2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 2007 by Ralf Baechle
8 #include <linux/clocksource.h>
9 #include <linux/init.h>
13 #include <asm/octeon/octeon.h>
14 #include <asm/octeon/cvmx-ipd-defs.h>
17 * Set the current core's cvmcount counter to the value of the
18 * IPD_CLK_COUNT. We do this on all cores as they are brought
19 * on-line. This allows for a read from a local cpu register to
20 * access a synchronized counter.
23 void octeon_init_cvmcount(void)
28 /* Clobber loops so GCC will not unroll the following while loop. */
29 asm("" : "+r" (loops
));
31 local_irq_save(flags
);
33 * Loop several times so we are executing from the cache,
34 * which should give more deterministic timing.
37 write_c0_cvmcount(cvmx_read_csr(CVMX_IPD_CLK_COUNT
));
38 local_irq_restore(flags
);
41 static cycle_t
octeon_cvmcount_read(struct clocksource
*cs
)
43 return read_c0_cvmcount();
46 static struct clocksource clocksource_mips
= {
47 .name
= "OCTEON_CVMCOUNT",
48 .read
= octeon_cvmcount_read
,
49 .mask
= CLOCKSOURCE_MASK(64),
50 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
53 void __init
plat_time_init(void)
55 clocksource_mips
.rating
= 300;
56 clocksource_set_clock(&clocksource_mips
, mips_hpt_frequency
);
57 clocksource_register(&clocksource_mips
);