[PATCH v21 01/13] clocksource: arm_arch_timer: introduce two functions to get the frequency from mmio and sysreg.
From: fu.wei at linaro.org <hidden>
Date: 2017-02-06 18:51:13
Also in:
linux-acpi, linux-watchdog, lkml
Subsystem:
arm architected timer driver, clocksource, clockevent drivers, the rest · Maintainers:
Mark Rutland, Marc Zyngier, Daniel Lezcano, Thomas Gleixner, Linus Torvalds
From: Fu Wei <redacted> The patch introduce two new functions: arch_timer_get_sysreg_freq and arch_timer_get_mmio_freq, and applys them in arch_timer_detect_rate. These will be used for getting the frequency from mmio and sysreg to prepare for reworking counter frequency detection. Signed-off-by: Fu Wei <redacted> --- drivers/clocksource/arm_arch_timer.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 46a1709..1d273d6 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c@@ -554,6 +554,23 @@ static int arch_timer_starting_cpu(unsigned int cpu) return 0; } +static u32 arch_timer_get_sysreg_freq(void) +{ + /* + * Try to get the frequency from the CNTFRQ of sysreg. + */ + return arch_timer_get_cntfrq(); +} + +static u32 arch_timer_get_mmio_freq(void __iomem *cntbase) +{ + /* + * Try to get the frequency from the CNTFRQ of timer frame registers. + * Note: please verify cntbase in caller. + */ + return readl_relaxed(cntbase + CNTFRQ); +} + static void arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) {
@@ -568,9 +585,9 @@ arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) if (!acpi_disabled || of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) { if (cntbase) - arch_timer_rate = readl_relaxed(cntbase + CNTFRQ); + arch_timer_rate = arch_timer_get_mmio_freq(cntbase); else - arch_timer_rate = arch_timer_get_cntfrq(); + arch_timer_rate = arch_timer_get_sysreg_freq(); } /* Check the timer frequency. */
--
2.9.3