xref: /openbmc/qemu/hw/gpio/mpc8xxx.c (revision 8fa3b702)
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/irq.h"
24 #include "hw/sysbus.h"
25 #include "migration/vmstate.h"
26 #include "qemu/module.h"
27 #include "qom/object.h"
28 
29 #define TYPE_MPC8XXX_GPIO "mpc8xxx_gpio"
30 typedef struct MPC8XXXGPIOState MPC8XXXGPIOState;
31 DECLARE_INSTANCE_CHECKER(MPC8XXXGPIOState, MPC8XXX_GPIO,
32                          TYPE_MPC8XXX_GPIO)
33 
34 struct MPC8XXXGPIOState {
35     SysBusDevice parent_obj;
36 
37     MemoryRegion iomem;
38     qemu_irq irq;
39     qemu_irq out[32];
40 
41     uint32_t dir;
42     uint32_t odr;
43     uint32_t dat;
44     uint32_t ier;
45     uint32_t imr;
46     uint32_t icr;
47 };
48 
49 static const VMStateDescription vmstate_mpc8xxx_gpio = {
50     .name = "mpc8xxx_gpio",
51     .version_id = 1,
52     .minimum_version_id = 1,
53     .fields = (VMStateField[]) {
54         VMSTATE_UINT32(dir, MPC8XXXGPIOState),
55         VMSTATE_UINT32(odr, MPC8XXXGPIOState),
56         VMSTATE_UINT32(dat, MPC8XXXGPIOState),
57         VMSTATE_UINT32(ier, MPC8XXXGPIOState),
58         VMSTATE_UINT32(imr, MPC8XXXGPIOState),
59         VMSTATE_UINT32(icr, MPC8XXXGPIOState),
60         VMSTATE_END_OF_LIST()
61     }
62 };
63 
64 static void mpc8xxx_gpio_update(MPC8XXXGPIOState *s)
65 {
66     qemu_set_irq(s->irq, !!(s->ier & s->imr));
67 }
68 
69 static uint64_t mpc8xxx_gpio_read(void *opaque, hwaddr offset,
70                                   unsigned size)
71 {
72     MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
73 
74     if (size != 4) {
75         /* All registers are 32bit */
76         return 0;
77     }
78 
79     switch (offset) {
80     case 0x0: /* Direction */
81         return s->dir;
82     case 0x4: /* Open Drain */
83         return s->odr;
84     case 0x8: /* Data */
85         return s->dat;
86     case 0xC: /* Interrupt Event */
87         return s->ier;
88     case 0x10: /* Interrupt Mask */
89         return s->imr;
90     case 0x14: /* Interrupt Control */
91         return s->icr;
92     default:
93         return 0;
94     }
95 }
96 
97 static void mpc8xxx_write_data(MPC8XXXGPIOState *s, uint32_t new_data)
98 {
99     uint32_t old_data = s->dat;
100     uint32_t diff = old_data ^ new_data;
101     int i;
102 
103     for (i = 0; i < 32; i++) {
104         uint32_t mask = 0x80000000 >> i;
105         if (!(diff & mask)) {
106             continue;
107         }
108 
109         if (s->dir & mask) {
110             /* Output */
111             qemu_set_irq(s->out[i], (new_data & mask) != 0);
112         }
113     }
114 
115     s->dat = new_data;
116 }
117 
118 static void mpc8xxx_gpio_write(void *opaque, hwaddr offset,
119                         uint64_t value, unsigned size)
120 {
121     MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
122 
123     if (size != 4) {
124         /* All registers are 32bit */
125         return;
126     }
127 
128     switch (offset) {
129     case 0x0: /* Direction */
130         s->dir = value;
131         break;
132     case 0x4: /* Open Drain */
133         s->odr = value;
134         break;
135     case 0x8: /* Data */
136         mpc8xxx_write_data(s, value);
137         break;
138     case 0xC: /* Interrupt Event */
139         s->ier &= ~value;
140         break;
141     case 0x10: /* Interrupt Mask */
142         s->imr = value;
143         break;
144     case 0x14: /* Interrupt Control */
145         s->icr = value;
146         break;
147     }
148 
149     mpc8xxx_gpio_update(s);
150 }
151 
152 static void mpc8xxx_gpio_reset(DeviceState *dev)
153 {
154     MPC8XXXGPIOState *s = MPC8XXX_GPIO(dev);
155 
156     s->dir = 0;
157     s->odr = 0;
158     s->dat = 0;
159     s->ier = 0;
160     s->imr = 0;
161     s->icr = 0;
162 }
163 
164 static void mpc8xxx_gpio_set_irq(void * opaque, int irq, int level)
165 {
166     MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
167     uint32_t mask;
168 
169     mask = 0x80000000 >> irq;
170     if ((s->dir & mask) == 0) {
171         uint32_t old_value = s->dat & mask;
172 
173         s->dat &= ~mask;
174         if (level)
175             s->dat |= mask;
176 
177         if (!(s->icr & irq) || (old_value && !level)) {
178             s->ier |= mask;
179         }
180 
181         mpc8xxx_gpio_update(s);
182     }
183 }
184 
185 static const MemoryRegionOps mpc8xxx_gpio_ops = {
186     .read = mpc8xxx_gpio_read,
187     .write = mpc8xxx_gpio_write,
188     .endianness = DEVICE_BIG_ENDIAN,
189 };
190 
191 static void mpc8xxx_gpio_initfn(Object *obj)
192 {
193     DeviceState *dev = DEVICE(obj);
194     MPC8XXXGPIOState *s = MPC8XXX_GPIO(obj);
195     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
196 
197     memory_region_init_io(&s->iomem, obj, &mpc8xxx_gpio_ops,
198                           s, "mpc8xxx_gpio", 0x1000);
199     sysbus_init_mmio(sbd, &s->iomem);
200     sysbus_init_irq(sbd, &s->irq);
201     qdev_init_gpio_in(dev, mpc8xxx_gpio_set_irq, 32);
202     qdev_init_gpio_out(dev, s->out, 32);
203 }
204 
205 static void mpc8xxx_gpio_class_init(ObjectClass *klass, void *data)
206 {
207     DeviceClass *dc = DEVICE_CLASS(klass);
208 
209     dc->vmsd = &vmstate_mpc8xxx_gpio;
210     dc->reset = mpc8xxx_gpio_reset;
211 }
212 
213 static const TypeInfo mpc8xxx_gpio_info = {
214     .name          = TYPE_MPC8XXX_GPIO,
215     .parent        = TYPE_SYS_BUS_DEVICE,
216     .instance_size = sizeof(MPC8XXXGPIOState),
217     .instance_init = mpc8xxx_gpio_initfn,
218     .class_init    = mpc8xxx_gpio_class_init,
219 };
220 
221 static void mpc8xxx_gpio_register_types(void)
222 {
223     type_register_static(&mpc8xxx_gpio_info);
224 }
225 
226 type_init(mpc8xxx_gpio_register_types)
227