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   1 /*
   2  * Copyright © 2024 Keith Packard <keithp@keithp.com>
   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, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  17  */
  18
  19 #include "ao.h"
  20 #include "ao_pwm.h"
  21
  22 static uint8_t  pwm_running;
  23
  24 static uint16_t pwm_value[NUM_PWM];
  25
  26 static void
  27 ao_pwm_up(void)
  28 {
  29         if (pwm_running++ == 0) {
  30                 struct stm_tim234       *tim = &AO_PWM_TIMER;
  31
  32                 tim->ccr1 = 0;
  33                 tim->ccr2 = 0;
  34                 tim->ccr3 = 0;
  35                 tim->ccr4 = 0;
  36                 tim->arr = PWM_MAX - 1; /* turn on the timer */
  37                 tim->cr1 = ((STM_TIM234_CR1_CKD_1 << STM_TIM234_CR1_CKD) |
  38                             (0 << STM_TIM234_CR1_ARPE) |
  39                             (STM_TIM234_CR1_CMS_EDGE << STM_TIM234_CR1_CMS) |
  40                             (STM_TIM234_CR1_DIR_UP << STM_TIM234_CR1_DIR) |
  41                             (0 << STM_TIM234_CR1_OPM) |
  42                             (0 << STM_TIM234_CR1_URS) |
  43                             (0 << STM_TIM234_CR1_UDIS) |
  44                             (1 << STM_TIM234_CR1_CEN));
  45
  46                 /* Set the timer running */
  47                 tim->egr = (1 << STM_TIM234_EGR_UG);
  48         }
  49 }
  50
  51 static void
  52 ao_pwm_down(void)
  53 {
  54         if (--pwm_running == 0) {
  55                 struct stm_tim234       *tim = &AO_PWM_TIMER;
  56
  57                 tim->arr = 0;
  58                 tim->cr1 = ((STM_TIM234_CR1_CKD_1 << STM_TIM234_CR1_CKD) |
  59                             (0 << STM_TIM234_CR1_ARPE) |
  60                             (STM_TIM234_CR1_CMS_EDGE << STM_TIM234_CR1_CMS) |
  61                             (STM_TIM234_CR1_DIR_UP << STM_TIM234_CR1_DIR) |
  62                             (0 << STM_TIM234_CR1_OPM) |
  63                             (0 << STM_TIM234_CR1_URS) |
  64                             (0 << STM_TIM234_CR1_UDIS) |
  65                             (0 << STM_TIM234_CR1_CEN));
  66
  67                 /* Stop the timer */
  68                 tim->egr = (1 << STM_TIM234_EGR_UG);
  69         }
  70 }
  71
  72 void
  73 ao_pwm_set(uint8_t pwm, uint16_t value)
  74 {
  75         struct stm_tim234       *tim = &AO_PWM_TIMER;
  76
  77 #if PWM_MAX < UINT16_MAX
  78         if (value > PWM_MAX)
  79                 value = PWM_MAX;
  80 #endif
  81         if (value != 0) {
  82                 if (pwm_value[pwm] == 0)
  83                         ao_pwm_up();
  84         }
  85         switch (pwm) {
  86         case 0:
  87                 tim->ccr1 = value;
  88                 break;
  89         case 1:
  90                 tim->ccr2 = value;
  91                 break;
  92         case 2:
  93                 tim->ccr3 = value;
  94                 break;
  95         case 3:
  96                 tim->ccr4 = value;
  97                 break;
  98         }
  99         if (value == 0) {
 100                 if (pwm_value[pwm] != 0)
 101                         ao_pwm_down();
 102         }
 103         pwm_value[pwm] = value;
 104 }
 105
 106 static void
 107 ao_pwm_cmd(void)
 108 {
 109         uint8_t ch;
 110         uint16_t val;
 111
 112         ch = (uint8_t) ao_cmd_decimal();
 113         val = (uint16_t) ao_cmd_decimal();
 114         if (ao_cmd_status != ao_cmd_success)
 115                 return;
 116
 117         printf("Set channel %d to %d\n", ch, val);
 118         ao_pwm_set(ch, val);
 119 }
 120
 121 static const struct ao_cmds ao_pwm_cmds[] = {
 122         { ao_pwm_cmd,   "P <ch> <val>\0Set PWM ch to val" },
 123         { 0, NULL },
 124 };
 125
 126 void
 127 ao_pwm_init(void)
 128 {
 129         struct stm_tim234       *tim = &AO_PWM_TIMER;
 130
 131         stm_rcc.apb1enr |= (1 << AO_PWM_TIMER_ENABLE);
 132
 133         tim->cr1 = 0;
 134         tim->psc = AO_PWM_TIMER_SCALE - 1;
 135         tim->cnt = 0;
 136         tim->ccer = ((1 << STM_TIM234_CCER_CC1E) |
 137                      (0 << STM_TIM234_CCER_CC1P) |
 138                      (1 << STM_TIM234_CCER_CC2E) |
 139                      (0 << STM_TIM234_CCER_CC2P) |
 140                      (1 << STM_TIM234_CCER_CC3E) |
 141                      (0 << STM_TIM234_CCER_CC3P) |
 142                      (1 << STM_TIM234_CCER_CC4E) |
 143                      (0 << STM_TIM234_CCER_CC4P));
 144
 145         tim->ccmr1 = ((0 << STM_TIM234_CCMR1_OC2CE) |
 146                       (STM_TIM234_CCMR1_OC2M_PWM_MODE_1 << STM_TIM234_CCMR1_OC2M) |
 147                       (0 << STM_TIM234_CCMR1_OC2PE) |
 148                       (0 << STM_TIM234_CCMR1_OC2FE) |
 149                       (STM_TIM234_CCMR1_CC2S_OUTPUT << STM_TIM234_CCMR1_CC2S) |
 150
 151                       (0 << STM_TIM234_CCMR1_OC1CE) |
 152                       (STM_TIM234_CCMR1_OC1M_PWM_MODE_1 << STM_TIM234_CCMR1_OC1M) |
 153                       (0 << STM_TIM234_CCMR1_OC1PE) |
 154                       (0 << STM_TIM234_CCMR1_OC1FE) |
 155                       (STM_TIM234_CCMR1_CC1S_OUTPUT << STM_TIM234_CCMR1_CC1S));
 156
 157
 158         tim->ccmr2 = ((0 << STM_TIM234_CCMR2_OC4CE) |
 159                       (STM_TIM234_CCMR2_OC4M_PWM_MODE_1 << STM_TIM234_CCMR2_OC4M) |
 160                       (0 << STM_TIM234_CCMR2_OC4PE) |
 161                       (0 << STM_TIM234_CCMR2_OC4FE) |
 162                       (STM_TIM234_CCMR2_CC4S_OUTPUT << STM_TIM234_CCMR2_CC4S) |
 163
 164                       (0 << STM_TIM234_CCMR2_OC3CE) |
 165                       (STM_TIM234_CCMR2_OC3M_PWM_MODE_1 << STM_TIM234_CCMR2_OC3M) |
 166                       (0 << STM_TIM234_CCMR2_OC3PE) |
 167                       (0 << STM_TIM234_CCMR2_OC3FE) |
 168                       (STM_TIM234_CCMR2_CC3S_OUTPUT << STM_TIM234_CCMR2_CC3S));
 169         tim->egr = 0;
 170
 171         tim->sr = 0;
 172         tim->dier = 0;
 173         tim->smcr = 0;
 174         tim->cr2 = ((0 << STM_TIM234_CR2_TI1S) |
 175                     (STM_TIM234_CR2_MMS_RESET<< STM_TIM234_CR2_MMS) |
 176                     (0 << STM_TIM234_CR2_CCDS));
 177
 178         stm_set_afio_mapr(AO_AFIO_PWM_REMAP,
 179                           AO_AFIO_PWM_REMAP_VAL,
 180                           AO_AFIO_PWM_REMAP_MASK);
 181
 182         ao_enable_port(AO_PWM_0_GPIO);
 183
 184         stm_gpio_conf(AO_PWM_0_GPIO, AO_PWM_0_PIN,
 185                       STM_GPIO_CR_MODE_OUTPUT_2MHZ,
 186                       STM_GPIO_CR_CNF_OUTPUT_AF_PUSH_PULL);
 187 #if NUM_PWM > 1
 188         stm_gpio_conf(AO_PWM_1_GPIO, AO_PWM_1_PIN,
 189                       STM_GPIO_CR_MODE_OUTPUT_2MHZ,
 190                       STM_GPIO_CR_CNF_OUTPUT_AF_PUSH_PULL);
 191 #endif
 192 #if NUM_PWM > 2
 193         stm_gpio_conf(AO_PWM_2_GPIO, AO_PWM_2_PIN,
 194                       STM_GPIO_CR_MODE_OUTPUT_2MHZ,
 195                       STM_GPIO_CR_CNF_OUTPUT_AF_PUSH_PULL);
 196 #endif
 197 #if NUM_PWM > 3
 198         stm_gpio_conf(AO_PWM_3_GPIO, AO_PWM_3_PIN,
 199                       STM_GPIO_CR_MODE_OUTPUT_2MHZ,
 200                       STM_GPIO_CR_CNF_OUTPUT_AF_PUSH_PULL);
 201 #endif
 202         ao_cmd_register(&ao_pwm_cmds[0]);
 203 }