> On Feb 28, 2016, at 1:58 AM, Mihai Seba <[email protected]> wrote:
>
> Hi guys,
>
> I'm trying to control a gpio using PRU but I not understand something. First
> of all, I know that for certain pins, there is the PRU mode for writing and
> reading (mode 5 and 6) and for gpio is mode 7. My question is, can I control
> the pin in mode 7 with PRU?
>
> I already tried to control a pin in mode 5 or 6 with PRU and everything seems
> to work. But what I don't understand from documentation is that if I can
> control it in mode 7, and I'm asking that because I saw some examples with
> pin used in mode 7 ( gpio) controlled by PRU ( output or capture).
When you use the PRU I/O modes, then you get very fast I/O, but if you use GPIO
in Mode7 then you have to control the GPIO via the GPIO registers and that will
be much slower.
Regards,
John
>
> I already have some code but it seems that it doesn't work.
> //pru
> #include <stdint.h>
> #include "pru_cfg.h"
> #include "pru_ctrl.h"
> #define GROUP_ADDRESS 0x44E07000
> #define GPIO_CTRL 0x130
> #define GPIO_DATAOUT 0x13C
> #define HWREG(x) (*((volatile unsigned int *)(x)))
> unsigned int *shared_ram = (unsigned int *) 0x10000;
> volatile register unsigned int __R31;
> int finish = 0;
> static void delay(uint32_t microseconds);
> /**
> * Configurations for shared ram
> * shared_ram[0]=finish
> * shared_ram[1]=pullup/down
> * shared_ram[2]=event
> * shared_ram[3]=sample event
> * shared_ram[4:260]=data to arm
> */
> int main(void) {
>
> /* Clear SYSCFG[STANDBY_INIT] to enable OCP master port*/
> uint8_t ii;
> uint8_t value;
>
> CT_CFG.SYSCFG_bit.STANDBY_INIT = 0;
>
> // /* Enable GPIO0 Module.GPIO0_CTRL Register*/
> // HWREG((GROUP_ADDRESS|GPIO_CTRL)) = 0x00;
>
> /*Set pins as output*/
> HWREG((GROUP_ADDRESS|0x1B4)) = 0x0f;
>
> while (!finish) {
> value=shared_ram[0];
> HWREG((GROUP_ADDRESS|GPIO_DATAOUT))^=(1<<20);
> __R31 = 35;
> delay(100);
> }
> __halt();
> /**/
> return 0;
> }
>
> void delay(uint32_t microseconds) {
> while (0 < microseconds) {
> __delay_cycles(200); /*if 1 cycle takes 5 ns, in 1 us PRU
> executes 200 cycles*/
> --microseconds;
> }
> }
>
>
> //host
> #include <stdio.h>
> #include <pthread.h>
> #include <string.h>
> #include <stdlib.h>
> #include <unistd.h>
> #include <signal.h>
> #include <sys/time.h>
> #include <fcntl.h>
> #include <sys/mman.h>
>
> #include <prussdrv.h>
> #include <pruss_intc_mapping.h>
>
> #define PRU_NUM 0
> #define START_ADDR 0x00000000 /*took from pru.map file*/
> #ifndef START_ADDR
> #error "START_ADDR must be defined"
> #endif
>
>
> unsigned int* shared_ram = NULL;
> pthread_t thread;
> int finish = 0;
>
>
>
>
> void init_pru_program(){
> tpruss_intc_initdata pruss_intc_initdata = PRUSS_INTC_INITDATA;
> prussdrv_init();
> prussdrv_open(PRU_EVTOUT_1);
> prussdrv_pruintc_init(&pruss_intc_initdata);
>
> prussdrv_load_datafile(PRU_NUM, "./data.bin");
> prussdrv_exec_program_at(PRU_NUM, "./text.bin", START_ADDR);
> }
>
> void signal_handler(int signal){
> finish = 1;
> }
>
> void* threaded_function(void* param){
> printf("Started thread\n");
> while(!finish){
>
> // Wait for interrupt from PRU
> // prussdrv_pru_wait_event(PRU_EVTOUT_1);
> // prussdrv_pru_clear_event(PRU_EVTOUT_1, PRU1_ARM_INTERRUPT);
> shared_ram[0]=1;
> sleep(1);
> shared_ram[0]=0;
> sleep(1);
> // Read number in shared ram
> // printf("Got input: %u\n", shared_ram[0]);
> }
>
> return NULL;
> }
>
> void start_thread(){
> pthread_attr_t attr;
> if(pthread_attr_init(&attr)){
> printf("Cannot start a new thread.\n");
> exit(1);
> }
> if(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED)){
> printf("Cannot start a new thread.");
> exit(1);
> }
> if(pthread_create(&thread, &attr, &threaded_function, NULL)){
> printf("Cannot start a new thread.");
> exit(1);
> }
> }
>
> void stop_thread(){
> while(pthread_cancel(thread)){
> printf("Stopping thread");
> }
> printf("Stopped thread");
> }
>
> int main(int argc, const char *argv[]){
> printf("\n\n");
>
> // Listen to SIGINT signals (program termination)
> signal(SIGINT, signal_handler);
>
>
> // Load and run binary into pru0
> init_pru_program();
>
> // Get pointer to shared ram
> void* p;
> prussdrv_map_prumem(PRUSS0_SHARED_DATARAM, &p);
> shared_ram = (unsigned int*)p;
>
> // Start input polling thread
> start_thread();
>
> while(!finish)
> {
>
> }
>
> printf("Disabling PRU.\n");
> prussdrv_pru_disable(PRU_NUM);
> prussdrv_exit ();
>
> stop_thread();
>
> return 0;
> }
>
> --
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> <http://beagleboard.org/discuss>
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