]>
Commit | Line | Data |
---|---|---|
1 | /* | |
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> | |
11 | #include <dm.h> | |
12 | #include <serial.h> | |
13 | ||
14 | DECLARE_GLOBAL_DATA_PTR; | |
15 | ||
16 | struct 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 | ||
27 | ||
28 | struct arc_serial_platdata { | |
29 | struct arc_serial_regs *reg; | |
30 | unsigned int uartclk; | |
31 | }; | |
32 | ||
33 | /* 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 | ||
38 | static int arc_serial_setbrg(struct udevice *dev, int baudrate) | |
39 | { | |
40 | 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; | |
43 | ||
44 | writeb(arc_console_baud & 0xff, ®s->baudl); | |
45 | ||
46 | #ifdef CONFIG_ARC | |
47 | /* | |
48 | * UART ISS(Instruction Set simulator) emulation has a subtle bug: | |
49 | * A existing value of Baudh = 0 is used as a indication to startup | |
50 | * it's internal state machine. | |
51 | * Thus if baudh is set to 0, 2 times, it chokes. | |
52 | * This happens with BAUD=115200 and the formaula above | |
53 | * Until that is fixed, when running on ISS, we will set baudh to !0 | |
54 | */ | |
55 | if (gd->arch.running_on_hw) | |
56 | writeb((arc_console_baud & 0xff00) >> 8, ®s->baudh); | |
57 | else | |
58 | writeb(1, ®s->baudh); | |
59 | #else | |
60 | writeb((arc_console_baud & 0xff00) >> 8, ®s->baudh); | |
61 | #endif | |
62 | ||
63 | return 0; | |
64 | } | |
65 | ||
66 | static int arc_serial_putc(struct udevice *dev, const char c) | |
67 | { | |
68 | struct arc_serial_platdata *plat = dev->platdata; | |
69 | struct arc_serial_regs *const regs = plat->reg; | |
70 | ||
71 | if (c == '\n') | |
72 | arc_serial_putc(dev, '\r'); | |
73 | ||
74 | while (!(readb(®s->status) & UART_TXEMPTY)) | |
75 | ; | |
76 | ||
77 | writeb(c, ®s->data); | |
78 | ||
79 | return 0; | |
80 | } | |
81 | ||
82 | static int arc_serial_tstc(struct arc_serial_regs *const regs) | |
83 | { | |
84 | return !(readb(®s->status) & UART_RXEMPTY); | |
85 | } | |
86 | ||
87 | static int arc_serial_pending(struct udevice *dev, bool input) | |
88 | { | |
89 | struct arc_serial_platdata *plat = dev->platdata; | |
90 | struct arc_serial_regs *const regs = plat->reg; | |
91 | uint32_t status = readb(®s->status); | |
92 | ||
93 | if (input) | |
94 | return status & UART_RXEMPTY ? 0 : 1; | |
95 | else | |
96 | return status & UART_TXEMPTY ? 0 : 1; | |
97 | } | |
98 | ||
99 | static int arc_serial_getc(struct udevice *dev) | |
100 | { | |
101 | struct arc_serial_platdata *plat = dev->platdata; | |
102 | struct arc_serial_regs *const regs = plat->reg; | |
103 | ||
104 | while (!arc_serial_tstc(regs)) | |
105 | ; | |
106 | ||
107 | /* Check for overflow errors */ | |
108 | if (readb(®s->status) & UART_OVERFLOW_ERR) | |
109 | return 0; | |
110 | ||
111 | return readb(®s->data) & 0xFF; | |
112 | } | |
113 | ||
114 | static int arc_serial_probe(struct udevice *dev) | |
115 | { | |
116 | return 0; | |
117 | } | |
118 | ||
119 | static const struct dm_serial_ops arc_serial_ops = { | |
120 | .putc = arc_serial_putc, | |
121 | .pending = arc_serial_pending, | |
122 | .getc = arc_serial_getc, | |
123 | .setbrg = arc_serial_setbrg, | |
124 | }; | |
125 | ||
126 | static const struct udevice_id arc_serial_ids[] = { | |
127 | { .compatible = "snps,arc-uart" }, | |
128 | { } | |
129 | }; | |
130 | ||
131 | static int arc_serial_ofdata_to_platdata(struct udevice *dev) | |
132 | { | |
133 | struct arc_serial_platdata *plat = dev_get_platdata(dev); | |
134 | DECLARE_GLOBAL_DATA_PTR; | |
135 | ||
136 | plat->reg = (struct arc_serial_regs *)fdtdec_get_addr(gd->fdt_blob, | |
137 | dev->of_offset, "reg"); | |
138 | plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset, | |
139 | "clock-frequency", 0); | |
140 | ||
141 | return 0; | |
142 | } | |
143 | ||
144 | U_BOOT_DRIVER(serial_arc) = { | |
145 | .name = "serial_arc", | |
146 | .id = UCLASS_SERIAL, | |
147 | .of_match = arc_serial_ids, | |
148 | .ofdata_to_platdata = arc_serial_ofdata_to_platdata, | |
149 | .probe = arc_serial_probe, | |
150 | .ops = &arc_serial_ops, | |
151 | .flags = DM_FLAG_PRE_RELOC, | |
152 | }; |