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/*
* Copyright 2013 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <libpayload.h>
#include <stdint.h>
struct mmio32_uart {
union {
uint32_t thr; // Transmit holding register.
uint32_t rbr; // Receive buffer register.
uint32_t dll; // Divisor latch lsb.
};
union {
uint32_t ier; // Interrupt enable register.
uint32_t dlm; // Divisor latch msb.
};
union {
uint32_t iir; // Interrupt identification register.
uint32_t fcr; // FIFO control register.
};
uint32_t lcr; // Line control register.
uint32_t mcr; // Modem control register.
uint32_t lsr; // Line status register.
uint32_t msr; // Modem status register.
} __attribute__ ((packed));
enum {
LSR_DR = 0x1 << 0, // Data ready.
LSR_OE = 0x1 << 1, // Overrun.
LSR_PE = 0x1 << 2, // Parity error.
LSR_FE = 0x1 << 3, // Framing error.
LSR_BI = 0x1 << 4, // Break.
LSR_THRE = 0x1 << 5, // Xmit holding register empty.
LSR_TEMT = 0x1 << 6, // Xmitter empty.
LSR_ERR = 0x1 << 7 // Error.
};
static struct mmio32_uart *uart = NULL;
void serial_putchar(unsigned int c)
{
while (!(readl(&uart->lsr) & LSR_THRE))
/* wait for transmit register to clear */;
writel((char)c, &uart->thr);
if (c == '\n')
serial_putchar('\r');
}
int serial_havechar(void)
{
uint8_t lsr = readl(&uart->lsr);
return (lsr & LSR_DR) == LSR_DR;
}
int serial_getchar(void)
{
while (!serial_havechar())
/* wait for character */;
return readl(&uart->rbr);
}
static struct console_output_driver mmio32_serial_output = {
.putchar = &serial_putchar
};
static struct console_input_driver mmio32_serial_input = {
.havekey = &serial_havechar,
.getchar = &serial_getchar
};
void serial_init(void)
{
if (!lib_sysinfo.serial || !lib_sysinfo.serial->baseaddr)
return;
uart = (struct mmio32_uart *)(uintptr_t)lib_sysinfo.serial->baseaddr;
}
void serial_console_init(void)
{
serial_init();
if (uart) {
console_add_output_driver(&mmio32_serial_output);
console_add_input_driver(&mmio32_serial_input);
}
}
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