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/*
* Copyright (c) 2021, Nico Weber <thakis@chromium.org>
* Copyright (c) 2021, Jesse Buhagiar <jooster669@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Types.h>
namespace Prekernel {
struct UARTRegisters;
// Abstracts the PL011 UART on a Raspberry Pi.
// (The BCM2711 on a Raspberry Pi 4 has five PL011 UARTs; this is always the first of those.)
class UART {
public:
static UART& the();
void send(u32 c);
u32 receive();
void print_str(const char* s)
{
while (*s)
send(*s++);
}
void print_num(u64 n)
{
char buf[21];
int i = 0;
do {
buf[i++] = (n % 10) + '0';
n /= 10;
} while (n);
for (i--; i >= 0; i--)
send(buf[i]);
}
void print_hex(u64 n)
{
char buf[17];
static const char* digits = "0123456789ABCDEF";
int i = 0;
do {
buf[i++] = digits[n % 16];
n /= 16;
} while (n);
send(static_cast<u32>('0'));
send(static_cast<u32>('x'));
buf[16] = '\0';
for (i--; i >= 0; i--) {
send(buf[i]);
}
}
private:
UART();
void set_baud_rate(int baud_rate, int uart_frequency_in_hz);
void wait_until_we_can_send();
void wait_until_we_can_receive();
UARTRegisters volatile* m_registers;
};
}
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