summaryrefslogtreecommitdiffstats
path: root/drivers/cadence/uart/aarch64
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cadence/uart/aarch64')
-rw-r--r--drivers/cadence/uart/aarch64/cdns_console.S220
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/cadence/uart/aarch64/cdns_console.S b/drivers/cadence/uart/aarch64/cdns_console.S
new file mode 100644
index 0000000..4c1a80e
--- /dev/null
+++ b/drivers/cadence/uart/aarch64/cdns_console.S
@@ -0,0 +1,220 @@
+/*
+ * Copyright (c) 2016-2020, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <arch.h>
+#include <asm_macros.S>
+#include <assert_macros.S>
+#include <console_macros.S>
+#include <drivers/cadence/cdns_uart.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_cdns_core_init
+ .globl console_cdns_core_putc
+ .globl console_cdns_core_getc
+ .globl console_cdns_core_flush
+
+ .globl console_cdns_putc
+ .globl console_cdns_getc
+ .globl console_cdns_flush
+
+ /* -----------------------------------------------
+ * int console_cdns_core_init(uintptr_t base_addr)
+ * Function to initialize the console without a
+ * C Runtime to print debug information. This
+ * function will be accessed by console_init and
+ * crash reporting.
+ * We assume that the bootloader already set up
+ * the HW (baud, ...) and only enable the trans-
+ * mitter and receiver here.
+ * In: x0 - console base address
+ * Out: return 1 on success else 0 on error
+ * Clobber list : x1, x2, x3
+ * -----------------------------------------------
+ */
+func console_cdns_core_init
+ /* Check the input base address */
+ cbz x0, core_init_fail
+
+ /* RX/TX enabled & reset */
+ mov w3, #(R_UART_CR_TX_EN | R_UART_CR_RX_EN | R_UART_CR_TXRST | R_UART_CR_RXRST)
+ str w3, [x0, #R_UART_CR]
+
+ mov w0, #1
+ ret
+core_init_fail:
+ mov w0, wzr
+ ret
+endfunc console_cdns_core_init
+
+ .globl console_cdns_register
+
+ /* -----------------------------------------------
+ * int console_cdns_register(uintptr_t baseaddr,
+ * uint32_t clock, uint32_t baud,
+ * console_t *console);
+ * Function to initialize and register a new CDNS
+ * 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_cdns_register
+ mov x7, x30
+ mov x6, x3
+ cbz x6, register_fail
+ str x0, [x6, #CONSOLE_T_BASE]
+
+ bl console_cdns_core_init
+ cbz x0, register_fail
+
+ mov x0, x6
+ mov x30, x7
+ finish_console_register cdns putc=1, getc=1, flush=1
+
+register_fail:
+ ret x7
+endfunc console_cdns_register
+
+ /* --------------------------------------------------------
+ * int console_cdns_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_cdns_core_putc
+#if ENABLE_ASSERTIONS
+ cmp x1, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
+ /* Prepend '\r' to '\n' */
+ cmp w0, #0xA
+ b.ne 2f
+1:
+ /* Check if the transmit FIFO is empty */
+ ldr w2, [x1, #R_UART_SR]
+ tbz w2, #UART_SR_INTR_TEMPTY_BIT, 1b
+ mov w2, #0xD
+ str w2, [x1, #R_UART_TX]
+2:
+ /* Check if the transmit FIFO is empty */
+ ldr w2, [x1, #R_UART_SR]
+ tbz w2, #UART_SR_INTR_TEMPTY_BIT, 2b
+ str w0, [x1, #R_UART_TX]
+ ret
+endfunc console_cdns_core_putc
+
+ /* --------------------------------------------------------
+ * int console_cdns_putc(int c, console_t *cdns)
+ * 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_cdns_putc
+#if ENABLE_ASSERTIONS
+ cmp x1, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x1, [x1, #CONSOLE_T_BASE]
+ b console_cdns_core_putc
+endfunc console_cdns_putc
+
+ /* ---------------------------------------------
+ * int console_cdns_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_cdns_core_getc
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
+ /* Check if the receive FIFO is empty */
+ ldr w1, [x0, #R_UART_SR]
+ tbnz w1, #UART_SR_INTR_REMPTY_BIT, no_char
+ ldr w1, [x0, #R_UART_RX]
+ mov w0, w1
+ ret
+no_char:
+ mov w0, #ERROR_NO_PENDING_CHAR
+ ret
+endfunc console_cdns_core_getc
+
+ /* ---------------------------------------------
+ * int console_cdns_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_cdns_getc
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x0, [x0, #CONSOLE_T_BASE]
+ b console_cdns_core_getc
+endfunc console_cdns_getc
+
+ /* ---------------------------------------------
+ * void console_cdns_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_cdns_core_flush
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ /* Placeholder */
+ ret
+endfunc console_cdns_core_flush
+
+ /* ---------------------------------------------
+ * void console_cdns_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_cdns_flush
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x0, [x0, #CONSOLE_T_BASE]
+ b console_cdns_core_flush
+endfunc console_cdns_flush