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/*
* Copyright (c) 2016, Toradex AG
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice, this list
* of conditions and the following disclaimer.
*
* o 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 distribution.
*
* o Neither the name of Freescale Semiconductor, Inc. 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 LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER 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 OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdio.h>
#include <errno.h>
#include "FreeRTOS.h"
#include "task.h"
#include "semphr.h"
#include "string.h"
#include "assert.h"
#include "rpmsg/rpmsg.h"
#include "plat_porting.h"
#include <ccm_vf6xx.h>
#include "debug_console_vf6xx.h"
#include "pin_mux.h"
/*
* function decalaration for platform provided facility
*/
extern void platform_interrupt_enable(void);
extern void platform_interrupt_disable(void);
#define MAX_STRING_SIZE 496 /* Maximum size to hold the data A7 gives */
/*
* For the most worst case, master will send 3 consecutive messages which remote
* do not process.
* The synchronization between remote and master is that each time endpoint callback
* is called, the MU Receive interrupt is temperorily disabled. Until the next time
* remote consumes the message, the interrupt will not be enabled again.
* When the interrupt is not enabled, Master can not send the notify, it will blocks
* there and can not send further message.
* In the worst case, master send the first message, it triggles the ISR in remote
* side, remote ISR clear the MU status bit so master can send the second message
* and notify again, master can continue to send the 3rd message but will blocks
* when trying to notify. Meanwhile, remote side is still in the first ISR which
* has a loop to receive all the 3 messages.
* Master is blocked and can not send the 4th message, remote side ISR copies all
* this 3 message to app buffer and informs the app layer to consume them. After
* a message is consumed, the ISR is enabled again and the second notify is received.
* This unblocks the master to complete the 3rd notify and send the next message.
* The 4th notify will not complete until remote consumes the second message.
* The situation goes on and we can see application layer need a maximum size 3
* buffer to hold the unconsumed messages. STRING_BUFFER_CNT is therefore set to 3
*/
#define STRING_BUFFER_CNT 3
/*
* APP decided interrupt priority
*/
#define APP_MSCM_IRQ_PRIORITY 3
/* Internal functions */
static void rpmsg_channel_created(struct rpmsg_channel *rp_chnl);
static void rpmsg_channel_deleted(struct rpmsg_channel *rp_chnl);
static void rpmsg_read_cb(struct rpmsg_channel *, void *, int, void *, unsigned long);
/* Globals */
static struct remote_device *rdev;
static struct rpmsg_channel *app_chnl;
static char strVar[STRING_BUFFER_CNT][MAX_STRING_SIZE + 1];
static uint8_t app_idx = 0;
static uint8_t handler_idx = 0;
static SemaphoreHandle_t app_sema;
/*!
* @brief A basic RPMSG task
*/
void StrEchoTask(void *pvParameters)
{
printf("RPMSG String Echo Demo...\r\n");
app_sema = xSemaphoreCreateCounting(STRING_BUFFER_CNT + 1, 0);
printf("RPMSG Init as Remote\r\n");
/*
* RPMSG Init as REMOTE
*/
rpmsg_init(0, &rdev, rpmsg_channel_created, rpmsg_channel_deleted, rpmsg_read_cb, RPMSG_MASTER);
/*
* rpmsg_channel_created will post the first semaphore
*/
xSemaphoreTake(app_sema, portMAX_DELAY);
printf("Name service handshake is done, M4 has setup a rpmsg channel [%lu ---> %lu]\r\n", app_chnl->src, app_chnl->dst);
/*
* String Echo demo loop
*/
for (;;) {
xSemaphoreTake(app_sema, portMAX_DELAY);
/*
* Take from next app string buffer
*/
if ((strlen(strVar[app_idx]) == 2) && (strVar[app_idx][0] == 0xd) && (strVar[app_idx][1] == 0xa))
printf("Get New Line From A5 From Slot %d\r\n", app_idx);
else
printf("Get Message From A5 : \"%s\" [len : %d] from slot %d\r\n", strVar[app_idx], strlen(strVar[app_idx]), app_idx);
/*
* echo back
*/
rpmsg_send(app_chnl, (void*)strVar[app_idx], strlen(strVar[app_idx]));
app_idx = (app_idx + 1) % STRING_BUFFER_CNT;
/*
* once a message is consumed, the MSCM receive interrupt can be enabled
* again
*/
platform_interrupt_enable();
}
}
int main(void)
{
/* Init Clock Control and UART */
CCM_GetClocks();
CCM_ControlGate(ccmCcgrGateUart2, ccmClockNeededAll);
configure_uart_pins(UART2);
vf6xx_DbgConsole_Init(UART2, ccmIpgBusClk, 115200);
printf("Starting RPMSG String Echo Demo...\r\n");
/*
* Prepare for the MSCM Interrupt
* MSCM must be initialized before rpmsg init is called
*/
platform_interrupt_enable();
NVIC_SetPriority(CPU2CPU_INT0_IRQ, APP_MSCM_IRQ_PRIORITY);
NVIC_SetPriority(CPU2CPU_INT1_IRQ, APP_MSCM_IRQ_PRIORITY);
// Create a demo task which will print Hello world and echo user's input.
xTaskCreate(StrEchoTask, "String Echo Task", configMINIMAL_STACK_SIZE,
NULL, tskIDLE_PRIORITY+1, NULL);
// Start FreeRTOS scheduler.
vTaskStartScheduler();
// Should never reach this point.
while (true);
}
/* rpmsg_rx_callback will call into this for a channel creation event*/
static void rpmsg_channel_created(struct rpmsg_channel *rp_chnl)
{
/*
* we should give the created rp_chnl handler to app layer
*/
app_chnl = rp_chnl;
/*
* sync to application layer
*/
xSemaphoreGiveFromISR(app_sema, NULL);
}
static void rpmsg_channel_deleted(struct rpmsg_channel *rp_chnl)
{
rpmsg_destroy_ept(rp_chnl->rp_ept);
}
static void rpmsg_read_cb(struct rpmsg_channel *rp_chnl, void *data, int len,
void * priv, unsigned long src)
{
/*
* Temperorily Disable MSCM Receive Interrupt to avoid master
* sending too many messages and remote will fail to keep pace
* to consume
*/
platform_interrupt_disable();
/*
* Copy to next app string buffer
*/
assert(len <= MAX_STRING_SIZE);
memcpy((void*)strVar[handler_idx], data, len);
/*
* Add trailing '\0'
*/
strVar[handler_idx][len] = 0;
handler_idx = (handler_idx + 1) % STRING_BUFFER_CNT;
xSemaphoreGiveFromISR(app_sema, NULL);
}
/*******************************************************************************
* EOF
******************************************************************************/
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