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;
   9         union {
  10                 unsigned char probe_steady, mode_changed;
  11         };
  12         uint16_t mode_pwm[N_PWMLED_MODES];
  13         int16_t err_sums[N_PWMLED_MODES];
  14 } pwmled_t;
  15
  16 pwmled_t pwmleds[N_PWMLEDS];
  17
  18 #define PWMLED2_TESTING_WITH_350MA_LED
  19
  20 #define SENSE_MOHM      33      /* 0.033 Ohm */
  21 /*
  22  * Voltage in uV at ADC reading == 1 is 1100/gain/1024
  23  * ADC module returns sum of 1 << PWMLED_ADC_SHIFT measurements
  24  * Voltage in uV measured is current in mA * sense resistance in mOhm
  25  */
  26 #define MA_GAIN_TO_ADC(ma, gain) ((uint16_t) \
  27         ((uint32_t)(ma) \
  28         * (SENSE_MOHM) \
  29         * (1 << (PWMLED_ADC_SHIFT)) \
  30         * 1024 \
  31         / (1100000/(gain))))
  32
  33 static uint16_t adc_max[N_PWMLEDS] = {
  34 #ifdef TESTING_FW
  35         MA_GAIN_TO_ADC( 400, 20),
  36         MA_GAIN_TO_ADC(  30, 20),
  37         MA_GAIN_TO_ADC( 800,  1)
  38 #else
  39         MA_GAIN_TO_ADC( 900, 20),
  40         MA_GAIN_TO_ADC(  30, 20),
  41         MA_GAIN_TO_ADC(2500,  1)
  42 #endif
  43 };
  44
  45 static uint16_t adc_targets_0[] = {
  46         MA_GAIN_TO_ADC(  50, 20),
  47         MA_GAIN_TO_ADC( 100, 20),
  48         MA_GAIN_TO_ADC( 200, 20),
  49         MA_GAIN_TO_ADC( 350, 20),
  50 };
  51
  52 static uint16_t adc_targets_1[] = {
  53         MA_GAIN_TO_ADC(   5, 20),
  54         MA_GAIN_TO_ADC(  10, 20),
  55         MA_GAIN_TO_ADC(  20, 20),
  56 };
  57
  58 static uint16_t adc_targets_2[] = {
  59         MA_GAIN_TO_ADC(  50,  1),
  60         MA_GAIN_TO_ADC( 100,  1),
  61         MA_GAIN_TO_ADC( 200,  1),
  62         MA_GAIN_TO_ADC( 350,  1),
  63 };
  64
  65 static uint16_t adc_vals[N_PWMLEDS*N_PWMLED_MODES];
  66
  67 #define ST_DISABLED 0
  68 #define ST_OFF      1
  69 #define ST_PROBING  2
  70 #define ST_ON       3
  71 // The above are constructed so that the following work:
  72 #define ST_IS_ON(s)     ((s) & 0x02)
  73 #define ST_CAN_SET_MODE(s)      ((s) & 0x01)
  74
  75 void init_pwmled()
  76 {
  77         unsigned char i, j;
  78
  79         for (i = 0; i < N_PWMLEDS; i++) {
  80                 pwmled_t *led = pwmleds + i;
  81                 led->err_sum = 0;
  82                 led->target = adc_vals[i*N_PWMLED_MODES];
  83                 led->mode = 1;
  84                 led->probe_steady = 0;
  85                 led->state = ST_OFF;
  86                 led->pwm = 1;
  87                 pwm_set(i, led->pwm);
  88
  89                 for (j = 0; j < N_PWMLED_MODES; j++) {
  90                         led->mode_pwm[j] = 0;
  91                         led->err_sums[j] = 0;
  92                 }
  93         }
  94
  95         pwmled_set_brightness(PWMLED_BRIGHTNESS(0, 2, 1, 0, 2));
  96 }
  97
  98 void pwmled_set_mode(unsigned char n, unsigned char mode)
  99 {
 100         pwmled_t *led = pwmleds + n;
 101
 102         if (!ST_CAN_SET_MODE(led->state))
 103                 return;
 104
 105         if (led->mode) { // save the previous state
 106                 led->mode_pwm[led->mode - 1] = led->pwm;
 107                 led->err_sums[led->mode - 1] = led->err_sum;
 108         }
 109
 110         led->mode = mode;
 111
 112         if (mode > 0 && mode <= N_PWMLED_MODES) {
 113                 led->target = adc_vals[n*N_PWMLED_MODES + mode - 1];
 114                 led->state = ST_ON;
 115                 led->pwm = led->mode_pwm[mode - 1];
 116                 led->err_sum = led->err_sums[mode - 1];
 117                 led->mode_changed = 1;
 118                 pwm_set(n, led->pwm);
 119         } else {
 120                 led->state = ST_OFF;
 121                 pwm_off(n);
 122         }
 123 }
 124
 125 void pwmled_set_brightness(uint16_t brightness)
 126 {
 127         unsigned char i;
 128
 129         adc_vals[0] = adc_targets_0[brightness & 0x7];
 130         adc_vals[1] = adc_targets_0[(brightness >> 3) & 0x7];
 131         adc_vals[2] = adc_vals[1];
 132
 133         adc_vals[3] = adc_targets_1[(brightness >> 6) & 0x7];
 134         adc_vals[4] = adc_vals[3];
 135         adc_vals[5] = adc_vals[3];
 136
 137         adc_vals[6] = adc_targets_2[(brightness >> 9) & 0x7];
 138         adc_vals[7] = adc_targets_2[(brightness >> 12) & 0x7];
 139         adc_vals[8] = adc_vals[7];
 140
 141         for (i = 0; i < N_PWMLEDS; i++) {
 142                 pwmleds[i].err_sum = 0;
 143                 pwmled_set_mode(i, pwmleds[i].mode);
 144         }
 145 }
 146
 147 #define PWMLED_PROBE_STEADY_COUNT 10
 148
 149 static inline unsigned char pwmled_probed_ok(unsigned char n, uint16_t old_pwm)
 150 {
 151         pwmled_t *led = pwmleds + n;
 152
 153         if (led->pwm == old_pwm) {
 154                 if (led->probe_steady < PWMLED_PROBE_STEADY_COUNT)
 155                         led->probe_steady++;
 156         } else {
 157                 led->probe_steady = 0;
 158         }
 159
 160         if (led->probe_steady < PWMLED_PROBE_STEADY_COUNT
 161                 && old_pwm <= led->pwm)
 162                 return 0;
 163
 164         // probed OK
 165         led->mode_pwm[led->mode - 1] = led->pwm;
 166         led->err_sums[led->mode - 1] = 0;
 167
 168         // next mode to probe?
 169         if (led->mode < N_PWMLED_MODES) {
 170                 led->probe_steady = 0;
 171                 led->err_sum = 0;
 172
 173                 led->mode++;
 174                 led->target = adc_vals[n*N_PWMLED_MODES+led->mode-1];
 175
 176                 return 0;
 177         } else {
 178                 unsigned char i;
 179
 180                 led->state = ST_OFF;
 181                 pwm_off(n);
 182
 183                 log_byte(0xF0);
 184                 log_byte(n);
 185                 log_word(jiffies);
 186
 187                 for (i = 0; i < N_PWMLED_MODES; i++)
 188                         log_word(led->mode_pwm[i]);
 189
 190                 log_flush();
 191
 192                 pattern_reload();
 193
 194                 return 1;
 195         }
 196 }
 197
 198 static inline void pwmled_err(unsigned char n)
 199 {
 200         pwmleds[n].state = ST_DISABLED;
 201         pwm_off(n);
 202
 203         log_byte(0xF1);
 204         log_byte(n);
 205         log_word(jiffies);
 206         log_flush();
 207 }
 208
 209
 210 void pwmled_adc(unsigned char n, uint16_t adcval)
 211 {
 212         pwmled_t *led = pwmleds + n;
 213         uint16_t old_pwm;
 214         int32_t sum;
 215         unsigned char shift;
 216
 217         if (!ST_IS_ON(led->state))
 218                 return;
 219
 220         if (led->state == ST_ON && led->mode_changed) {
 221                 led->mode_changed--;
 222                 return;
 223         }
 224         // FIXME: test for maximum adcval value (adc_max[n])
 225
 226         old_pwm = led->pwm;
 227
 228         // shift = led->state == ST_PROBING ? 3 : 8;
 229         shift = 3;
 230
 231         sum = ((int32_t)led->pwm << shift)
 232                 + led->err_sum + led->target - adcval;
 233
 234         if (sum < 0)
 235                 sum = 0;
 236
 237         led->pwm = sum >> shift;
 238         sum -= led->pwm << shift;
 239         led->err_sum = sum;
 240
 241         if (led->pwm >= PWM_MAX
 242                 || (n == 1 && led->pwm > PWM_MAX/2 && adcval < 0x08)) {
 243                 pwmled_err(n);
 244                 return;
 245         }
 246
 247         if (led->state == ST_PROBING)
 248                 if (pwmled_probed_ok(n, old_pwm))
 249                         return;
 250
 251         if (led->pwm == old_pwm)
 252                 return;
 253
 254         pwm_set(n, led->pwm);
 255 }
 256