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From: fu.wei@linaro.org
To: rjw@rjwysocki.net, lenb@kernel.org, daniel.lezcano@linaro.org,
	tglx@linutronix.de, marc.zyngier@arm.com, mark.rutland@arm.com,
	lorenzo.pieralisi@arm.com, sudeep.holla@arm.com,
	hanjun.guo@linaro.org
Cc: linux-arm-kernel@lists.infradead.org,
	linaro-acpi@lists.linaro.org, linux-kernel@vger.kernel.org,
	linux-acpi@vger.kernel.org, rruigrok@codeaurora.org,
	harba@codeaurora.org, cov@codeaurora.org, timur@codeaurora.org,
	graeme.gregory@linaro.org, al.stone@linaro.org, jcm@redhat.com,
	wei@redhat.com, arnd@arndb.de, catalin.marinas@arm.com,
	will.deacon@arm.com, Suravee.Suthikulpanit@amd.com,
	leo.duran@amd.com, wim@iguana.be, linux@roeck-us.net,
	linux-watchdog@vger.kernel.org, tn@semihalf.com,
	christoffer.dall@linaro.org, julien.grall@arm.com,
	Fu Wei <fu.wei@linaro.org>
Subject: [PATCH v19 06/15] clocksource/drivers/arm_arch_timer: Rework counter frequency detection.
Date: Wed, 21 Dec 2016 14:45:54 +0800	[thread overview]
Message-ID: <20161221064603.11830-7-fu.wei@linaro.org> (raw)
In-Reply-To: <20161221064603.11830-1-fu.wei@linaro.org>

From: Fu Wei <fu.wei@linaro.org>

Currently, the counter frequency detection call(arch_timer_detect_rate)
combines all the ways to get counter frequency: device-tree property,
system coprocessor register, MMIO timer. But in the most of use cases,
we don't need all the ways to try:
For example, reading device-tree property will be needed only when
system boot with device-tree, getting frequency from MMIO timer register
will beneeded only when we init MMIO timer.

This patch separates paths to determine frequency:
Separate out device-tree code, keep them in device-tree init function.
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>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
---
 drivers/clocksource/arm_arch_timer.c | 49 +++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 18 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index c7b4482..9a1f138 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -488,27 +488,31 @@ static int arch_timer_starting_cpu(unsigned int cpu)
 	return 0;
 }
 
-static void
-arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np)
+static void arch_timer_detect_rate(void)
 {
-	/* Who has more than one independent system counter? */
-	if (arch_timer_rate)
-		return;
+	/*
+	 * Try to get the timer frequency from
+	 * cntfrq_el0(system coprocessor register).
+	 */
+	if (!arch_timer_rate)
+		arch_timer_rate = arch_timer_get_cntfrq();
+
+	/* Check the timer frequency. */
+	if (!arch_timer_rate)
+		pr_warn("frequency not available\n");
+}
 
+static void arch_timer_mem_detect_rate(void __iomem *cntbase)
+{
 	/*
-	 * Try to determine the frequency from the device tree or CNTFRQ,
-	 * if ACPI is enabled, get the frequency from CNTFRQ ONLY.
+	 * Try to determine the frequency from
+	 * CNTFRQ in memory-mapped timer.
 	 */
-	if (!acpi_disabled ||
-	    of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
-		if (cntbase)
-			arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
-		else
-			arch_timer_rate = arch_timer_get_cntfrq();
-	}
+	if (!arch_timer_rate)
+		arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
 
 	/* Check the timer frequency. */
-	if (arch_timer_rate == 0)
+	if (!arch_timer_rate)
 		pr_warn("frequency not available\n");
 }
 
@@ -886,7 +890,9 @@ static int __init arch_timer_of_init(struct device_node *np)
 	for (i = ARCH_TIMER_PHYS_SECURE_PPI; i < ARCH_TIMER_MAX_TIMER_PPI; i++)
 		arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
 
-	arch_timer_detect_rate(NULL, np);
+	if (!arch_timer_rate &&
+	    of_property_read_u32(np, "clock-frequency", &arch_timer_rate))
+		arch_timer_detect_rate();
 
 	arch_timer_c3stop = !of_property_read_bool(np, "always-on");
 
@@ -994,7 +1000,14 @@ static int __init arch_timer_mem_init(struct device_node *np)
 		goto out;
 	}
 
-	arch_timer_detect_rate(base, np);
+	/*
+	 * Try to determine the frequency from the device tree,
+	 * if fail, get the frequency from CNTFRQ.
+	 */
+	if (!arch_timer_rate &&
+	    of_property_read_u32(np, "clock-frequency", &arch_timer_rate))
+		arch_timer_mem_detect_rate(base);
+
 	ret = arch_timer_mem_register(base, irq);
 	if (ret)
 		goto out;
@@ -1056,7 +1069,7 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table)
 		gtdt->non_secure_el2_flags);
 
 	/* Get the frequency from CNTFRQ */
-	arch_timer_detect_rate(NULL, NULL);
+	arch_timer_detect_rate();
 
 	arch_timer_uses_ppi = arch_timer_select_ppi();
 	if (!arch_timer_ppi[arch_timer_uses_ppi]) {
-- 
2.9.3

  parent reply	other threads:[~2016-12-21  6:47 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-21  6:45 [PATCH v19 00/15] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer fu.wei
2016-12-21  6:45 ` [PATCH v19 01/15] clocksource/drivers/arm_arch_timer: Move enums and defines to header file fu.wei
2016-12-21  6:45 ` [PATCH v19 02/15] clocksource/drivers/arm_arch_timer: Add a new enum for spi type fu.wei
2016-12-21  6:45 ` [PATCH v19 03/15] clocksource/drivers/arm_arch_timer: Improve printk relevant code fu.wei
2016-12-21  6:45 ` [PATCH v19 04/15] clocksource/drivers/arm_arch_timer: rename some enums and defines fu.wei
2016-12-21  6:45 ` [PATCH v19 05/15] clocksource/drivers/arm_arch_timer: rework PPI determination fu.wei
2017-01-16 17:29   ` Mark Rutland
2017-01-17 23:49     ` Fu Wei
2016-12-21  6:45 ` fu.wei [this message]
2017-01-16 17:50   ` [PATCH v19 06/15] clocksource/drivers/arm_arch_timer: Rework counter frequency detection Mark Rutland
2017-01-18  4:27     ` Fu Wei
2016-12-21  6:45 ` [PATCH v19 07/15] clocksource/drivers/arm_arch_timer: Refactor arch_timer_needs_probing fu.wei
2016-12-21  6:45 ` [PATCH v19 08/15] clocksource/drivers/arm_arch_timer: move arch_timer_needs_of_probing into DT init call fu.wei
2016-12-21  6:45 ` [PATCH v19 09/15] clocksource/drivers/arm_arch_timer: Introduce some new structs to prepare for GTDT fu.wei
2016-12-21  6:45 ` [PATCH v19 10/15] clocksource/drivers/arm_arch_timer: Refactor the timer init code " fu.wei
2017-01-16 18:30   ` Mark Rutland
2017-01-17 10:30     ` Fu Wei
2017-01-17 10:39       ` Fu Wei
2017-01-17 12:18       ` Timur Tabi
2017-01-17 12:29         ` Mark Rutland
2017-01-17 13:22           ` Fu Wei
2016-12-21  6:45 ` [PATCH v19 11/15] acpi/arm64: Add GTDT table parse driver fu.wei
2016-12-21  6:46 ` [PATCH v19 12/15] clocksource/drivers/arm_arch_timer: Simplify ACPI support code fu.wei
2016-12-21  6:46 ` [PATCH v19 13/15] acpi/arm64: Add memory-mapped timer support in GTDT driver fu.wei
2016-12-21  6:46 ` [PATCH v19 14/15] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer fu.wei
2016-12-21  6:46 ` [PATCH v19 15/15] acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver fu.wei
2017-01-16  6:26 ` [PATCH v19 00/15] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer Fu Wei
2017-01-16 12:01   ` Mark Rutland
2017-01-16 12:04     ` Fu Wei
2017-01-16 17:00 ` Mark Rutland
2017-01-17  9:14   ` Fu Wei

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