diff options
| -rw-r--r-- | sys/arch/sgi/dev/dsrtc.c | 66 |
1 files changed, 59 insertions, 7 deletions
diff --git a/sys/arch/sgi/dev/dsrtc.c b/sys/arch/sgi/dev/dsrtc.c index f33889e7afb..6d9e7036ec8 100644 --- a/sys/arch/sgi/dev/dsrtc.c +++ b/sys/arch/sgi/dev/dsrtc.c @@ -1,4 +1,4 @@ -/* $OpenBSD: dsrtc.c,v 1.2 2009/04/13 21:17:54 miod Exp $ */ +/* $OpenBSD: dsrtc.c,v 1.3 2009/04/20 20:31:06 miod Exp $ */ /* * Copyright (c) 2001-2004 Opsycon AB (www.opsycon.se / www.opsycon.com) @@ -95,13 +95,65 @@ tobcd(int x) int dsrtc_match_ioc(struct device *parent, void *match, void *aux) { - switch (sys_config.system_type) { - case SGI_OCTANE: - case SGI_O200: - return 1; - default: + struct ioc_attach_args *iaa = aux; + bus_space_handle_t ih, ih2; + uint c, c2, c3; + int rc = 0; + + /* + * The IOC3 RTC is either a Dallas (now Maxim) DS1386 or compatible + * (likely a more recent DS1687), or a Mostek (now SGS Thomson) + * MK48T35. + */ + + if (bus_space_map(iaa->iaa_memt, IOC3_BYTEBUS_1, 1, 0, &ih) != 0) return 0; - } + + if (bus_space_map(iaa->iaa_memt, IOC3_BYTEBUS_2, 1, 0, &ih2) != 0) + goto unmap; + + /* + * Check the low 4 bits of control register C. If any is set, + * or if the values written to them stick, then this is not + * a Dallas chip. + * + * Note that the value we read the next few times can't be + * compared to the first value read, as the upper four bits + * are cleared by reading them. And might get set again + * between two reads. + */ + + bus_space_write_1(iaa->iaa_memt, ih, 0, DS1687_CTRL_C); + c = bus_space_read_1(iaa->iaa_memt, ih2, 0); + if ((c & 0x0f) != 0) + goto done; + + bus_space_write_1(iaa->iaa_memt, ih, 0, DS1687_CTRL_C); + bus_space_write_1(iaa->iaa_memt, ih2, 0, c | 0x0f); + + bus_space_write_1(iaa->iaa_memt, ih, 0, DS1687_CTRL_C); + c2 = bus_space_read_1(iaa->iaa_memt, ih2, 0); + if ((c2 & 0x0f) == 0) + rc = 1; + + bus_space_write_1(iaa->iaa_memt, ih, 0, DS1687_CTRL_C); + bus_space_write_1(iaa->iaa_memt, ih2, 0, c2 | 0x0f); + + bus_space_write_1(iaa->iaa_memt, ih, 0, DS1687_CTRL_C); + c3 = bus_space_read_1(iaa->iaa_memt, ih2, 0); + if ((c3 & 0x0f) != 0) + rc = 0; + + /* write back first value read in case this is not a Dallas chip */ + bus_space_write_1(iaa->iaa_memt, ih, 0, DS1687_CTRL_C); + bus_space_write_1(iaa->iaa_memt, ih2, 0, c); + +done: + bus_space_unmap(iaa->iaa_memt, ih2, 1); +unmap: + bus_space_unmap(iaa->iaa_memt, ih, 1); + + return rc; } void |