From 4246cc3f6d718e2f28fbeb73fc8c3c39dfb9d7f0 Mon Sep 17 00:00:00 2001
From: gamblor21 <mark.komus@gmail.com>
Date: Tue, 2 Mar 2021 19:32:06 -0600
Subject: [PATCH] Counter and PWMOut slice conflict check

---
 locale/circuitpython.pot                      |  4 ++++
 .../raspberrypi/common-hal/countio/Counter.c  |  9 ++++++++
 ports/raspberrypi/common-hal/pwmio/PWMOut.c   | 23 +++++++++++++++++++
 ports/raspberrypi/common-hal/pwmio/PWMOut.h   |  4 ++++
 4 files changed, 40 insertions(+)

diff --git a/locale/circuitpython.pot b/locale/circuitpython.pot
index 7414c39737..7a9d0ce4b0 100644
--- a/locale/circuitpython.pot
+++ b/locale/circuitpython.pot
@@ -1691,6 +1691,10 @@ msgstr ""
 msgid "PWM slice already in use"
 msgstr ""
 
+#: ports/raspberrypi/common-hal/countio/Counter.c
+msgid "PWM slice channel A already in use"
+msgstr ""
+
 #: ports/mimxrt10xx/common-hal/displayio/ParallelBus.c
 #: ports/raspberrypi/common-hal/displayio/ParallelBus.c
 #: ports/stm/common-hal/displayio/ParallelBus.c
diff --git a/ports/raspberrypi/common-hal/countio/Counter.c b/ports/raspberrypi/common-hal/countio/Counter.c
index 4a1ccad0cd..69629a0848 100644
--- a/ports/raspberrypi/common-hal/countio/Counter.c
+++ b/ports/raspberrypi/common-hal/countio/Counter.c
@@ -4,6 +4,8 @@
 #include "py/mpstate.h"
 #include "supervisor/shared/translate.h"
 
+#include "common-hal/pwmio/PWMOut.h"
+
 #include "src/rp2_common/hardware_gpio/include/hardware/gpio.h"
 #include "src/rp2_common/hardware_pwm/include/hardware/pwm.h"
 #include "src/rp2_common/hardware_irq/include/hardware/irq.h"
@@ -23,6 +25,11 @@ void common_hal_countio_counter_construct(countio_counter_obj_t* self,
         mp_raise_RuntimeError(translate("PWM slice already in use"));
     }
 
+    uint8_t channel = pwm_gpio_to_channel(self->pin_a);
+    if (!pwmio_claim_slice_channels(self->slice_num)) {
+        mp_raise_RuntimeError(translate("PWM slice channel A already in use"));
+    }
+
     pwm_clear_irq(self->slice_num);
     pwm_set_irq_enabled(self->slice_num, true);
     irq_set_exclusive_handler(PWM_IRQ_WRAP, counter_interrupt_handler);
@@ -53,6 +60,8 @@ void common_hal_countio_counter_deinit(countio_counter_obj_t* self) {
     pwm_set_enabled(self->slice_num, false);
     pwm_set_irq_enabled(self->slice_num, false);
 
+    pwmio_release_slice_channels(self->slice_num);
+
     reset_pin_number(self->pin_a);
 
     MP_STATE_PORT(counting)[self->slice_num] = NULL;
diff --git a/ports/raspberrypi/common-hal/pwmio/PWMOut.c b/ports/raspberrypi/common-hal/pwmio/PWMOut.c
index 00b461880c..348d99ebe2 100644
--- a/ports/raspberrypi/common-hal/pwmio/PWMOut.c
+++ b/ports/raspberrypi/common-hal/pwmio/PWMOut.c
@@ -61,6 +61,29 @@ static uint32_t _mask(uint8_t slice, uint8_t channel) {
     return 1 << (slice * CHANNELS_PER_SLICE + channel);
 }
 
+bool pwmio_claim_slice_channels(uint8_t slice) {
+    uint32_t channel_use_mask_a = _mask(slice, 0);
+    uint32_t channel_use_mask_b = _mask(slice, 1);
+
+    if ((channel_use & channel_use_mask_a) != 0) {
+        return false;
+    }
+    if ((channel_use & channel_use_mask_b) != 0) {
+        return false;
+    }
+
+    channel_use |= channel_use_mask_a;
+    channel_use |= channel_use_mask_b;
+    return true;
+}
+
+void pwmio_release_slice_channels(uint8_t slice) {
+    uint32_t channel_mask = _mask(slice, 0);
+    channel_use &= ~channel_mask;
+    channel_mask = _mask(slice, 1);
+    channel_use &= ~channel_mask;
+}
+
 void common_hal_pwmio_pwmout_never_reset(pwmio_pwmout_obj_t *self) {
     never_reset_channel |= _mask(self->slice, self->channel);
 
diff --git a/ports/raspberrypi/common-hal/pwmio/PWMOut.h b/ports/raspberrypi/common-hal/pwmio/PWMOut.h
index 0070e188b5..6c0dda2dba 100644
--- a/ports/raspberrypi/common-hal/pwmio/PWMOut.h
+++ b/ports/raspberrypi/common-hal/pwmio/PWMOut.h
@@ -46,4 +46,8 @@ void pwmout_reset(void);
 // Private API for AudioPWMOut.
 void pwmio_pwmout_set_top(pwmio_pwmout_obj_t* self, uint16_t top);
 
+// Private API for countio to claim both channels on a slice
+bool pwmio_claim_slice_channels(uint8_t slice);
+void pwmio_release_slice_channels(uint8_t slice);
+
 #endif // MICROPY_INCLUDED_ATMEL_SAMD_COMMON_HAL_PWMIO_PWMOUT_H