1 files changed, 164 insertions, 0 deletions
diff --git a/plat/mediatek/common/drivers/uart/8250_console.S b/plat/mediatek/common/drivers/uart/8250_console.S
new file mode 100644
index 00000000..94a6c02a
--- /dev/null
+++ b/plat/mediatek/common/drivers/uart/8250_console.S
@@ -0,0 +1,164 @@
+/*
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <asm_macros.S>
+#include <uart8250.h>
+
+	.globl	console_core_init
+	.globl	console_core_putc
+	.globl	console_core_getc
+	.globl	console_core_flush
+
+	/* -----------------------------------------------
+	 * int console_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 else 0 on error
+	 * Clobber list : x1, x2, x3
+	 * -----------------------------------------------
+	 */
+func console_core_init
+	/* Check the input base address */
+	cbz	x0, core_init_fail
+	/* Check baud rate and uart clock for sanity */
+	cbz	w1, core_init_fail
+	cbz	w2, core_init_fail
+
+	/* Disable interrupt */
+	str	wzr, [x0, #UART_IER]
+
+	/* Force DTR and RTS to high */
+	mov	w3, #(UART_MCR_DTR | UART_MCR_RTS)
+	str	w3, [x0, #UART_MCR]
+
+	/* Check high speed */
+	movz	w3, #:abs_g1:115200
+	movk	w3, #:abs_g0_nc:115200
+	cmp	w2, w3
+	b.hi	1f
+
+	/* Non high speed */
+	lsl	w2, w2, #4
+	mov	w3, wzr
+	b	2f
+
+	/* High speed */
+1:	lsl	w2, w2, #2
+	mov	w3, #2
+
+	/* Set high speed UART register */
+2:	str	w3, [x0, #UART_HIGHSPEED]
+
+	/* Calculate divisor */
+	udiv	w3, w1, w2	/* divisor = uartclk / (quot * baudrate) */
+	msub	w1, w3, w2, w1	/* remainder = uartclk % (quot * baudrate) */
+	lsr	w2, w2, #1
+	cmp	w1, w2
+	cinc	w3, w3, hs
+
+	/* Set line configuration, access divisor latches */
+	mov	w1, #(UART_LCR_DLAB | UART_LCR_WLS_8)
+	str	w1, [x0, #UART_LCR]
+
+	/* Set the divisor */
+	and	w1, w3, #0xff
+	str	w1, [x0, #UART_DLL]
+	lsr	w1, w3, #8
+	and	w1, w1, #0xff
+	str	w1, [x0, #UART_DLH]
+
+	/* Hide the divisor latches */
+	mov	w1, #UART_LCR_WLS_8
+	str	w1, [x0, #UART_LCR]
+
+	/* Enable FIFOs, and clear receive and transmit */
+	mov	w1, #(UART_FCR_FIFO_EN | UART_FCR_CLEAR_RCVR |	\
+			UART_FCR_CLEAR_XMIT)
+	str	w1, [x0, #UART_FCR]
+
+	mov	w0, #1
+	ret
+core_init_fail:
+	mov	w0, wzr
+	ret
+endfunc console_core_init
+
+	/* --------------------------------------------------------
+	 * int console_core_putc(int c, unsigned long 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_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_LSR]
+	and	w2, w2, #UART_LSR_THRE
+	cbz	w2, 1b
+	mov	w2, #0xD
+	str	w2, [x1, #UART_THR]
+
+	/* Check if the transmit FIFO is full */
+2:	ldr	w2, [x1, #UART_LSR]
+	and	w2, w2, #UART_LSR_THRE
+	cbz	w2, 2b
+	str	w0, [x1, #UART_THR]
+	ret
+putc_error:
+	mov	w0, #-1
+	ret
+endfunc console_core_putc
+
+	/* ---------------------------------------------
+	 * int console_core_getc(unsigned long base_addr)
+	 * Function to get a character from the console.
+	 * It returns the character grabbed on success
+	 * or -1 on error.
+	 * In : x0 - console base address
+	 * Clobber list : x0, x1
+	 * ---------------------------------------------
+	 */
+func console_core_getc
+	cbz	x0, getc_error
+
+	/* Check if the receive FIFO is empty */
+1:	ldr	w1, [x0, #UART_LSR]
+	tbz	w1, #UART_LSR_DR, 1b
+	ldr	w0, [x0, #UART_RBR]
+	ret
+getc_error:
+	mov	w0, #-1
+	ret
+endfunc console_core_getc
+
+	/* ---------------------------------------------
+	 * int console_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 : return -1 on error else return 0.
+	 * Clobber list : x0, x1
+	 * ---------------------------------------------
+	 */
+func console_core_flush
+	/* Placeholder */
+	mov	w0, #0
+	ret
+endfunc console_core_flush