From 778eeb1b199b85bec79b49ac483b013e270636ea Mon Sep 17 00:00:00 2001 From: "Steven J. Hill" Date: Fri, 7 Dec 2012 03:51:04 +0000 Subject: [PATCH] MIPS: Add new GIC clocksource. Add new clocksource that uses the counter present on the MIPS Global Interrupt Controller. Signed-off-by: Steven J. Hill Patchwork: http://patchwork.linux-mips.org/patch/4681/ Signed-off-by: John Crispin --- arch/mips/Kconfig | 4 ++ arch/mips/include/asm/gic.h | 1 + arch/mips/include/asm/time.h | 2 +- arch/mips/kernel/Makefile | 1 + arch/mips/kernel/csrc-gic.c | 49 +++++++++++++++++++ arch/mips/mti-malta/malta-time.c | 83 +++++++++++++++++++------------- 6 files changed, 106 insertions(+), 34 deletions(-) create mode 100644 arch/mips/kernel/csrc-gic.c diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index daeafe26cfb2..8f8666c8f28d 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -296,6 +296,7 @@ config MIPS_MALTA select BOOT_RAW select CEVT_R4K select CSRC_R4K + select CSRC_GIC select DMA_NONCOHERENT select GENERIC_ISA_DMA select HAVE_PCSPKR_PLATFORM @@ -928,6 +929,9 @@ config CSRC_POWERTV config CSRC_R4K bool +config CSRC_GIC + bool + config CSRC_SB1250 bool diff --git a/arch/mips/include/asm/gic.h b/arch/mips/include/asm/gic.h index 37620db588be..bbddd257c243 100644 --- a/arch/mips/include/asm/gic.h +++ b/arch/mips/include/asm/gic.h @@ -359,6 +359,7 @@ struct gic_shared_intr_map { /* Mapped interrupt to pin X, then GIC will generate the vector (X+1). */ #define GIC_PIN_TO_VEC_OFFSET (1) +extern int gic_present; extern unsigned long _gic_base; extern unsigned int gic_irq_base; extern unsigned int gic_irq_flags[]; diff --git a/arch/mips/include/asm/time.h b/arch/mips/include/asm/time.h index 761f2e92119e..d77a535d83eb 100644 --- a/arch/mips/include/asm/time.h +++ b/arch/mips/include/asm/time.h @@ -75,7 +75,7 @@ extern int init_r4k_clocksource(void); static inline int init_mips_clocksource(void) { -#ifdef CONFIG_CSRC_R4K +#if defined(CONFIG_CSRC_R4K) && !defined(CONFIG_CSRC_GIC) return init_r4k_clocksource(); #else return 0; diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile index 6c17e1f3d0ec..f416de34c9eb 100644 --- a/arch/mips/kernel/Makefile +++ b/arch/mips/kernel/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_CSRC_IOASIC) += csrc-ioasic.o obj-$(CONFIG_CSRC_POWERTV) += csrc-powertv.o obj-$(CONFIG_CSRC_R4K) += csrc-r4k.o obj-$(CONFIG_CSRC_SB1250) += csrc-sb1250.o +obj-$(CONFIG_CSRC_GIC) += csrc-gic.o obj-$(CONFIG_SYNC_R4K) += sync-r4k.o obj-$(CONFIG_STACKTRACE) += stacktrace.o diff --git a/arch/mips/kernel/csrc-gic.c b/arch/mips/kernel/csrc-gic.c new file mode 100644 index 000000000000..5dca24bce51b --- /dev/null +++ b/arch/mips/kernel/csrc-gic.c @@ -0,0 +1,49 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. + */ +#include +#include + +#include +#include + +static cycle_t gic_hpt_read(struct clocksource *cs) +{ + unsigned int hi, hi2, lo; + + do { + GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_63_32), hi); + GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_31_00), lo); + GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_63_32), hi2); + } while (hi2 != hi); + + return (((cycle_t) hi) << 32) + lo; +} + +static struct clocksource gic_clocksource = { + .name = "GIC", + .read = gic_hpt_read, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +void __init gic_clocksource_init(unsigned int frequency) +{ + unsigned int config, bits; + + /* Calculate the clocksource mask. */ + GICREAD(GIC_REG(SHARED, GIC_SH_CONFIG), config); + bits = 32 + ((config & GIC_SH_CONFIG_COUNTBITS_MSK) >> + (GIC_SH_CONFIG_COUNTBITS_SHF - 2)); + + /* Set clocksource mask. */ + gic_clocksource.mask = CLOCKSOURCE_MASK(bits); + + /* Calculate a somewhat reasonable rating value. */ + gic_clocksource.rating = 200 + frequency / 10000000; + + clocksource_register_hz(&gic_clocksource, frequency); +} diff --git a/arch/mips/mti-malta/malta-time.c b/arch/mips/mti-malta/malta-time.c index 115f5bc06003..a144b89cf9ba 100644 --- a/arch/mips/mti-malta/malta-time.c +++ b/arch/mips/mti-malta/malta-time.c @@ -17,7 +17,6 @@ * * Setting up the clock on the MIPS boards. */ - #include #include #include @@ -25,7 +24,6 @@ #include #include #include -#include #include #include @@ -34,11 +32,11 @@ #include #include #include -#include #include #include #include #include +#include #include #include @@ -46,6 +44,7 @@ #include unsigned long cpu_khz; +int gic_frequency; static int mips_cpu_timer_irq; static int mips_cpu_perf_irq; @@ -61,44 +60,50 @@ static void mips_perf_dispatch(void) do_IRQ(mips_cpu_perf_irq); } +static unsigned int freqround(unsigned int freq, unsigned int amount) +{ + freq += amount; + freq -= freq % (amount*2); + return freq; +} + /* - * Estimate CPU frequency. Sets mips_hpt_frequency as a side-effect + * Estimate CPU and GIC frequencies. */ -static unsigned int __init estimate_cpu_frequency(void) +static void __init estimate_frequencies(void) { - unsigned int prid = read_c0_prid() & 0xffff00; - unsigned int count; - unsigned long flags; - unsigned int start; + unsigned int count, start; + unsigned int giccount = 0, gicstart = 0; local_irq_save(flags); - /* Start counter exactly on falling edge of update flag */ + /* Start counter exactly on falling edge of update flag. */ while (CMOS_READ(RTC_REG_A) & RTC_UIP); while (!(CMOS_READ(RTC_REG_A) & RTC_UIP)); - /* Start r4k counter. */ + /* Initialize counters. */ start = read_c0_count(); + if (gic_present) + GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_31_00), gicstart); - /* Read counter exactly on falling edge of update flag */ + /* Read counter exactly on falling edge of update flag. */ while (CMOS_READ(RTC_REG_A) & RTC_UIP); while (!(CMOS_READ(RTC_REG_A) & RTC_UIP)); - count = read_c0_count() - start; + count = read_c0_count(); + if (gic_present) + GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_31_00), giccount); - /* restore interrupts */ local_irq_restore(flags); - mips_hpt_frequency = count; - if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) && - (prid != (PRID_COMP_MIPS | PRID_IMP_25KF))) - count *= 2; - - count += 5000; /* round */ - count -= count%10000; + count -= start; + if (gic_present) + giccount -= gicstart; - return count; + mips_hpt_frequency = count; + if (gic_present) + gic_frequency = giccount; } void read_persistent_clock(struct timespec *ts) @@ -144,22 +149,34 @@ unsigned int __cpuinit get_c0_compare_int(void) void __init plat_time_init(void) { - unsigned int est_freq; - - /* Set Data mode - binary. */ - CMOS_WRITE(CMOS_READ(RTC_CONTROL) | RTC_DM_BINARY, RTC_CONTROL); - - est_freq = estimate_cpu_frequency(); + unsigned int prid = read_c0_prid() & 0xffff00; + unsigned int freq; - printk("CPU frequency %d.%02d MHz\n", est_freq/1000000, - (est_freq%1000000)*100/1000000); + estimate_frequencies(); - cpu_khz = est_freq / 1000; + freq = mips_hpt_frequency; + if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) && + (prid != (PRID_COMP_MIPS | PRID_IMP_25KF))) + freq *= 2; + freq = freqround(freq, 5000); + pr_debug("CPU frequency %d.%02d MHz\n", freq/1000000, + (freq%1000000)*100/1000000); + cpu_khz = freq / 1000; + + if (gic_present) { + freq = freqround(gic_frequency, 5000); + pr_debug("GIC frequency %d.%02d MHz\n", freq/1000000, + (freq%1000000)*100/1000000); + gic_clocksource_init(gic_frequency); + } else + init_r4k_clocksource(); - mips_scroll_message(); -#ifdef CONFIG_I8253 /* Only Malta has a PIT */ +#ifdef CONFIG_I8253 + /* Only Malta has a PIT. */ setup_pit_timer(); #endif + mips_scroll_message(); + plat_perf_setup(); } -- 2.20.1