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/*
* Copyright © 2017-2022 The Crust Firmware Authors.
* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0-only
*/
#include <division.h>
#include <error.h>
#include <mmio.h>
#include "uart.h"
static int
uart_probe(const struct device *dev)
{
const struct simple_device *self = to_simple_device(dev);
int err;
if ((err = simple_device_probe(dev)))
return err;
if (CONFIG_SERIAL_BAUD) {
uint32_t rate = clock_get_rate(&self->clock);
uint32_t divisor = udiv_round(rate, 16 * CONFIG_SERIAL_BAUD);
uintptr_t regs = self->regs;
/* Set the clock divisor. */
mmio_write_32(regs + UART_LCR, UART_LCR_DLAB);
mmio_write_32(regs + UART_DLH, divisor >> 8);
mmio_write_32(regs + UART_DLL, divisor);
/* Set the UART to 8 data bits, no parity, 1 stop bit. */
mmio_write_32(regs + UART_LCR, UART_LCR_DLS8);
/* Enable the FIFOs. */
mmio_write_32(regs + UART_FCR, UART_FCR_FIFOE);
}
return SUCCESS;
}
const struct driver uart_driver = {
.probe = uart_probe,
.release = simple_device_release,
};
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