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+/*
+ * Copyright (c) 2014, STMicroelectronics International N.V.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <platform_config.h>
+#include <asm.S>
+#include <kernel/unwind.h>
+
+#define ASC_BAUDRATE 0x00
+#define ASC_TXBUFFER 0x04
+#define ASC_RXBUFFER 0x08
+#define ASC_CONTROL 0x0c
+#define ASC_INTENABLE 0x10
+#define ASC_STATUS 0x14
+#define ASC_GUARDTIME 0x18
+#define ASC_TIMEOUT 0x1c
+#define ASC_TXRESET 0x20
+#define ASC_RXRESET 0x24
+#define ASC_RETRIES 0x28
+
+.section .text.asc
+
+
+/*
+ * void __asc_flush(vaddr_t base)
+ *
+ * Clobbers r0-r3
+ */
+FUNC __asc_flush , :
+UNWIND( .fnstart)
+
+ ADD r3, r0, #ASC_STATUS
+
+flush_wait:
+ LDR r1, [r3]
+ ANDS r1, r1, #0x02 /* AND TX FIFO EMPTY flag */
+ BEQ flush_wait /* ANDS should have set Z bit if zero */
+
+ LDR r0, =0
+ BX lr
+UNWIND( .fnend)
+END_FUNC __asc_flush
+
+/*
+ * int __asc_xmit_char(char p, vaddr_t base) - Transmit a single character.
+ *
+ * R0 is the 1-byte character to be transmited
+ * R1 is the base address of the uart
+ * Clobbers r0-r3
+ */
+FUNC __asc_xmit_char , :
+UNWIND( .fnstart)
+
+ ADD r2, r1, #ASC_TXBUFFER
+ ADD r3, r1, #ASC_STATUS
+
+ /* Output byte */
+
+ /* Spin until TX FIFO ready */
+__asc_char_crwait:
+ LDR r1, [r3]
+ ANDS r1, r1, #0x04 /* AND TX FIFO HALF EMPTY flag */
+ BEQ __asc_char_crwait /* ANDS should have set Z bit if zero */
+
+ MOVS r1, r0
+ LDR r0, =0xFF
+ AND r1, r1, r0
+ BEQ __asc_char_exit
+ CMP r1, #0xa /* r1 == \n (line feed) ? */
+ BNE __asc_char_notlf
+
+ /* Transmit character extra carriage return for each line feed */
+ LDR r1, =0x0d
+ STR r1, [r2]
+
+ LDR r1, =0x0a /* replace line feed */
+
+__asc_char_notlf:
+ /* Transmit character */
+ STR r1, [r2]
+
+__asc_char_exit:
+ LDR r0, =0
+ BX lr
+UNWIND( .fnend)
+END_FUNC __asc_xmit_char