xref: /openbmc/qemu/hw/gpio/mpc8xxx.c (revision f1733749)
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 
28 #define TYPE_MPC8XXX_GPIO "mpc8xxx_gpio"
29 #define MPC8XXX_GPIO(obj) OBJECT_CHECK(MPC8XXXGPIOState, (obj), TYPE_MPC8XXX_GPIO)
30 
31 typedef struct MPC8XXXGPIOState {
32     SysBusDevice parent_obj;
33 
34     MemoryRegion iomem;
35     qemu_irq irq;
36     qemu_irq out[32];
37 
38     uint32_t dir;
39     uint32_t odr;
40     uint32_t dat;
41     uint32_t ier;
42     uint32_t imr;
43     uint32_t icr;
44 } MPC8XXXGPIOState;
45 
46 static const VMStateDescription vmstate_mpc8xxx_gpio = {
47     .name = "mpc8xxx_gpio",
48     .version_id = 1,
49     .minimum_version_id = 1,
50     .fields = (VMStateField[]) {
51         VMSTATE_UINT32(dir, MPC8XXXGPIOState),
52         VMSTATE_UINT32(odr, MPC8XXXGPIOState),
53         VMSTATE_UINT32(dat, MPC8XXXGPIOState),
54         VMSTATE_UINT32(ier, MPC8XXXGPIOState),
55         VMSTATE_UINT32(imr, MPC8XXXGPIOState),
56         VMSTATE_UINT32(icr, MPC8XXXGPIOState),
57         VMSTATE_END_OF_LIST()
58     }
59 };
60 
61 static void mpc8xxx_gpio_update(MPC8XXXGPIOState *s)
62 {
63     qemu_set_irq(s->irq, !!(s->ier & s->imr));
64 }
65 
66 static uint64_t mpc8xxx_gpio_read(void *opaque, hwaddr offset,
67                                   unsigned size)
68 {
69     MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
70 
71     if (size != 4) {
72         /* All registers are 32bit */
73         return 0;
74     }
75 
76     switch (offset) {
77     case 0x0: /* Direction */
78         return s->dir;
79     case 0x4: /* Open Drain */
80         return s->odr;
81     case 0x8: /* Data */
82         return s->dat;
83     case 0xC: /* Interrupt Event */
84         return s->ier;
85     case 0x10: /* Interrupt Mask */
86         return s->imr;
87     case 0x14: /* Interrupt Control */
88         return s->icr;
89     default:
90         return 0;
91     }
92 }
93 
94 static void mpc8xxx_write_data(MPC8XXXGPIOState *s, uint32_t new_data)
95 {
96     uint32_t old_data = s->dat;
97     uint32_t diff = old_data ^ new_data;
98     int i;
99 
100     for (i = 0; i < 32; i++) {
101         uint32_t mask = 0x80000000 >> i;
102         if (!(diff & mask)) {
103             continue;
104         }
105 
106         if (s->dir & mask) {
107             /* Output */
108             qemu_set_irq(s->out[i], (new_data & mask) != 0);
109         }
110     }
111 
112     s->dat = new_data;
113 }
114 
115 static void mpc8xxx_gpio_write(void *opaque, hwaddr offset,
116                         uint64_t value, unsigned size)
117 {
118     MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
119 
120     if (size != 4) {
121         /* All registers are 32bit */
122         return;
123     }
124 
125     switch (offset) {
126     case 0x0: /* Direction */
127         s->dir = value;
128         break;
129     case 0x4: /* Open Drain */
130         s->odr = value;
131         break;
132     case 0x8: /* Data */
133         mpc8xxx_write_data(s, value);
134         break;
135     case 0xC: /* Interrupt Event */
136         s->ier &= ~value;
137         break;
138     case 0x10: /* Interrupt Mask */
139         s->imr = value;
140         break;
141     case 0x14: /* Interrupt Control */
142         s->icr = value;
143         break;
144     }
145 
146     mpc8xxx_gpio_update(s);
147 }
148 
149 static void mpc8xxx_gpio_reset(DeviceState *dev)
150 {
151     MPC8XXXGPIOState *s = MPC8XXX_GPIO(dev);
152 
153     s->dir = 0;
154     s->odr = 0;
155     s->dat = 0;
156     s->ier = 0;
157     s->imr = 0;
158     s->icr = 0;
159 }
160 
161 static void mpc8xxx_gpio_set_irq(void * opaque, int irq, int level)
162 {
163     MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
164     uint32_t mask;
165 
166     mask = 0x80000000 >> irq;
167     if ((s->dir & mask) == 0) {
168         uint32_t old_value = s->dat & mask;
169 
170         s->dat &= ~mask;
171         if (level)
172             s->dat |= mask;
173 
174         if (!(s->icr & irq) || (old_value && !level)) {
175             s->ier |= mask;
176         }
177 
178         mpc8xxx_gpio_update(s);
179     }
180 }
181 
182 static const MemoryRegionOps mpc8xxx_gpio_ops = {
183     .read = mpc8xxx_gpio_read,
184     .write = mpc8xxx_gpio_write,
185     .endianness = DEVICE_BIG_ENDIAN,
186 };
187 
188 static void mpc8xxx_gpio_initfn(Object *obj)
189 {
190     DeviceState *dev = DEVICE(obj);
191     MPC8XXXGPIOState *s = MPC8XXX_GPIO(obj);
192     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
193 
194     memory_region_init_io(&s->iomem, obj, &mpc8xxx_gpio_ops,
195                           s, "mpc8xxx_gpio", 0x1000);
196     sysbus_init_mmio(sbd, &s->iomem);
197     sysbus_init_irq(sbd, &s->irq);
198     qdev_init_gpio_in(dev, mpc8xxx_gpio_set_irq, 32);
199     qdev_init_gpio_out(dev, s->out, 32);
200 }
201 
202 static void mpc8xxx_gpio_class_init(ObjectClass *klass, void *data)
203 {
204     DeviceClass *dc = DEVICE_CLASS(klass);
205 
206     dc->vmsd = &vmstate_mpc8xxx_gpio;
207     dc->reset = mpc8xxx_gpio_reset;
208 }
209 
210 static const TypeInfo mpc8xxx_gpio_info = {
211     .name          = TYPE_MPC8XXX_GPIO,
212     .parent        = TYPE_SYS_BUS_DEVICE,
213     .instance_size = sizeof(MPC8XXXGPIOState),
214     .instance_init = mpc8xxx_gpio_initfn,
215     .class_init    = mpc8xxx_gpio_class_init,
216 };
217 
218 static void mpc8xxx_gpio_register_types(void)
219 {
220     type_register_static(&mpc8xxx_gpio_info);
221 }
222 
223 type_init(mpc8xxx_gpio_register_types)
224