Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a2c5d4ed authored by James Hogan's avatar James Hogan
Browse files

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: default avatarJames Hogan <james.hogan@imgtec.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
parent bc3966bf

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -5039,6 +5039,7 @@ S: Supported 
F:	arch/metag/

F:	Documentation/metag/

F:	Documentation/devicetree/bindings/metag/

F:	drivers/clocksource/metag_generic.c



MICROBLAZE ARCHITECTURE

M:	Michal Simek <monstr@monstr.eu>

arch/metag/include/asm/clock.h

0 → 100644
+51 −0
Original line number Diff line number Diff line 
/*

 * 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 <asm/mach/arch.h>



/**

 * 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_ */

arch/metag/include/asm/delay.h

0 → 100644
+29 −0
Original line number Diff line number Diff line 
#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 */

arch/metag/include/asm/mach/arch.h

+4 −0
Original line number Diff line number Diff line
@@ -16,10 +16,13 @@ 


#include <linux/stddef.h>



#include <asm/clock.h>



/**

 * 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;

arch/metag/kernel/clock.c

0 → 100644
+53 −0
Original line number Diff line number Diff line 
/*

 * 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 <linux/delay.h>

#include <linux/io.h>



#include <asm/param.h>

#include <asm/clock.h>



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;

}