diff options
Diffstat (limited to 'drivers/nxp/uart/nxp_console.S')
-rw-r--r-- | drivers/nxp/uart/nxp_console.S | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/drivers/nxp/uart/nxp_console.S b/drivers/nxp/uart/nxp_console.S new file mode 100644 index 0000000..77149ae --- /dev/null +++ b/drivers/nxp/uart/nxp_console.S @@ -0,0 +1,297 @@ +/* + * 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 |