From a2c5d4ed92bbc02ff4a37efc2adffe7d145abe4f Mon Sep 17 00:00:00 2001 From: James Hogan Date: Tue, 9 Oct 2012 10:54:39 +0100 Subject: metag: Time keeping Add time keeping code for metag. Meta hardware threads have 2 timers. The background timer (TXTIMER) is used as a free-running time base, and the interrupt timer (TXTIMERI) is used for the timer interrupt. Both counters traditionally count at approximately 1MHz. Signed-off-by: James Hogan Cc: John Stultz Cc: Thomas Gleixner --- arch/metag/include/asm/clock.h | 51 ++++++++++++++++++++++++++++++++++++ arch/metag/include/asm/delay.h | 29 +++++++++++++++++++++ arch/metag/include/asm/mach/arch.h | 4 +++ arch/metag/kernel/clock.c | 53 ++++++++++++++++++++++++++++++++++++++ arch/metag/kernel/time.c | 15 +++++++++++ 5 files changed, 152 insertions(+) create mode 100644 arch/metag/include/asm/clock.h create mode 100644 arch/metag/include/asm/delay.h create mode 100644 arch/metag/kernel/clock.c create mode 100644 arch/metag/kernel/time.c (limited to 'arch') diff --git a/arch/metag/include/asm/clock.h b/arch/metag/include/asm/clock.h new file mode 100644 index 000000000000..3e2915a280c7 --- /dev/null +++ b/arch/metag/include/asm/clock.h @@ -0,0 +1,51 @@ +/* + * arch/metag/include/asm/clock.h + * + * Copyright (C) 2012 Imagination Technologies Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _METAG_CLOCK_H_ +#define _METAG_CLOCK_H_ + +#include + +/** + * struct meta_clock_desc - Meta Core clock callbacks. + * @get_core_freq: Get the frequency of the Meta core. If this is NULL, the + * core frequency will be determined like this: + * Meta 1: based on loops_per_jiffy. + * Meta 2: (EXPAND_TIMER_DIV + 1) MHz. + */ +struct meta_clock_desc { + unsigned long (*get_core_freq)(void); +}; + +extern struct meta_clock_desc _meta_clock; + +/* + * Set up the default clock, ensuring all callbacks are valid - only accessible + * during boot. + */ +void setup_meta_clocks(struct meta_clock_desc *desc); + +/** + * get_coreclock() - Get the frequency of the Meta core clock. + * + * Returns: The Meta core clock frequency in Hz. + */ +static inline unsigned long get_coreclock(void) +{ + /* + * Use the current clock callback. If set correctly this will provide + * the most accurate frequency as it can be calculated directly from the + * PLL configuration. otherwise a default callback will have been set + * instead. + */ + return _meta_clock.get_core_freq(); +} + +#endif /* _METAG_CLOCK_H_ */ diff --git a/arch/metag/include/asm/delay.h b/arch/metag/include/asm/delay.h new file mode 100644 index 000000000000..9c92f996957a --- /dev/null +++ b/arch/metag/include/asm/delay.h @@ -0,0 +1,29 @@ +#ifndef _METAG_DELAY_H +#define _METAG_DELAY_H + +/* + * Copyright (C) 1993 Linus Torvalds + * + * Delay routines calling functions in arch/metag/lib/delay.c + */ + +/* Undefined functions to get compile-time errors */ +extern void __bad_udelay(void); +extern void __bad_ndelay(void); + +extern void __udelay(unsigned long usecs); +extern void __ndelay(unsigned long nsecs); +extern void __const_udelay(unsigned long xloops); +extern void __delay(unsigned long loops); + +/* 0x10c7 is 2**32 / 1000000 (rounded up) */ +#define udelay(n) (__builtin_constant_p(n) ? \ + ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \ + __udelay(n)) + +/* 0x5 is 2**32 / 1000000000 (rounded up) */ +#define ndelay(n) (__builtin_constant_p(n) ? \ + ((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \ + __ndelay(n)) + +#endif /* _METAG_DELAY_H */ diff --git a/arch/metag/include/asm/mach/arch.h b/arch/metag/include/asm/mach/arch.h index 6845d80857e4..12c5664fea6e 100644 --- a/arch/metag/include/asm/mach/arch.h +++ b/arch/metag/include/asm/mach/arch.h @@ -16,10 +16,13 @@ #include +#include + /** * struct machine_desc - Describes a board controlled by a Meta. * @name: Board/SoC name. * @dt_compat: Array of device tree 'compatible' strings. + * @clocks: Clock callbacks. * * @nr_irqs: Maximum number of IRQs. * If 0, defaults to NR_IRQS in asm-generic/irq.h. @@ -37,6 +40,7 @@ struct machine_desc { const char *name; const char **dt_compat; + struct meta_clock_desc *clocks; unsigned int nr_irqs; diff --git a/arch/metag/kernel/clock.c b/arch/metag/kernel/clock.c new file mode 100644 index 000000000000..defc84056f18 --- /dev/null +++ b/arch/metag/kernel/clock.c @@ -0,0 +1,53 @@ +/* + * arch/metag/kernel/clock.c + * + * Copyright (C) 2012 Imagination Technologies Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include + +#include +#include + +struct meta_clock_desc _meta_clock; + +/* Default machine get_core_freq callback. */ +static unsigned long get_core_freq_default(void) +{ +#ifdef CONFIG_METAG_META21 + /* + * Meta 2 cores divide down the core clock for the Meta timers, so we + * can estimate the core clock from the divider. + */ + return (metag_in32(EXPAND_TIMER_DIV) + 1) * 1000000; +#else + /* + * On Meta 1 we don't know the core clock, but assuming the Meta timer + * is correct it can be estimated based on loops_per_jiffy. + */ + return (loops_per_jiffy * HZ * 5) >> 1; +#endif +} + +/** + * setup_meta_clocks() - Set up the Meta clock. + * @desc: Clock descriptor usually provided by machine description + * + * Ensures all callbacks are valid. + */ +void __init setup_meta_clocks(struct meta_clock_desc *desc) +{ + /* copy callbacks */ + if (desc) + _meta_clock = *desc; + + /* set fallback functions */ + if (!_meta_clock.get_core_freq) + _meta_clock.get_core_freq = get_core_freq_default; +} + diff --git a/arch/metag/kernel/time.c b/arch/metag/kernel/time.c new file mode 100644 index 000000000000..17dc10733b2f --- /dev/null +++ b/arch/metag/kernel/time.c @@ -0,0 +1,15 @@ +/* + * Copyright (C) 2005-2013 Imagination Technologies Ltd. + * + * This file contains the Meta-specific time handling details. + * + */ + +#include + +#include + +void __init time_init(void) +{ + metag_generic_timer_init(); +} -- cgit v1.2.3