xref: /qemu/hw/misc/macio/gpio.c (revision d64db833d6e3cbe9ea5f36342480f920f3675cea)
1 /*
2  * PowerMac NewWorld MacIO GPIO emulation
3  *
4  * Copyright (c) 2016 Benjamin Herrenschmidt
5  * Copyright (c) 2018 Mark Cave-Ayland
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "hw/qdev-properties.h"
28 #include "migration/vmstate.h"
29 #include "hw/misc/macio/macio.h"
30 #include "hw/misc/macio/gpio.h"
31 #include "hw/irq.h"
32 #include "hw/nmi.h"
33 #include "qemu/log.h"
34 #include "qemu/module.h"
35 #include "trace.h"
36 
37 enum MacioGPIORegisterBits {
38     OUT_DATA   = 1,
39     IN_DATA    = 2,
40     OUT_ENABLE = 4,
41 };
42 
43 void macio_set_gpio(MacIOGPIOState *s, uint32_t gpio, bool state)
44 {
45     uint8_t new_reg;
46 
47     trace_macio_set_gpio(gpio, state);
48 
49     if (s->gpio_regs[gpio] & OUT_ENABLE) {
50         qemu_log_mask(LOG_GUEST_ERROR,
51                       "GPIO: Setting GPIO %d while it's an output\n", gpio);
52     }
53 
54     new_reg = s->gpio_regs[gpio] & ~IN_DATA;
55     if (state) {
56         new_reg |= IN_DATA;
57     }
58 
59     if (new_reg == s->gpio_regs[gpio]) {
60         return;
61     }
62 
63     s->gpio_regs[gpio] = new_reg;
64 
65     /*
66      * Note that we probably need to get access to the MPIC config to
67      * decode polarity since qemu always use "raise" regardless.
68      *
69      * For now, we hard wire known GPIOs
70      */
71 
72     switch (gpio) {
73     case 1:
74         /* Level low */
75         if (!state) {
76             trace_macio_gpio_irq_assert(gpio);
77             qemu_irq_raise(s->gpio_extirqs[gpio]);
78         } else {
79             trace_macio_gpio_irq_deassert(gpio);
80             qemu_irq_lower(s->gpio_extirqs[gpio]);
81         }
82         break;
83 
84     case 9:
85         /* Edge, triggered by NMI below */
86         if (state) {
87             trace_macio_gpio_irq_assert(gpio);
88             qemu_irq_raise(s->gpio_extirqs[gpio]);
89         } else {
90             trace_macio_gpio_irq_deassert(gpio);
91             qemu_irq_lower(s->gpio_extirqs[gpio]);
92         }
93         break;
94 
95     default:
96         qemu_log_mask(LOG_UNIMP, "GPIO: setting unimplemented GPIO %d", gpio);
97     }
98 }
99 
100 static void macio_gpio_write(void *opaque, hwaddr addr, uint64_t value,
101                              unsigned size)
102 {
103     MacIOGPIOState *s = opaque;
104     uint8_t ibit;
105 
106     trace_macio_gpio_write(addr, value);
107 
108     /* Levels regs are read-only */
109     if (addr < 8) {
110         return;
111     }
112 
113     addr -= 8;
114     if (addr < 36) {
115         value &= ~IN_DATA;
116 
117         if (value & OUT_ENABLE) {
118             ibit = (value & OUT_DATA) << 1;
119         } else {
120             ibit = s->gpio_regs[addr] & IN_DATA;
121         }
122 
123         s->gpio_regs[addr] = value | ibit;
124     }
125 }
126 
127 static uint64_t macio_gpio_read(void *opaque, hwaddr addr, unsigned size)
128 {
129     MacIOGPIOState *s = opaque;
130     uint64_t val = 0;
131 
132     /* Levels regs */
133     if (addr < 8) {
134         val = s->gpio_levels[addr];
135     } else {
136         addr -= 8;
137 
138         if (addr < 36) {
139             val = s->gpio_regs[addr];
140         }
141     }
142 
143     trace_macio_gpio_read(addr, val);
144     return val;
145 }
146 
147 static const MemoryRegionOps macio_gpio_ops = {
148     .read = macio_gpio_read,
149     .write = macio_gpio_write,
150     .endianness = DEVICE_LITTLE_ENDIAN,
151     .impl = {
152         .min_access_size = 1,
153         .max_access_size = 1,
154     },
155 };
156 
157 static void macio_gpio_init(Object *obj)
158 {
159     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
160     MacIOGPIOState *s = MACIO_GPIO(obj);
161     int i;
162 
163     for (i = 0; i < 10; i++) {
164         sysbus_init_irq(sbd, &s->gpio_extirqs[i]);
165     }
166 
167     memory_region_init_io(&s->gpiomem, OBJECT(s), &macio_gpio_ops, obj,
168                           "gpio", 0x30);
169     sysbus_init_mmio(sbd, &s->gpiomem);
170 }
171 
172 static const VMStateDescription vmstate_macio_gpio = {
173     .name = "macio_gpio",
174     .version_id = 0,
175     .minimum_version_id = 0,
176     .fields = (const VMStateField[]) {
177         VMSTATE_UINT8_ARRAY(gpio_levels, MacIOGPIOState, 8),
178         VMSTATE_UINT8_ARRAY(gpio_regs, MacIOGPIOState, 36),
179         VMSTATE_END_OF_LIST()
180     }
181 };
182 
183 static void macio_gpio_reset(DeviceState *dev)
184 {
185     MacIOGPIOState *s = MACIO_GPIO(dev);
186 
187     /* GPIO 1 is up by default */
188     macio_set_gpio(s, 1, true);
189 }
190 
191 static void macio_gpio_nmi(NMIState *n, int cpu_index, Error **errp)
192 {
193     macio_set_gpio(MACIO_GPIO(n), 9, true);
194     macio_set_gpio(MACIO_GPIO(n), 9, false);
195 }
196 
197 static void macio_gpio_class_init(ObjectClass *oc, const void *data)
198 {
199     DeviceClass *dc = DEVICE_CLASS(oc);
200     NMIClass *nc = NMI_CLASS(oc);
201 
202     device_class_set_legacy_reset(dc, macio_gpio_reset);
203     dc->vmsd = &vmstate_macio_gpio;
204     nc->nmi_monitor_handler = macio_gpio_nmi;
205 }
206 
207 static const TypeInfo macio_gpio_init_info = {
208     .name          = TYPE_MACIO_GPIO,
209     .parent        = TYPE_SYS_BUS_DEVICE,
210     .instance_size = sizeof(MacIOGPIOState),
211     .instance_init = macio_gpio_init,
212     .class_init    = macio_gpio_class_init,
213     .interfaces = (const InterfaceInfo[]) {
214         { TYPE_NMI },
215         { }
216     },
217 };
218 
219 static void macio_gpio_register_types(void)
220 {
221     type_register_static(&macio_gpio_init_info);
222 }
223 
224 type_init(macio_gpio_register_types)
225