modules/hardware/pwm_ng/pwm_ng.c

   1 /*
   2  *  Copyright Droids Corporation, Microb Technology, Eirbot (2005)
   3  *
   4  *  This program is free software; you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License as published by
   6  *  the Free Software Foundation; either version 2 of the License, or
   7  *  (at your option) any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *  GNU General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License
  15  *  along with this program; if not, write to the Free Software
  16  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  *
  18  *  Copyright Droids-corporation - Olivier MATZ - 2009
  19  */
  20 #include <string.h>
  21
  22 #include <aversive.h>
  23 #include <aversive/parts.h>
  24 #include <aversive/timers.h>
  25
  26 #include "pwm_ng.h"
  27
  28 /* value to be used for limiting inputs */
  29 #define PWM_SIGNIFICANT_BITS 12
  30 #define PWM_MAX ((1<< PWM_SIGNIFICANT_BITS)-1)
  31 #define PWM_MIN (-PWM_MAX)
  32
  33 #define PWM_NG_TYPE_8   0
  34 #define PWM_NG_TYPE_16  1
  35
  36 #define PWM_NG_NBITS_8   0
  37 #define PWM_NG_NBITS_9   1
  38 #define PWM_NG_NBITS_10  2
  39
  40 void pwm_ng_init(struct pwm_ng *pwm, uint8_t timer_nbits,
  41                  uint8_t pwm_nbits, uint8_t pwm_mode,
  42                  volatile void *ocrn,
  43                  uint8_t com0, volatile uint8_t *tccrn,
  44                  volatile uint8_t *pwm_port, uint8_t pwm_bit,
  45                  volatile uint8_t *sign_port, uint8_t sign_bit)
  46 {
  47         memset(pwm, 0, sizeof(*pwm));
  48
  49         if (timer_nbits == 8) {
  50                 pwm->type = PWM_NG_TYPE_8;
  51                 pwm->u.ocr8 = ocrn;
  52                 *pwm->u.ocr8 = 0;
  53         }
  54         else {
  55                 pwm->type = PWM_NG_TYPE_16;
  56                 pwm->u.ocr16 = ocrn;
  57                 *pwm->u.ocr16 = 0;
  58         }
  59         switch (pwm_nbits) {
  60         case 9:
  61                 pwm->nbits = PWM_NG_NBITS_9;
  62                 break;
  63         case 10:
  64                 pwm->nbits = PWM_NG_NBITS_10;
  65                 break;
  66         case 8:
  67         default:
  68                 pwm->nbits = PWM_NG_NBITS_8;
  69                 break;
  70         }
  71         pwm->mode = pwm_mode;
  72
  73         *tccrn &= ~(0x03 << com0);
  74         if (pwm_mode & PWM_NG_MODE_REVERSE)
  75                 *tccrn |= (0x01 << com0);
  76         else
  77                 *tccrn |= (0x02 << com0);
  78
  79         DDR(*pwm_port) |= (1 << pwm_bit);
  80
  81         if ((pwm_mode & PWM_NG_MODE_SIGNED) && (sign_port))
  82                 DDR(*sign_port) |= (1 << sign_bit);
  83         pwm->sign_port = sign_port;
  84         pwm->sign_bit = sign_bit;
  85 }
  86
  87 static inline void pwm_sign_set(struct pwm_ng *pwm)
  88 {
  89         if (pwm->mode & PWM_NG_MODE_SIGN_INVERTED)
  90                 *pwm->sign_port &= ~(1 << pwm->sign_bit);
  91         else
  92                 *pwm->sign_port |= (1 << pwm->sign_bit);
  93 }
  94
  95 static inline void pwm_sign_reset(struct pwm_ng *pwm)
  96 {
  97         if (pwm->mode &PWM_NG_MODE_SIGN_INVERTED)
  98                 *pwm->sign_port |= (1 << pwm->sign_bit);
  99         else
 100                 *pwm->sign_port &= ~(1 << pwm->sign_bit);
 101 }
 102
 103 static inline int32_t pwm_invert_value(struct pwm_ng *pwm, int32_t value)
 104 {
 105         if (pwm->mode & PWM_NG_MODE_SPECIAL_SIGN)
 106                 return value & PWM_MAX;
 107         else
 108                 return -value;
 109 }
 110
 111 #include <stdio.h>
 112 void pwm_ng_set(void *data, int32_t value)
 113 {
 114         struct pwm_ng *pwm = data;
 115         uint8_t nbits = 8 + pwm->nbits;
 116
 117         MAX(value, PWM_MAX);
 118         if (pwm->mode & PWM_NG_MODE_SIGNED) {
 119                 MIN(value, PWM_MIN);
 120                 if (value < 0) {
 121                         pwm_sign_set(pwm);
 122                         value = pwm_invert_value(pwm, value);
 123                 }
 124                 else {
 125                         pwm_sign_reset(pwm);
 126                 }
 127         }
 128         else {
 129                 MIN(value, 0);
 130         }
 131         if (pwm->type == PWM_NG_TYPE_8)
 132                 *pwm->u.ocr8 = (uint8_t) (value >> (PWM_SIGNIFICANT_BITS - 8));
 133         else
 134                 *pwm->u.ocr16 = (value >> (PWM_SIGNIFICANT_BITS - nbits));
 135 }
 136