xref: /openbmc/qemu/hw/misc/macio/gpio.c (revision 99d423e5)
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/hw.h"
28 #include "hw/ppc/mac.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 "trace.h"
34 
35 
36 void macio_set_gpio(MacIOGPIOState *s, uint32_t gpio, bool state)
37 {
38     uint8_t new_reg;
39 
40     trace_macio_set_gpio(gpio, state);
41 
42     if (s->gpio_regs[gpio] & 4) {
43         qemu_log_mask(LOG_GUEST_ERROR,
44                       "GPIO: Setting GPIO %d while it's an output\n", gpio);
45     }
46 
47     new_reg = s->gpio_regs[gpio] & ~2;
48     if (state) {
49         new_reg |= 2;
50     }
51 
52     if (new_reg == s->gpio_regs[gpio]) {
53         return;
54     }
55 
56     s->gpio_regs[gpio] = new_reg;
57 
58     /* This is will work until we fix the binding between MacIO and
59      * the MPIC properly so we can route all GPIOs and avoid going
60      * via the top level platform code.
61      *
62      * Note that we probably need to get access to the MPIC config to
63      * decode polarity since qemu always use "raise" regardless.
64      *
65      * For now, we hard wire known GPIOs
66      */
67 
68     switch (gpio) {
69     case 1:
70         /* Level low */
71         if (!state) {
72             trace_macio_gpio_irq_assert(gpio);
73             qemu_irq_raise(s->gpio_extirqs[gpio]);
74         } else {
75             trace_macio_gpio_irq_deassert(gpio);
76             qemu_irq_lower(s->gpio_extirqs[gpio]);
77         }
78         break;
79 
80     case 9:
81         /* Edge, triggered by NMI below */
82         if (state) {
83             trace_macio_gpio_irq_assert(gpio);
84             qemu_irq_raise(s->gpio_extirqs[gpio]);
85         } else {
86             trace_macio_gpio_irq_deassert(gpio);
87             qemu_irq_lower(s->gpio_extirqs[gpio]);
88         }
89         break;
90 
91     default:
92         qemu_log_mask(LOG_UNIMP, "GPIO: setting unimplemented GPIO %d", gpio);
93     }
94 }
95 
96 static void macio_gpio_write(void *opaque, hwaddr addr, uint64_t value,
97                              unsigned size)
98 {
99     MacIOGPIOState *s = opaque;
100     uint8_t ibit;
101 
102     trace_macio_gpio_write(addr, value);
103 
104     /* Levels regs are read-only */
105     if (addr < 8) {
106         return;
107     }
108 
109     addr -= 8;
110     if (addr < 36) {
111         value &= ~2;
112 
113         if (value & 4) {
114             ibit = (value & 1) << 1;
115         } else {
116             ibit = s->gpio_regs[addr] & 2;
117         }
118 
119         s->gpio_regs[addr] = value | ibit;
120     }
121 }
122 
123 static uint64_t macio_gpio_read(void *opaque, hwaddr addr, unsigned size)
124 {
125     MacIOGPIOState *s = opaque;
126     uint64_t val = 0;
127 
128     /* Levels regs */
129     if (addr < 8) {
130         val = s->gpio_levels[addr];
131     } else {
132         addr -= 8;
133 
134         if (addr < 36) {
135             val = s->gpio_regs[addr];
136         }
137     }
138 
139     trace_macio_gpio_write(addr, val);
140     return val;
141 }
142 
143 static const MemoryRegionOps macio_gpio_ops = {
144     .read = macio_gpio_read,
145     .write = macio_gpio_write,
146     .endianness = DEVICE_LITTLE_ENDIAN,
147     .impl = {
148         .min_access_size = 1,
149         .max_access_size = 1,
150     },
151 };
152 
153 static void macio_gpio_realize(DeviceState *dev, Error **errp)
154 {
155     MacIOGPIOState *s = MACIO_GPIO(dev);
156 
157     s->gpio_extirqs[1] = qdev_get_gpio_in(DEVICE(s->pic),
158                                           NEWWORLD_EXTING_GPIO1);
159     s->gpio_extirqs[9] = qdev_get_gpio_in(DEVICE(s->pic),
160                                           NEWWORLD_EXTING_GPIO9);
161 }
162 
163 static void macio_gpio_init(Object *obj)
164 {
165     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
166     MacIOGPIOState *s = MACIO_GPIO(obj);
167 
168     object_property_add_link(obj, "pic", TYPE_OPENPIC,
169                              (Object **) &s->pic,
170                              qdev_prop_allow_set_link_before_realize,
171                              0, NULL);
172 
173     memory_region_init_io(&s->gpiomem, OBJECT(s), &macio_gpio_ops, obj,
174                           "gpio", 0x30);
175     sysbus_init_mmio(sbd, &s->gpiomem);
176 }
177 
178 static const VMStateDescription vmstate_macio_gpio = {
179     .name = "macio_gpio",
180     .version_id = 0,
181     .minimum_version_id = 0,
182     .fields = (VMStateField[]) {
183         VMSTATE_UINT8_ARRAY(gpio_levels, MacIOGPIOState, 8),
184         VMSTATE_UINT8_ARRAY(gpio_regs, MacIOGPIOState, 36),
185         VMSTATE_END_OF_LIST()
186     }
187 };
188 
189 static void macio_gpio_reset(DeviceState *dev)
190 {
191     MacIOGPIOState *s = MACIO_GPIO(dev);
192 
193     /* GPIO 1 is up by default */
194     macio_set_gpio(s, 1, true);
195 }
196 
197 static void macio_gpio_nmi(NMIState *n, int cpu_index, Error **errp)
198 {
199     macio_set_gpio(MACIO_GPIO(n), 9, true);
200     macio_set_gpio(MACIO_GPIO(n), 9, false);
201 }
202 
203 static void macio_gpio_class_init(ObjectClass *oc, void *data)
204 {
205     DeviceClass *dc = DEVICE_CLASS(oc);
206     NMIClass *nc = NMI_CLASS(oc);
207 
208     dc->realize = macio_gpio_realize;
209     dc->reset = macio_gpio_reset;
210     dc->vmsd = &vmstate_macio_gpio;
211     nc->nmi_monitor_handler = macio_gpio_nmi;
212 }
213 
214 static const TypeInfo macio_gpio_init_info = {
215     .name          = TYPE_MACIO_GPIO,
216     .parent        = TYPE_SYS_BUS_DEVICE,
217     .instance_size = sizeof(MacIOGPIOState),
218     .instance_init = macio_gpio_init,
219     .class_init    = macio_gpio_class_init,
220     .interfaces = (InterfaceInfo[]) {
221         { TYPE_NMI },
222         { }
223     },
224 };
225 
226 static void macio_gpio_register_types(void)
227 {
228     type_register_static(&macio_gpio_init_info);
229 }
230 
231 type_init(macio_gpio_register_types)
232