xref: /openbmc/qemu/hw/char/omap_uart.c (revision fcf5ef2a)
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 "sysemu/char.h"
22 #include "hw/hw.h"
23 #include "hw/arm/omap.h"
24 #include "hw/char/serial.h"
25 #include "exec/address-spaces.h"
26 
27 /* UARTs */
28 struct omap_uart_s {
29     MemoryRegion iomem;
30     hwaddr base;
31     SerialState *serial; /* TODO */
32     struct omap_target_agent_s *ta;
33     omap_clk fclk;
34     qemu_irq irq;
35 
36     uint8_t eblr;
37     uint8_t syscontrol;
38     uint8_t wkup;
39     uint8_t cfps;
40     uint8_t mdr[2];
41     uint8_t scr;
42     uint8_t clksel;
43 };
44 
45 void omap_uart_reset(struct omap_uart_s *s)
46 {
47     s->eblr = 0x00;
48     s->syscontrol = 0;
49     s->wkup = 0x3f;
50     s->cfps = 0x69;
51     s->clksel = 0;
52 }
53 
54 struct omap_uart_s *omap_uart_init(hwaddr base,
55                 qemu_irq irq, omap_clk fclk, omap_clk iclk,
56                 qemu_irq txdma, qemu_irq rxdma,
57                 const char *label, CharDriverState *chr)
58 {
59     struct omap_uart_s *s = g_new0(struct omap_uart_s, 1);
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"),
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         omap_badwidth_write8(opaque, addr, value);
116         return;
117     }
118 
119     switch (addr) {
120     case 0x20:	/* MDR1 */
121         s->mdr[0] = value & 0x7f;
122         break;
123     case 0x24:	/* MDR2 */
124         s->mdr[1] = value & 0xff;
125         break;
126     case 0x40:	/* SCR */
127         s->scr = value & 0xff;
128         break;
129     case 0x48:	/* EBLR (OMAP2) */
130         s->eblr = value & 0xff;
131         break;
132     case 0x4C:	/* OSC_12M_SEL (OMAP1) */
133         s->clksel = value & 1;
134         break;
135     case 0x44:	/* SSR */
136     case 0x50:	/* MVR */
137     case 0x58:	/* SYSS (OMAP2) */
138         OMAP_RO_REG(addr);
139         break;
140     case 0x54:	/* SYSC (OMAP2) */
141         s->syscontrol = value & 0x1d;
142         if (value & 2)
143             omap_uart_reset(s);
144         break;
145     case 0x5c:	/* WER (OMAP2) */
146         s->wkup = value & 0x7f;
147         break;
148     case 0x60:	/* CFPS (OMAP2) */
149         s->cfps = value & 0xff;
150         break;
151     default:
152         OMAP_BAD_REG(addr);
153     }
154 }
155 
156 static const MemoryRegionOps omap_uart_ops = {
157     .read = omap_uart_read,
158     .write = omap_uart_write,
159     .endianness = DEVICE_NATIVE_ENDIAN,
160 };
161 
162 struct omap_uart_s *omap2_uart_init(MemoryRegion *sysmem,
163                 struct omap_target_agent_s *ta,
164                 qemu_irq irq, omap_clk fclk, omap_clk iclk,
165                 qemu_irq txdma, qemu_irq rxdma,
166                 const char *label, CharDriverState *chr)
167 {
168     hwaddr base = omap_l4_attach(ta, 0, NULL);
169     struct omap_uart_s *s = omap_uart_init(base, irq,
170                     fclk, iclk, txdma, rxdma, label, chr);
171 
172     memory_region_init_io(&s->iomem, NULL, &omap_uart_ops, s, "omap.uart", 0x100);
173 
174     s->ta = ta;
175 
176     memory_region_add_subregion(sysmem, base + 0x20, &s->iomem);
177 
178     return s;
179 }
180 
181 void omap_uart_attach(struct omap_uart_s *s, CharDriverState *chr)
182 {
183     /* TODO: Should reuse or destroy current s->serial */
184     s->serial = serial_mm_init(get_system_memory(), s->base, 2, s->irq,
185                                omap_clk_getrate(s->fclk) / 16,
186                                chr ?: qemu_chr_new("null", "null"),
187                                DEVICE_NATIVE_ENDIAN);
188 }
189