From: Fu Wei fu.wei@linaro.org
Currently, the counter frequency detection call(arch_timer_detect_rate) includes getting the frequency from the device-tree property, the per-cpu arch-timer and the memory-mapped (MMIO) timer interfaces. But reading device-tree property will be needed only when system boot with device-tree, and reading from the per-cpu arch-timer and the memory-mapped (MMIO) timer interfaces will be needed only when the system initializes the relevant timer.
This patch separates out device-tree code, keep them in device-tree init function, and removes arch_timer_detect_rate founction, then uses the arch_timer_get_cntfrq and arch_timer_mem_get_cntfrq directly.
Signed-off-by: Fu Wei fu.wei@linaro.org --- drivers/clocksource/arm_arch_timer.c | 58 +++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 28 deletions(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 843f923..29ca7d6 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -560,30 +560,6 @@ static u32 arch_timer_mem_get_cntfrq(void __iomem *cntbase) return readl_relaxed(cntbase + CNTFRQ); }
-static void -arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) -{ - /* Who has more than one independent system counter? */ - if (arch_timer_rate) - return; - - /* - * Try to determine the frequency from the device tree or CNTFRQ, - * if ACPI is enabled, get the frequency from CNTFRQ ONLY. - */ - if (!acpi_disabled || - of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) { - if (cntbase) - arch_timer_rate = arch_timer_mem_get_cntfrq(cntbase); - else - arch_timer_rate = arch_timer_get_cntfrq(); - } - - /* Check the timer frequency. */ - if (arch_timer_rate == 0) - pr_warn("frequency not available\n"); -} - static void arch_timer_banner(unsigned type) { pr_info("%s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n", @@ -958,7 +934,17 @@ 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); + /* + * Try to determine the frequency from the device tree, + * if fail, get the frequency from the sysreg CNTFRQ. + */ + if (!arch_timer_rate && + of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) + arch_timer_rate = arch_timer_get_cntfrq(); + if (!arch_timer_rate) { + pr_err(FW_BUG "frequency not available.\n"); + return -EINVAL; + }
arch_timer_c3stop = !of_property_read_bool(np, "always-on");
@@ -1069,7 +1055,19 @@ 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 the CNTFRQ reg of MMIO timer. + */ + if (!arch_timer_rate && + of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) + arch_timer_rate = arch_timer_mem_get_cntfrq(base); + if (!arch_timer_rate) { + pr_err(FW_BUG "MMIO frequency not available.\n"); + ret = -EINVAL; + goto out; + } + ret = arch_timer_mem_register(base, irq); if (ret) goto out; @@ -1130,8 +1128,12 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table) map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt, gtdt->non_secure_el2_flags);
- /* Get the frequency from CNTFRQ */ - arch_timer_detect_rate(NULL, NULL); + /* Get the frequency from the sysreg CNTFRQ */ + arch_timer_rate = arch_timer_get_cntfrq(); + if (!arch_timer_rate) { + pr_err(FW_BUG "frequency not available.\n"); + return -EINVAL; + }
arch_timer_uses_ppi = arch_timer_select_ppi(); if (!arch_timer_ppi[arch_timer_uses_ppi]) {