diff options
Diffstat (limited to 'sys/dev/i2c')
| -rw-r--r-- | sys/dev/i2c/i2c_scan.c | 147 |
1 files changed, 102 insertions, 45 deletions
diff --git a/sys/dev/i2c/i2c_scan.c b/sys/dev/i2c/i2c_scan.c index d3c5a6632d4..865641102b1 100644 --- a/sys/dev/i2c/i2c_scan.c +++ b/sys/dev/i2c/i2c_scan.c @@ -1,4 +1,4 @@ -/* $OpenBSD: i2c_scan.c,v 1.52 2006/01/06 01:48:45 deraadt Exp $ */ +/* $OpenBSD: i2c_scan.c,v 1.53 2006/01/09 18:50:23 deraadt Exp $ */ /* * Copyright (c) 2005 Theo de Raadt <deraadt@openbsd.org> @@ -69,7 +69,7 @@ void iicprobeinit(struct i2cbus_attach_args *, u_int8_t); u_int8_t iicprobenc(u_int8_t); u_int8_t iicprobe(u_int8_t); u_int16_t iicprobew(u_int8_t); -int lm75probe(void); +char *lm75probe(void); char *amd1032cloneprobe(u_int8_t); void iic_dump(struct device *, u_int8_t, char *); @@ -103,7 +103,7 @@ iicprobenc(u_int8_t cmd) u_int16_t iicprobew(u_int8_t cmd) { - u_int16_t data2; + u_int8_t data[2]; /* * If we think we are talking to an evil Maxim 1617 or clone, @@ -113,10 +113,10 @@ iicprobew(u_int8_t cmd) return (0xffff); probe_ic->ic_acquire_bus(probe_ic->ic_cookie, 0); if (iic_exec(probe_ic, I2C_OP_READ_WITH_STOP, - probe_addr, &cmd, 1, &data2, 2, 0) != 0) - data2 = 0xffff; + probe_addr, &cmd, 1, &data, 2, 0) != 0) + data[0] = data[1] = 0xff; probe_ic->ic_release_bus(probe_ic->ic_cookie, 0); - return (data2); + return ((data[0] << 8) | data[1]); } u_int8_t @@ -128,52 +128,108 @@ iicprobe(u_int8_t cmd) return (probe_val[cmd]); } +#define LM75TEMP 0x00 +#define LM75CONF 0x01 +#define LM75Thyst 0x02 +#define LM75Tos 0x03 +#define LM77Tlow 0x04 +#define LM77Thigh 0x05 +#define LM75TMASK 0xff80 /* 9 bits in temperature registers */ +#define LM77TMASK 0xfff8 /* 13 bits in temperature registers */ + /* - * 0x06 and 0x07 return whatever value was read before, and the - * chip loops every 8 registers. + * The LM75/LM77 family are very hard to detect. Thus, we check for + * all other possible chips first. These chips do not have an ID + * register. They do have a few quirks though: + * register 0x06 and 0x07 return whatever value was read before + * the LM75 lacks registers 0x04 and 0x05, so those act as above + * the chip registers loop every 8 registers + * The downside is that we must read almost every register to guess + * if this is an LM75 or LM77. */ -int +char * lm75probe(void) { - u_int16_t mains[6]; - u_int8_t main; - int i; - - main = iicprobenc(0x01); - mains[0] = iicprobew(0x02); - mains[1] = iicprobew(0x03); - - if (main == 0xff && mains[0] == 0xffff && mains[1] == 0xffff) - return (0); - mains[2] = iicprobew(0x04); /* read Low Limit */ - if (iicprobew(0x07) != mains[2] || iicprobew(0x07) != mains[2]) - return (0); - - mains[3] = iicprobew(0x05); /* read High limit */ - mains[4] = iicprobew(0x06); - mains[5] = iicprobew(0x07); - if (mains[4] != mains[3] || mains[5] != mains[3]) - return (0); - -#if 0 - printf("lm75probe: %02x %04x %04x %04x %04x %04x %04x\n", main, - mains[0], mains[1], mains[2], mains[3], mains[4], mains[5]); + u_int16_t temp, thyst, tos, tlow, thigh, mask = LM75TMASK; + u_int8_t conf; + int ret = 75, i; + + temp = iicprobew(LM75TEMP) & mask; + conf = iicprobenc(LM75CONF); + thyst = iicprobew(LM75Thyst) & mask; + tos = iicprobew(LM75Tos) & mask; + + /* totally bogus data */ + if (conf == 0xff && temp == 0xffff && thyst == 0xffff) + return (NULL); + + /* All values the same? Very unlikely */ + if (temp == thyst && thyst == tos) + return (NULL); + +#if notsure + /* more register aliasing effects that indicate not a lm75 */ + if ((temp >> 8) == conf) + return (NULL); #endif - /* a real lm75/77 repeats it's registers.... */ + /* + * LM77/LM75 registers 6, 7 + * echo whatever was read just before them from reg 0, 1, or 2 + */ + for (i = 6; i <= 7; i++) { + if ((iicprobew(LM75TEMP) & mask) != (iicprobew(i) & mask) || + (iicprobew(LM75Thyst) & mask) != (iicprobew(i) & mask) || + (iicprobew(LM75Tos) & mask) != (iicprobew(i) & mask)) + return (NULL); + } + + /* + * LM75 has no registers 4 or 5, and they will act as echos too + * If we find that 4 and 5 are not echos, then we may have a LM77 + */ + for (i = 4; i <= 5; i++) { + if ((iicprobew(LM75TEMP) & mask) == (iicprobew(i) & mask) && + (iicprobew(LM75Thyst) & mask) == (iicprobew(i) & mask) && + (iicprobew(LM75Tos) & mask) == (iicprobew(i) & mask)) + continue; + ret = 77; + mask = LM77TMASK; + + /* mask size changed, must re-read for the next checks */ + thyst = iicprobew(LM75Thyst) & mask; + tos = iicprobew(LM75Tos) & mask; + tlow = iicprobew(LM77Tlow) & mask; + thigh = iicprobew(LM77Thigh) & mask; + break; + } + + /* a real LM75/LM77 repeats it's registers.... */ for (i = 0x08; i <= 0xf8; i += 8) { - if (main != iicprobenc(0x01 + i) || - mains[0] != iicprobew(0x02 + i) || - mains[1] != iicprobew(0x03 + i) || - mains[2] != iicprobew(0x04 + i) || - mains[3] != iicprobew(0x05 + i) || - mains[4] != iicprobew(0x06 + i) || - mains[5] != iicprobew(0x07 + i)) - return (0); + if (conf != iicprobenc(LM75CONF + i) || + thyst != (iicprobew(LM75Thyst + i) & mask) || + tos != (iicprobew(LM75Tos + i) & mask)) + return (NULL); + tos = iicprobew(LM75Tos) & mask; + if (tos != (iicprobew(0x06 + i) & mask) || + tos != (iicprobew(0x07 + i) & mask)) + return (NULL); + if (ret == 75) { + tos = iicprobew(LM75Tos) & mask; + if (tos != (iicprobew(LM77Tlow + i) & mask) || + tos != (iicprobew(LM77Thigh + i) & mask)) + return (NULL); + } else { + if (tlow != (iicprobew(LM77Tlow + i) & mask) || + thigh != (iicprobew(LM77Thigh + i) & mask)) + return (NULL); + } } /* We hope */ - return (1); + if (ret == 75) + return ("lm75"); + return ("lm77"); } char * @@ -495,9 +551,10 @@ iic_probe(struct device *self, struct i2cbus_attach_args *iba, u_int8_t addr) } else if (iicprobe(0x16) == 0x41 && ((iicprobe(0x17) & 0xf0) == 0x40) && (addr == 0x2c || addr == 0x2d || addr == 0x2e)) { name = "adm1026"; - } else if ((addr & 0xfc) == 0x48 && lm75probe()) { - name = "lm75"; - } else if (name == NULL) { + } else if (name == NULL && (addr & 0xfc) == 0x48) { + name = lm75probe(); + } + if (name == NULL) { name = amd1032cloneprobe(addr); if (name) skip_fc = 1; |