xref: /openbmc/qemu/hw/gpio/mpc8xxx.c (revision 3d9569b8)
1 /*
2  *  GPIO Controller for a lot of Freescale SoCs
3  *
4  * Copyright (C) 2014 Freescale Semiconductor, Inc. All rights reserved.
5  *
6  * Author: Alexander Graf, <agraf@suse.de>
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #include "qemu/osdep.h"
23 #include "hw/sysbus.h"
24 #include "qemu/module.h"
25 
26 #define TYPE_MPC8XXX_GPIO "mpc8xxx_gpio"
27 #define MPC8XXX_GPIO(obj) OBJECT_CHECK(MPC8XXXGPIOState, (obj), TYPE_MPC8XXX_GPIO)
28 
29 typedef struct MPC8XXXGPIOState {
30     SysBusDevice parent_obj;
31 
32     MemoryRegion iomem;
33     qemu_irq irq;
34     qemu_irq out[32];
35 
36     uint32_t dir;
37     uint32_t odr;
38     uint32_t dat;
39     uint32_t ier;
40     uint32_t imr;
41     uint32_t icr;
42 } MPC8XXXGPIOState;
43 
44 static const VMStateDescription vmstate_mpc8xxx_gpio = {
45     .name = "mpc8xxx_gpio",
46     .version_id = 1,
47     .minimum_version_id = 1,
48     .fields = (VMStateField[]) {
49         VMSTATE_UINT32(dir, MPC8XXXGPIOState),
50         VMSTATE_UINT32(odr, MPC8XXXGPIOState),
51         VMSTATE_UINT32(dat, MPC8XXXGPIOState),
52         VMSTATE_UINT32(ier, MPC8XXXGPIOState),
53         VMSTATE_UINT32(imr, MPC8XXXGPIOState),
54         VMSTATE_UINT32(icr, MPC8XXXGPIOState),
55         VMSTATE_END_OF_LIST()
56     }
57 };
58 
59 static void mpc8xxx_gpio_update(MPC8XXXGPIOState *s)
60 {
61     qemu_set_irq(s->irq, !!(s->ier & s->imr));
62 }
63 
64 static uint64_t mpc8xxx_gpio_read(void *opaque, hwaddr offset,
65                                   unsigned size)
66 {
67     MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
68 
69     if (size != 4) {
70         /* All registers are 32bit */
71         return 0;
72     }
73 
74     switch (offset) {
75     case 0x0: /* Direction */
76         return s->dir;
77     case 0x4: /* Open Drain */
78         return s->odr;
79     case 0x8: /* Data */
80         return s->dat;
81     case 0xC: /* Interrupt Event */
82         return s->ier;
83     case 0x10: /* Interrupt Mask */
84         return s->imr;
85     case 0x14: /* Interrupt Control */
86         return s->icr;
87     default:
88         return 0;
89     }
90 }
91 
92 static void mpc8xxx_write_data(MPC8XXXGPIOState *s, uint32_t new_data)
93 {
94     uint32_t old_data = s->dat;
95     uint32_t diff = old_data ^ new_data;
96     int i;
97 
98     for (i = 0; i < 32; i++) {
99         uint32_t mask = 0x80000000 >> i;
100         if (!(diff & mask)) {
101             continue;
102         }
103 
104         if (s->dir & mask) {
105             /* Output */
106             qemu_set_irq(s->out[i], (new_data & mask) != 0);
107         }
108     }
109 
110     s->dat = new_data;
111 }
112 
113 static void mpc8xxx_gpio_write(void *opaque, hwaddr offset,
114                         uint64_t value, unsigned size)
115 {
116     MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
117 
118     if (size != 4) {
119         /* All registers are 32bit */
120         return;
121     }
122 
123     switch (offset) {
124     case 0x0: /* Direction */
125         s->dir = value;
126         break;
127     case 0x4: /* Open Drain */
128         s->odr = value;
129         break;
130     case 0x8: /* Data */
131         mpc8xxx_write_data(s, value);
132         break;
133     case 0xC: /* Interrupt Event */
134         s->ier &= ~value;
135         break;
136     case 0x10: /* Interrupt Mask */
137         s->imr = value;
138         break;
139     case 0x14: /* Interrupt Control */
140         s->icr = value;
141         break;
142     }
143 
144     mpc8xxx_gpio_update(s);
145 }
146 
147 static void mpc8xxx_gpio_reset(DeviceState *dev)
148 {
149     MPC8XXXGPIOState *s = MPC8XXX_GPIO(dev);
150 
151     s->dir = 0;
152     s->odr = 0;
153     s->dat = 0;
154     s->ier = 0;
155     s->imr = 0;
156     s->icr = 0;
157 }
158 
159 static void mpc8xxx_gpio_set_irq(void * opaque, int irq, int level)
160 {
161     MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
162     uint32_t mask;
163 
164     mask = 0x80000000 >> irq;
165     if ((s->dir & mask) == 0) {
166         uint32_t old_value = s->dat & mask;
167 
168         s->dat &= ~mask;
169         if (level)
170             s->dat |= mask;
171 
172         if (!(s->icr & irq) || (old_value && !level)) {
173             s->ier |= mask;
174         }
175 
176         mpc8xxx_gpio_update(s);
177     }
178 }
179 
180 static const MemoryRegionOps mpc8xxx_gpio_ops = {
181     .read = mpc8xxx_gpio_read,
182     .write = mpc8xxx_gpio_write,
183     .endianness = DEVICE_BIG_ENDIAN,
184 };
185 
186 static void mpc8xxx_gpio_initfn(Object *obj)
187 {
188     DeviceState *dev = DEVICE(obj);
189     MPC8XXXGPIOState *s = MPC8XXX_GPIO(obj);
190     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
191 
192     memory_region_init_io(&s->iomem, obj, &mpc8xxx_gpio_ops,
193                           s, "mpc8xxx_gpio", 0x1000);
194     sysbus_init_mmio(sbd, &s->iomem);
195     sysbus_init_irq(sbd, &s->irq);
196     qdev_init_gpio_in(dev, mpc8xxx_gpio_set_irq, 32);
197     qdev_init_gpio_out(dev, s->out, 32);
198 }
199 
200 static void mpc8xxx_gpio_class_init(ObjectClass *klass, void *data)
201 {
202     DeviceClass *dc = DEVICE_CLASS(klass);
203 
204     dc->vmsd = &vmstate_mpc8xxx_gpio;
205     dc->reset = mpc8xxx_gpio_reset;
206 }
207 
208 static const TypeInfo mpc8xxx_gpio_info = {
209     .name          = TYPE_MPC8XXX_GPIO,
210     .parent        = TYPE_SYS_BUS_DEVICE,
211     .instance_size = sizeof(MPC8XXXGPIOState),
212     .instance_init = mpc8xxx_gpio_initfn,
213     .class_init    = mpc8xxx_gpio_class_init,
214 };
215 
216 static void mpc8xxx_gpio_register_types(void)
217 {
218     type_register_static(&mpc8xxx_gpio_info);
219 }
220 
221 type_init(mpc8xxx_gpio_register_types)
222