| 1 | /* $NetBSD: acpipmtimer.c,v 1.8 2009/08/18 17:47:46 dyoung Exp $ */ |
| 2 | |
| 3 | #include <sys/cdefs.h> |
| 4 | __KERNEL_RCSID(0, "$NetBSD: acpipmtimer.c,v 1.8 2009/08/18 17:47:46 dyoung Exp $" ); |
| 5 | |
| 6 | #include <sys/types.h> |
| 7 | |
| 8 | #include <sys/systm.h> |
| 9 | #include <sys/device.h> |
| 10 | #include <sys/malloc.h> |
| 11 | #include <sys/bus.h> |
| 12 | #include <sys/time.h> |
| 13 | #include <sys/timetc.h> |
| 14 | |
| 15 | #include <dev/ic/acpipmtimer.h> |
| 16 | |
| 17 | #define ACPI_PM_TIMER_FREQUENCY 3579545 |
| 18 | |
| 19 | struct hwtc { |
| 20 | struct timecounter tc; |
| 21 | bus_space_tag_t t; |
| 22 | bus_space_handle_t h; |
| 23 | bus_size_t off; |
| 24 | }; |
| 25 | |
| 26 | static u_int acpihwtimer_read_safe(struct timecounter *); |
| 27 | static u_int acpihwtimer_read_fast(struct timecounter *); |
| 28 | |
| 29 | acpipmtimer_t |
| 30 | acpipmtimer_attach(device_t dev, |
| 31 | bus_space_tag_t t, bus_space_handle_t h, bus_size_t off, |
| 32 | int flags) |
| 33 | { |
| 34 | struct hwtc *tc; |
| 35 | |
| 36 | tc = malloc(sizeof(struct hwtc), M_DEVBUF, M_WAITOK|M_ZERO); |
| 37 | if (tc == NULL) |
| 38 | return NULL; |
| 39 | |
| 40 | tc->tc.tc_name = device_xname(dev); |
| 41 | tc->tc.tc_frequency = ACPI_PM_TIMER_FREQUENCY; |
| 42 | if (flags & ACPIPMT_32BIT) |
| 43 | tc->tc.tc_counter_mask = 0xffffffff; |
| 44 | else |
| 45 | tc->tc.tc_counter_mask = 0x00ffffff; |
| 46 | if (flags & ACPIPMT_BADLATCH) { |
| 47 | tc->tc.tc_get_timecount = acpihwtimer_read_safe; |
| 48 | tc->tc.tc_quality = 900; |
| 49 | } else { |
| 50 | tc->tc.tc_get_timecount = acpihwtimer_read_fast; |
| 51 | tc->tc.tc_quality = 1000; |
| 52 | } |
| 53 | |
| 54 | tc->t = t; |
| 55 | tc->h = h; |
| 56 | tc->off = off; |
| 57 | |
| 58 | tc->tc.tc_priv = tc; |
| 59 | tc_init(&tc->tc); |
| 60 | aprint_normal("%s: %d-bit timer\n" , tc->tc.tc_name, |
| 61 | (flags & ACPIPMT_32BIT ? 32 : 24)); |
| 62 | return tc; |
| 63 | } |
| 64 | |
| 65 | int |
| 66 | acpipmtimer_detach(acpipmtimer_t timer, int flags) |
| 67 | { |
| 68 | struct hwtc *tc = timer; |
| 69 | |
| 70 | return tc_detach(&tc->tc); |
| 71 | } |
| 72 | |
| 73 | #define r(h) bus_space_read_4(h->t, h->h, h->off) |
| 74 | |
| 75 | static u_int |
| 76 | acpihwtimer_read_safe(struct timecounter *tc) |
| 77 | { |
| 78 | struct hwtc *h = tc->tc_priv; |
| 79 | uint32_t t1, t2, t3; |
| 80 | |
| 81 | t2 = r(h); |
| 82 | t3 = r(h); |
| 83 | do { |
| 84 | t1 = t2; |
| 85 | t2 = t3; |
| 86 | t3 = r(h); |
| 87 | } while ((t1 > t2) || (t2 > t3)); |
| 88 | return (t2); |
| 89 | } |
| 90 | |
| 91 | static u_int |
| 92 | acpihwtimer_read_fast(struct timecounter *tc) |
| 93 | { |
| 94 | struct hwtc *h = tc->tc_priv; |
| 95 | |
| 96 | return r(h); |
| 97 | } |
| 98 | |