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/*
* Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <asm_macros.S>
#include <assert_macros.S>
#include <console_macros.S>
#include <drivers/amlogic/meson_console.h>
.globl console_meson_register
.globl console_meson_init
.globl console_meson_putc
.globl console_meson_getc
.globl console_meson_flush
.globl console_meson_core_putc
.globl console_meson_core_getc
.globl console_meson_core_flush
/* -----------------------------------------------
* Hardware definitions
* -----------------------------------------------
*/
#define MESON_WFIFO_OFFSET 0x0
#define MESON_RFIFO_OFFSET 0x4
#define MESON_CONTROL_OFFSET 0x8
#define MESON_STATUS_OFFSET 0xC
#define MESON_MISC_OFFSET 0x10
#define MESON_REG5_OFFSET 0x14
#define MESON_CONTROL_CLR_ERROR_BIT 24
#define MESON_CONTROL_RX_RESET_BIT 23
#define MESON_CONTROL_TX_RESET_BIT 22
#define MESON_CONTROL_RX_ENABLE_BIT 13
#define MESON_CONTROL_TX_ENABLE_BIT 12
#define MESON_STATUS_RX_EMPTY_BIT 20
#define MESON_STATUS_TX_FULL_BIT 21
#define MESON_STATUS_TX_EMPTY_BIT 22
#define MESON_REG5_USE_XTAL_CLK_BIT 24
#define MESON_REG5_USE_NEW_RATE_BIT 23
#define MESON_REG5_NEW_BAUD_RATE_MASK 0x7FFFFF
/* -----------------------------------------------
* int console_meson_register(uintptr_t base,
* uint32_t clk, uint32_t baud,
* console_t *console);
* Function to initialize and register a new MESON
* 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_t struct
* Out: return 1 on success, 0 on error
* Clobber list : x0, x1, x2, x6, x7, x14
* -----------------------------------------------
*/
func console_meson_register
mov x7, x30
mov x6, x3
cbz x6, register_fail
str x0, [x6, #CONSOLE_T_BASE]
bl console_meson_init
cbz x0, register_fail
mov x0, x6
mov x30, x7
finish_console_register meson putc=1, getc=ENABLE_CONSOLE_GETC, flush=1
register_fail:
ret x7
endfunc console_meson_register
/* -----------------------------------------------
* int console_meson_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 else 0 on error
* Clobber list : x0-x3
* -----------------------------------------------
*/
func console_meson_init
cmp w0, #0
beq init_fail
mov_imm w3, 24000000 /* TODO: This only works with a 24 MHz clock. */
cmp w1, w3
bne init_fail
cmp w2, #0
beq init_fail
/* Set baud rate: value = ((clock / 3) / baudrate) - 1 */
mov w3, #3
udiv w3, w1, w3
udiv w3, w3, w2
sub w3, w3, #1
orr w3, w3, #((1 << MESON_REG5_USE_XTAL_CLK_BIT) | \
(1 << MESON_REG5_USE_NEW_RATE_BIT))
str w3, [x0, #MESON_REG5_OFFSET]
/* Reset UART and clear error flag */
ldr w3, [x0, #MESON_CONTROL_OFFSET]
orr w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \
(1 << MESON_CONTROL_RX_RESET_BIT) | \
(1 << MESON_CONTROL_TX_RESET_BIT))
str w3, [x0, #MESON_CONTROL_OFFSET]
bic w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \
(1 << MESON_CONTROL_RX_RESET_BIT) | \
(1 << MESON_CONTROL_TX_RESET_BIT))
str w3, [x0, #MESON_CONTROL_OFFSET]
/* Enable transfer and receive FIFO */
orr w3, w3, #((1 << MESON_CONTROL_RX_ENABLE_BIT) | \
(1 << MESON_CONTROL_TX_ENABLE_BIT))
str w3, [x0, #MESON_CONTROL_OFFSET]
/* Success */
mov w0, #1
ret
init_fail:
mov w0, wzr
ret
endfunc console_meson_init
/* --------------------------------------------------------
* int console_meson_putc(int c, console_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_meson_putc
#if ENABLE_ASSERTIONS
cmp x1, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
ldr x1, [x1, #CONSOLE_T_BASE]
b console_meson_core_putc
endfunc console_meson_putc
/* --------------------------------------------------------
* int console_meson_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_meson_core_putc
#if ENABLE_ASSERTIONS
cmp x1, #0
ASM_ASSERT(ne)
#endif
/* Prepend '\r' to '\n' */
cmp w0, #0xA
b.ne 2f
/* Wait until the transmit FIFO isn't full */
1: ldr w2, [x1, #MESON_STATUS_OFFSET]
tbnz w2, #MESON_STATUS_TX_FULL_BIT, 1b
/* Write '\r' if needed */
mov w2, #0xD
str w2, [x1, #MESON_WFIFO_OFFSET]
/* Wait until the transmit FIFO isn't full */
2: ldr w2, [x1, #MESON_STATUS_OFFSET]
tbnz w2, #MESON_STATUS_TX_FULL_BIT, 2b
/* Write input character */
str w0, [x1, #MESON_WFIFO_OFFSET]
ret
endfunc console_meson_core_putc
/* ---------------------------------------------
* int console_meson_getc(console_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 : x0 - pointer to console_t structure
* Out: w0 - character if available, else -1
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_meson_getc
#if ENABLE_ASSERTIONS
cmp x0, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
ldr x0, [x0, #CONSOLE_T_BASE]
b console_meson_core_getc
endfunc console_meson_getc
/* ---------------------------------------------
* int console_meson_core_getc(uintptr_t base_addr)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 if no character is available.
* In : x0 - console base address
* Out: w0 - character if available, else -1
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_meson_core_getc
#if ENABLE_ASSERTIONS
cmp x0, #0
ASM_ASSERT(ne)
#endif
/* Is the receive FIFO empty? */
ldr w1, [x0, #MESON_STATUS_OFFSET]
tbnz w1, #MESON_STATUS_RX_EMPTY_BIT, 1f
/* Read one character from the RX FIFO */
ldr w0, [x0, #MESON_RFIFO_OFFSET]
ret
1:
mov w0, #ERROR_NO_PENDING_CHAR
ret
endfunc console_meson_core_getc
/* ---------------------------------------------
* void console_meson_flush(console_t *console)
* Function to force a write of all buffered
* data that hasn't been output.
* In : x0 - pointer to console_t structure
* Out : void.
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_meson_flush
#if ENABLE_ASSERTIONS
cmp x0, #0
ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
ldr x0, [x0, #CONSOLE_T_BASE]
b console_meson_core_flush
endfunc console_meson_flush
/* ---------------------------------------------
* void console_meson_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 : void.
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_meson_core_flush
#if ENABLE_ASSERTIONS
cmp x0, #0
ASM_ASSERT(ne)
#endif
/* Wait until the transmit FIFO is empty */
1: ldr w1, [x0, #MESON_STATUS_OFFSET]
tbz w1, #MESON_STATUS_TX_EMPTY_BIT, 1b
ret
endfunc console_meson_core_flush
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