rasberrypi: IncrementalEncoder: factor out state machine

jepler · jepler · commit 3ce0b512f8e2 · 2021-04-08T16:25:47.000-05:00
diff --git a/ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.c b/ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.c
@@ -28,6 +28,7 @@
 
 #include <hardware/regs/pio.h>
 #include "common-hal/rotaryio/IncrementalEncoder.h"
+#include "shared-module/rotaryio/IncrementalEncoder.h"
 #include "bindings/rp2pio/__init__.h"
 #include "bindings/rp2pio/StateMachine.h"
 
@@ -88,12 +89,10 @@ void common_hal_rotaryio_incrementalencoder_construct(rotaryio_incrementalencode
     common_hal_rp2pio_statemachine_run(&self->state_machine, encoder_init, MP_ARRAY_SIZE(encoder_init));
 
     // We're guaranteed by the init code that some output will be available promptly
-    uint8_t state;
-    common_hal_rp2pio_statemachine_readinto(&self->state_machine, &state, 1, 1);
-    // Top two bits of self->last_state don't matter, because they'll be gone as soon as
-    // interrupt handler is called.
-    self->last_state = state & 3;
+    uint8_t quiescent_state;
+    common_hal_rp2pio_statemachine_readinto(&self->state_machine, &quiescent_state, 1, 1);
 
+    shared_module_softencoder_state_init(self, quiescent_state & 3);
     common_hal_rp2pio_statemachine_set_interrupt_handler(&self->state_machine, incrementalencoder_interrupt_handler, self, PIO_IRQ0_INTF_SM0_RXNEMPTY_BITS);
 }
 
@@ -109,67 +108,13 @@ void common_hal_rotaryio_incrementalencoder_deinit(rotaryio_incrementalencoder_o
     common_hal_rp2pio_statemachine_deinit(&self->state_machine);
 }
 
-mp_int_t common_hal_rotaryio_incrementalencoder_get_position(rotaryio_incrementalencoder_obj_t *self) {
-    return self->position;
-}
-
-void common_hal_rotaryio_incrementalencoder_set_position(rotaryio_incrementalencoder_obj_t *self,
-    mp_int_t new_position) {
-    self->position = new_position;
-}
-
 STATIC void incrementalencoder_interrupt_handler(void *self_in) {
     rotaryio_incrementalencoder_obj_t *self = self_in;
-    // This table also works for detent both at 11 and 00
-    // For 11 at detent:
-    // Turning cw: 11->01->00->10->11
-    // Turning ccw: 11->10->00->01->11
-    // For 00 at detent:
-    // Turning cw: 00->10->11->10->00
-    // Turning ccw: 00->01->11->10->00
-
-    // index table by state <oldA><oldB><newA><newB>
-    #define BAD 7
-    static const int8_t transitions[16] = {
-        0,    // 00 -> 00 no movement
-        -1,   // 00 -> 01 3/4 ccw (11 detent) or 1/4 ccw (00 at detent)
-        +1,   // 00 -> 10 3/4 cw or 1/4 cw
-        BAD,  // 00 -> 11 non-Gray-code transition
-        +1,   // 01 -> 00 2/4 or 4/4 cw
-        0,    // 01 -> 01 no movement
-        BAD,  // 01 -> 10 non-Gray-code transition
-        -1,   // 01 -> 11 4/4 or 2/4 ccw
-        -1,   // 10 -> 00 2/4 or 4/4 ccw
-        BAD,  // 10 -> 01 non-Gray-code transition
-        0,    // 10 -> 10 no movement
-        +1,   // 10 -> 11 4/4 or 2/4 cw
-        BAD,  // 11 -> 00 non-Gray-code transition
-        +1,   // 11 -> 01 1/4 or 3/4 cw
-        -1,   // 11 -> 10 1/4 or 3/4 ccw
-        0,    // 11 -> 11 no movement
-    };
 
     while (common_hal_rp2pio_statemachine_get_in_waiting(&self->state_machine)) {
         // Bypass all the logic of StateMachine.c:_transfer, we need something
         // very simple and fast for an interrupt!
-        uint8_t new = self->state_machine.pio->rxf[self->state_machine.state_machine];
-
-        // Shift the old AB bits to the "old" position, and set the new AB bits.
-        self->last_state = (self->last_state & 0x3) << 2 | (new & 0x3);
-
-        int8_t quarter_incr = transitions[self->last_state];
-        if (quarter_incr == BAD) {
-            // Missed a transition. We don't know which way we're going, so do nothing.
-            return;
-        }
-
-        self->quarter_count += quarter_incr;
-        if (self->quarter_count >= 4) {
-            self->position += 1;
-            self->quarter_count = 0;
-        } else if (self->quarter_count <= -4) {
-            self->position -= 1;
-            self->quarter_count = 0;
-        }
+        uint8_t new_state = self->state_machine.pio->rxf[self->state_machine.state_machine];
+        shared_module_softencoder_state_update(self, new_state);
     }
 }
diff --git a/ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.h b/ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.h
@@ -34,7 +34,7 @@
 typedef struct {
     mp_obj_base_t base;
     rp2pio_statemachine_obj_t state_machine;
-    uint8_t last_state : 4;   // <old A><old B><new A><new B>
+    uint8_t state : 4;   // <old A><old B><new A><new B>
     int8_t quarter_count : 4; // count intermediate transitions between detents
     mp_int_t position;
 } rotaryio_incrementalencoder_obj_t;
diff --git a/ports/raspberrypi/mpconfigport.mk b/ports/raspberrypi/mpconfigport.mk
@@ -26,6 +26,7 @@ CIRCUITPY_BITOPS ?= 1
 CIRCUITPY_PWMIO ?= 1
 CIRCUITPY_RGBMATRIX ?= 1
 CIRCUITPY_ROTARYIO ?= 1
+CIRCUITPY_ROTARYIO_SOFTENCODER = 1
 
 # Things that need to be implemented.
 # Use PWM interally
diff --git a/py/circuitpy_defns.mk b/py/circuitpy_defns.mk
@@ -518,6 +518,7 @@ SRC_SHARED_MODULE_ALL = \
 	random/__init__.c \
 	rgbmatrix/RGBMatrix.c \
 	rgbmatrix/__init__.c \
+	rotaryio/IncrementalEncoder.c \
 	sharpdisplay/SharpMemoryFramebuffer.c \
 	sharpdisplay/__init__.c \
 	socket/__init__.c \
diff --git a/py/circuitpy_mpconfig.mk b/py/circuitpy_mpconfig.mk
@@ -271,6 +271,9 @@ CFLAGS += -DCIRCUITPY_RGBMATRIX=$(CIRCUITPY_RGBMATRIX)
 CIRCUITPY_ROTARYIO ?= 1
 CFLAGS += -DCIRCUITPY_ROTARYIO=$(CIRCUITPY_ROTARYIO)
 
+CIRCUITPY_ROTARYIO_SOFTENCODER ?= 0
+CFLAGS += -DCIRCUITPY_ROTARYIO_SOFTENCODER=$(CIRCUITPY_ROTARYIO_SOFTENCODER)
+
 CIRCUITPY_RTC ?= 1
 CFLAGS += -DCIRCUITPY_RTC=$(CIRCUITPY_RTC)
 
diff --git a/shared-module/rotaryio/IncrementalEncoder.c b/shared-module/rotaryio/IncrementalEncoder.c
@@ -0,0 +1,84 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Jeff Epler for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#if CIRCUITPY_ROTARYIO && CIRCUITPY_ROTARYIO_SOFTENCODER
+#include "shared-module/rotaryio/IncrementalEncoder.h"
+#include "common-hal/rotaryio/IncrementalEncoder.h"
+
+void shared_module_softencoder_state_init(rotaryio_incrementalencoder_obj_t *self, uint8_t quiescent_state) {
+    self->state = quiescent_state;
+    self->quarter_count = 0;
+    common_hal_rotaryio_incrementalencoder_set_position(self, 0);
+}
+
+void shared_module_softencoder_state_update(rotaryio_incrementalencoder_obj_t *self, uint8_t new_state) {
+    #define BAD 7
+    static const int8_t transitions[16] = {
+        0,    // 00 -> 00 no movement
+        -1,   // 00 -> 01 3/4 ccw (11 detent) or 1/4 ccw (00 at detent)
+        +1,   // 00 -> 10 3/4 cw or 1/4 cw
+        BAD,  // 00 -> 11 non-Gray-code transition
+        +1,   // 01 -> 00 2/4 or 4/4 cw
+        0,    // 01 -> 01 no movement
+        BAD,  // 01 -> 10 non-Gray-code transition
+        -1,   // 01 -> 11 4/4 or 2/4 ccw
+        -1,   // 10 -> 00 2/4 or 4/4 ccw
+        BAD,  // 10 -> 01 non-Gray-code transition
+        0,    // 10 -> 10 no movement
+        +1,   // 10 -> 11 4/4 or 2/4 cw
+        BAD,  // 11 -> 00 non-Gray-code transition
+        +1,   // 11 -> 01 1/4 or 3/4 cw
+        -1,   // 11 -> 10 1/4 or 3/4 ccw
+        0,    // 11 -> 11 no movement
+    };
+
+    new_state &= 0x3;
+    int idx = (self->state << 2) | new_state;
+    self->state = new_state;
+
+    int8_t quarter_incr = transitions[idx];
+    if (quarter_incr == BAD) {
+        // Missed a transition. We don't know which way we're going, so do nothing.
+        return;
+    }
+
+    if (self->quarter_count >= 4) {
+        self->position += 1;
+        self->quarter_count = 0;
+    } else if (self->quarter_count <= -4) {
+        self->position -= 1;
+        self->quarter_count = 0;
+    }
+}
+
+mp_int_t common_hal_rotaryio_incrementalencoder_get_position(rotaryio_incrementalencoder_obj_t *self) {
+    return self->position;
+}
+
+void common_hal_rotaryio_incrementalencoder_set_position(rotaryio_incrementalencoder_obj_t *self, mp_int_t position) {
+    self->position = position;
+}
+#endif
diff --git a/shared-module/rotaryio/IncrementalEncoder.h b/shared-module/rotaryio/IncrementalEncoder.h
@@ -0,0 +1,34 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Jeff Epler for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include "common-hal/rotaryio/IncrementalEncoder.h"
+
+void shared_module_softencoder_state_init(rotaryio_incrementalencoder_obj_t *self, uint8_t quiescent_state);
+void shared_module_softencoder_state_update(rotaryio_incrementalencoder_obj_t *self, uint8_t new_state);
+mp_int_t common_hal_rotaryio_incrementalencoder_get_position(rotaryio_incrementalencoder_obj_t *self);
+void common_hal_rotaryio_incrementalencoder_set_position(rotaryio_incrementalencoder_obj_t *self, mp_int_t position);
