65 lines
1.5 KiB
C
65 lines
1.5 KiB
C
/*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Copyright 2018 Canaan Inc.
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* Copyright (c) 2019 Western Digital Corporation or its affiliates.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "sysctl.h"
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#include "uarths.h"
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static volatile struct uarths *const uarths =
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(volatile struct uarths *)UARTHS_BASE_ADDR;
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void uarths_init(u32 baud_rate, enum uarths_stopbit stopbit)
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{
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u32 freq = sysctl_get_cpu_freq();
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u16 div = freq / baud_rate - 1;
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/* Set UART registers */
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uarths->div.div = div;
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uarths->txctrl.nstop = stopbit;
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uarths->txctrl.txen = 1;
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uarths->rxctrl.rxen = 1;
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uarths->txctrl.txcnt = 0;
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uarths->rxctrl.rxcnt = 0;
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uarths->ip.txwm = 1;
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uarths->ip.rxwm = 0;
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uarths->ie.txwm = 1;
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uarths->ie.rxwm = 0;
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/* Clear input */
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if (!uarths->rxdata.empty)
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(void)uarths_getc();
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}
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void uarths_putc(char c)
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{
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while (uarths->txdata.full)
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;
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uarths->txdata.data = (u8)c;
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}
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int uarths_getc(void)
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{
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struct uarths_rxdata rx = uarths->rxdata;
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if (rx.empty)
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return -1;
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return rx.data;
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}
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