xref: /openbmc/qemu/hw/char/omap_uart.c (revision 59a3a1c0)
1 /*
2  * TI OMAP processors UART emulation.
3  *
4  * Copyright (C) 2006-2008 Andrzej Zaborowski  <balrog@zabor.org>
5  * Copyright (C) 2007-2009 Nokia Corporation
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 or
10  * (at your option) version 3 of the License.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with this program; if not, see <http://www.gnu.org/licenses/>.
19  */
20 #include "qemu/osdep.h"
21 #include "chardev/char.h"
22 #include "hw/arm/omap.h"
23 #include "hw/char/serial.h"
24 #include "exec/address-spaces.h"
25 
26 /* UARTs */
27 struct omap_uart_s {
28     MemoryRegion iomem;
29     hwaddr base;
30     SerialState *serial; /* TODO */
31     struct omap_target_agent_s *ta;
32     omap_clk fclk;
33     qemu_irq irq;
34 
35     uint8_t eblr;
36     uint8_t syscontrol;
37     uint8_t wkup;
38     uint8_t cfps;
39     uint8_t mdr[2];
40     uint8_t scr;
41     uint8_t clksel;
42 };
43 
44 void omap_uart_reset(struct omap_uart_s *s)
45 {
46     s->eblr = 0x00;
47     s->syscontrol = 0;
48     s->wkup = 0x3f;
49     s->cfps = 0x69;
50     s->clksel = 0;
51 }
52 
53 struct omap_uart_s *omap_uart_init(hwaddr base,
54                 qemu_irq irq, omap_clk fclk, omap_clk iclk,
55                 qemu_irq txdma, qemu_irq rxdma,
56                 const char *label, Chardev *chr)
57 {
58     struct omap_uart_s *s = g_new0(struct omap_uart_s, 1);
59 
60     s->base = base;
61     s->fclk = fclk;
62     s->irq = irq;
63     s->serial = serial_mm_init(get_system_memory(), base, 2, irq,
64                                omap_clk_getrate(fclk)/16,
65                                chr ?: qemu_chr_new(label, "null", NULL),
66                                DEVICE_NATIVE_ENDIAN);
67     return s;
68 }
69 
70 static uint64_t omap_uart_read(void *opaque, hwaddr addr,
71                                unsigned size)
72 {
73     struct omap_uart_s *s = (struct omap_uart_s *) opaque;
74 
75     if (size == 4) {
76         return omap_badwidth_read8(opaque, addr);
77     }
78 
79     switch (addr) {
80     case 0x20:	/* MDR1 */
81         return s->mdr[0];
82     case 0x24:	/* MDR2 */
83         return s->mdr[1];
84     case 0x40:	/* SCR */
85         return s->scr;
86     case 0x44:	/* SSR */
87         return 0x0;
88     case 0x48:	/* EBLR (OMAP2) */
89         return s->eblr;
90     case 0x4C:	/* OSC_12M_SEL (OMAP1) */
91         return s->clksel;
92     case 0x50:	/* MVR */
93         return 0x30;
94     case 0x54:	/* SYSC (OMAP2) */
95         return s->syscontrol;
96     case 0x58:	/* SYSS (OMAP2) */
97         return 1;
98     case 0x5c:	/* WER (OMAP2) */
99         return s->wkup;
100     case 0x60:	/* CFPS (OMAP2) */
101         return s->cfps;
102     }
103 
104     OMAP_BAD_REG(addr);
105     return 0;
106 }
107 
108 static void omap_uart_write(void *opaque, hwaddr addr,
109                             uint64_t value, unsigned size)
110 {
111     struct omap_uart_s *s = (struct omap_uart_s *) opaque;
112 
113     if (size == 4) {
114         omap_badwidth_write8(opaque, addr, value);
115         return;
116     }
117 
118     switch (addr) {
119     case 0x20:	/* MDR1 */
120         s->mdr[0] = value & 0x7f;
121         break;
122     case 0x24:	/* MDR2 */
123         s->mdr[1] = value & 0xff;
124         break;
125     case 0x40:	/* SCR */
126         s->scr = value & 0xff;
127         break;
128     case 0x48:	/* EBLR (OMAP2) */
129         s->eblr = value & 0xff;
130         break;
131     case 0x4C:	/* OSC_12M_SEL (OMAP1) */
132         s->clksel = value & 1;
133         break;
134     case 0x44:	/* SSR */
135     case 0x50:	/* MVR */
136     case 0x58:	/* SYSS (OMAP2) */
137         OMAP_RO_REG(addr);
138         break;
139     case 0x54:	/* SYSC (OMAP2) */
140         s->syscontrol = value & 0x1d;
141         if (value & 2)
142             omap_uart_reset(s);
143         break;
144     case 0x5c:	/* WER (OMAP2) */
145         s->wkup = value & 0x7f;
146         break;
147     case 0x60:	/* CFPS (OMAP2) */
148         s->cfps = value & 0xff;
149         break;
150     default:
151         OMAP_BAD_REG(addr);
152     }
153 }
154 
155 static const MemoryRegionOps omap_uart_ops = {
156     .read = omap_uart_read,
157     .write = omap_uart_write,
158     .endianness = DEVICE_NATIVE_ENDIAN,
159 };
160 
161 struct omap_uart_s *omap2_uart_init(MemoryRegion *sysmem,
162                 struct omap_target_agent_s *ta,
163                 qemu_irq irq, omap_clk fclk, omap_clk iclk,
164                 qemu_irq txdma, qemu_irq rxdma,
165                 const char *label, Chardev *chr)
166 {
167     hwaddr base = omap_l4_attach(ta, 0, NULL);
168     struct omap_uart_s *s = omap_uart_init(base, irq,
169                     fclk, iclk, txdma, rxdma, label, chr);
170 
171     memory_region_init_io(&s->iomem, NULL, &omap_uart_ops, s, "omap.uart", 0x100);
172 
173     s->ta = ta;
174 
175     memory_region_add_subregion(sysmem, base + 0x20, &s->iomem);
176 
177     return s;
178 }
179 
180 void omap_uart_attach(struct omap_uart_s *s, Chardev *chr)
181 {
182     /* TODO: Should reuse or destroy current s->serial */
183     s->serial = serial_mm_init(get_system_memory(), s->base, 2, s->irq,
184                                omap_clk_getrate(s->fclk) / 16,
185                                chr ?: qemu_chr_new("null", "null", NULL),
186                                DEVICE_NATIVE_ENDIAN);
187 }
188