swap ev3-pru0 and ev3-pru1 project

it turns out that the existing soft-UART driver uses PRU0, so we want the tacho counter to be PRU1

ev3-pru0/AM18xx_PRU.cmd

@@ -14,7 +14,7 @@
 MEMORY
 {
       PAGE 0:
-	/* 2kB PRU0/1 Instruction RAM */
+	/* 4kB PRU0/1 Instruction RAM */
 	PRU_IMEM	: org = 0x00000000 len = 0x00001000
 
       PAGE 1:

ev3-pru0/main.c

@@ -15,174 +15,54 @@
 
 #include "resource_table.h"
 
-/* from Linux */
-
-#define EV3_PRU_TACHO_RING_BUF_SIZE 1024 /* must be power of 2! */
-
-enum ev3_pru_tacho_msg_type {
-	/* Host >< PRU: request memory map address of ring buffer data */
-	EV3_PRU_TACHO_MSG_DATA_ADDR,
-};
-
-struct ev3_pru_tacho_msg {
-	uint32_t type;
-	uint32_t value;
-};
-
-enum ev3_pru_tacho {
-	EV3_PRU_TACHO_A,
-	EV3_PRU_TACHO_B,
-	EV3_PRU_TACHO_C,
-	EV3_PRU_TACHO_D,
-	NUM_EV3_PRU_TACHO
-};
-
-struct ev3_pru_tacho_remote_data {
-	uint32_t position[NUM_EV3_PRU_TACHO][EV3_PRU_TACHO_RING_BUF_SIZE];
-	uint32_t timestamp[NUM_EV3_PRU_TACHO][EV3_PRU_TACHO_RING_BUF_SIZE];
-	uint32_t head[NUM_EV3_PRU_TACHO];
-};
-
-/* end Linux */
-
-enum direction {
-	REVERSE = -1,
-	UNKNOWN = 0,
-	FORWARD = 1
-};
-
-#define REMOTE_DATA_ADDR 0x80002000
-#define REMOTE_DATA (*(struct ev3_pru_tacho_remote_data *)(REMOTE_DATA_ADDR))
 
 // system events to/from ARM
 
 // PRU0
 #define HOST_INT	(uint32_t)(1 << 30)	// host interrupt 0
-#define EVENT_FROM_ARM	32
-#define EVENT_TO_ARM	33
+#define EVENT_FROM_ARM	60
+#define EVENT_TO_ARM	61
 
 // PRU1
 //#define HOST_INT	(uint32_t)(1 << 31)	// host interrupt 1
-//#define EVENT_FROM_ARM	34
-//#define EVENT_TO_ARM	35
+//#define EVENT_FROM_ARM	62
+//#define EVENT_TO_ARM	63
 
 volatile uint32_t register __R31;
 
-// This is 512B (RPMSG_BUF_SIZE), so it won't fit in PRU RAM, so put it in shared RAM
-#define payload ((void *)(REMOTE_DATA_ADDR + sizeof(struct ev3_pru_tacho_remote_data)))
-
-#define INTA GPIO.IN_DATA45_bit.GP5P11	// GPIO 5[11]
-#define INTB GPIO.IN_DATA45_bit.GP5P8	// GPIO 5[8]
-#define INTC GPIO.IN_DATA45_bit.GP5P13	// GPIO 5[13]
-#define INTD GPIO.IN_DATA67_bit.GP6P9	// GPIO 6[9]
-
-#define DIRA GPIO.IN_DATA01_bit.GP0P4	// GPIO 0[4]
-#define DIRB GPIO.IN_DATA23_bit.GP2P9	// GPIO 2[9]
-#define DIRC GPIO.IN_DATA23_bit.GP3P14	// GPIO 3[14]
-#define DIRD GPIO.IN_DATA23_bit.GP2P8	// GPIO 2[8]
-
-#define TACHO_STATE(x) ((INT##x << 1) | DIR##x)
-
-static uint8_t tacho_state[NUM_EV3_PRU_TACHO];
-static uint32_t tacho_prev_timestamp[NUM_EV3_PRU_TACHO];
-static uint32_t tacho_counts[NUM_EV3_PRU_TACHO];
-
-static void update_tacho_state(enum ev3_pru_tacho idx, uint8_t new_state)
-{
-	uint8_t current_state = tacho_state[idx] & 0x3;
-	enum direction new_dir = UNKNOWN;
-	uint32_t now, elapsed;
-
-	switch (current_state) {
-		case 0x0:
-			if (new_state == 0x1) {
-				new_dir = REVERSE;
-			} else if (new_state == 0x2) {
-				new_dir = FORWARD;
-			}
-			break;
-
-		case 0x1:
-			if (new_state == 0x3) {
-				new_dir = REVERSE;
-			} else if (new_state == 0x0) {
-				new_dir = FORWARD;
-			}
-			break;
-
-		case 0x3:
-			if (new_state == 0x2) {
-				new_dir = REVERSE;
-			} else if (new_state == 0x1) {
-				new_dir = FORWARD;
-			}
-			break;
-
-		case 0x2:
-			if (new_state == 0x0) {
-				new_dir = REVERSE;
-			} else if (new_state == 0x3) {
-				new_dir = FORWARD;
-			}
-			break;
-	}
-
-	tacho_state[idx] = new_state;
-	tacho_counts[idx] += new_dir;
+// only have 512B for stack/data, so this won't fit
+//uint8_t payload[RPMSG_BUF_SIZE];
+// using 128K shared RAM for now
+#define payload ((uint8_t *)(0x8001F200))
 
-	now = TIMER64P0.TIM34;
-	elapsed = now - tacho_prev_timestamp[idx];
-
-	// if there was a change in count or if count hasn't changed for 50ms
-	if (new_dir || elapsed > (50 * 1000000 * 3 / 125)) {
-		uint32_t new_head = (REMOTE_DATA.head[idx] + 1) & (EV3_PRU_TACHO_RING_BUF_SIZE - 1);
-
-		tacho_prev_timestamp[idx] = now;
-
-		REMOTE_DATA.position[idx][new_head] = tacho_counts[idx];
-		REMOTE_DATA.timestamp[idx][new_head] = now;
-		REMOTE_DATA.head[idx] = new_head;
-	}
-}
+#define LED (GPIO.OUT_DATA67_bit.GP6P7)
 
 int main(void) {
 	volatile uint8_t *status;
 	struct pru_rpmsg_transport transport;
 	uint16_t src, dst, len;
 
 	// Clear the status of the PRU-system event that the ARM will use to 'kick' us
-	PRU_INTC.STATIDXCLR = EVENT_FROM_ARM;
+	PRU_INTC.STATIDXCLR_bit.INDEX = EVENT_FROM_ARM;
 
 	// Wait until Linux gives us the OK that the driver is loaded
 	status = &resource_table.rpmsg_vdev.status;
 	while (!(*status & VIRTIO_CONFIG_S_DRIVER_OK));
 
-	pru_virtqueue_init(&transport.virtqueue0, &resource_table.vring0, EVENT_TO_ARM, EVENT_FROM_ARM);
-	pru_virtqueue_init(&transport.virtqueue1, &resource_table.vring1, EVENT_TO_ARM, EVENT_FROM_ARM);
+	pru_rpmsg_init(&transport, &resource_table.vring0, &resource_table.vring1, EVENT_TO_ARM, EVENT_FROM_ARM);
 
-	while (pru_rpmsg_channel(RPMSG_NS_CREATE, &transport, "ev3-tacho-rpmsg", 0) != PRU_RPMSG_SUCCESS);
+	while (pru_rpmsg_channel(RPMSG_NS_CREATE, &transport, "rpmsg-client-sample", 0) != PRU_RPMSG_SUCCESS);
 
 	while (true) {
-		// wait for the ARM to kick us
-		while (!(__R31 & HOST_INT)) {
-			update_tacho_state(EV3_PRU_TACHO_A, TACHO_STATE(A));
-			update_tacho_state(EV3_PRU_TACHO_B, TACHO_STATE(B));
-			update_tacho_state(EV3_PRU_TACHO_C, TACHO_STATE(C));
-			update_tacho_state(EV3_PRU_TACHO_D, TACHO_STATE(D));
-		}
-
-		// clear the interrupt
-		PRU_INTC.STATIDXCLR = EVENT_FROM_ARM;
-
-		// Receive all available messages, multiple messages can be sent per kick
-		while (pru_rpmsg_receive(&transport, &src, &dst, payload, &len) == PRU_RPMSG_SUCCESS) {
-			struct ev3_pru_tacho_msg *msg = payload;
-
-			switch (msg->type) {
-			case EV3_PRU_TACHO_MSG_DATA_ADDR:
-				msg->value = REMOTE_DATA_ADDR;
-				pru_rpmsg_send(&transport, dst, src, msg, sizeof(*msg));
-				break;
+		// Check bit 30 of register R31 to see if the ARM has kicked us
+		if (__R31 & HOST_INT) {
+			// clear the interrupt
+			PRU_INTC.STATIDXCLR_bit.INDEX = EVENT_FROM_ARM;
+
+			// Receive all available messages, multiple messages can be sent per kick
+			while (pru_rpmsg_receive(&transport, &src, &dst, payload, &len) == PRU_RPMSG_SUCCESS) {
+				// Echo the message back
+				pru_rpmsg_send(&transport, dst, src, payload, len);
 			}
 		}
 	}

ev3-pru0/resource_table.h

@@ -1,33 +1,33 @@
 /*
- * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/ 
+ * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
  * Copyright (C) 2018 David Lechner <[email protected]>
  *
- * Redistribution and use in source and binary forms, with or without 
- * modification, are permitted provided that the following conditions 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
  * are met:
- * 
- * 	* Redistributions of source code must retain the above copyright 
+ *
+ * 	* Redistributions of source code must retain the above copyright
  * 	  notice, this list of conditions and the following disclaimer.
- * 
+ *
  * 	* Redistributions in binary form must reproduce the above copyright
- * 	  notice, this list of conditions and the following disclaimer in the 
- * 	  documentation and/or other materials provided with the   
+ * 	  notice, this list of conditions and the following disclaimer in the
+ * 	  documentation and/or other materials provided with the
  * 	  distribution.
- * 
+ *
  * 	* Neither the name of Texas Instruments Incorporated nor the names of
  * 	  its contributors may be used to endorse or promote products derived
  * 	  from this software without specific prior written permission.
- * 
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
@@ -42,7 +42,7 @@
 /*
  * The feature bitmap for virtio rpmsg
  */
-#define VIRTIO_RPMSG_F_NS	0 //name service notifications
+#define VIRTIO_RPMSG_F_NS	0	//name service notifications
 
 /* This firmware supports name service notifications as one of its features */
 #define RPMSG_FEATURES		(1 << VIRTIO_RPMSG_F_NS)
@@ -62,8 +62,7 @@ struct custom_resource_table {
 
 #pragma DATA_SECTION(resource_table, ".resource_table")
 #pragma RETAIN(resource_table)
-struct custom_resource_table resource_table =
-{
+struct custom_resource_table resource_table = {
 	.base = {
 		.ver = 1,
 		.num = NUM_RESOURCES,
@@ -77,23 +76,23 @@ struct custom_resource_table resource_table =
 		.id = VIRTIO_ID_RPMSG,
 		.notifyid = 0,
 		.dfeatures = RPMSG_FEATURES,
-		.gfeatures = 0,      //will be populated by host
+		.gfeatures = 0,	//will be populated by host
 		.config_len = 0,
 		.status = 0,
 		.num_of_vrings = 2,
 		.reserved = { 0, 0 },
 	},
 	.vring0 = {
-		.da = 0,	//will be populated by host
-		.align = 16,
-		.num = 16,	// must be power of 2
+		.da       = 0,	//will be populated by host
+		.align    = 16,
+		.num      = 16,	// must be power of 2
 		.notifyid = 0,	//will be populated by host
 		.reserved = 0,
 	},
 	.vring1 = {
-		.da = 0,	//will be populated by host
-		.align = 16,
-		.num = 16,	// must be power of 2
+		.da       = 0,	//will be populated by host
+		.align    = 16,
+		.num      = 16,	// must be power of 2
 		.notifyid = 0,	//will be populated by host
 		.reserved = 0,
 	},