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/*
* Copyright (c) 2013-2014, 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 <arch.h>
#include <asm_macros.S>
#include <pl011.h>
.globl console_init
.globl console_putc
.globl console_core_init
.globl console_core_putc
.globl console_getc
/*
* The console base is in the data section and not in .bss
* even though it is zero-init. In particular, this allows
* the console functions to start using this variable before
* the runtime memory is initialized for images which do not
* need to copy the .data section from ROM to RAM.
*/
.section .data.console_base ; .align 3
console_base: .quad 0x0
/* -----------------------------------------------
* int console_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. It saves
* the console base to the data section.
* In: x0 - console base address
* w1 - Uart clock in Hz
* w2 - Baud rate
* out: return 1 on success.
* Clobber list : x1 - x3
* -----------------------------------------------
*/
func console_init
adrp x3, console_base
str x0, [x3, :lo12:console_base]
b console_core_init
/* -----------------------------------------------
* 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
* Clobber list : x1, x2
* -----------------------------------------------
*/
func console_core_init
/* Check the input base address */
cbz x0, init_fail
/* Check baud rate and uart clock for sanity */
cbz w1, init_fail
cbz w2, init_fail
/* Program the baudrate */
/* Divisor = (Uart clock * 4) / baudrate */
lsl w1, w1, #2
udiv w2, w1, w2
/* IBRD = Divisor >> 6 */
lsr w1, w2, #6
/* Write the IBRD */
str w1, [x0, #UARTIBRD]
/* FBRD = Divisor & 0x3F */
and w1, w2, #0x3f
/* Write the FBRD */
str w1, [x0, #UARTFBRD]
mov w1, #PL011_LINE_CONTROL
str w1, [x0, #UARTLCR_H]
/* Clear any pending errors */
str wzr, [x0, #UARTECR]
/* Enable tx, rx, and uart overall */
mov w1, #(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
str w1, [x0, #UARTCR]
mov w0, #1
init_fail:
ret
/* ---------------------------------------------
* int console_putc(int c)
* Function to output a character over the
* console. It returns the character printed on
* success or -1 on error.
* In : x0 - character to be printed
* Out : return -1 on error else return character.
* Clobber list : x1, x2
* ---------------------------------------------
*/
func console_putc
adrp x2, console_base
ldr x1, [x2, :lo12:console_base]
b console_core_putc
/* --------------------------------------------------------
* int console_core_putc(int c, unsigned int 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
1:
/* Check if the transmit FIFO is full */
ldr w2, [x1, #UARTFR]
tbnz w2, #PL011_UARTFR_TXFF_BIT, 1b
mov w2, #0xD
str w2, [x1, #UARTDR]
2:
/* Check if the transmit FIFO is full */
ldr w2, [x1, #UARTFR]
tbnz w2, #PL011_UARTFR_TXFF_BIT, 2b
str w0, [x1, #UARTDR]
ret
putc_error:
mov w0, #-1
ret
/* ---------------------------------------------
* int console_getc(void)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on error.
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_getc
adrp x0, console_base
ldr x1, [x0, :lo12:console_base]
cbz x1, getc_error
1:
/* Check if the receive FIFO is empty */
ldr w0, [x1, #UARTFR]
tbnz w0, #PL011_UARTFR_RXFE_BIT, 1b
ldr w0, [x1, #UARTDR]
ret
getc_error:
mov w0, #-1
ret
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