Add PWMOut

4 files changed, 135 insertions, 50 deletions

diff --git a/ports/esp32s2/Makefile b/ports/esp32s2/Makefile
index b29697688..09c35fd3a 100644
--- a/ports/esp32s2/Makefile
+++ b/ports/esp32s2/Makefile
@@ -262,7 +262,7 @@ all: $(BUILD)/firmware.bin $(BUILD)/firmware.uf2
 
 $(BUILD)/firmware.elf: $(OBJ) | $(ESP_IDF_COMPONENTS_EXPANDED) $(ESP_AUTOGEN_LD)
 	$(STEPECHO) "LINK $@"
-	$(Q)$(CC) -o $@ $(LDFLAGS) $^ $(ESP_IDF_COMPONENTS_EXPANDED) $(BINARY_BLOBS) build-$(BOARD)/esp-idf/esp-idf/newlib/libnewlib.a -u newlib_include_pthread_impl
+	$(Q)$(CC) -o $@ $(LDFLAGS) $^ $(ESP_IDF_COMPONENTS_EXPANDED) $(BINARY_BLOBS) build-$(BOARD)/esp-idf/esp-idf/newlib/libnewlib.a -u newlib_include_pthread_impl -Wl,--start-group $(LIBS) -Wl,--end-group
 	# $(Q)$(SIZE) $@ | $(PYTHON3) $(TOP)/tools/build_memory_info.py $(BUILD)/esp-idf/esp-idf/esp32s2/esp32s2_out.ld
 
 $(BUILD)/circuitpython-firmware.bin: $(BUILD)/firmware.elf
diff --git a/ports/esp32s2/common-hal/pulseio/PWMOut.c b/ports/esp32s2/common-hal/pulseio/PWMOut.c
index 8f96433c0..15fe96a22 100644
--- a/ports/esp32s2/common-hal/pulseio/PWMOut.c
+++ b/ports/esp32s2/common-hal/pulseio/PWMOut.c
@@ -24,31 +24,33 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
+#include <math.h>
 
 #include "common-hal/pulseio/PWMOut.h"
 #include "shared-bindings/pulseio/PWMOut.h"
 #include "py/runtime.h"
 #include "driver/ledc.h"
 
-#define LEDC_LS_TIMER          LEDC_TIMER_1
-#define LEDC_LS_MODE           LEDC_LOW_SPEED_MODE
-#define LEDC_LS_CH0_GPIO       (18)
-#define LEDC_LS_CH0_CHANNEL    LEDC_CHANNEL_0
-#define LEDC_LS_CH1_GPIO       (19)
-#define LEDC_LS_CH1_CHANNEL    LEDC_CHANNEL_1
-#define LEDC_LS_CH2_GPIO       (4)
-#define LEDC_LS_CH2_CHANNEL    LEDC_CHANNEL_2
-#define LEDC_LS_CH3_GPIO       (5)
-#define LEDC_LS_CH3_CHANNEL    LEDC_CHANNEL_3
-
-#define LEDC_TEST_CH_NUM       (4)
-#define LEDC_TEST_DUTY         (4000)
-#define LEDC_TEST_FADE_TIME    (3000)
-
+#define INDEX_EMPTY 0xFF
 
+STATIC uint32_t reserved_timer_freq[LEDC_TIMER_MAX];
+STATIC uint8_t reserved_channels[LEDC_CHANNEL_MAX] = {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
+STATIC bool never_reset_tim[LEDC_TIMER_MAX];
+STATIC bool never_reset_chan[LEDC_CHANNEL_MAX];
 
 void pwmout_reset(void) {
+    for (size_t i = 0; i < LEDC_CHANNEL_MAX; i++ ) {
+        ledc_stop(LEDC_LOW_SPEED_MODE, i, 0);
+        if (!never_reset_chan[i]) {
+            reserved_channels[i] = INDEX_EMPTY;
+        }
+    }
+    for (size_t i = 0; i < LEDC_TIMER_MAX; i++ ) {
+        ledc_timer_rst(LEDC_LOW_SPEED_MODE, i);
+        if (!never_reset_tim[i]) {
+            reserved_timer_freq[i] = 0;
+        }
+    }
 }
 
 pwmout_result_t common_hal_pulseio_pwmout_construct(pulseio_pwmout_obj_t* self,
@@ -56,65 +58,142 @@ pwmout_result_t common_hal_pulseio_pwmout_construct(pulseio_pwmout_obj_t* self,
                                                     uint16_t duty,
                                                     uint32_t frequency,
                                                     bool variable_frequency) {
-    ledc_timer_config_t ledc_timer = {
-        .duty_resolution = LEDC_TIMER_16_BIT,   // resolution of PWM duty
-        .freq_hz = frequency,                   // frequency of PWM signal
-        .speed_mode = LEDC_LS_MODE,             // timer mode
-        .timer_num = LEDC_LS_TIMER,             // timer index
-        .clk_cfg = LEDC_AUTO_CLK,               // Auto select the source clock
-    };
-    // Set configuration of timer0 for high speed channels
-    ledc_timer_config(&ledc_timer);
-
-    ledc_channel_config_t pwm_channel = {
-        .channel    = LEDC_LS_CH0_CHANNEL,
-        .duty       = 0,
-        .gpio_num   = pin->number,
-        .speed_mode = LEDC_LS_MODE,
-        .hpoint     = 0,
-        .timer_sel  = LEDC_LS_TIMER
-    };
-
-    // Set LED Controller with previously prepared configuration
-    for (ch = 0; ch < LEDC_TEST_CH_NUM; ch++) {
-        ledc_channel_config(&ledc_channel[ch]);
+    // Calculate duty cycle
+    uint32_t duty_bits = 0;
+    uint32_t interval = LEDC_APB_CLK_HZ/frequency;
+    for (size_t i = 0; i < 32; i++) {
+        if(!(interval >> i)) {
+            duty_bits = i - 1;
+            break;
+        }
+    }
+    if (duty_bits < 1) {
+        mp_raise_ValueError(translate("Invalid frequency"));
+    } else if (duty_bits >= LEDC_TIMER_14_BIT) {
+        duty_bits = LEDC_TIMER_13_BIT;
+    }
+
+    // Find a viable timer
+    size_t timer_index = INDEX_EMPTY;
+    size_t channel_index = INDEX_EMPTY;
+    for (size_t i = 0; i < LEDC_TIMER_MAX; i++) {
+        if ((reserved_timer_freq[i] == frequency) && !variable_frequency) {
+            //prioritize matched frequencies so we don't needlessly take slots
+            timer_index = i;
+            break;
+        } else if (reserved_timer_freq[i] == 0) {
+            timer_index = i;
+            break;
+        }
+    }
+    if (timer_index == INDEX_EMPTY) {
+        // Running out of timers isn't pin related on ESP32S2 so we can't re-use error messages
+        mp_raise_ValueError(translate("No more timers available"));
+    }
+
+    // Find a viable channel
+    for (size_t i = 0; i < LEDC_CHANNEL_MAX; i++) {
+        if (reserved_channels[i] == INDEX_EMPTY) {
+            channel_index = i;
+            break;
+        }
     }
+    if (channel_index == INDEX_EMPTY) {
+        mp_raise_ValueError(translate("No more channels available"));
+    }
+
+    // Run configuration
+    self->tim_handle.timer_num = timer_index;
+    self->tim_handle.duty_resolution = duty_bits;
+    self->tim_handle.freq_hz = frequency;
+    self->tim_handle.speed_mode = LEDC_LOW_SPEED_MODE;
+    self->tim_handle.clk_cfg = LEDC_AUTO_CLK;
+
+    if (ledc_timer_config(&(self->tim_handle)) != ESP_OK) {
+        mp_raise_ValueError(translate("Could not initialize timer"));
+    }
+
+    self->chan_handle.channel = channel_index;
+    self->chan_handle.duty = duty >> (16 - duty_bits);
+    self->chan_handle.gpio_num = pin->number;
+    self->chan_handle.speed_mode = LEDC_LOW_SPEED_MODE; // Only LS is allowed on ESP32-S2
+    self->chan_handle.hpoint = 0;
+    self->chan_handle.timer_sel = timer_index;
 
-    for (ch = 0; ch < LEDC_TEST_CH_NUM; ch++) {
-        ledc_set_duty(ledc_channel[ch].speed_mode, ledc_channel[ch].channel, duty*2);
-        ledc_update_duty(ledc_channel[ch].speed_mode, ledc_channel[ch].channel);
+    if (ledc_channel_config(&(self->chan_handle))) {
+        mp_raise_ValueError(translate("Could not initialize channel"));
     }
 
+    // Make reservations
+    reserved_timer_freq[timer_index] = frequency;
+    reserved_channels[channel_index] = timer_index;
+
+    self->variable_frequency = variable_frequency;
+    self->pin_number = pin->number;
+    self->deinited = false;
+    self->duty_resolution = duty_bits;
+    claim_pin(pin);
+
+    // Set initial duty
+    ledc_set_duty(LEDC_LOW_SPEED_MODE, self->chan_handle.channel, duty >> (16 - duty_bits));
+    ledc_update_duty(LEDC_LOW_SPEED_MODE, self->chan_handle.channel);
+
     return PWMOUT_OK;
 }
 
 void common_hal_pulseio_pwmout_never_reset(pulseio_pwmout_obj_t *self) {
+    never_reset_tim[self->tim_handle.timer_num] = true;
+    never_reset_chan[self->chan_handle.channel] = true;
 }
 
 void common_hal_pulseio_pwmout_reset_ok(pulseio_pwmout_obj_t *self) {
+    never_reset_tim[self->tim_handle.timer_num] = false;
+    never_reset_chan[self->chan_handle.channel] = false;
 }
 
 bool common_hal_pulseio_pwmout_deinited(pulseio_pwmout_obj_t* self) {
-    return false;
+    return self->deinited == true;
 }
 
 void common_hal_pulseio_pwmout_deinit(pulseio_pwmout_obj_t* self) {
+    if (common_hal_pulseio_pwmout_deinited(self)) {
+        return;
+    }
+    ledc_stop(LEDC_LOW_SPEED_MODE, self->chan_handle.channel, 0);
+    ledc_timer_rst(LEDC_LOW_SPEED_MODE, self->tim_handle.timer_num);
+    // Search if any other channel is using the timer
+    bool taken = false;
+    for (size_t i =0; i < LEDC_CHANNEL_MAX; i++) {
+        if (reserved_channels[i] == self->tim_handle.timer_num) {
+            taken = true;
+        }
+    }
+    // Variable frequency means there's only one channel on the timer
+    if (!taken || self->variable_frequency) {
+        reserved_timer_freq[self->tim_handle.timer_num] = 0;
+    }
+    reset_pin_number(self->pin_number);
+    reserved_channels[self->chan_handle.channel] = INDEX_EMPTY;
+    self->deinited = true;
 }
 
 void common_hal_pulseio_pwmout_set_duty_cycle(pulseio_pwmout_obj_t* self, uint16_t duty) {
+    ledc_set_duty(LEDC_LOW_SPEED_MODE, self->chan_handle.channel,  duty >> (16 - self->duty_resolution));
+    ledc_update_duty(LEDC_LOW_SPEED_MODE, self->chan_handle.channel);
 }
 
 uint16_t common_hal_pulseio_pwmout_get_duty_cycle(pulseio_pwmout_obj_t* self) {
-    return false;
+    return ledc_get_duty(LEDC_LOW_SPEED_MODE, self->chan_handle.channel) << (16 - self->duty_resolution);
 }
 
 void common_hal_pulseio_pwmout_set_frequency(pulseio_pwmout_obj_t* self, uint32_t frequency) {
+    ledc_set_freq(LEDC_LOW_SPEED_MODE, self->tim_handle.timer_num, frequency);
 }
 
 uint32_t common_hal_pulseio_pwmout_get_frequency(pulseio_pwmout_obj_t* self) {
-    return false;
+    return ledc_get_freq(LEDC_LOW_SPEED_MODE, self->tim_handle.timer_num);
 }
 
 bool common_hal_pulseio_pwmout_get_variable_frequency(pulseio_pwmout_obj_t* self) {
-    return false;
+    return self->variable_frequency;
 }
diff --git a/ports/esp32s2/common-hal/pulseio/PWMOut.h b/ports/esp32s2/common-hal/pulseio/PWMOut.h
index 28484e923..90a0c3ed9 100644
--- a/ports/esp32s2/common-hal/pulseio/PWMOut.h
+++ b/ports/esp32s2/common-hal/pulseio/PWMOut.h
@@ -28,14 +28,16 @@
 #define MICROPY_INCLUDED_ESP32S2_COMMON_HAL_PULSEIO_PWMOUT_H
 
 #include "common-hal/microcontroller/Pin.h"
+#include "driver/ledc.h"
 
 typedef struct {
     mp_obj_base_t base;
-    uint8_t channel;
+    ledc_timer_config_t tim_handle;
+    ledc_channel_config_t chan_handle;
+    uint16_t pin_number;
+    uint8_t duty_resolution;
     bool variable_frequency: 1;
-    uint16_t duty_cycle;
-    uint32_t frequency;
-    uint32_t period;
+    bool deinited: 1;
 } pulseio_pwmout_obj_t;
 
 void pwmout_reset(void);
diff --git a/ports/esp32s2/supervisor/port.c b/ports/esp32s2/supervisor/port.c
index a80550b30..e4767e514 100644
--- a/ports/esp32s2/supervisor/port.c
+++ b/ports/esp32s2/supervisor/port.c
@@ -38,6 +38,7 @@
 #include "common-hal/busio/I2C.h"
 #include "common-hal/busio/SPI.h"
 #include "common-hal/busio/UART.h"
+#include "common-hal/pulseio/PWMOut.h"
 #include "supervisor/memory.h"
 #include "supervisor/shared/tick.h"
 
@@ -64,6 +65,9 @@ void reset_port(void) {
     // A larger delay so the idle task can run and do any IDF cleanup needed.
     vTaskDelay(4);
 
+#if CIRCUITPY_PULSEIO
+    pwmout_reset();
+#endif
 #if CIRCUITPY_BUSIO
     i2c_reset();
     spi_reset();