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authorwdenk <wdenk>2002-11-03 00:24:07 +0000
committerwdenk <wdenk>2002-11-03 00:24:07 +0000
commitc609719b8d1b2dca590e0ed499016d041203e403 (patch)
tree7ea1755d80903ff972f312a249eb856061d40e15 /dtt/lm75.c
parent5b1d713721c3ea02549940133f09236783dda1f9 (diff)
downloadblackbird-obmc-uboot-c609719b8d1b2dca590e0ed499016d041203e403.tar.gz
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+/*
+ * (C) Copyright 2001
+ * Bill Hunter, Wave 7 Optics, williamhunter@mediaone.net
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * On Semiconductor's LM75 Temperature Sensor
+ */
+
+#include <common.h>
+
+#ifdef CONFIG_DTT_LM75
+#if !defined(CFG_EEPROM_PAGE_WRITE_ENABLE) || \
+ (CFG_EEPROM_PAGE_WRITE_BITS < 1)
+# error "CFG_EEPROM_PAGE_WRITE_ENABLE must be defined and CFG_EEPROM_PAGE_WRITE_BITS must be greater than 1 to use CONFIG_DTT_LM75"
+#endif
+
+#include <i2c.h>
+#include <dtt.h>
+
+
+/*
+ * Device code
+ */
+#define DTT_I2C_DEV_CODE 0x48 /* ON Semi's LM75 device */
+
+int dtt_read(int sensor, int reg)
+{
+ int dlen;
+ uchar data[2];
+
+ /*
+ * Validate 'reg' param
+ */
+ if((reg < 0) || (reg > 3))
+ return -1;
+
+ /*
+ * Calculate sensor address and register.
+ */
+ sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate address of lm75 */
+
+ /*
+ * Prepare to handle 2 byte result.
+ */
+ if ((reg == DTT_READ_TEMP) ||
+ (reg == DTT_TEMP_HYST) ||
+ (reg == DTT_TEMP_SET))
+ dlen = 2;
+ else
+ dlen = 1;
+
+ /*
+ * Now try to read the register.
+ */
+ if (i2c_read(sensor, reg, 1, data, dlen) != 0)
+ return -1;
+
+ /*
+ * Handle 2 byte result.
+ */
+ if (dlen == 2)
+ return ((int)((short)data[1] + (((short)data[0]) << 8)));
+
+
+ return (int)data[0];
+} /* dtt_read() */
+
+
+int dtt_write(int sensor, int reg, int val)
+{
+ int dlen;
+ uchar data[2];
+
+ /*
+ * Validate 'reg' param
+ */
+ if ((reg < 0) || (reg > 3))
+ return 1;
+
+ /*
+ * Calculate sensor address and register.
+ */
+ sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate address of lm75 */
+
+ /*
+ * Handle 2 byte values.
+ */
+ if ((reg == DTT_READ_TEMP) ||
+ (reg == DTT_TEMP_HYST) ||
+ (reg == DTT_TEMP_SET)) {
+ dlen = 2;
+ data[0] = (char)((val >> 8) & 0xff); /* MSB first */
+ data[1] = (char)(val & 0xff);
+ } else {
+ dlen = 1;
+ data[0] = (char)(val & 0xff);
+ }
+
+ /*
+ * Write value to register.
+ */
+ if (i2c_write(sensor, reg, 1, data, dlen) != 0)
+ return 1;
+
+ return 0;
+} /* dtt_write() */
+
+
+static int _dtt_init(int sensor)
+{
+ int val;
+
+ /*
+ * Setup TSET ( trip point ) register
+ */
+ val = ((CFG_DTT_MAX_TEMP * 2) << 7) & 0xff80; /* trip */
+ if (dtt_write(sensor, DTT_TEMP_SET, val) != 0)
+ return 1;
+
+ /*
+ * Setup THYST ( untrip point ) register - Hysteresis
+ */
+ val = (((CFG_DTT_MAX_TEMP - CFG_DTT_HYSTERESIS) * 2) << 7) & 0xff80;
+ if (dtt_write(sensor, DTT_TEMP_HYST, val) != 0)
+ return 1;
+
+ /*
+ * Setup configuraton register
+ */
+ /* config = 6 sample integration, int mode, active low, and enable */
+ val = 0x18;
+ if (dtt_write(sensor, DTT_CONFIG, val) != 0)
+ return 1;
+
+ return 0;
+} /* _dtt_init() */
+
+
+int dtt_init (void)
+{
+ int i;
+ unsigned char sensors[] = CONFIG_DTT_SENSORS;
+ const char *const header = "DTT: ";
+
+ for (i = 0; i < sizeof(sensors); i++) {
+ if (_dtt_init(sensors[i]) != 0)
+ printf("%s%d FAILED INIT\n", header, i+1);
+ else
+ printf("%s%d is %i C\n", header, i+1,
+ dtt_get_temp(sensors[i]));
+ }
+
+ return (0);
+} /* dtt_init() */
+
+int dtt_get_temp(int sensor)
+{
+ return (dtt_read(sensor, DTT_READ_TEMP) / 256);
+} /* dtt_get_temp() */
+
+#endif /* CONFIG_DTT_LM75 */
+
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