xref: /openbmc/qemu/hw/gpio/bcm2835_gpio.c (revision 09a274d8)
1 /*
2  * Raspberry Pi (BCM2835) GPIO Controller
3  *
4  * Copyright (c) 2017 Antfield SAS
5  *
6  * Authors:
7  *  Clement Deschamps <clement.deschamps@antfield.fr>
8  *  Luc Michel <luc.michel@antfield.fr>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
11  * See the COPYING file in the top-level directory.
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qemu/log.h"
16 #include "qemu/timer.h"
17 #include "qapi/error.h"
18 #include "hw/sysbus.h"
19 #include "hw/sd/sd.h"
20 #include "hw/gpio/bcm2835_gpio.h"
21 
22 #define GPFSEL0   0x00
23 #define GPFSEL1   0x04
24 #define GPFSEL2   0x08
25 #define GPFSEL3   0x0C
26 #define GPFSEL4   0x10
27 #define GPFSEL5   0x14
28 #define GPSET0    0x1C
29 #define GPSET1    0x20
30 #define GPCLR0    0x28
31 #define GPCLR1    0x2C
32 #define GPLEV0    0x34
33 #define GPLEV1    0x38
34 #define GPEDS0    0x40
35 #define GPEDS1    0x44
36 #define GPREN0    0x4C
37 #define GPREN1    0x50
38 #define GPFEN0    0x58
39 #define GPFEN1    0x5C
40 #define GPHEN0    0x64
41 #define GPHEN1    0x68
42 #define GPLEN0    0x70
43 #define GPLEN1    0x74
44 #define GPAREN0   0x7C
45 #define GPAREN1   0x80
46 #define GPAFEN0   0x88
47 #define GPAFEN1   0x8C
48 #define GPPUD     0x94
49 #define GPPUDCLK0 0x98
50 #define GPPUDCLK1 0x9C
51 
52 static uint32_t gpfsel_get(BCM2835GpioState *s, uint8_t reg)
53 {
54     int i;
55     uint32_t value = 0;
56     for (i = 0; i < 10; i++) {
57         uint32_t index = 10 * reg + i;
58         if (index < sizeof(s->fsel)) {
59             value |= (s->fsel[index] & 0x7) << (3 * i);
60         }
61     }
62     return value;
63 }
64 
65 static void gpfsel_set(BCM2835GpioState *s, uint8_t reg, uint32_t value)
66 {
67     int i;
68     for (i = 0; i < 10; i++) {
69         uint32_t index = 10 * reg + i;
70         if (index < sizeof(s->fsel)) {
71             int fsel = (value >> (3 * i)) & 0x7;
72             s->fsel[index] = fsel;
73         }
74     }
75 
76     /* SD controller selection (48-53) */
77     if (s->sd_fsel != 0
78             && (s->fsel[48] == 0) /* SD_CLK_R */
79             && (s->fsel[49] == 0) /* SD_CMD_R */
80             && (s->fsel[50] == 0) /* SD_DATA0_R */
81             && (s->fsel[51] == 0) /* SD_DATA1_R */
82             && (s->fsel[52] == 0) /* SD_DATA2_R */
83             && (s->fsel[53] == 0) /* SD_DATA3_R */
84             ) {
85         /* SDHCI controller selected */
86         sdbus_reparent_card(s->sdbus_sdhost, s->sdbus_sdhci);
87         s->sd_fsel = 0;
88     } else if (s->sd_fsel != 4
89             && (s->fsel[48] == 4) /* SD_CLK_R */
90             && (s->fsel[49] == 4) /* SD_CMD_R */
91             && (s->fsel[50] == 4) /* SD_DATA0_R */
92             && (s->fsel[51] == 4) /* SD_DATA1_R */
93             && (s->fsel[52] == 4) /* SD_DATA2_R */
94             && (s->fsel[53] == 4) /* SD_DATA3_R */
95             ) {
96         /* SDHost controller selected */
97         sdbus_reparent_card(s->sdbus_sdhci, s->sdbus_sdhost);
98         s->sd_fsel = 4;
99     }
100 }
101 
102 static int gpfsel_is_out(BCM2835GpioState *s, int index)
103 {
104     if (index >= 0 && index < 54) {
105         return s->fsel[index] == 1;
106     }
107     return 0;
108 }
109 
110 static void gpset(BCM2835GpioState *s,
111         uint32_t val, uint8_t start, uint8_t count, uint32_t *lev)
112 {
113     uint32_t changes = val & ~*lev;
114     uint32_t cur = 1;
115 
116     int i;
117     for (i = 0; i < count; i++) {
118         if ((changes & cur) && (gpfsel_is_out(s, start + i))) {
119             qemu_set_irq(s->out[start + i], 1);
120         }
121         cur <<= 1;
122     }
123 
124     *lev |= val;
125 }
126 
127 static void gpclr(BCM2835GpioState *s,
128         uint32_t val, uint8_t start, uint8_t count, uint32_t *lev)
129 {
130     uint32_t changes = val & *lev;
131     uint32_t cur = 1;
132 
133     int i;
134     for (i = 0; i < count; i++) {
135         if ((changes & cur) && (gpfsel_is_out(s, start + i))) {
136             qemu_set_irq(s->out[start + i], 0);
137         }
138         cur <<= 1;
139     }
140 
141     *lev &= ~val;
142 }
143 
144 static uint64_t bcm2835_gpio_read(void *opaque, hwaddr offset,
145         unsigned size)
146 {
147     BCM2835GpioState *s = (BCM2835GpioState *)opaque;
148 
149     switch (offset) {
150     case GPFSEL0:
151     case GPFSEL1:
152     case GPFSEL2:
153     case GPFSEL3:
154     case GPFSEL4:
155     case GPFSEL5:
156         return gpfsel_get(s, offset / 4);
157     case GPSET0:
158     case GPSET1:
159         /* Write Only */
160         return 0;
161     case GPCLR0:
162     case GPCLR1:
163         /* Write Only */
164         return 0;
165     case GPLEV0:
166         return s->lev0;
167     case GPLEV1:
168         return s->lev1;
169     case GPEDS0:
170     case GPEDS1:
171     case GPREN0:
172     case GPREN1:
173     case GPFEN0:
174     case GPFEN1:
175     case GPHEN0:
176     case GPHEN1:
177     case GPLEN0:
178     case GPLEN1:
179     case GPAREN0:
180     case GPAREN1:
181     case GPAFEN0:
182     case GPAFEN1:
183     case GPPUD:
184     case GPPUDCLK0:
185     case GPPUDCLK1:
186         /* Not implemented */
187         return 0;
188     default:
189         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
190                 __func__, offset);
191         break;
192     }
193 
194     return 0;
195 }
196 
197 static void bcm2835_gpio_write(void *opaque, hwaddr offset,
198         uint64_t value, unsigned size)
199 {
200     BCM2835GpioState *s = (BCM2835GpioState *)opaque;
201 
202     switch (offset) {
203     case GPFSEL0:
204     case GPFSEL1:
205     case GPFSEL2:
206     case GPFSEL3:
207     case GPFSEL4:
208     case GPFSEL5:
209         gpfsel_set(s, offset / 4, value);
210         break;
211     case GPSET0:
212         gpset(s, value, 0, 32, &s->lev0);
213         break;
214     case GPSET1:
215         gpset(s, value, 32, 22, &s->lev1);
216         break;
217     case GPCLR0:
218         gpclr(s, value, 0, 32, &s->lev0);
219         break;
220     case GPCLR1:
221         gpclr(s, value, 32, 22, &s->lev1);
222         break;
223     case GPLEV0:
224     case GPLEV1:
225         /* Read Only */
226         break;
227     case GPEDS0:
228     case GPEDS1:
229     case GPREN0:
230     case GPREN1:
231     case GPFEN0:
232     case GPFEN1:
233     case GPHEN0:
234     case GPHEN1:
235     case GPLEN0:
236     case GPLEN1:
237     case GPAREN0:
238     case GPAREN1:
239     case GPAFEN0:
240     case GPAFEN1:
241     case GPPUD:
242     case GPPUDCLK0:
243     case GPPUDCLK1:
244         /* Not implemented */
245         break;
246     default:
247         goto err_out;
248     }
249     return;
250 
251 err_out:
252     qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
253             __func__, offset);
254 }
255 
256 static void bcm2835_gpio_reset(DeviceState *dev)
257 {
258     BCM2835GpioState *s = BCM2835_GPIO(dev);
259 
260     int i;
261     for (i = 0; i < 6; i++) {
262         gpfsel_set(s, i, 0);
263     }
264 
265     s->sd_fsel = 0;
266 
267     /* SDHCI is selected by default */
268     sdbus_reparent_card(&s->sdbus, s->sdbus_sdhci);
269 
270     s->lev0 = 0;
271     s->lev1 = 0;
272 }
273 
274 static const MemoryRegionOps bcm2835_gpio_ops = {
275     .read = bcm2835_gpio_read,
276     .write = bcm2835_gpio_write,
277     .endianness = DEVICE_NATIVE_ENDIAN,
278 };
279 
280 static const VMStateDescription vmstate_bcm2835_gpio = {
281     .name = "bcm2835_gpio",
282     .version_id = 1,
283     .minimum_version_id = 1,
284     .fields = (VMStateField[]) {
285         VMSTATE_UINT8_ARRAY(fsel, BCM2835GpioState, 54),
286         VMSTATE_UINT32(lev0, BCM2835GpioState),
287         VMSTATE_UINT32(lev1, BCM2835GpioState),
288         VMSTATE_UINT8(sd_fsel, BCM2835GpioState),
289         VMSTATE_END_OF_LIST()
290     }
291 };
292 
293 static void bcm2835_gpio_init(Object *obj)
294 {
295     BCM2835GpioState *s = BCM2835_GPIO(obj);
296     DeviceState *dev = DEVICE(obj);
297     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
298 
299     qbus_create_inplace(&s->sdbus, sizeof(s->sdbus),
300                         TYPE_SD_BUS, DEVICE(s), "sd-bus");
301 
302     memory_region_init_io(&s->iomem, obj,
303             &bcm2835_gpio_ops, s, "bcm2835_gpio", 0x1000);
304     sysbus_init_mmio(sbd, &s->iomem);
305     qdev_init_gpio_out(dev, s->out, 54);
306 }
307 
308 static void bcm2835_gpio_realize(DeviceState *dev, Error **errp)
309 {
310     BCM2835GpioState *s = BCM2835_GPIO(dev);
311     Object *obj;
312     Error *err = NULL;
313 
314     obj = object_property_get_link(OBJECT(dev), "sdbus-sdhci", &err);
315     if (obj == NULL) {
316         error_setg(errp, "%s: required sdhci link not found: %s",
317                 __func__, error_get_pretty(err));
318         return;
319     }
320     s->sdbus_sdhci = SD_BUS(obj);
321 
322     obj = object_property_get_link(OBJECT(dev), "sdbus-sdhost", &err);
323     if (obj == NULL) {
324         error_setg(errp, "%s: required sdhost link not found: %s",
325                 __func__, error_get_pretty(err));
326         return;
327     }
328     s->sdbus_sdhost = SD_BUS(obj);
329 }
330 
331 static void bcm2835_gpio_class_init(ObjectClass *klass, void *data)
332 {
333     DeviceClass *dc = DEVICE_CLASS(klass);
334 
335     dc->vmsd = &vmstate_bcm2835_gpio;
336     dc->realize = &bcm2835_gpio_realize;
337     dc->reset = &bcm2835_gpio_reset;
338 }
339 
340 static const TypeInfo bcm2835_gpio_info = {
341     .name          = TYPE_BCM2835_GPIO,
342     .parent        = TYPE_SYS_BUS_DEVICE,
343     .instance_size = sizeof(BCM2835GpioState),
344     .instance_init = bcm2835_gpio_init,
345     .class_init    = bcm2835_gpio_class_init,
346 };
347 
348 static void bcm2835_gpio_register_types(void)
349 {
350     type_register_static(&bcm2835_gpio_info);
351 }
352 
353 type_init(bcm2835_gpio_register_types)
354