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/*
* Copyright (c) 2018, 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 "nxp_console.h"
.globl console_init
.globl console_putc
.globl console_getc
.globl console_flush
.globl console_core_init
.globl console_core_putc
.globl console_core_getc
.globl console_core_flush
/*
* 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 2
console_base: .word 0x0
/* -----------------------------------------------
* int console_init(uintptr_t 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: r0 - console base address
* r1 - Uart clock in Hz
* r2 - Baud rate
* out: return 1 on success else 0 on error
* Clobber list : r1 - r3
* -----------------------------------------------
*/
func console_init
ldr r3, =console_base
str r0, [r3]
b console_core_init
endfunc console_init
/* -----------------------------------------------
* int console_core_init(uintptr_t 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: r0 - console base address
* r1 - Uart clock in Hz
* r2 - Baud rate
* Out: return 1 on success else 0 on error
* Clobber list : r1, r2, r3, r4
* -----------------------------------------------
*/
func console_core_init
push {r4}
/* Check the input base address */
cmp r0, #0
beq core_init_fail
/* Check baud rate and uart clock for sanity */
cmp r1, #0
beq core_init_fail
cmp r2, #0
beq core_init_fail
/* Free up r1 as a scratch reg */
mov r4, r0
mov r0, r1
/* Reset UART via CR2 */
add r1, r4, #MXC_UART_CR2_OFFSET
movs r3, #0
str r3, [r4, #MXC_UART_CR2_OFFSET]
/* Wait for reset complete */
__wait_cr2_reset:
ldr r3, [r1, #0]
ands r3, #MXC_UART_CR2_SRST
beq __wait_cr2_reset
/* Enable UART */
movs r3, #MXC_UART_CR1_UARTEN
mov r1, r2
str r3, [r4, #MXC_UART_CR1_OFFSET]
/*
* Ignore RTC/CTS - disable reset
* Magic value #16423 =>
* MXC_UART_CR2_IRTS | MXC_UART_CR2_WS | MXC_UART_CR2_TXEN | MXC_UART_CR2_RXEN | MXC_UART_CR2_SRST
*/
movw r3, #16423
str r3, [r4, #MXC_UART_CR2_OFFSET]
/*
* No parity, autobaud detect-old, rxdmuxsel=1 (fixed i.mx7)
* Magic value => #132
* MXC_UART_CR3_ADNIMP | MXC_UART_CR3_RXDMUXSEL
*/
movs r3, #132
str r3, [r4, #MXC_UART_CR3_OFFSET]
/*
* Set CTS FIFO trigger to 32 bytes bits 15:10
* Magic value => #32768
* FIFO trigger bitmask 100000
* */
mov r3, #32768
str r3, [r4, #MXC_UART_CR4_OFFSET]
/*
* TX/RX-thresh = 2 bytes, DCE (bit6 = 0), refclk @24MHz / 4
* Magic value #2562
* MXC_UART_FCR_TXTL(TX_RX_THRESH) | MXC_UART_FCR_RXTL(TX_RX_THRESH) | MXC_UART_FCR_RFDIV2
*/
movw r3, #2562
str r3, [r4, #MXC_UART_FCR_OFFSET]
/* This BIR should be set to 0x0F prior to writing the BMR */
movs r3, #15
str r3, [r4, #MXC_UART_BIR_OFFSET]
/* Hard-code to 115200 @ 24 MHz */
movs r0, #104
str r0, [r4, #MXC_UART_BMR_OFFSET]
/* Indicate success */
movs r0, #1
pop {r4}
bx lr
core_init_fail:
pop {r4}
mov r0, #0
bx lr
endfunc console_core_init
/* ---------------------------------------------
* 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 : r0 - character to be printed
* Out : return -1 on error else return character.
* Clobber list : r1, r2
* ---------------------------------------------
*/
func console_putc
ldr r2, =console_base
ldr r1, [r2]
b console_core_putc
endfunc console_putc
/* --------------------------------------------------------
* int console_core_putc(int c, uintptr_t base_addr)
* Function to output a character over the console. It
* returns the character printed on success or -1 on error.
* In : r0 - character to be printed
* r1 - console base address
* Out : return -1 on error else return character.
* Clobber list : r2
* --------------------------------------------------------
*/
func console_core_putc
/* Check the input parameter */
cmp r1, #0
beq putc_error
/* Output specified character to UART shift-register */
str r0, [r1, #MXC_UART_TXD_OFFSET]
/* Wait for transmit MXC_UART_STAT2_OFFSET.MXC_UART_STAT2_TXDC == 1 */
__putc_spin_ready:
ldr r2, [r1, #MXC_UART_STAT2_OFFSET]
ands r2, #MXC_UART_STAT2_TXDC
beq __putc_spin_ready
/* Transmit complete do we need to fixup \n to \n\r */
cmp r0, #10
beq __putc_fixup_lf
/* No fixup necessary - exit here */
movs r0, #0
bx lr
/* Fixup \n to \n\r */
__putc_fixup_lf:
movs r0, #13
b console_core_putc
putc_error:
mov r0, #-1
bx lr
endfunc console_core_putc
/* ---------------------------------------------
* int console_getc(void)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on error.
* Out : return -1 on error else return character.
* Clobber list : r0, r1
* ---------------------------------------------
*/
func console_getc
ldr r1, =console_base
ldr r0, [r1]
b console_core_getc
endfunc console_getc
/* ---------------------------------------------
* int console_core_getc(void)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on error.
* In : r0 - console base address
* Out : return -1 on error else return character.
* Clobber list : r0, r1
* ---------------------------------------------
*/
func console_core_getc
cmp r0, #0
beq getc_error
1:
/* Check if the receive FIFO is empty */
/* TODO */
getc_error:
mov r0, #-1
bx lr
endfunc console_core_getc
/* ---------------------------------------------
* int console_flush(void)
* Function to force a write of all buffered
* data that hasn't been output. It returns 0
* upon successful completion, otherwise it
* returns -1.
* Clobber list : r0, r1
* ---------------------------------------------
*/
func console_flush
ldr r1, =console_base
ldr r0, [r1]
b console_core_flush
endfunc console_flush
/* ---------------------------------------------
* int console_core_flush(uintptr_t base_addr)
* Function to force a write of all buffered
* data that hasn't been output.
* In : r0 - console base address
* Out : return -1 on error else return 0.
* Clobber list : r0, r1
* ---------------------------------------------
*/
func console_core_flush
cmp r0, #0
beq flush_error
1:
/* Loop while the transmit FIFO is busy */
/* TODO */
mov r0, #0
bx lr
flush_error:
mov r0, #-1
bx lr
endfunc console_core_flush
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