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#ifndef COMMON_RPIBM_H
#define COMMON_RPIBM_H
// Header definitions for memory mapped IO and common utilities.
#include "shorthand.h"
//
// Utils.
//
// Wait for N processor cycles before returning. Implemented in start.s.
void delay(u64 ticks);
// Clear N bytes at the given address. Implemented in start.s.
void memzero(u64 src, u32 n);
#define MEM_BASE 0x3F000000
//
// GPIO Registers.
//
typedef struct GpioPinData {
vu32 reserved;
vu32 data[2];
} GpioPinData;
typedef struct GpioRegs {
vu32 func_select[6];
GpioPinData output_set;
GpioPinData output_clear;
GpioPinData level;
GpioPinData ev_detect_status;
GpioPinData re_detect_enable;
GpioPinData fe_detect_enable;
GpioPinData hi_detect_enable;
GpioPinData lo_detect_enable;
GpioPinData async_re_detect;
GpioPinData async_fe_detect;
vu32 reserved;
vu32 pupd_enable;
vu32 pupd_enable_clocks[2];
} GpioRegs;
typedef enum GpioFunc {
GPIO_INPUT = 0,
GPIO_OUTPUT = 1,
GPIO_ALT0 = 4,
GPIO_ALT1 = 5,
GPIO_ALT2 = 6,
GPIO_ALT3 = 7,
GPIO_ALT4 = 3,
GPIO_ALT5 = 2,
} GpioFunc;
#define GPIO ((GpioRegs *)(MEM_BASE + 0x00200000))
static inline void
gpio_pin_set_func(u8 pin, GpioFunc func) {
u8 start = (pin * 3) % 30;
u8 reg = pin / 10;
u32 selector = GPIO->func_select[reg];
selector &= ~(7 << start);
selector |= (func << start);
GPIO->func_select[reg] = selector;
}
static inline void
gpio_pin_enable(u8 pin) {
GPIO->pupd_enable = 0;
delay(150);
GPIO->pupd_enable_clocks[pin / 32] = 1 << (pin % 32);
delay(150);
GPIO->pupd_enable = 0;
GPIO->pupd_enable_clocks[pin / 32] = 0;
}
//
// AUX Registers.
//
typedef struct AuxRegs {
vu32 irq_status;
vu32 enables;
vu32 reserved[14];
vu32 mu_io;
vu32 mu_ier;
vu32 mu_iir;
vu32 mu_lcr;
vu32 mu_mcr;
vu32 mu_lsr;
vu32 mu_msr;
vu32 mu_scratch;
vu32 mu_control;
vu32 mu_status;
vu32 mu_baud_rate;
} AuxRegs;
#define AUX ((AuxRegs *)(MEM_BASE + 0x00215000))
static inline void
uart_init() {
gpio_pin_set_func(14, GPIO_ALT5);
gpio_pin_set_func(15, GPIO_ALT5);
gpio_pin_enable(14);
gpio_pin_enable(15);
AUX->enables = 1;
AUX->mu_control = 0;
AUX->mu_ier = 0;
AUX->mu_lcr = 3;
AUX->mu_mcr = 0;
AUX->mu_baud_rate = 270; // RPI3: 115200 @ 250 MHz
// AUX->mu_baud_rate = 541; // RPI4: 115200 @ 500 MHz
AUX->mu_control = 3;
return;
}
static inline void
uart_putc(char c) {
while(!(AUX->mu_lsr & (1 << 5)));
AUX->mu_io = c;
return;
}
static inline char
uart_getc() {
while(!(AUX->mu_lsr & 1));
u8 c = AUX->mu_io & 0xFF;
return c == '\r' ? '\n' : c;
}
static inline void
uart_puts(char *s) {
while(*s) {
if(*s == '\n') {
uart_putc('\r');
}
uart_putc(*s++);
}
}
#endif // COMMON_RPIBM_H
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