258 lines
7.3 KiB
ArmAsm
258 lines
7.3 KiB
ArmAsm
/*
|
|
* Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
|
|
*
|
|
* SPDX-License-Identifier: BSD-3-Clause
|
|
*/
|
|
|
|
#include <arch.h>
|
|
#include <asm_macros.S>
|
|
#include <console_macros.S>
|
|
#include <assert_macros.S>
|
|
#include "ls_16550.h"
|
|
|
|
/*
|
|
* "core" functions are low-level implementations that don't require
|
|
* writable memory and are thus safe to call in BL1 crash context.
|
|
*/
|
|
.globl console_ls_16550_core_init
|
|
.globl console_ls_16550_core_putc
|
|
.globl console_ls_16550_core_getc
|
|
|
|
.globl console_ls_16550_putc
|
|
.globl console_ls_16550_getc
|
|
.globl console_ls_16550_flush
|
|
|
|
/* -----------------------------------------------
|
|
* int console_ls_16550_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: x0 - console base address
|
|
* w1 - Uart clock in Hz
|
|
* w2 - Baud rate
|
|
* Out: return 1 on success, 0 on error
|
|
* Clobber list : x1, x2, x3
|
|
* -----------------------------------------------
|
|
*/
|
|
func console_ls_16550_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 / (16 * baudrate) */
|
|
lsl w2, w2, #4
|
|
udiv w2, w1, w2
|
|
and w1, w2, #0xff /* w1 = DLL */
|
|
lsr w2, w2, #8
|
|
and w2, w2, #0xff /* w2 = DLLM */
|
|
ldrb w3, [x0, #UARTLCR]
|
|
orr w3, w3, #UARTLCR_DLAB
|
|
strb w3, [x0, #UARTLCR] /* enable DLL, DLLM programming */
|
|
strb w1, [x0, #UARTDLL] /* program DLL */
|
|
strb w2, [x0, #UARTDLLM] /* program DLLM */
|
|
mov w2, #~UARTLCR_DLAB
|
|
and w3, w3, w2
|
|
strb w3, [x0, #UARTLCR] /* disable DLL, DLLM programming */
|
|
|
|
/* 8n1 */
|
|
mov w3, #3
|
|
strb w3, [x0, #UARTLCR]
|
|
/* no interrupt */
|
|
mov w3, #0
|
|
strb w3, [x0, #UARTIER]
|
|
/* enable fifo, DMA */
|
|
mov w3, #(UARTFCR_FIFOEN |UARTFCR_TXCLR | UARTFCR_RXCLR)
|
|
strb w3, [x0, #UARTFCR]
|
|
/* DTR + RTS */
|
|
mov w3, #3
|
|
str w3, [x0, #UARTMCR]
|
|
mov w0, #1
|
|
ret
|
|
init_fail:
|
|
mov w0, #0
|
|
ret
|
|
endfunc console_ls_16550_core_init
|
|
|
|
.globl console_ls_16550_register
|
|
|
|
/* -----------------------------------------------
|
|
* int console_ls_16550_register(console_ls_16550_t *console,
|
|
* uintptr_t base, uint32_t clk, uint32_t baud)
|
|
* Function to initialize and register a new 16550
|
|
* console. Storage passed in for the console struct
|
|
* *must* be persistent (i.e. not from the stack).
|
|
* In: x0 - UART register base address
|
|
* w1 - UART clock in Hz
|
|
* w2 - Baud rate
|
|
* x3 - pointer to empty console_ls_16550_t struct
|
|
* Out: return 1 on success, 0 on error
|
|
* Clobber list : x0, x1, x2, x6, x7, x14
|
|
* -----------------------------------------------
|
|
*/
|
|
func console_ls_16550_register
|
|
mov x7, x30
|
|
mov x6, x3
|
|
cbz x6, register_fail
|
|
str x0, [x6, #CONSOLE_T_16550_BASE]
|
|
|
|
bl console_ls_16550_core_init
|
|
cbz x0, register_fail
|
|
|
|
mov x0, x6
|
|
mov x30, x7
|
|
finish_console_register ls_16550 putc=1, getc=1, flush=1
|
|
|
|
register_fail:
|
|
ret x7
|
|
endfunc console_ls_16550_register
|
|
|
|
/* --------------------------------------------------------
|
|
* int console_ls_16550_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 : w0 - character to be printed
|
|
* x1 - console base address
|
|
* Out : return -1 on error else return character.
|
|
* Clobber list : x2
|
|
* --------------------------------------------------------
|
|
*/
|
|
func console_ls_16550_core_putc
|
|
#if ENABLE_ASSERTIONS
|
|
cmp x1, #0
|
|
ASM_ASSERT(ne)
|
|
#endif /* ENABLE_ASSERTIONS */
|
|
|
|
/* Prepend '\r' to '\n' */
|
|
cmp w0, #0xA //'\n'
|
|
b.ne 2f
|
|
/* Check if the transmit FIFO is full */
|
|
1: ldrb w2, [x1, #UARTLSR]
|
|
and w2, w2, #UARTLSR_THRE /* #(UARTLSR_TEMT | UARTLSR_THRE)*/
|
|
cmp w2, #(UARTLSR_THRE)
|
|
b.ne 1b
|
|
mov w2, #0xD /* '\r' */
|
|
strb w2, [x1, #UARTTX]
|
|
ldrb w2, [x1, #UARTFCR]
|
|
orr w2, w2, #UARTFCR_TXCLR
|
|
|
|
/* Check if the transmit FIFO is full */
|
|
2: ldrb w2, [x1, #UARTLSR]
|
|
and w2, w2, #(UARTLSR_THRE)
|
|
cmp w2, #(UARTLSR_THRE)
|
|
b.ne 2b
|
|
strb w0, [x1, #UARTTX]
|
|
ret
|
|
endfunc console_ls_16550_core_putc
|
|
|
|
/* --------------------------------------------------------
|
|
* int console_16550_putc(int c, console_ls_16550_t *console)
|
|
* 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 - pointer to console_t structure
|
|
* Out : return -1 on error else return character.
|
|
* Clobber list : x2
|
|
* --------------------------------------------------------
|
|
*/
|
|
func console_ls_16550_putc
|
|
#if ENABLE_ASSERTIONS
|
|
cmp x1, #0
|
|
ASM_ASSERT(ne)
|
|
#endif /* ENABLE_ASSERTIONS */
|
|
ldr x1, [x1, #CONSOLE_T_16550_BASE]
|
|
b console_ls_16550_core_putc
|
|
endfunc console_ls_16550_putc
|
|
|
|
/* ---------------------------------------------
|
|
* int console_ls_16550_core_getc(uintptr_t base_addr)
|
|
* Function to get a character from the console.
|
|
* It returns the character grabbed on success
|
|
* or -1 on if no character is available.
|
|
* In : x0 - console base address
|
|
* Out : w0 - character if available, else -1
|
|
* Clobber list : x0, x1
|
|
* ---------------------------------------------
|
|
*/
|
|
func console_ls_16550_core_getc
|
|
#if ENABLE_ASSERTIONS
|
|
cmp x0, #0
|
|
ASM_ASSERT(ne)
|
|
#endif /* ENABLE_ASSERTIONS */
|
|
|
|
/* Check if the receive FIFO is empty */
|
|
1: ldrb w1, [x0, #UARTLSR]
|
|
tbz w1, #UARTLSR_RDR, 1b
|
|
ldrb w0, [x0, #UARTRX]
|
|
ret
|
|
no_char:
|
|
mov w0, #ERROR_NO_PENDING_CHAR
|
|
ret
|
|
endfunc console_ls_16550_core_getc
|
|
|
|
/* ---------------------------------------------
|
|
* int console_ls_16550_getc(console_ls_16550_t *console)
|
|
* Function to get a character from the console.
|
|
* It returns the character grabbed on success
|
|
* or -1 on if no character is available.
|
|
* In : x0 - pointer to console_t structure
|
|
* Out : w0 - character if available, else -1
|
|
* Clobber list : x0, x1
|
|
* ---------------------------------------------
|
|
*/
|
|
func console_ls_16550_getc
|
|
#if ENABLE_ASSERTIONS
|
|
cmp x1, #0
|
|
ASM_ASSERT(ne)
|
|
#endif /* ENABLE_ASSERTIONS */
|
|
ldr x0, [x0, #CONSOLE_T_16550_BASE]
|
|
b console_ls_16550_core_getc
|
|
endfunc console_ls_16550_getc
|
|
|
|
/* ---------------------------------------------
|
|
* int console_ls_16550_core_flush(uintptr_t base_addr)
|
|
* Function to force a write of all buffered
|
|
* data that hasn't been output.
|
|
* In : x0 - console base address
|
|
* Out : return -1 on error else return 0.
|
|
* Clobber list : x0, x1
|
|
* ---------------------------------------------
|
|
*/
|
|
func console_ls_16550_core_flush
|
|
#if ENABLE_ASSERTIONS
|
|
cmp x0, #0
|
|
ASM_ASSERT(ne)
|
|
#endif /* ENABLE_ASSERTIONS */
|
|
|
|
/* Loop until the transmit FIFO is empty */
|
|
1: ldrb w1, [x0, #UARTLSR]
|
|
and w1, w1, #(UARTLSR_TEMT | UARTLSR_THRE)
|
|
cmp w1, #(UARTLSR_TEMT | UARTLSR_THRE)
|
|
b.ne 1b
|
|
|
|
mov w0, #0
|
|
ret
|
|
endfunc console_ls_16550_core_flush
|
|
|
|
/* ---------------------------------------------
|
|
* int console_ls_16550_flush(console_ls_16550_t *console)
|
|
* Function to force a write of all buffered
|
|
* data that hasn't been output.
|
|
* In : x0 - pointer to console_t structure
|
|
* Out : return -1 on error else return 0.
|
|
* Clobber list : x0, x1
|
|
* ---------------------------------------------
|
|
*/
|
|
func console_ls_16550_flush
|
|
#if ENABLE_ASSERTIONS
|
|
cmp x0, #0
|
|
ASM_ASSERT(ne)
|
|
#endif /* ENABLE_ASSERTIONS */
|
|
ldr x0, [x0, #CONSOLE_T_16550_BASE]
|
|
b console_ls_16550_core_flush
|
|
endfunc console_ls_16550_flush
|