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-rw-r--r--drivers/marvell/uart/a3700_console.S271
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/marvell/uart/a3700_console.S b/drivers/marvell/uart/a3700_console.S
new file mode 100644
index 0000000..c7eb165
--- /dev/null
+++ b/drivers/marvell/uart/a3700_console.S
@@ -0,0 +1,271 @@
+/*
+ * Copyright (C) 2016 Marvell International Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ * https://spdx.org/licenses
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <console_macros.S>
+#include <drivers/marvell/uart/a3700_console.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_a3700_core_putc
+ .globl console_a3700_core_init
+ .globl console_a3700_core_getc
+ .globl console_a3700_core_flush
+
+ .globl console_a3700_putc
+ .globl console_a3700_getc
+ .globl console_a3700_flush
+
+ /* -----------------------------------------------
+ * int console_a3700_core_init(unsigned long 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
+ * Clobber list : x1, x2, x3, x4
+ * -----------------------------------------------
+ */
+func console_a3700_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
+
+ /*
+ * Wait for the TX (THR and TSR) to be empty. If wait for 3ms, the TX FIFO is
+ * still not empty, TX FIFO will reset by all means.
+ */
+ mov w4, #30 /* max time out 30 * 100 us */
+2:
+ /* Check whether TX (THR and TSR) is empty */
+ ldr w3, [x0, #UART_STATUS_REG]
+ and w3, w3, #UARTLSR_TXEMPTY
+ cmp w3, #0
+ b.ne 4f
+
+ /* Delay */
+ mov w3, #60000 /* 60000 cycles of below 3 instructions on 1200 MHz CPU ~~ 100 us */
+3:
+ sub w3, w3, #1
+ cmp w3, #0
+ b.ne 3b
+
+ /* Check whether wait timeout expired */
+ sub w4, w4, #1
+ cmp w4, #0
+ b.ne 2b
+
+4:
+ /* Reset UART via North Bridge Peripheral */
+ mov_imm x4, MVEBU_NB_RESET_REG
+ ldr w3, [x4]
+ bic w3, w3, #MVEBU_NB_RESET_UART_N
+ str w3, [x4]
+ orr w3, w3, #MVEBU_NB_RESET_UART_N
+ str w3, [x4]
+
+ /* Reset FIFO */
+ mov w3, #UART_CTRL_RXFIFO_RESET
+ orr w3, w3, #UART_CTRL_TXFIFO_RESET
+ str w3, [x0, #UART_CTRL_REG]
+
+ /* Delay */
+ mov w3, #2000
+1:
+ sub w3, w3, #1
+ cmp w3, #0
+ b.ne 1b
+
+ /* Program the baudrate */
+ /* Divisor = Round(Uartclock / (16 * baudrate)) */
+ lsl w2, w2, #4
+ add w1, w1, w2, lsr #1
+ udiv w2, w1, w2
+ and w2, w2, #0x3ff /* clear all other bits to use default clock */
+
+ str w2, [x0, #UART_BAUD_REG]/* set baud rate divisor */
+
+ /* Set UART to default 16X scheme */
+ mov w3, #0
+ str w3, [x0, #UART_POSSR_REG]
+
+ /* No Parity, 1 Stop */
+ mov w3, #0
+ str w3, [x0, #UART_CTRL_REG]
+
+ mov w0, #1
+ ret
+init_fail:
+ mov w0, #0
+ ret
+endfunc console_a3700_core_init
+
+ .globl console_a3700_register
+
+ /* -----------------------------------------------
+ * int console_a3700_register(console_t *console,
+ uintptr_t base, uint32_t clk, uint32_t baud)
+ * Function to initialize and register a new a3700
+ * 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, x3, x4, x6, x7, x14
+ * -----------------------------------------------
+ */
+func console_a3700_register
+ mov x7, x30
+ mov x6, x3
+ cbz x6, register_fail
+ str x0, [x6, #CONSOLE_T_BASE]
+
+ bl console_a3700_core_init
+ cbz x0, register_fail
+
+ mov x0, x6
+ mov x30, x7
+ finish_console_register a3700, putc=1, getc=1, flush=1
+
+register_fail:
+ ret x7
+endfunc console_a3700_register
+
+ /* --------------------------------------------------------
+ * int console_a3700_core_putc(int c, unsigned int 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_a3700_core_putc
+ /* Check the input parameter */
+ cbz x1, putc_error
+
+ /* Prepend '\r' to '\n' */
+ cmp w0, #0xA
+ b.ne 2f
+ /* Check if the transmit FIFO is full */
+1: ldr w2, [x1, #UART_STATUS_REG]
+ and w2, w2, #UARTLSR_TXFIFOFULL
+ cmp w2, #UARTLSR_TXFIFOFULL
+ b.eq 1b
+ mov w2, #0xD /* '\r' */
+ str w2, [x1, #UART_TX_REG]
+
+ /* Check if the transmit FIFO is full */
+2: ldr w2, [x1, #UART_STATUS_REG]
+ and w2, w2, #UARTLSR_TXFIFOFULL
+ cmp w2, #UARTLSR_TXFIFOFULL
+ b.eq 2b
+ str w0, [x1, #UART_TX_REG]
+ ret
+putc_error:
+ mov w0, #-1
+ ret
+endfunc console_a3700_core_putc
+
+ /* --------------------------------------------------------
+ * int console_a3700_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_a3700_putc
+ ldr x1, [x1, #CONSOLE_T_BASE]
+ b console_a3700_core_putc
+endfunc console_a3700_putc
+
+ /* ---------------------------------------------
+ * int console_a3700_core_getc(void)
+ * Function to get a character from the console.
+ * It returns the character grabbed on success
+ * or -1 if no character is available.
+ * In : w0 - console base address
+ * Out : w0 - character if available, else -1
+ * Clobber list : x0, x1
+ * ---------------------------------------------
+ */
+func console_a3700_core_getc
+ /* Check if there is a pending character */
+ ldr w1, [x0, #UART_STATUS_REG]
+ and w1, w1, #UARTLSR_RXRDY
+ cmp w1, #UARTLSR_RXRDY
+ b.ne getc_no_char
+ ldr w0, [x0, #UART_RX_REG]
+ and w0, w0, #0xff
+ ret
+getc_no_char:
+ mov w0, #ERROR_NO_PENDING_CHAR
+ ret
+endfunc console_a3700_core_getc
+
+ /* ---------------------------------------------
+ * int console_a3700_getc(console_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_a3700_getc
+ ldr x0, [x0, #CONSOLE_T_BASE]
+ b console_a3700_core_getc
+endfunc console_a3700_getc
+
+ /* ---------------------------------------------
+ * void console_a3700_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_a3700_core_flush
+ /* Wait for the TX (THR and TSR) to be empty */
+1: ldr w1, [x0, #UART_STATUS_REG]
+ and w1, w1, #UARTLSR_TXEMPTY
+ cmp w1, #UARTLSR_TXEMPTY
+ b.ne 1b
+ ret
+endfunc console_a3700_core_flush
+
+ /* ---------------------------------------------
+ * void console_a3700_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_a3700_flush
+ ldr x0, [x0, #CONSOLE_T_BASE]
+ b console_a3700_core_flush
+endfunc console_a3700_flush
+