diff options
Diffstat (limited to 'plat/nvidia/tegra/drivers/spe/shared_console.S')
| -rw-r--r-- | plat/nvidia/tegra/drivers/spe/shared_console.S | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/plat/nvidia/tegra/drivers/spe/shared_console.S b/plat/nvidia/tegra/drivers/spe/shared_console.S new file mode 100644 index 0000000..d1b18dd --- /dev/null +++ b/plat/nvidia/tegra/drivers/spe/shared_console.S @@ -0,0 +1,187 @@ +/* + * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2020, NVIDIA Corporation. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ +#include <asm_macros.S> +#include <assert_macros.S> +#include <console_macros.S> + +#define CONSOLE_NUM_BYTES_SHIFT 24 +#define CONSOLE_FLUSH_DATA_TO_PORT (1 << 26) +#define CONSOLE_RING_DOORBELL (1 << 31) +#define CONSOLE_IS_BUSY (1 << 31) +#define CONSOLE_TIMEOUT 0xC000 /* 50 ms */ + + /* + * This file contains a driver implementation to make use of the + * real console implementation provided by the SPE firmware running + * SoCs after Tegra186. + * + * This console is shared by multiple components and the SPE firmware + * finally displays everything on the UART port. + */ + + .globl console_spe_core_init + .globl console_spe_core_putc + .globl console_spe_core_getc + .globl console_spe_core_flush + .globl console_spe_putc + .globl console_spe_getc + .globl console_spe_flush + .globl console_spe_register + +.macro check_if_console_is_ready base, tmp1, tmp2, label + /* wait until spe is ready or timeout expires */ + mrs \tmp2, cntps_tval_el1 +1: ldr \tmp1, [\base] + and \tmp1, \tmp1, #CONSOLE_IS_BUSY + cbz \tmp1, 2f + mrs \tmp1, cntps_tval_el1 + sub \tmp1, \tmp2, \tmp1 + cmp \tmp1, #CONSOLE_TIMEOUT + b.lt 1b + b \label +2: +.endm + + /* ------------------------------------------------- + * int console_spe_register(uintptr_t baseaddr, + * uint32_t clock, uint32_t baud, + * console_t *console); + * Function to initialize and register a new spe + * 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_spe_register + /* Check the input base address */ + cbz x0, register_fail + + /* Dont use clock or baud rate, so ok to overwrite them */ + check_if_console_is_ready x0, x1, x2, register_fail + + cbz x3, register_fail + str x0, [x3, #CONSOLE_T_BASE] + mov x0, x3 + finish_console_register spe putc=1, getc=1, flush=1 + +register_fail: + mov w0, wzr + ret +endfunc console_spe_register + + /* -------------------------------------------------------- + * int console_spe_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, x3 + * -------------------------------------------------------- + */ +func console_spe_core_putc + /* Check the input parameter */ + cbz x1, putc_error + + /* Prepend '\r' to '\n' */ + cmp w0, #0xA + b.ne not_eol + + check_if_console_is_ready x1, x2, x3, putc_error + + /* spe is ready */ + mov w2, #0xD /* '\r' */ + and w2, w2, #0xFF + mov w3, #(CONSOLE_RING_DOORBELL | (1 << CONSOLE_NUM_BYTES_SHIFT)) + orr w2, w2, w3 + str w2, [x1] + +not_eol: + check_if_console_is_ready x1, x2, x3, putc_error + + /* spe is ready */ + mov w2, w0 + and w2, w2, #0xFF + mov w3, #(CONSOLE_RING_DOORBELL | (1 << CONSOLE_NUM_BYTES_SHIFT)) + orr w2, w2, w3 + str w2, [x1] + + ret +putc_error: + mov w0, #-1 + ret +endfunc console_spe_core_putc + + /* -------------------------------------------------------- + * int console_spe_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_spe_putc + ldr x1, [x1, #CONSOLE_T_BASE] + b console_spe_core_putc +endfunc console_spe_putc + + /* --------------------------------------------- + * int console_spe_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_spe_getc + mov w0, #-1 + ret +endfunc console_spe_getc + + /* ------------------------------------------------- + * void console_spe_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_spe_core_flush +#if ENABLE_ASSERTIONS + cmp x0, #0 + ASM_ASSERT(ne) +#endif /* ENABLE_ASSERTIONS */ + + /* flush console */ + mov w1, #(CONSOLE_RING_DOORBELL | CONSOLE_FLUSH_DATA_TO_PORT) + str w1, [x0] + ret +endfunc console_spe_core_flush + + /* --------------------------------------------- + * void console_spe_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_spe_flush + ldr x0, [x0, #CONSOLE_T_BASE] + b console_spe_core_flush +endfunc console_spe_flush |