1 /******************************************************************************
2 *  Filename:       aon_batmon.c
3 *  Revised:        2015-10-21 16:28:04 +0200 (Wed, 21 Oct 2015)
4 *  Revision:       44798
5 *
6 *  Description:    Driver for the AON Battery and Temperature Monitor
7 *
8 *  Copyright (c) 2015, Texas Instruments Incorporated
9 *  All rights reserved.
10 *
11 *  Redistribution and use in source and binary forms, with or without
12 *  modification, are permitted provided that the following conditions are met:
13 *
14 *  1) Redistributions of source code must retain the above copyright notice,
15 *     this list of conditions and the following disclaimer.
16 *
17 *  2) Redistributions in binary form must reproduce the above copyright notice,
18 *     this list of conditions and the following disclaimer in the documentation
19 *     and/or other materials provided with the distribution.
20 *
21 *  3) Neither the name of the ORGANIZATION nor the names of its contributors may
22 *     be used to endorse or promote products derived from this software without
23 *     specific prior written permission.
24 *
25 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
26 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
29 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 *  POSSIBILITY OF SUCH DAMAGE.
36 *
37 ******************************************************************************/
38 
39 #include <driverlib/aon_batmon.h>
40 #include <inc/hw_fcfg1.h>
41 
42 //*****************************************************************************
43 // Need to know the AON_BATMON:TEMP.INT field width in order to sign extend correctly
44 // (This is not given in the hw_aon_batmon.h file and therefore hard coded here)
45 //*****************************************************************************
46 #define AON_BATMON_TEMP_INT_FIELD_WIDTH   9
47 //*****************************************************************************
48 //
49 // AONBatMonTemperatureGetDegC()
50 // Returns sign extended temperature in Deg C (-256 .. +255)
51 //
52 //*****************************************************************************
53 int32_t
AONBatMonTemperatureGetDegC(void)54 AONBatMonTemperatureGetDegC( void )
55 {
56    int32_t  signedTemp        ; // Signed extended temperature with 8 fractional bits
57    int32_t  tempCorrection    ; // Voltage dependent temp correction with 8 fractional bits
58    int8_t   voltageSlope      ; // Signed byte value representing the TEMP slope with battery voltage, in degrees C/V, with 4 fractional bits.
59 
60    //
61    // Shift left then right to sign extend the BATMON_TEMP field
62    //
63    signedTemp = ((((int32_t)HWREG( AON_BATMON_BASE + AON_BATMON_O_TEMP ))
64      << ( 32 - AON_BATMON_TEMP_INT_FIELD_WIDTH - AON_BATMON_TEMP_INT_S ))
65      >> ( 32 - AON_BATMON_TEMP_INT_FIELD_WIDTH - AON_BATMON_TEMP_INT_S ));
66 
67    //
68    // Typecasting voltageSlope to int8_t prior to assignment in order to make sure sign extension works properly
69    // Using byte read (HWREGB) in order to make more efficient code since voltageSlope is assigned to bits[7:0] of FCFG1_O_MISC_TRIM
70    //
71    voltageSlope      = ((int8_t)HWREGB( FCFG1_BASE + FCFG1_O_MISC_TRIM ));
72    tempCorrection    = (( voltageSlope * (((int32_t)HWREG( AON_BATMON_BASE + AON_BATMON_O_BAT )) - 0x300 )) >> 4 );
73 
74    return ((( signedTemp - tempCorrection ) + 0x80 ) >> 8 );
75 }
76 
77 
78 // See aon_batmon.h for implementation of remaining functions
79