xref: /openbmc/qemu/hw/misc/macio/gpio.c (revision 7a5951f6)
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/nmi.h"
32 #include "qemu/log.h"
33 #include "qemu/module.h"
34 #include "trace.h"
35 
36 
37 void macio_set_gpio(MacIOGPIOState *s, uint32_t gpio, bool state)
38 {
39     uint8_t new_reg;
40 
41     trace_macio_set_gpio(gpio, state);
42 
43     if (s->gpio_regs[gpio] & 4) {
44         qemu_log_mask(LOG_GUEST_ERROR,
45                       "GPIO: Setting GPIO %d while it's an output\n", gpio);
46     }
47 
48     new_reg = s->gpio_regs[gpio] & ~2;
49     if (state) {
50         new_reg |= 2;
51     }
52 
53     if (new_reg == s->gpio_regs[gpio]) {
54         return;
55     }
56 
57     s->gpio_regs[gpio] = new_reg;
58 
59     /*
60      * Note that we probably need to get access to the MPIC config to
61      * decode polarity since qemu always use "raise" regardless.
62      *
63      * For now, we hard wire known GPIOs
64      */
65 
66     switch (gpio) {
67     case 1:
68         /* Level low */
69         if (!state) {
70             trace_macio_gpio_irq_assert(gpio);
71             qemu_irq_raise(s->gpio_extirqs[gpio]);
72         } else {
73             trace_macio_gpio_irq_deassert(gpio);
74             qemu_irq_lower(s->gpio_extirqs[gpio]);
75         }
76         break;
77 
78     case 9:
79         /* Edge, triggered by NMI below */
80         if (state) {
81             trace_macio_gpio_irq_assert(gpio);
82             qemu_irq_raise(s->gpio_extirqs[gpio]);
83         } else {
84             trace_macio_gpio_irq_deassert(gpio);
85             qemu_irq_lower(s->gpio_extirqs[gpio]);
86         }
87         break;
88 
89     default:
90         qemu_log_mask(LOG_UNIMP, "GPIO: setting unimplemented GPIO %d", gpio);
91     }
92 }
93 
94 static void macio_gpio_write(void *opaque, hwaddr addr, uint64_t value,
95                              unsigned size)
96 {
97     MacIOGPIOState *s = opaque;
98     uint8_t ibit;
99 
100     trace_macio_gpio_write(addr, value);
101 
102     /* Levels regs are read-only */
103     if (addr < 8) {
104         return;
105     }
106 
107     addr -= 8;
108     if (addr < 36) {
109         value &= ~2;
110 
111         if (value & 4) {
112             ibit = (value & 1) << 1;
113         } else {
114             ibit = s->gpio_regs[addr] & 2;
115         }
116 
117         s->gpio_regs[addr] = value | ibit;
118     }
119 }
120 
121 static uint64_t macio_gpio_read(void *opaque, hwaddr addr, unsigned size)
122 {
123     MacIOGPIOState *s = opaque;
124     uint64_t val = 0;
125 
126     /* Levels regs */
127     if (addr < 8) {
128         val = s->gpio_levels[addr];
129     } else {
130         addr -= 8;
131 
132         if (addr < 36) {
133             val = s->gpio_regs[addr];
134         }
135     }
136 
137     trace_macio_gpio_write(addr, val);
138     return val;
139 }
140 
141 static const MemoryRegionOps macio_gpio_ops = {
142     .read = macio_gpio_read,
143     .write = macio_gpio_write,
144     .endianness = DEVICE_LITTLE_ENDIAN,
145     .impl = {
146         .min_access_size = 1,
147         .max_access_size = 1,
148     },
149 };
150 
151 static void macio_gpio_init(Object *obj)
152 {
153     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
154     MacIOGPIOState *s = MACIO_GPIO(obj);
155     int i;
156 
157     for (i = 0; i < 10; i++) {
158         sysbus_init_irq(sbd, &s->gpio_extirqs[i]);
159     }
160 
161     memory_region_init_io(&s->gpiomem, OBJECT(s), &macio_gpio_ops, obj,
162                           "gpio", 0x30);
163     sysbus_init_mmio(sbd, &s->gpiomem);
164 }
165 
166 static const VMStateDescription vmstate_macio_gpio = {
167     .name = "macio_gpio",
168     .version_id = 0,
169     .minimum_version_id = 0,
170     .fields = (VMStateField[]) {
171         VMSTATE_UINT8_ARRAY(gpio_levels, MacIOGPIOState, 8),
172         VMSTATE_UINT8_ARRAY(gpio_regs, MacIOGPIOState, 36),
173         VMSTATE_END_OF_LIST()
174     }
175 };
176 
177 static void macio_gpio_reset(DeviceState *dev)
178 {
179     MacIOGPIOState *s = MACIO_GPIO(dev);
180 
181     /* GPIO 1 is up by default */
182     macio_set_gpio(s, 1, true);
183 }
184 
185 static void macio_gpio_nmi(NMIState *n, int cpu_index, Error **errp)
186 {
187     macio_set_gpio(MACIO_GPIO(n), 9, true);
188     macio_set_gpio(MACIO_GPIO(n), 9, false);
189 }
190 
191 static void macio_gpio_class_init(ObjectClass *oc, void *data)
192 {
193     DeviceClass *dc = DEVICE_CLASS(oc);
194     NMIClass *nc = NMI_CLASS(oc);
195 
196     dc->reset = macio_gpio_reset;
197     dc->vmsd = &vmstate_macio_gpio;
198     nc->nmi_monitor_handler = macio_gpio_nmi;
199 }
200 
201 static const TypeInfo macio_gpio_init_info = {
202     .name          = TYPE_MACIO_GPIO,
203     .parent        = TYPE_SYS_BUS_DEVICE,
204     .instance_size = sizeof(MacIOGPIOState),
205     .instance_init = macio_gpio_init,
206     .class_init    = macio_gpio_class_init,
207     .interfaces = (InterfaceInfo[]) {
208         { TYPE_NMI },
209         { }
210     },
211 };
212 
213 static void macio_gpio_register_types(void)
214 {
215     type_register_static(&macio_gpio_init_info);
216 }
217 
218 type_init(macio_gpio_register_types)
219