xref: /openbmc/qemu/hw/char/omap_uart.c (revision dccfcd0e)
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 "sysemu/char.h"
21 #include "hw/hw.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, CharDriverState *chr)
57 {
58     struct omap_uart_s *s = (struct omap_uart_s *)
59             g_malloc0(sizeof(struct omap_uart_s));
60 
61     s->base = base;
62     s->fclk = fclk;
63     s->irq = irq;
64     s->serial = serial_mm_init(get_system_memory(), base, 2, irq,
65                                omap_clk_getrate(fclk)/16,
66                                chr ?: qemu_chr_new(label, "null", NULL),
67                                DEVICE_NATIVE_ENDIAN);
68     return s;
69 }
70 
71 static uint64_t omap_uart_read(void *opaque, hwaddr addr,
72                                unsigned size)
73 {
74     struct omap_uart_s *s = (struct omap_uart_s *) opaque;
75 
76     if (size == 4) {
77         return omap_badwidth_read8(opaque, addr);
78     }
79 
80     switch (addr) {
81     case 0x20:	/* MDR1 */
82         return s->mdr[0];
83     case 0x24:	/* MDR2 */
84         return s->mdr[1];
85     case 0x40:	/* SCR */
86         return s->scr;
87     case 0x44:	/* SSR */
88         return 0x0;
89     case 0x48:	/* EBLR (OMAP2) */
90         return s->eblr;
91     case 0x4C:	/* OSC_12M_SEL (OMAP1) */
92         return s->clksel;
93     case 0x50:	/* MVR */
94         return 0x30;
95     case 0x54:	/* SYSC (OMAP2) */
96         return s->syscontrol;
97     case 0x58:	/* SYSS (OMAP2) */
98         return 1;
99     case 0x5c:	/* WER (OMAP2) */
100         return s->wkup;
101     case 0x60:	/* CFPS (OMAP2) */
102         return s->cfps;
103     }
104 
105     OMAP_BAD_REG(addr);
106     return 0;
107 }
108 
109 static void omap_uart_write(void *opaque, hwaddr addr,
110                             uint64_t value, unsigned size)
111 {
112     struct omap_uart_s *s = (struct omap_uart_s *) opaque;
113 
114     if (size == 4) {
115         return omap_badwidth_write8(opaque, addr, value);
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, CharDriverState *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, &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, CharDriverState *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