arm-trusted-firmware/drivers/arm/pl011/aarch32/pl011_console.S
Soby Mathew cc5859ca19 Multi-console: Deprecate the finish_console_register macro
The `finish_console_register` macro is used by the multi console
framework to register the `console_t` driver callbacks. It relied
on weak references to the `ldr` instruction to populate 0 to the
callback in case the driver has not defined the appropriate
function. Use of `ldr` instruction to load absolute address to a
reference makes the binary position dependant. These instructions
should be replaced with adrp/adr instruction for position independant
executable(PIE). But adrp/adr instructions don't work well with weak
references as described in GNU ld bugzilla issue 22589.

This patch defines a new version of `finish_console_register` macro
which can spcify which driver callbacks are valid and deprecates the
old one. If any of the argument is not specified, then the macro
populates 0 for that callback. Hence the functionality of the previous
deprecated macro is preserved. The USE_FINISH_CONSOLE_REG_2 define
is used to select the new variant of the macro and will be removed
once the deprecated variant is removed.

All the upstream console drivers have been migrated to use the new
macro in this patch.

NOTE: Platforms be aware that the new variant of the
`finish_console_register` should be used and the old variant is
deprecated.

Change-Id: Ia6a67aaf2aa3ba93932992d683587bbd0ad25259
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
2018-10-19 17:34:52 +01:00

277 lines
7.4 KiB
ArmAsm

/*
* Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <asm_macros.S>
#include <assert_macros.S>
#define USE_FINISH_CONSOLE_REG_2
#include <console_macros.S>
#include <pl011.h>
/*
* Pull in generic functions to provide backwards compatibility for
* platform makefiles
*/
#include "../../../console/aarch32/console.S"
/*
* "core" functions are low-level implementations that don't require
* writeable memory and are thus safe to call in BL1 crash context.
*/
.globl console_pl011_core_init
.globl console_pl011_core_putc
.globl console_pl011_core_getc
.globl console_pl011_core_flush
.globl console_pl011_putc
.globl console_pl011_getc
.globl console_pl011_flush
/* -----------------------------------------------
* 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
* -----------------------------------------------
*/
func console_pl011_core_init
/* Check the input base address */
cmp r0, #0
beq core_init_fail
#if !PL011_GENERIC_UART
/* Check baud rate and uart clock for sanity */
cmp r1, #0
beq core_init_fail
cmp r2, #0
beq core_init_fail
/* Disable the UART before initialization */
ldr r3, [r0, #UARTCR]
bic r3, r3, #PL011_UARTCR_UARTEN
str r3, [r0, #UARTCR]
/* Program the baudrate */
/* Divisor = (Uart clock * 4) / baudrate */
lsl r1, r1, #2
udiv r2, r1, r2
/* IBRD = Divisor >> 6 */
lsr r1, r2, #6
/* Write the IBRD */
str r1, [r0, #UARTIBRD]
/* FBRD = Divisor & 0x3F */
and r1, r2, #0x3f
/* Write the FBRD */
str r1, [r0, #UARTFBRD]
mov r1, #PL011_LINE_CONTROL
str r1, [r0, #UARTLCR_H]
/* Clear any pending errors */
mov r1, #0
str r1, [r0, #UARTECR]
/* Enable tx, rx, and uart overall */
ldr r1, =(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
str r1, [r0, #UARTCR]
#endif
mov r0, #1
bx lr
core_init_fail:
mov r0, #0
bx lr
endfunc console_pl011_core_init
#if MULTI_CONSOLE_API
.globl console_pl011_register
/* -------------------------------------------------------
* int console_pl011_register(uintptr_t baseaddr,
* uint32_t clock, uint32_t baud,
* console_pl011_t *console);
* Function to initialize and register a new PL011
* console. Storage passed in for the console struct
* *must* be persistent (i.e. not from the stack).
* In: r0 - UART register base address
* r1 - UART clock in Hz
* r2 - Baud rate
* r3 - pointer to empty console_pl011_t struct
* Out: return 1 on success, 0 on error
* Clobber list : r0, r1, r2
* -------------------------------------------------------
*/
func console_pl011_register
push {r4, lr}
mov r4, r3
cmp r4, #0
beq register_fail
str r0, [r4, #CONSOLE_T_PL011_BASE]
bl console_pl011_core_init
cmp r0, #0
beq register_fail
mov r0, r4
pop {r4, lr}
finish_console_register pl011 putc=1, getc=1, flush=1
register_fail:
pop {r4, pc}
endfunc console_pl011_register
#else
.globl console_core_init
.globl console_core_putc
.globl console_core_getc
.globl console_core_flush
.equ console_core_init, console_pl011_core_init
.equ console_core_putc, console_pl011_core_putc
.equ console_core_getc, console_pl011_core_getc
.equ console_core_flush, console_pl011_core_flush
#endif
/* --------------------------------------------------------
* 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_pl011_core_putc
/* Check the input parameter */
cmp r1, #0
beq putc_error
/* Prepend '\r' to '\n' */
cmp r0, #0xA
bne 2f
1:
/* Check if the transmit FIFO is full */
ldr r2, [r1, #UARTFR]
tst r2, #PL011_UARTFR_TXFF
bne 1b
mov r2, #0xD
str r2, [r1, #UARTDR]
2:
/* Check if the transmit FIFO is full */
ldr r2, [r1, #UARTFR]
tst r2, #PL011_UARTFR_TXFF
bne 2b
str r0, [r1, #UARTDR]
bx lr
putc_error:
mov r0, #-1
bx lr
endfunc console_pl011_core_putc
/* --------------------------------------------------------
* int console_pl011_putc(int c, console_pl011_t *console)
* 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 - pointer to console_t structure
* Out : return -1 on error else return character.
* Clobber list: r2
* -------------------------------------------------------
*/
func console_pl011_putc
#if ENABLE_ASSERTIONS
cmp r1, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
ldr r1, [r1, #CONSOLE_T_PL011_BASE]
b console_pl011_core_putc
endfunc console_pl011_putc
/* ---------------------------------------------
* int console_core_getc(uintptr_t base_addr)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on error.
* In : r0 - console base address
* Clobber list : r0, r1
* ---------------------------------------------
*/
func console_pl011_core_getc
cmp r0, #0
beq getc_error
1:
/* Check if the receive FIFO is empty */
ldr r1, [r0, #UARTFR]
tst r1, #PL011_UARTFR_RXFE
bne 1b
ldr r1, [r0, #UARTDR]
mov r0, r1
bx lr
getc_error:
mov r0, #-1
bx lr
endfunc console_pl011_core_getc
/* ------------------------------------------------
* int console_pl011_getc(console_pl011_t *console)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 if no character is available.
* In : r0 - pointer to console_t structure
* Out: r0 - character if available, else -1
* Clobber list: r0, r1
* ------------------------------------------------
*/
func console_pl011_getc
#if ENABLE_ASSERTIONS
cmp r0, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
ldr r0, [r0, #CONSOLE_T_PL011_BASE]
b console_pl011_core_getc
endfunc console_pl011_getc
/* ---------------------------------------------
* 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_pl011_core_flush
cmp r0, #0
beq flush_error
1:
/* Loop while the transmit FIFO is busy */
ldr r1, [r0, #UARTFR]
tst r1, #PL011_UARTFR_BUSY
bne 1b
mov r0, #0
bx lr
flush_error:
mov r0, #-1
bx lr
endfunc console_pl011_core_flush
/* ---------------------------------------------
* int console_pl011_flush(console_pl011_t *console)
* Function to force a write of all buffered
* data that hasn't been output.
* In : r0 - pointer to console_t structure
* Out : return -1 on error else return 0.
* Clobber list: r0, r1
* ---------------------------------------------
*/
func console_pl011_flush
#if ENABLE_ASSERTIONS
cmp r0, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
ldr r0, [r0, #CONSOLE_T_PL011_BASE]
b console_pl011_core_flush
endfunc console_pl011_flush