firmware/pwmled.c

   1 #include <avr/io.h>
   2
   3 #include "lights.h"
   4
   5 typedef struct {
   6         uint16_t target, pwm;
   7         int16_t err_sum;
   8         unsigned char mode, state, probe_steady;
   9         uint16_t mode_pwm[N_PWMLED_MODES];
  10         int16_t err_sums[N_PWMLED_MODES];
  11 } pwmled_t;
  12
  13 pwmled_t pwmleds[N_PWMLEDS];
  14
  15 #define PWMLED2_TESTING_WITH_350MA_LED
  16
  17 #define SENSE_MOHM      33      /* 0.033 Ohm */
  18 /*
  19  * Voltage in uV at ADC reading == 1 is 1100/gain/1024
  20  * ADC module returns sum of 1 << PWMLED_ADC_SHIFT measurements
  21  * Voltage in uV measured is current in mA * sense resistance in mOhm
  22  */
  23 #define MA_GAIN_TO_ADC(ma, gain) ((uint16_t) \
  24         ((uint32_t)(ma) \
  25         * (SENSE_MOHM) \
  26         * (1 << (PWMLED_ADC_SHIFT)) \
  27         * 1024 \
  28         / (1100000/(gain))))
  29
  30 static uint16_t adc_max[N_PWMLEDS] = {
  31 #ifdef TESTING_FW
  32         MA_GAIN_TO_ADC( 400, 20),
  33         MA_GAIN_TO_ADC(  30, 20),
  34         MA_GAIN_TO_ADC( 800,  1)
  35 #else
  36         MA_GAIN_TO_ADC( 900, 20),
  37         MA_GAIN_TO_ADC(  30, 20),
  38         MA_GAIN_TO_ADC(2500,  1)
  39 #endif
  40 };
  41
  42 static uint16_t adc_vals[N_PWMLEDS*N_PWMLED_MODES] = {
  43 #ifdef TESTING_FW
  44         /* pwmled0 */
  45         MA_GAIN_TO_ADC(  50, 20),
  46         MA_GAIN_TO_ADC( 100, 20),
  47         MA_GAIN_TO_ADC( 200, 20),
  48         MA_GAIN_TO_ADC( 300, 20),
  49         /* pwmled1 */
  50         MA_GAIN_TO_ADC(   5, 20),
  51         MA_GAIN_TO_ADC(  10, 20),
  52         MA_GAIN_TO_ADC(  15, 20),
  53         MA_GAIN_TO_ADC(  20, 20),
  54         /* pwmled2 */
  55         MA_GAIN_TO_ADC(  50,  1),
  56         MA_GAIN_TO_ADC( 100,  1),
  57         MA_GAIN_TO_ADC( 150,  1),
  58         MA_GAIN_TO_ADC( 200,  1)
  59 #else
  60         /* pwmled0 */
  61         MA_GAIN_TO_ADC( 100, 20),
  62         MA_GAIN_TO_ADC( 300, 20),
  63         MA_GAIN_TO_ADC( 700, 20),
  64         MA_GAIN_TO_ADC( 800, 20),
  65         /* pwmled1 */
  66         MA_GAIN_TO_ADC(   5, 20),
  67         MA_GAIN_TO_ADC(  10, 20),
  68         MA_GAIN_TO_ADC(  18, 20),
  69         MA_GAIN_TO_ADC(  23, 20),
  70         /* pwmled2 */
  71         MA_GAIN_TO_ADC( 200,  1),
  72         MA_GAIN_TO_ADC( 400,  1),
  73         MA_GAIN_TO_ADC( 800,  1),
  74         MA_GAIN_TO_ADC(1500,  1)
  75 #endif
  76 };
  77
  78 #define ST_DISABLED 0
  79 #define ST_OFF      1
  80 #define ST_PROBING  2
  81 #define ST_ON       3
  82 // The above are constructed so that the following work:
  83 #define ST_IS_ON(s)     ((s) & 0x02)
  84 #define ST_CAN_SET_MODE(s)      ((s) & 0x01)
  85
  86 void init_pwmled()
  87 {
  88         unsigned char i, j;
  89
  90         for (i = 0; i < N_PWMLEDS; i++) {
  91                 pwmled_t *led = pwmleds + i;
  92                 led->err_sum = 0;
  93                 led->target = adc_vals[i*N_PWMLED_MODES];
  94                 led->pwm = 0;
  95                 led->mode = 1;
  96                 led->state = ST_PROBING;
  97                 led->probe_steady = 0;
  98
  99                 for (j = 0; j < N_PWMLED_MODES; j++) {
 100                         led->mode_pwm[j] = 0;
 101                         led->err_sums[j] = 0;
 102                 }
 103         }
 104 }
 105
 106 void pwmled_set_mode(unsigned char n, unsigned char mode)
 107 {
 108         pwmled_t *led = pwmleds + n;
 109
 110         if (!ST_CAN_SET_MODE(led->state))
 111                 return;
 112
 113         if (led->mode) { // save the previous state
 114                 led->mode_pwm[led->mode - 1] = led->pwm;
 115                 led->err_sums[led->mode - 1] = led->err_sum;
 116         }
 117
 118         led->mode = mode;
 119
 120         if (mode > 0 && mode <= N_PWMLED_MODES) {
 121                 led->target = adc_vals[n*N_PWMLED_MODES + mode - 1];
 122                 led->state = ST_ON;
 123                 led->pwm = led->mode_pwm[mode - 1];
 124                 led->err_sum = led->err_sums[mode - 1];
 125                 pwm_set(n, led->pwm);
 126         } else {
 127                 led->state = ST_OFF;
 128                 pwm_off(n);
 129         }
 130 }
 131
 132 #define PWMLED_PROBE_STEADY_COUNT 10
 133
 134 static inline unsigned char pwmled_probed_ok(unsigned char n, uint16_t old_pwm)
 135 {
 136         pwmled_t *led = pwmleds + n;
 137
 138         if (led->pwm == old_pwm) {
 139                 if (led->probe_steady < PWMLED_PROBE_STEADY_COUNT)
 140                         led->probe_steady++;
 141         } else {
 142                 led->probe_steady = 0;
 143         }
 144
 145         if (led->probe_steady < PWMLED_PROBE_STEADY_COUNT
 146                 && old_pwm <= led->pwm)
 147                 return 0;
 148
 149         // probed OK
 150         led->mode_pwm[led->mode - 1] = led->pwm;
 151         led->err_sums[led->mode - 1] = 0;
 152
 153         // next mode to probe?
 154         if (led->mode < N_PWMLED_MODES) {
 155                 led->probe_steady = 0;
 156                 led->err_sum = 0;
 157
 158                 led->mode++;
 159                 led->target = adc_vals[n*N_PWMLED_MODES+led->mode-1];
 160
 161                 return 0;
 162         } else {
 163                 unsigned char i;
 164
 165                 led->state = ST_OFF;
 166                 pwm_off(n);
 167
 168                 log_byte(0xF0);
 169                 log_byte(n);
 170                 log_word(jiffies);
 171
 172                 for (i = 0; i < N_PWMLED_MODES; i++)
 173                         log_word(led->mode_pwm[i]);
 174
 175                 log_flush();
 176
 177                 pattern_reload();
 178
 179                 return 1;
 180         }
 181 }
 182
 183 static inline void pwmled_err(unsigned char n)
 184 {
 185         pwmleds[n].state = ST_DISABLED;
 186         pwm_off(n);
 187
 188         log_byte(0xF1);
 189         log_byte(n);
 190         log_word(jiffies);
 191         log_flush();
 192 }
 193
 194
 195 void pwmled_adc(unsigned char n, uint16_t adcval)
 196 {
 197         pwmled_t *led = pwmleds + n;
 198         uint16_t old_pwm;
 199         int32_t sum;
 200         unsigned char shift;
 201
 202         if (!ST_IS_ON(led->state))
 203                 return;
 204
 205         // FIXME: test for maximum adcval value (adc_max[n])
 206
 207         old_pwm = led->pwm;
 208
 209         shift = led->state == ST_PROBING ? 3 : 5;
 210
 211         sum = ((int32_t)led->pwm << shift)
 212                 + led->err_sum + led->target - adcval;
 213
 214         if (sum < 0)
 215                 sum = 0;
 216
 217         led->pwm = sum >> shift;
 218         sum -= led->pwm << shift;
 219         led->err_sum = sum;
 220
 221         if (led->pwm >= PWM_MAX) {
 222                 pwmled_err(n);
 223                 return;
 224         }
 225
 226         if (led->state == ST_PROBING)
 227                 if (pwmled_probed_ok(n, old_pwm))
 228                         return;
 229
 230         if (led->pwm == old_pwm)
 231                 return;
 232
 233         pwm_set(n, led->pwm);
 234 }
 235