xref: /openbmc/qemu/hw/misc/macio/gpio.c (revision 2fc979cb)
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/ppc/mac.h"
28 #include "hw/qdev-properties.h"
29 #include "migration/vmstate.h"
30 #include "hw/misc/macio/macio.h"
31 #include "hw/misc/macio/gpio.h"
32 #include "hw/nmi.h"
33 #include "qemu/log.h"
34 #include "qemu/module.h"
35 #include "trace.h"
36 
37 
38 void macio_set_gpio(MacIOGPIOState *s, uint32_t gpio, bool state)
39 {
40     uint8_t new_reg;
41 
42     trace_macio_set_gpio(gpio, state);
43 
44     if (s->gpio_regs[gpio] & 4) {
45         qemu_log_mask(LOG_GUEST_ERROR,
46                       "GPIO: Setting GPIO %d while it's an output\n", gpio);
47     }
48 
49     new_reg = s->gpio_regs[gpio] & ~2;
50     if (state) {
51         new_reg |= 2;
52     }
53 
54     if (new_reg == s->gpio_regs[gpio]) {
55         return;
56     }
57 
58     s->gpio_regs[gpio] = new_reg;
59 
60     /* This is will work until we fix the binding between MacIO and
61      * the MPIC properly so we can route all GPIOs and avoid going
62      * via the top level platform code.
63      *
64      * Note that we probably need to get access to the MPIC config to
65      * decode polarity since qemu always use "raise" regardless.
66      *
67      * For now, we hard wire known GPIOs
68      */
69 
70     switch (gpio) {
71     case 1:
72         /* Level low */
73         if (!state) {
74             trace_macio_gpio_irq_assert(gpio);
75             qemu_irq_raise(s->gpio_extirqs[gpio]);
76         } else {
77             trace_macio_gpio_irq_deassert(gpio);
78             qemu_irq_lower(s->gpio_extirqs[gpio]);
79         }
80         break;
81 
82     case 9:
83         /* Edge, triggered by NMI below */
84         if (state) {
85             trace_macio_gpio_irq_assert(gpio);
86             qemu_irq_raise(s->gpio_extirqs[gpio]);
87         } else {
88             trace_macio_gpio_irq_deassert(gpio);
89             qemu_irq_lower(s->gpio_extirqs[gpio]);
90         }
91         break;
92 
93     default:
94         qemu_log_mask(LOG_UNIMP, "GPIO: setting unimplemented GPIO %d", gpio);
95     }
96 }
97 
98 static void macio_gpio_write(void *opaque, hwaddr addr, uint64_t value,
99                              unsigned size)
100 {
101     MacIOGPIOState *s = opaque;
102     uint8_t ibit;
103 
104     trace_macio_gpio_write(addr, value);
105 
106     /* Levels regs are read-only */
107     if (addr < 8) {
108         return;
109     }
110 
111     addr -= 8;
112     if (addr < 36) {
113         value &= ~2;
114 
115         if (value & 4) {
116             ibit = (value & 1) << 1;
117         } else {
118             ibit = s->gpio_regs[addr] & 2;
119         }
120 
121         s->gpio_regs[addr] = value | ibit;
122     }
123 }
124 
125 static uint64_t macio_gpio_read(void *opaque, hwaddr addr, unsigned size)
126 {
127     MacIOGPIOState *s = opaque;
128     uint64_t val = 0;
129 
130     /* Levels regs */
131     if (addr < 8) {
132         val = s->gpio_levels[addr];
133     } else {
134         addr -= 8;
135 
136         if (addr < 36) {
137             val = s->gpio_regs[addr];
138         }
139     }
140 
141     trace_macio_gpio_write(addr, val);
142     return val;
143 }
144 
145 static const MemoryRegionOps macio_gpio_ops = {
146     .read = macio_gpio_read,
147     .write = macio_gpio_write,
148     .endianness = DEVICE_LITTLE_ENDIAN,
149     .impl = {
150         .min_access_size = 1,
151         .max_access_size = 1,
152     },
153 };
154 
155 static void macio_gpio_realize(DeviceState *dev, Error **errp)
156 {
157     MacIOGPIOState *s = MACIO_GPIO(dev);
158 
159     s->gpio_extirqs[1] = qdev_get_gpio_in(DEVICE(s->pic),
160                                           NEWWORLD_EXTING_GPIO1);
161     s->gpio_extirqs[9] = qdev_get_gpio_in(DEVICE(s->pic),
162                                           NEWWORLD_EXTING_GPIO9);
163 }
164 
165 static void macio_gpio_init(Object *obj)
166 {
167     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
168     MacIOGPIOState *s = MACIO_GPIO(obj);
169 
170     object_property_add_link(obj, "pic", TYPE_OPENPIC,
171                              (Object **) &s->pic,
172                              qdev_prop_allow_set_link_before_realize,
173                              0);
174 
175     memory_region_init_io(&s->gpiomem, OBJECT(s), &macio_gpio_ops, obj,
176                           "gpio", 0x30);
177     sysbus_init_mmio(sbd, &s->gpiomem);
178 }
179 
180 static const VMStateDescription vmstate_macio_gpio = {
181     .name = "macio_gpio",
182     .version_id = 0,
183     .minimum_version_id = 0,
184     .fields = (VMStateField[]) {
185         VMSTATE_UINT8_ARRAY(gpio_levels, MacIOGPIOState, 8),
186         VMSTATE_UINT8_ARRAY(gpio_regs, MacIOGPIOState, 36),
187         VMSTATE_END_OF_LIST()
188     }
189 };
190 
191 static void macio_gpio_reset(DeviceState *dev)
192 {
193     MacIOGPIOState *s = MACIO_GPIO(dev);
194 
195     /* GPIO 1 is up by default */
196     macio_set_gpio(s, 1, true);
197 }
198 
199 static void macio_gpio_nmi(NMIState *n, int cpu_index, Error **errp)
200 {
201     macio_set_gpio(MACIO_GPIO(n), 9, true);
202     macio_set_gpio(MACIO_GPIO(n), 9, false);
203 }
204 
205 static void macio_gpio_class_init(ObjectClass *oc, void *data)
206 {
207     DeviceClass *dc = DEVICE_CLASS(oc);
208     NMIClass *nc = NMI_CLASS(oc);
209 
210     dc->realize = macio_gpio_realize;
211     dc->reset = macio_gpio_reset;
212     dc->vmsd = &vmstate_macio_gpio;
213     nc->nmi_monitor_handler = macio_gpio_nmi;
214 }
215 
216 static const TypeInfo macio_gpio_init_info = {
217     .name          = TYPE_MACIO_GPIO,
218     .parent        = TYPE_SYS_BUS_DEVICE,
219     .instance_size = sizeof(MacIOGPIOState),
220     .instance_init = macio_gpio_init,
221     .class_init    = macio_gpio_class_init,
222     .interfaces = (InterfaceInfo[]) {
223         { TYPE_NMI },
224         { }
225     },
226 };
227 
228 static void macio_gpio_register_types(void)
229 {
230     type_register_static(&macio_gpio_init_info);
231 }
232 
233 type_init(macio_gpio_register_types)
234