From b09ca1ecf6d499d5a33f978c905d2fbcc79b55d9 Mon Sep 17 00:00:00 2001 From: Hanjun Guo Date: Tue, 24 Mar 2015 14:02:50 +0000 Subject: clocksource / arch_timer: Parse GTDT to initialize arch timer Using the information presented by GTDT (Generic Timer Description Table) to initialize the arch timer (not memory-mapped). CC: Daniel Lezcano CC: Thomas Gleixner Originally-by: Amit Daniel Kachhap Tested-by: Suravee Suthikulpanit Tested-by: Yijing Wang Tested-by: Mark Langsdorf Tested-by: Jon Masters Tested-by: Timur Tabi Tested-by: Robert Richter Acked-by: Robert Richter Acked-by: Daniel Lezcano Reviewed-by: Grant Likely Signed-off-by: Hanjun Guo Signed-off-by: Will Deacon --- drivers/clocksource/arm_arch_timer.c | 132 ++++++++++++++++++++++++++++------- 1 file changed, 105 insertions(+), 27 deletions(-) (limited to 'drivers/clocksource') diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index a3025e7ae35f..ea62fc79e1e8 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -371,8 +372,12 @@ arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) if (arch_timer_rate) return; - /* Try to determine the frequency from the device tree or CNTFRQ */ - if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) { + /* + * 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 = readl_relaxed(cntbase + CNTFRQ); else @@ -691,28 +696,8 @@ static void __init arch_timer_common_init(void) arch_timer_arch_init(); } -static void __init arch_timer_init(struct device_node *np) +static void __init arch_timer_init(void) { - int i; - - if (arch_timers_present & ARCH_CP15_TIMER) { - pr_warn("arch_timer: multiple nodes in dt, skipping\n"); - return; - } - - arch_timers_present |= ARCH_CP15_TIMER; - for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++) - arch_timer_ppi[i] = irq_of_parse_and_map(np, i); - arch_timer_detect_rate(NULL, np); - - /* - * If we cannot rely on firmware initializing the timer registers then - * we should use the physical timers instead. - */ - if (IS_ENABLED(CONFIG_ARM) && - of_property_read_bool(np, "arm,cpu-registers-not-fw-configured")) - arch_timer_use_virtual = false; - /* * If HYP mode is available, we know that the physical timer * has been configured to be accessible from PL1. Use it, so @@ -731,13 +716,39 @@ static void __init arch_timer_init(struct device_node *np) } } - arch_timer_c3stop = !of_property_read_bool(np, "always-on"); - arch_timer_register(); arch_timer_common_init(); } -CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_init); -CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_init); + +static void __init arch_timer_of_init(struct device_node *np) +{ + int i; + + if (arch_timers_present & ARCH_CP15_TIMER) { + pr_warn("arch_timer: multiple nodes in dt, skipping\n"); + return; + } + + arch_timers_present |= ARCH_CP15_TIMER; + for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++) + arch_timer_ppi[i] = irq_of_parse_and_map(np, i); + + arch_timer_detect_rate(NULL, np); + + arch_timer_c3stop = !of_property_read_bool(np, "always-on"); + + /* + * If we cannot rely on firmware initializing the timer registers then + * we should use the physical timers instead. + */ + if (IS_ENABLED(CONFIG_ARM) && + of_property_read_bool(np, "arm,cpu-registers-not-fw-configured")) + arch_timer_use_virtual = false; + + arch_timer_init(); +} +CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init); +CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init); static void __init arch_timer_mem_init(struct device_node *np) { @@ -804,3 +815,70 @@ static void __init arch_timer_mem_init(struct device_node *np) } CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem", arch_timer_mem_init); + +#ifdef CONFIG_ACPI +static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags) +{ + int trigger, polarity; + + if (!interrupt) + return 0; + + trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE + : ACPI_LEVEL_SENSITIVE; + + polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW + : ACPI_ACTIVE_HIGH; + + return acpi_register_gsi(NULL, interrupt, trigger, polarity); +} + +/* Initialize per-processor generic timer */ +static int __init arch_timer_acpi_init(struct acpi_table_header *table) +{ + struct acpi_table_gtdt *gtdt; + + if (arch_timers_present & ARCH_CP15_TIMER) { + pr_warn("arch_timer: already initialized, skipping\n"); + return -EINVAL; + } + + gtdt = container_of(table, struct acpi_table_gtdt, header); + + arch_timers_present |= ARCH_CP15_TIMER; + + arch_timer_ppi[PHYS_SECURE_PPI] = + map_generic_timer_interrupt(gtdt->secure_el1_interrupt, + gtdt->secure_el1_flags); + + arch_timer_ppi[PHYS_NONSECURE_PPI] = + map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt, + gtdt->non_secure_el1_flags); + + arch_timer_ppi[VIRT_PPI] = + map_generic_timer_interrupt(gtdt->virtual_timer_interrupt, + gtdt->virtual_timer_flags); + + arch_timer_ppi[HYP_PPI] = + 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); + + /* Always-on capability */ + arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON); + + arch_timer_init(); + return 0; +} + +/* Initialize all the generic timers presented in GTDT */ +void __init acpi_generic_timer_init(void) +{ + if (acpi_disabled) + return; + + acpi_table_parse(ACPI_SIG_GTDT, arch_timer_acpi_init); +} +#endif -- cgit v1.2.3-59-g8ed1b