From 6a9a7ff0eb0d1f4d43d2ac7113575706d7b26979 Mon Sep 17 00:00:00 2001 From: "Mark M. Hoffman" Date: Tue, 2 Dec 2003 05:53:27 +0000 Subject: [PATCH] (mmh) Pulled the TEMP_TO_REG and TEMP_FROM_REG functions into a separate header and gave them the prefix LM75_. Also rewrote them according to the lm75 datasheet. The next step is to replace all the various scattered (broken?) copies of these functions (especially in Winbond subclients) with this one. git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@2130 7894878c-1315-0410-8ee3-d5d059ff63e0 --- kernel/chips/lm75.c | 18 ++++++----------- kernel/chips/lm75.h | 49 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+), 12 deletions(-) create mode 100644 kernel/chips/lm75.h diff --git a/kernel/chips/lm75.c b/kernel/chips/lm75.c index 0fc8d0a8..2a7a75cd 100644 --- a/kernel/chips/lm75.c +++ b/kernel/chips/lm75.c @@ -24,6 +24,7 @@ #include #include #include "version.h" +#include "lm75.h" /* Addresses to scan */ static unsigned short normal_i2c[] = { SENSORS_I2C_END }; @@ -42,13 +43,6 @@ SENSORS_INSMOD_1(lm75); #define LM75_REG_TEMP_HYST 0x02 #define LM75_REG_TEMP_OS 0x03 -/* Conversions. Rounding and limit checking is only done on the TO_REG - variants. Note that you should be a bit careful with which arguments - these macros are called: arguments may be evaluated more than once. - Fixing this is just not worth it. */ -#define TEMP_FROM_REG(val) ((((val & 0x7fff) >> 7) * 5) | ((val & 0x8000)?-256:0)) -#define TEMP_TO_REG(val) (SENSORS_LIMIT((val<0?(0x200+((val)/5))<<7:(((val) + 2) / 5) << 7),0,0xffff)) - /* Each client has this additional data */ struct lm75_data { int sysctl_id; @@ -288,18 +282,18 @@ void lm75_temp(struct i2c_client *client, int operation, int ctl_name, *nrels_mag = 1; else if (operation == SENSORS_PROC_REAL_READ) { lm75_update_client(client); - results[0] = TEMP_FROM_REG(data->temp_os); - results[1] = TEMP_FROM_REG(data->temp_hyst); - results[2] = TEMP_FROM_REG(data->temp); + results[0] = LM75_TEMP_FROM_REG(data->temp_os); + results[1] = LM75_TEMP_FROM_REG(data->temp_hyst); + results[2] = LM75_TEMP_FROM_REG(data->temp); *nrels_mag = 3; } else if (operation == SENSORS_PROC_REAL_WRITE) { if (*nrels_mag >= 1) { - data->temp_os = TEMP_TO_REG(results[0]); + data->temp_os = LM75_TEMP_TO_REG(results[0]); lm75_write_value(client, LM75_REG_TEMP_OS, data->temp_os); } if (*nrels_mag >= 2) { - data->temp_hyst = TEMP_TO_REG(results[1]); + data->temp_hyst = LM75_TEMP_TO_REG(results[1]); lm75_write_value(client, LM75_REG_TEMP_HYST, data->temp_hyst); } diff --git a/kernel/chips/lm75.h b/kernel/chips/lm75.h new file mode 100644 index 00000000..2180f976 --- /dev/null +++ b/kernel/chips/lm75.h @@ -0,0 +1,49 @@ +/* + lm75.h - Part of lm_sensors, Linux kernel modules for hardware + monitoring + Copyright (c) 2003 Mark M. Hoffman + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +/* + This file contains common code for encoding/decoding LM75 type + temperature readings, which are emulated by many of the chips + we support. As the user is unlikely to load more than one driver + which contains this code, we don't worry about the wasted space. +*/ + +#include + +/* straight from the datasheet */ +#define LM75_TEMP_MIN (-550) +#define LM75_TEMP_MAX 1250 + +/* TEMP: 0.1C/bit (-55C to +125C) + REG: (0.5C/bit, two's complement) << 7 */ +static inline u16 LM75_TEMP_TO_REG(int temp) +{ + int ntemp = SENSORS_LIMIT(temp, LM75_TEMP_MIN, LM75_TEMP_MAX); + ntemp += (ntemp<0 ? -2 : 2); + return (u16)((ntemp / 5) << 7); +} + +static inline int LM75_TEMP_FROM_REG(u16 reg) +{ + /* use integer division instead of equivalent right shift to + guarantee arithmetic shift and preserve the sign */ + return ((s16)reg / 128) * 5; +} +