diff options
Diffstat (limited to 'arch/metag/kernel/clock.c')
-rw-r--r-- | arch/metag/kernel/clock.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/metag/kernel/clock.c b/arch/metag/kernel/clock.c new file mode 100644 index 0000000..defc840 --- /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 <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; +} + |