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// See LICENSE for license details.
// This is the program which ships on the HiFive1
// board, executing out of SPI Flash at 0x20400000.
#include <stdint.h>
#include "platform.h"
#ifndef _SIFIVE_HIFIVE1_H
#error "'led_fade' is designed to run on HiFive1 and/or E300 Arty Dev Kit."
#endif
static const char led_msg[] = "\a\n\r\n\r\
55555555555555555555555555555555555555555555555\n\r\
5555555 Are the LEDs Changing? [y/n] 555555555\n\r\
55555555555555555555555555555555555555555555555\n\r";
static const char sifive_msg[] = "\n\r\
\n\r\
SIFIVE, INC.\n\r\
\n\r\
5555555555555555555555555\n\r\
5555 5555\n\r\
5555 5555\n\r\
5555 5555\n\r\
5555 5555555555555555555555\n\r\
5555 555555555555555555555555\n\r\
5555 5555\n\r\
5555 5555\n\r\
5555 5555\n\r\
5555555555555555555555555555 55555\n\r\
55555 555555555 55555\n\r\
55555 55555 55555\n\r\
55555 5 55555\n\r\
55555 55555\n\r\
55555 55555\n\r\
55555 55555\n\r\
55555 55555\n\r\
55555 55555\n\r\
555555555\n\r\
55555\n\r\
5\n\r\
\n\r\
'led_fade' Demo \n\r\
\n\r";
static void _putc(char c) {
while ((int32_t) UART0_REG(UART_REG_TXFIFO) < 0);
UART0_REG(UART_REG_TXFIFO) = c;
}
int _getc(char * c){
int32_t val = (int32_t) UART0_REG(UART_REG_RXFIFO);
if (val > 0) {
*c = val & 0xFF;
return 1;
}
return 0;
}
static void _puts(const char * s) {
while (*s != '\0'){
_putc(*s++);
}
}
int main (void){
// Make sure the HFROSC is on before the next line:
PRCI_REG(PRCI_HFROSCCFG) |= ROSC_EN(1);
// Run off 16 MHz Crystal for accuracy. Note that the
// first line is
PRCI_REG(PRCI_PLLCFG) = (PLL_REFSEL(1) | PLL_BYPASS(1));
PRCI_REG(PRCI_PLLCFG) |= (PLL_SEL(1));
// Turn off HFROSC to save power
PRCI_REG(PRCI_HFROSCCFG) &= ~(ROSC_EN(1));
// Configure UART to print
GPIO_REG(GPIO_OUTPUT_VAL) |= IOF0_UART0_MASK;
GPIO_REG(GPIO_OUTPUT_EN) |= IOF0_UART0_MASK;
GPIO_REG(GPIO_IOF_SEL) &= ~IOF0_UART0_MASK;
GPIO_REG(GPIO_IOF_EN) |= IOF0_UART0_MASK;
// 115200 Baud Rate
UART0_REG(UART_REG_DIV) = 138;
UART0_REG(UART_REG_TXCTRL) = UART_TXEN;
UART0_REG(UART_REG_RXCTRL) = UART_RXEN;
// Wait a bit to avoid corruption on the UART.
// (In some cases, switching to the IOF can lead
// to output glitches, so need to let the UART
// reciever time out and resynchronize to the real
// start of the stream.
volatile int i=0;
while(i < 10000){i++;}
_puts(sifive_msg);
//_puts("Config String:\n\r");
//_puts(*((const char **) 0x100C));
//_puts("\n\r");
_puts(led_msg);
uint16_t r=0xFF;
uint16_t g=0;
uint16_t b=0;
char c = 0;
// Set up RGB PWM
PWM1_REG(PWM_CFG) = 0;
// To balance the power consumption, make one left, one right, and one center aligned.
PWM1_REG(PWM_CFG) = (PWM_CFG_ENALWAYS) | (PWM_CFG_CMP2CENTER);
PWM1_REG(PWM_COUNT) = 0;
// Period is approximately 244 Hz
// the LEDs are intentionally left somewhat dim,
// as the full brightness can be painful to look at.
PWM1_REG(PWM_CMP0) = 0;
GPIO_REG(GPIO_IOF_SEL) |= ( (1 << GREEN_LED_OFFSET) | (1 << BLUE_LED_OFFSET) | (1 << RED_LED_OFFSET));
GPIO_REG(GPIO_IOF_EN ) |= ( (1 << GREEN_LED_OFFSET) | (1 << BLUE_LED_OFFSET) | (1 << RED_LED_OFFSET));
GPIO_REG(GPIO_OUTPUT_XOR) &= ~( (1 << GREEN_LED_OFFSET) | (1 << BLUE_LED_OFFSET));
GPIO_REG(GPIO_OUTPUT_XOR) |= (1 << RED_LED_OFFSET);
while(1){
volatile uint64_t * now = (volatile uint64_t*)(CLINT_CTRL_ADDR + CLINT_MTIME);
volatile uint64_t then = *now + 100;
while (*now < then) { }
if(r > 0 && b == 0){
r--;
g++;
}
if(g > 0 && r == 0){
g--;
b++;
}
if(b > 0 && g == 0){
r++;
b--;
}
uint32_t G = g;
uint32_t R = r;
uint32_t B = b;
PWM1_REG(PWM_CMP1) = G << 4; // PWM is low on the left, GPIO is low on the left side, LED is ON on the left.
PWM1_REG(PWM_CMP2) = (B << 1) << 4; // PWM is high on the middle, GPIO is low in the middle, LED is ON in the middle.
PWM1_REG(PWM_CMP3) = 0xFFFF - (R << 4); // PWM is low on the left, GPIO is low on the right, LED is on on the right.
// Check for user input
if (c == 0){
if (_getc(&c) != 0){
_putc(c);
_puts("\n\r");
if ((c == 'y') || (c == 'Y')){
_puts("PASS\n\r");
} else{
_puts("FAIL\n\r");
}
}
}
}
}
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