xref: /optee_os/core/drivers/scif.c (revision 0abbda6e29d25e36cc30c373503ee56ab2d22655)
1 /*
2  * Copyright (c) 2016, GlobalLogic
3  * Copyright (c) 2017, Linaro Limited
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright notice,
10  * this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright notice,
13  * this list of conditions and the following disclaimer in the documentation
14  * and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 #include <drivers/scif.h>
29 #include <io.h>
30 #include <util.h>
31 
32 #define SCIF_SCFSR		(0x10)
33 #define SCIF_SCFTDR		(0x0C)
34 #define SCIF_SCFCR		(0x18)
35 #define SCIF_SCFDR		(0x1C)
36 
37 #define SCFSR_TDFE		BIT(5)
38 #define SCFSR_TEND		BIT(6)
39 
40 #define SCFDR_T_SHIFT		8
41 
42 #define SCIF_TX_FIFO_SIZE	16
43 
44 static vaddr_t chip_to_base(struct serial_chip *chip)
45 {
46 	struct scif_uart_data *pd =
47 		container_of(chip, struct scif_uart_data, chip);
48 
49 	return io_pa_or_va(&pd->base);
50 }
51 
52 static void scif_uart_flush(struct serial_chip *chip)
53 {
54 	vaddr_t base = chip_to_base(chip);
55 
56 	while (!(read16(base + SCIF_SCFSR) & SCFSR_TEND))
57 		;
58 }
59 
60 static void scif_uart_putc(struct serial_chip *chip, int ch)
61 {
62 	vaddr_t base = chip_to_base(chip);
63 
64 	/* Wait until there is space in the FIFO */
65 	while ((read16(base + SCIF_SCFDR) >> SCFDR_T_SHIFT) >=
66 		SCIF_TX_FIFO_SIZE)
67 		;
68 	write8(ch, base + SCIF_SCFTDR);
69 	write16(read16(base + SCIF_SCFSR) & ~(SCFSR_TEND | SCFSR_TDFE),
70 		base + SCIF_SCFSR);
71 }
72 
73 static const struct serial_ops scif_uart_ops = {
74 	.flush = scif_uart_flush,
75 	.putc = scif_uart_putc,
76 };
77 
78 void scif_uart_init(struct scif_uart_data *pd, vaddr_t base)
79 {
80 	pd->base.pa = base;
81 	pd->chip.ops = &scif_uart_ops;
82 
83 	/* Bootloader should initialize device for us */
84 	scif_uart_flush(&pd->chip);
85 }
86