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-rw-r--r--drivers/hwmon/lm73.c181
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/hwmon/lm73.c b/drivers/hwmon/lm73.c
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+/*
+ * (C) Copyright 2007
+ * Larry Johnson, lrj@acm.org
+ *
+ * based on dtt/lm75.c which is ...
+ *
+ * (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
+ */
+
+/*
+ * National Semiconductor LM73 Temperature Sensor
+ */
+
+#include <common.h>
+
+#ifdef CONFIG_DTT_LM73
+#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_LM73"
+#endif
+
+#include <i2c.h>
+#include <dtt.h>
+
+/*
+ * Device code
+ */
+#define DTT_I2C_DEV_CODE 0x48 /* National Semi's LM73 device */
+
+int dtt_read(int sensor, int reg)
+{
+ int dlen;
+ uchar data[2];
+
+ /*
+ * Validate 'reg' param and get register size.
+ */
+ switch (reg) {
+ case DTT_CONFIG:
+ case DTT_CONTROL:
+ dlen = 1;
+ break;
+ case DTT_READ_TEMP:
+ case DTT_TEMP_HIGH:
+ case DTT_TEMP_LOW:
+ case DTT_ID:
+ dlen = 2;
+ break;
+ default:
+ return -1;
+ }
+ /*
+ * Calculate sensor address and register.
+ */
+ sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate LM73 addr */
+ /*
+ * Now try to read the register.
+ */
+ if (i2c_read(sensor, reg, 1, data, dlen) != 0)
+ return -1;
+ /*
+ * Handle 2 byte result.
+ */
+ if (2 == dlen)
+ 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 and handle register size
+ */
+ switch (reg) {
+ case DTT_CONFIG:
+ case DTT_CONTROL:
+ dlen = 1;
+ data[0] = (char)(val & 0xff);
+ break;
+ case DTT_TEMP_HIGH:
+ case DTT_TEMP_LOW:
+ dlen = 2;
+ data[0] = (char)((val >> 8) & 0xff); /* MSB first */
+ data[1] = (char)(val & 0xff);
+ break;
+ default:
+ return -1;
+ }
+ /*
+ * Calculate sensor address and register.
+ */
+ sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate LM73 addr */
+ /*
+ * Write value to register.
+ */
+ return i2c_write(sensor, reg, 1, data, dlen) != 0;
+} /* dtt_write() */
+
+static int _dtt_init(int sensor)
+{
+ int val;
+
+ /*
+ * Validate the Identification register
+ */
+ if (0x0190 != dtt_read(sensor, DTT_ID))
+ return 1;
+ /*
+ * Setup THIGH (upper-limit) and TLOW (lower-limit) registers
+ */
+ val = CFG_DTT_MAX_TEMP << 7;
+ if (dtt_write(sensor, DTT_TEMP_HIGH, val))
+ return 1;
+
+ val = CFG_DTT_MIN_TEMP << 7;
+ if (dtt_write(sensor, DTT_TEMP_LOW, val))
+ return 1;
+ /*
+ * Setup configuraton register
+ */
+ /* config = alert active low, disabled, and reset */
+ val = 0x64;
+ if (dtt_write(sensor, DTT_CONFIG, val))
+ return 1;
+ /*
+ * Setup control/status register
+ */
+ /* control = temp resolution 0.25C */
+ val = 0x00;
+ if (dtt_write(sensor, DTT_CONTROL, val))
+ return 1;
+
+ dtt_read(sensor, DTT_CONTROL); /* clear temperature flags */
+ 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) + 0x0040) >> 7;
+} /* dtt_get_temp() */
+
+#endif /* CONFIG_DTT_LM73 */