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/*
* Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 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.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 <asm_macros.S>
#include <uart8250.h>
.globl console_core_init
.globl console_core_putc
.globl console_core_getc
/* -----------------------------------------------
* int console_core_init(unsigned long base_addr,
* unsigned int uart_clk, unsigned int baud_rate)
* Function to initialize the console without a
* C Runtime to print debug information. This
* function will be accessed by console_init and
* crash reporting.
* In: x0 - console base address
* w1 - Uart clock in Hz
* w2 - Baud rate
* Out: return 1 on success else 0 on error
* Clobber list : x1, x2, x3
* -----------------------------------------------
*/
func console_core_init
/* Check the input base address */
cbz x0, core_init_fail
/* Check baud rate and uart clock for sanity */
cbz w1, core_init_fail
cbz w2, core_init_fail
/* Disable interrupt */
str wzr, [x0, #UART_IER]
/* Force DTR and RTS to high */
mov w3, #(UART_MCR_DTR | UART_MCR_RTS)
str w3, [x0, #UART_MCR]
/* Check high speed */
movz w3, #:abs_g1:115200
movk w3, #:abs_g0_nc:115200
cmp w2, w3
b.hi 1f
/* Non high speed */
lsl w2, w2, #4
mov w3, wzr
b 2f
/* High speed */
1: lsl w2, w2, #2
mov w3, #2
/* Set high speed UART register */
2: str w3, [x0, #UART_HIGHSPEED]
/* Calculate divisor */
udiv w3, w1, w2 /* divisor = uartclk / (quot * baudrate) */
msub w1, w3, w2, w1 /* remainder = uartclk % (quot * baudrate) */
lsr w2, w2, #1
cmp w1, w2
cinc w3, w3, hs
/* Set line configuration, access divisor latches */
mov w1, #(UART_LCR_DLAB | UART_LCR_WLS_8)
str w1, [x0, #UART_LCR]
/* Set the divisor */
and w1, w3, #0xff
str w1, [x0, #UART_DLL]
lsr w1, w3, #8
and w1, w1, #0xff
str w1, [x0, #UART_DLH]
/* Hide the divisor latches */
mov w1, #UART_LCR_WLS_8
str w1, [x0, #UART_LCR]
/* Enable FIFOs, and clear receive and transmit */
mov w1, #(UART_FCR_FIFO_EN | UART_FCR_CLEAR_RCVR | \
UART_FCR_CLEAR_XMIT)
str w1, [x0, #UART_FCR]
mov w0, #1
ret
core_init_fail:
mov w0, wzr
ret
endfunc console_core_init
/* --------------------------------------------------------
* int console_core_putc(int c, unsigned long base_addr)
* Function to output a character over the console. It
* returns the character printed on success or -1 on error.
* In : w0 - character to be printed
* x1 - console base address
* Out : return -1 on error else return character.
* Clobber list : x2
* --------------------------------------------------------
*/
func console_core_putc
/* Check the input parameter */
cbz x1, putc_error
/* Prepend '\r' to '\n' */
cmp w0, #0xA
b.ne 2f
/* Check if the transmit FIFO is full */
1: ldr w2, [x1, #UART_LSR]
and w2, w2, #UART_LSR_THRE
cbz w2, 1b
mov w2, #0xD
str w2, [x1, #UART_THR]
/* Check if the transmit FIFO is full */
2: ldr w2, [x1, #UART_LSR]
and w2, w2, #UART_LSR_THRE
cbz w2, 2b
str w0, [x1, #UART_THR]
ret
putc_error:
mov w0, #-1
ret
endfunc console_core_putc
/* ---------------------------------------------
* int console_core_getc(unsigned long base_addr)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on error.
* In : x0 - console base address
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_core_getc
cbz x0, getc_error
/* Check if the receive FIFO is empty */
1: ldr w1, [x0, #UART_LSR]
tbz w1, #UART_LSR_DR, 1b
ldr w0, [x0, #UART_RBR]
ret
getc_error:
mov w0, #-1
ret
endfunc console_core_getc
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