tmp105: Create API for TMP105 temperature sensor.

* Define enum for TMP105 registers
* Move tmp105_set() from I2C to TMP105 header
* Document units and range of temperature as preconditions

Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Alex Horn <alex.horn@cs.ox.ac.uk>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

hw/i2c.h

@@ -73,9 +73,6 @@ void *wm8750_dac_buffer(void *opaque, int samples);
 void wm8750_dac_commit(void *opaque);
 void wm8750_set_bclk_in(void *opaque, int new_hz);
 
-/* tmp105.c */
-void tmp105_set(I2CSlave *i2c, int temp);
-
 /* lm832x.c */
 void lm832x_key_event(DeviceState *dev, int key, int state);
 

hw/tmp105.c

@@ -20,6 +20,7 @@
 
 #include "hw.h"
 #include "i2c.h"
+#include "tmp105.h"
 
 typedef struct {
     I2CSlave i2c;
@@ -92,22 +93,22 @@ static void tmp105_read(TMP105State *s)
     }
 
     switch (s->pointer & 3) {
-    case 0:	/* Temperature */
+    case TMP105_REG_TEMPERATURE:
         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
         s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
                 (0xf0 << ((~s->config >> 5) & 3));		/* R */
         break;
 
-    case 1:	/* Configuration */
+    case TMP105_REG_CONFIG:
         s->buf[s->len ++] = s->config;
         break;
 
-    case 2:	/* T_LOW */
+    case TMP105_REG_T_LOW:
         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
         s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
         break;
 
-    case 3:	/* T_HIGH */
+    case TMP105_REG_T_HIGH:
         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
         s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
         break;
@@ -117,10 +118,10 @@ static void tmp105_read(TMP105State *s)
 static void tmp105_write(TMP105State *s)
 {
     switch (s->pointer & 3) {
-    case 0:	/* Temperature */
+    case TMP105_REG_TEMPERATURE:
         break;
 
-    case 1:	/* Configuration */
+    case TMP105_REG_CONFIG:
         if (s->buf[0] & ~s->config & (1 << 0))			/* SD */
             printf("%s: TMP105 shutdown\n", __FUNCTION__);
         s->config = s->buf[0];
@@ -128,8 +129,8 @@ static void tmp105_write(TMP105State *s)
         tmp105_alarm_update(s);
         break;
 
-    case 2:	/* T_LOW */
-    case 3:	/* T_HIGH */
+    case TMP105_REG_T_LOW:
+    case TMP105_REG_T_HIGH:
         if (s->len >= 3)
             s->limit[s->pointer & 1] = (int16_t)
                     ((((uint16_t) s->buf[0]) << 8) | s->buf[1]);

hw/tmp105.h

@@ -0,0 +1,67 @@
+/*
+ * Texas Instruments TMP105 Temperature Sensor
+ *
+ * Browse the data sheet:
+ *
+ *    http://www.ti.com/lit/gpn/tmp105
+ *
+ * Copyright (C) 2012 Alex Horn <alex.horn@cs.ox.ac.uk>
+ * Copyright (C) 2008-2012 Andrzej Zaborowski <balrogg@gmail.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later. See the COPYING file in the top-level directory.
+ */
+#ifndef QEMU_TMP105_H
+#define QEMU_TMP105_H
+
+#include "i2c.h"
+
+/**
+ * TMP105Reg:
+ * @TMP105_REG_TEMPERATURE: Temperature register
+ * @TMP105_REG_CONFIG: Configuration register
+ * @TMP105_REG_T_LOW: Low temperature register (also known as T_hyst)
+ * @TMP105_REG_T_HIGH: High temperature register (also known as T_OS)
+ *
+ * The following temperature sensors are
+ * compatible with the TMP105 registers:
+ * - adt75
+ * - ds1775
+ * - ds75
+ * - lm75
+ * - lm75a
+ * - max6625
+ * - max6626
+ * - mcp980x
+ * - stds75
+ * - tcn75
+ * - tmp100
+ * - tmp101
+ * - tmp105
+ * - tmp175
+ * - tmp275
+ * - tmp75
+ **/
+typedef enum TMP105Reg {
+    TMP105_REG_TEMPERATURE = 0,
+    TMP105_REG_CONFIG,
+    TMP105_REG_T_LOW,
+    TMP105_REG_T_HIGH,
+} TMP105Reg;
+
+/**
+ * tmp105_set:
+ * @i2c: dispatcher to TMP105 hardware model
+ * @temp: temperature with 0.001 centigrades units in the range -40 C to +125 C
+ *
+ * Sets the temperature of the TMP105 hardware model.
+ *
+ * Bits 5 and 6 (value 32 and 64) in the register indexed by TMP105_REG_CONFIG
+ * determine the precision of the temperature. See Table 8 in the data sheet.
+ *
+ * @see_also: I2C_SLAVE macro
+ * @see_also: http://www.ti.com/lit/gpn/tmp105
+ */
+void tmp105_set(I2CSlave *i2c, int temp);
+
+#endif