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/* Copyright 2018 Canaan Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "sysctl.h"
#include "uarths.h"
static volatile struct uarths *const uarths =
(volatile struct uarths *)UARTHS_BASE_ADDR;
void uarths_init(u32 baud_rate, enum uarths_stopbit stopbit)
{
u32 freq = sysctl_clock_get_freq(SYSCTL_CLOCK_CPU);
u16 div = freq / baud_rate - 1;
/* Set UART registers */
uarths->div.div = div;
uarths->txctrl.nstop = stopbit;
uarths->txctrl.txen = 1;
uarths->rxctrl.rxen = 1;
uarths->txctrl.txcnt = 0;
uarths->rxctrl.rxcnt = 0;
uarths->ip.txwm = 0;
uarths->ip.rxwm = 0;
uarths->ie.txwm = 0;
uarths->ie.rxwm = 0;
}
void uarths_putc(char c)
{
while (uarths->txdata.full);
uarths->txdata.data = (u8)c;
}
char uarths_getc(void)
{
struct uarths_rxdata recv = uarths->rxdata;
if (recv.empty)
return '\0';
return recv.data;
}
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