("frequency not available\n");
+ } else if (rate && arch_timer_rate != rate) {
+ pr_warn("got different frequency, keep original.\n");
+ }
+}
+static void arch_timer_detect_rate(void)
+{
/*
- * Try to determine the frequency from the MMIO timer or the sysreg.
+ * Try to get the timer frequency from the sysreg CNTFRQ.
*/
- if (cntbase)
- arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
- else
- arch_timer_rate = arch_timer_get_cntfrq();
+ __arch_timer_determine_rate(arch_timer_get_cntfrq());
+}
- /* Check the timer frequency. */
- if (arch_timer_rate == 0)
- pr_warn("frequency not available\n");
+static void arch_timer_mem_detect_rate(void __iomem *cntbase)
+{
+ /*
+ * Try to get the timer frequency from the CNTFRQ reg of MMIO timer.
+ */
+ __arch_timer_determine_rate(readl_relaxed(cntbase + CNTFRQ));
}
static void arch_timer_banner(unsigned type)
@@ -887,7 +897,7 @@ static int __init arch_timer_of_init(struct device_node *np)
*/
if (!arch_timer_rate &&
of_property_read_u32(np, "clock-frequency", &arch_timer_rate))
- arch_timer_detect_rate(NULL);
+ arch_timer_detect_rate();
arch_timer_c3stop = !of_property_read_bool(np, "always-on");
@@ -1001,7 +1011,7 @@ static int __init arch_timer_mem_init(struct device_node *np)
*/
if (!arch_timer_rate &&
of_property_read_u32(np, "clock-frequency", &arch_timer_rate))
- arch_timer_detect_rate(base);
+ arch_timer_mem_detect_rate(base);
ret = arch_timer_mem_register(base, irq);
if (ret)
@@ -1064,7 +1074,7 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table)
gtdt->non_secure_el2_flags);
/* Get the frequency from the sysreg CNTFRQ */
- arch_timer_detect_rate(NULL);
+ arch_timer_detect_rate();
arch_timer_uses_ppi = arch_timer_select_ppi();
if (!arch_timer_ppi[arch_timer_uses_ppi]) {
--
2.9.3
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[PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer fu.wei@linaro.org - 2017-01-18 14:30 +0100
[PATCH v20 01/17] clocksource/drivers/arm_arch_timer: Improve printk relevant code fu.wei@linaro.org - 2017-01-18 14:30 +0100
[PATCH v20 02/17] clocksource/drivers/arm_arch_timer: Rename the timer type macros. fu.wei@linaro.org - 2017-01-18 14:30 +0100
[PATCH v20 06/17] clocksource/drivers/arm_arch_timer: rework PPI determination fu.wei@linaro.org - 2017-01-18 14:30 +0100
[PATCH v20 12/17] clocksource/drivers/arm_arch_timer: Refactor MMIO timer probing. fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer fu.wei@linaro.org - 2017-01-18 14:40 +0100
Re: [PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 10:20 +0100
Re: [PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer Fu Wei <fu.wei@linaro.org> - 2017-01-19 11:10 +0100
Re: [PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 13:50 +0100
[PATCH v20 11/17] clocksource/drivers/arm_arch_timer: Introduce some new structs to prepare for GTDT fu.wei@linaro.org - 2017-01-18 14:40 +0100
Re: [PATCH v20 11/17] clocksource/drivers/arm_arch_timer: Introduce some new structs to prepare for GTDT Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 09:30 +0100
Re: [PATCH v20 11/17] clocksource/drivers/arm_arch_timer: Introduce some new structs to prepare for GTDT Fu Wei <fu.wei@linaro.org> - 2017-01-19 11:00 +0100
[PATCH v20 07/17] clocksource/drivers/arm_arch_timer: Separate out device-tree code from arch_timer_detect_rate fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 09/17] clocksource/drivers/arm_arch_timer: Refactor arch_timer_needs_probing fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver fu.wei@linaro.org - 2017-01-18 14:40 +0100
Re: [PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 10:20 +0100
Re: [PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver Fu Wei <fu.wei@linaro.org> - 2017-01-19 11:40 +0100
Re: [PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver Mark Rutland <mark.rutland@arm.com> - 2017-01-19 12:20 +0100
Re: [PATCH v20 13/17] acpi/arm64: Add GTDT table parse driver Fu Wei <fu.wei@linaro.org> - 2017-01-19 13:30 +0100
[PATCH v20 05/17] clocksource/drivers/arm_arch_timer: Add a new enum for spi type fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. fu.wei@linaro.org - 2017-01-18 14:40 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 09:10 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-19 10:50 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 13:50 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Mark Rutland <mark.rutland@arm.com> - 2017-01-24 18:30 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-25 07:50 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-25 08:30 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Christopher Covington <cov@codeaurora.org> - 2017-01-25 16:40 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Mark Rutland <mark.rutland@arm.com> - 2017-01-25 18:40 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-26 07:00 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Mark Rutland <mark.rutland@arm.com> - 2017-01-25 18:30 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Fu Wei <fu.wei@linaro.org> - 2017-01-26 06:50 +0100
Re: [PATCH v20 08/17] clocksource/drivers/arm_arch_timer: Rework counter frequency detection. Mark Rutland <mark.rutland@arm.com> - 2017-01-30 19:00 +0100
[PATCH v20 10/17] clocksource/drivers/arm_arch_timer: Move arch_timer_needs_of_probing into DT init call fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 14/17] clocksource/drivers/arm_arch_timer: Simplify ACPI support code. fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 15/17] acpi/arm64: Add memory-mapped timer support in GTDT driver fu.wei@linaro.org - 2017-01-18 14:40 +0100
[PATCH v20 17/17] acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver fu.wei@linaro.org - 2017-01-18 14:50 +0100
Re: [PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer Hanjun Guo <hanjun.guo@linaro.org> - 2017-01-19 10:30 +0100
Re: [PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer Fu Wei <fu.wei@linaro.org> - 2017-01-19 12:20 +0100
Re: [PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer Mark Rutland <mark.rutland@arm.com> - 2017-01-23 20:00 +0100
Re: [PATCH v20 00/17] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer Fu Wei <fu.wei@linaro.org> - 2017-01-24 06:20 +0100
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