1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
4 * Scott McNutt <smcnutt@psyent.com>
5 */
6
7 #include <common.h>
8 #include <dm.h>
9 #include <errno.h>
10 #include <serial.h>
11 #include <asm/io.h>
12 #include <linux/bitops.h>
13
14 /* data register */
15 #define ALTERA_JTAG_RVALID BIT(15) /* Read valid */
16
17 /* control register */
18 #define ALTERA_JTAG_AC BIT(10) /* activity indicator */
19 #define ALTERA_JTAG_RRDY BIT(12) /* read available */
20 #define ALTERA_JTAG_WSPACE(d) ((d) >> 16) /* Write space avail */
21 /* Write fifo size. FIXME: this should be extracted with sopc2dts */
22 #define ALTERA_JTAG_WRITE_DEPTH 64
23
24 struct altera_jtaguart_regs {
25 u32 data; /* Data register */
26 u32 control; /* Control register */
27 };
28
29 struct altera_jtaguart_plat {
30 struct altera_jtaguart_regs *regs;
31 };
32
altera_jtaguart_setbrg(struct udevice * dev,int baudrate)33 static int altera_jtaguart_setbrg(struct udevice *dev, int baudrate)
34 {
35 return 0;
36 }
37
altera_jtaguart_putc(struct udevice * dev,const char ch)38 static int altera_jtaguart_putc(struct udevice *dev, const char ch)
39 {
40 struct altera_jtaguart_plat *plat = dev_get_plat(dev);
41 struct altera_jtaguart_regs *const regs = plat->regs;
42 u32 st = readl(®s->control);
43
44 #ifdef CONFIG_ALTERA_JTAG_UART_BYPASS
45 if (!(st & ALTERA_JTAG_AC)) /* no connection yet */
46 return -ENETUNREACH;
47 #endif
48
49 if (ALTERA_JTAG_WSPACE(st) == 0)
50 return -EAGAIN;
51
52 writel(ch, ®s->data);
53
54 return 0;
55 }
56
altera_jtaguart_pending(struct udevice * dev,bool input)57 static int altera_jtaguart_pending(struct udevice *dev, bool input)
58 {
59 struct altera_jtaguart_plat *plat = dev_get_plat(dev);
60 struct altera_jtaguart_regs *const regs = plat->regs;
61 u32 st = readl(®s->control);
62
63 if (input)
64 return st & ALTERA_JTAG_RRDY ? 1 : 0;
65 else
66 return !(ALTERA_JTAG_WSPACE(st) == ALTERA_JTAG_WRITE_DEPTH);
67 }
68
altera_jtaguart_getc(struct udevice * dev)69 static int altera_jtaguart_getc(struct udevice *dev)
70 {
71 struct altera_jtaguart_plat *plat = dev_get_plat(dev);
72 struct altera_jtaguart_regs *const regs = plat->regs;
73 u32 val;
74
75 val = readl(®s->data);
76
77 if (!(val & ALTERA_JTAG_RVALID))
78 return -EAGAIN;
79
80 return val & 0xff;
81 }
82
altera_jtaguart_probe(struct udevice * dev)83 static int altera_jtaguart_probe(struct udevice *dev)
84 {
85 #ifdef CONFIG_ALTERA_JTAG_UART_BYPASS
86 struct altera_jtaguart_plat *plat = dev_get_plat(dev);
87 struct altera_jtaguart_regs *const regs = plat->regs;
88
89 writel(ALTERA_JTAG_AC, ®s->control); /* clear AC flag */
90 #endif
91 return 0;
92 }
93
altera_jtaguart_of_to_plat(struct udevice * dev)94 static int altera_jtaguart_of_to_plat(struct udevice *dev)
95 {
96 struct altera_jtaguart_plat *plat = dev_get_plat(dev);
97
98 plat->regs = map_physmem(dev_read_addr(dev),
99 sizeof(struct altera_jtaguart_regs),
100 MAP_NOCACHE);
101
102 return 0;
103 }
104
105 static const struct dm_serial_ops altera_jtaguart_ops = {
106 .putc = altera_jtaguart_putc,
107 .pending = altera_jtaguart_pending,
108 .getc = altera_jtaguart_getc,
109 .setbrg = altera_jtaguart_setbrg,
110 };
111
112 static const struct udevice_id altera_jtaguart_ids[] = {
113 { .compatible = "altr,juart-1.0" },
114 {}
115 };
116
117 U_BOOT_DRIVER(altera_jtaguart) = {
118 .name = "altera_jtaguart",
119 .id = UCLASS_SERIAL,
120 .of_match = altera_jtaguart_ids,
121 .of_to_plat = altera_jtaguart_of_to_plat,
122 .plat_auto = sizeof(struct altera_jtaguart_plat),
123 .probe = altera_jtaguart_probe,
124 .ops = &altera_jtaguart_ops,
125 };
126
127 #ifdef CONFIG_DEBUG_UART_ALTERA_JTAGUART
128
129 #include <debug_uart.h>
130
_debug_uart_init(void)131 static inline void _debug_uart_init(void)
132 {
133 }
134
_debug_uart_putc(int ch)135 static inline void _debug_uart_putc(int ch)
136 {
137 struct altera_jtaguart_regs *regs = (void *)CONFIG_DEBUG_UART_BASE;
138
139 while (1) {
140 u32 st = readl(®s->control);
141
142 if (ALTERA_JTAG_WSPACE(st))
143 break;
144 }
145
146 writel(ch, ®s->data);
147 }
148
149 DEBUG_UART_FUNCS
150
151 #endif
152