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Alexey Brodkin22a240c2013-12-13 10:35:11 +04001/*
2 * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 */
9
10#include <common.h>
Alexey Brodkin01496c42015-03-17 14:55:14 +030011#include <dm.h>
Alexey Brodkin22a240c2013-12-13 10:35:11 +040012#include <serial.h>
13
14DECLARE_GLOBAL_DATA_PTR;
15
16struct arc_serial_regs {
17 unsigned int id0;
18 unsigned int id1;
19 unsigned int id2;
20 unsigned int id3;
21 unsigned int data;
22 unsigned int status;
23 unsigned int baudl;
24 unsigned int baudh;
25};
26
Alexey Brodkin01496c42015-03-17 14:55:14 +030027
28struct arc_serial_platdata {
29 struct arc_serial_regs *reg;
30 unsigned int uartclk;
31};
32
Alexey Brodkin22a240c2013-12-13 10:35:11 +040033/* Bit definitions of STATUS register */
34#define UART_RXEMPTY (1 << 5)
35#define UART_OVERFLOW_ERR (1 << 1)
36#define UART_TXEMPTY (1 << 7)
37
Alexey Brodkin01496c42015-03-17 14:55:14 +030038static int arc_serial_setbrg(struct udevice *dev, int baudrate)
Alexey Brodkin22a240c2013-12-13 10:35:11 +040039{
Alexey Brodkin01496c42015-03-17 14:55:14 +030040 struct arc_serial_platdata *plat = dev->platdata;
41 struct arc_serial_regs *const regs = plat->reg;
42 int arc_console_baud = gd->cpu_clk / (baudrate * 4) - 1;
Alexey Brodkin22a240c2013-12-13 10:35:11 +040043
Alexey Brodkin94b54002014-02-08 10:10:02 +040044 writeb(arc_console_baud & 0xff, &regs->baudl);
Alexey Brodkin94b54002014-02-08 10:10:02 +040045 writeb((arc_console_baud & 0xff00) >> 8, &regs->baudh);
Alexey Brodkin22a240c2013-12-13 10:35:11 +040046
Alexey Brodkin22a240c2013-12-13 10:35:11 +040047 return 0;
48}
49
Alexey Brodkin01496c42015-03-17 14:55:14 +030050static int arc_serial_putc(struct udevice *dev, const char c)
Alexey Brodkin22a240c2013-12-13 10:35:11 +040051{
Alexey Brodkin01496c42015-03-17 14:55:14 +030052 struct arc_serial_platdata *plat = dev->platdata;
53 struct arc_serial_regs *const regs = plat->reg;
54
Alexey Brodkin94b54002014-02-08 10:10:02 +040055 while (!(readb(&regs->status) & UART_TXEMPTY))
Alexey Brodkin22a240c2013-12-13 10:35:11 +040056 ;
57
Alexey Brodkin94b54002014-02-08 10:10:02 +040058 writeb(c, &regs->data);
Alexey Brodkin01496c42015-03-17 14:55:14 +030059
60 return 0;
Alexey Brodkin22a240c2013-12-13 10:35:11 +040061}
62
Alexey Brodkin01496c42015-03-17 14:55:14 +030063static int arc_serial_tstc(struct arc_serial_regs *const regs)
Alexey Brodkin22a240c2013-12-13 10:35:11 +040064{
Alexey Brodkin94b54002014-02-08 10:10:02 +040065 return !(readb(&regs->status) & UART_RXEMPTY);
Alexey Brodkin22a240c2013-12-13 10:35:11 +040066}
67
Alexey Brodkin01496c42015-03-17 14:55:14 +030068static int arc_serial_pending(struct udevice *dev, bool input)
Alexey Brodkin22a240c2013-12-13 10:35:11 +040069{
Alexey Brodkin01496c42015-03-17 14:55:14 +030070 struct arc_serial_platdata *plat = dev->platdata;
71 struct arc_serial_regs *const regs = plat->reg;
72 uint32_t status = readb(&regs->status);
73
74 if (input)
75 return status & UART_RXEMPTY ? 0 : 1;
76 else
77 return status & UART_TXEMPTY ? 0 : 1;
78}
79
80static int arc_serial_getc(struct udevice *dev)
81{
82 struct arc_serial_platdata *plat = dev->platdata;
83 struct arc_serial_regs *const regs = plat->reg;
84
85 while (!arc_serial_tstc(regs))
Alexey Brodkin22a240c2013-12-13 10:35:11 +040086 ;
87
88 /* Check for overflow errors */
Alexey Brodkin94b54002014-02-08 10:10:02 +040089 if (readb(&regs->status) & UART_OVERFLOW_ERR)
Alexey Brodkin22a240c2013-12-13 10:35:11 +040090 return 0;
91
Alexey Brodkin94b54002014-02-08 10:10:02 +040092 return readb(&regs->data) & 0xFF;
Alexey Brodkin22a240c2013-12-13 10:35:11 +040093}
94
Alexey Brodkin01496c42015-03-17 14:55:14 +030095static int arc_serial_probe(struct udevice *dev)
96{
97 return 0;
98}
99
100static const struct dm_serial_ops arc_serial_ops = {
101 .putc = arc_serial_putc,
102 .pending = arc_serial_pending,
103 .getc = arc_serial_getc,
104 .setbrg = arc_serial_setbrg,
Alexey Brodkin22a240c2013-12-13 10:35:11 +0400105};
106
Alexey Brodkin01496c42015-03-17 14:55:14 +0300107static const struct udevice_id arc_serial_ids[] = {
108 { .compatible = "snps,arc-uart" },
109 { }
110};
111
112static int arc_serial_ofdata_to_platdata(struct udevice *dev)
Alexey Brodkin22a240c2013-12-13 10:35:11 +0400113{
Alexey Brodkin01496c42015-03-17 14:55:14 +0300114 struct arc_serial_platdata *plat = dev_get_platdata(dev);
115 DECLARE_GLOBAL_DATA_PTR;
116
Simon Glass4e9838c2015-08-11 08:33:29 -0600117 plat->reg = (struct arc_serial_regs *)dev_get_addr(dev);
Simon Glasse160f7d2017-01-17 16:52:55 -0700118 plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
Alexey Brodkin01496c42015-03-17 14:55:14 +0300119 "clock-frequency", 0);
120
121 return 0;
Alexey Brodkin22a240c2013-12-13 10:35:11 +0400122}
123
Alexey Brodkin01496c42015-03-17 14:55:14 +0300124U_BOOT_DRIVER(serial_arc) = {
125 .name = "serial_arc",
126 .id = UCLASS_SERIAL,
127 .of_match = arc_serial_ids,
128 .ofdata_to_platdata = arc_serial_ofdata_to_platdata,
129 .probe = arc_serial_probe,
130 .ops = &arc_serial_ops,
131 .flags = DM_FLAG_PRE_RELOC,
132};