xref: /openbmc/qemu/hw/gpio/sifive_gpio.c (revision effd60c8)
1 /*
2  * SiFive System-on-Chip general purpose input/output register definition
3  *
4  * Copyright 2019 AdaCore
5  *
6  * Base on nrf51_gpio.c:
7  *
8  * Copyright 2018 Steffen Görtz <contrib@steffen-goertz.de>
9  *
10  * This code is licensed under the GPL version 2 or later.  See
11  * the COPYING file in the top-level directory.
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qemu/log.h"
16 #include "hw/irq.h"
17 #include "hw/qdev-properties.h"
18 #include "hw/gpio/sifive_gpio.h"
19 #include "migration/vmstate.h"
20 #include "trace.h"
21 
22 static void update_output_irq(SIFIVEGPIOState *s)
23 {
24     uint32_t pending;
25     uint32_t pin;
26 
27     pending = s->high_ip & s->high_ie;
28     pending |= s->low_ip & s->low_ie;
29     pending |= s->rise_ip & s->rise_ie;
30     pending |= s->fall_ip & s->fall_ie;
31 
32     for (int i = 0; i < s->ngpio; i++) {
33         pin = 1 << i;
34         qemu_set_irq(s->irq[i], (pending & pin) != 0);
35         trace_sifive_gpio_update_output_irq(i, (pending & pin) != 0);
36     }
37 }
38 
39 static void update_state(SIFIVEGPIOState *s)
40 {
41     size_t i;
42     bool prev_ival, in, in_mask, port, out_xor, pull, output_en, input_en,
43         rise_ip, fall_ip, low_ip, high_ip, oval, actual_value, ival;
44 
45     for (i = 0; i < s->ngpio; i++) {
46 
47         prev_ival = extract32(s->value, i, 1);
48         in        = extract32(s->in, i, 1);
49         in_mask   = extract32(s->in_mask, i, 1);
50         port      = extract32(s->port, i, 1);
51         out_xor   = extract32(s->out_xor, i, 1);
52         pull      = extract32(s->pue, i, 1);
53         output_en = extract32(s->output_en, i, 1);
54         input_en  = extract32(s->input_en, i, 1);
55         rise_ip   = extract32(s->rise_ip, i, 1);
56         fall_ip   = extract32(s->fall_ip, i, 1);
57         low_ip    = extract32(s->low_ip, i, 1);
58         high_ip   = extract32(s->high_ip, i, 1);
59 
60         /* Output value (IOF not supported) */
61         oval = output_en && (port ^ out_xor);
62 
63         /* Pin both driven externally and internally */
64         if (output_en && in_mask) {
65             qemu_log_mask(LOG_GUEST_ERROR, "GPIO pin %zu short circuited\n", i);
66         }
67 
68         if (in_mask) {
69             /* The pin is driven by external device */
70             actual_value = in;
71         } else if (output_en) {
72             /* The pin is driven by internal circuit */
73             actual_value = oval;
74         } else {
75             /* Floating? Apply pull-up resistor */
76             actual_value = pull;
77         }
78 
79         if (output_en) {
80             qemu_set_irq(s->output[i], actual_value);
81         }
82 
83         /* Input value */
84         ival = input_en && actual_value;
85 
86         /* Interrupts */
87         high_ip = high_ip || ival;
88         s->high_ip = deposit32(s->high_ip, i, 1, high_ip);
89 
90         low_ip = low_ip || !ival;
91         s->low_ip = deposit32(s->low_ip,  i, 1, low_ip);
92 
93         rise_ip = rise_ip || (ival && !prev_ival);
94         s->rise_ip = deposit32(s->rise_ip, i, 1, rise_ip);
95 
96         fall_ip = fall_ip || (!ival && prev_ival);
97         s->fall_ip = deposit32(s->fall_ip, i, 1, fall_ip);
98 
99         /* Update value */
100         s->value = deposit32(s->value, i, 1, ival);
101     }
102     update_output_irq(s);
103 }
104 
105 static uint64_t sifive_gpio_read(void *opaque, hwaddr offset, unsigned int size)
106 {
107     SIFIVEGPIOState *s = SIFIVE_GPIO(opaque);
108     uint64_t r = 0;
109 
110     switch (offset) {
111     case SIFIVE_GPIO_REG_VALUE:
112         r = s->value;
113         break;
114 
115     case SIFIVE_GPIO_REG_INPUT_EN:
116         r = s->input_en;
117         break;
118 
119     case SIFIVE_GPIO_REG_OUTPUT_EN:
120         r = s->output_en;
121         break;
122 
123     case SIFIVE_GPIO_REG_PORT:
124         r = s->port;
125         break;
126 
127     case SIFIVE_GPIO_REG_PUE:
128         r = s->pue;
129         break;
130 
131     case SIFIVE_GPIO_REG_DS:
132         r = s->ds;
133         break;
134 
135     case SIFIVE_GPIO_REG_RISE_IE:
136         r = s->rise_ie;
137         break;
138 
139     case SIFIVE_GPIO_REG_RISE_IP:
140         r = s->rise_ip;
141         break;
142 
143     case SIFIVE_GPIO_REG_FALL_IE:
144         r = s->fall_ie;
145         break;
146 
147     case SIFIVE_GPIO_REG_FALL_IP:
148         r = s->fall_ip;
149         break;
150 
151     case SIFIVE_GPIO_REG_HIGH_IE:
152         r = s->high_ie;
153         break;
154 
155     case SIFIVE_GPIO_REG_HIGH_IP:
156         r = s->high_ip;
157         break;
158 
159     case SIFIVE_GPIO_REG_LOW_IE:
160         r = s->low_ie;
161         break;
162 
163     case SIFIVE_GPIO_REG_LOW_IP:
164         r = s->low_ip;
165         break;
166 
167     case SIFIVE_GPIO_REG_IOF_EN:
168         r = s->iof_en;
169         break;
170 
171     case SIFIVE_GPIO_REG_IOF_SEL:
172         r = s->iof_sel;
173         break;
174 
175     case SIFIVE_GPIO_REG_OUT_XOR:
176         r = s->out_xor;
177         break;
178 
179     default:
180         qemu_log_mask(LOG_GUEST_ERROR,
181                 "%s: bad read offset 0x%" HWADDR_PRIx "\n",
182                       __func__, offset);
183     }
184 
185     trace_sifive_gpio_read(offset, r);
186 
187     return r;
188 }
189 
190 static void sifive_gpio_write(void *opaque, hwaddr offset,
191                               uint64_t value, unsigned int size)
192 {
193     SIFIVEGPIOState *s = SIFIVE_GPIO(opaque);
194 
195     trace_sifive_gpio_write(offset, value);
196 
197     switch (offset) {
198 
199     case SIFIVE_GPIO_REG_INPUT_EN:
200         s->input_en = value;
201         break;
202 
203     case SIFIVE_GPIO_REG_OUTPUT_EN:
204         s->output_en = value;
205         break;
206 
207     case SIFIVE_GPIO_REG_PORT:
208         s->port = value;
209         break;
210 
211     case SIFIVE_GPIO_REG_PUE:
212         s->pue = value;
213         break;
214 
215     case SIFIVE_GPIO_REG_DS:
216         s->ds = value;
217         break;
218 
219     case SIFIVE_GPIO_REG_RISE_IE:
220         s->rise_ie = value;
221         break;
222 
223     case SIFIVE_GPIO_REG_RISE_IP:
224          /* Write 1 to clear */
225         s->rise_ip &= ~value;
226         break;
227 
228     case SIFIVE_GPIO_REG_FALL_IE:
229         s->fall_ie = value;
230         break;
231 
232     case SIFIVE_GPIO_REG_FALL_IP:
233          /* Write 1 to clear */
234         s->fall_ip &= ~value;
235         break;
236 
237     case SIFIVE_GPIO_REG_HIGH_IE:
238         s->high_ie = value;
239         break;
240 
241     case SIFIVE_GPIO_REG_HIGH_IP:
242          /* Write 1 to clear */
243         s->high_ip &= ~value;
244         break;
245 
246     case SIFIVE_GPIO_REG_LOW_IE:
247         s->low_ie = value;
248         break;
249 
250     case SIFIVE_GPIO_REG_LOW_IP:
251          /* Write 1 to clear */
252         s->low_ip &= ~value;
253         break;
254 
255     case SIFIVE_GPIO_REG_IOF_EN:
256         s->iof_en = value;
257         break;
258 
259     case SIFIVE_GPIO_REG_IOF_SEL:
260         s->iof_sel = value;
261         break;
262 
263     case SIFIVE_GPIO_REG_OUT_XOR:
264         s->out_xor = value;
265         break;
266 
267     default:
268         qemu_log_mask(LOG_GUEST_ERROR,
269                       "%s: bad write offset 0x%" HWADDR_PRIx "\n",
270                       __func__, offset);
271     }
272 
273     update_state(s);
274 }
275 
276 static const MemoryRegionOps gpio_ops = {
277     .read =  sifive_gpio_read,
278     .write = sifive_gpio_write,
279     .endianness = DEVICE_LITTLE_ENDIAN,
280     .impl.min_access_size = 4,
281     .impl.max_access_size = 4,
282 };
283 
284 static void sifive_gpio_set(void *opaque, int line, int value)
285 {
286     SIFIVEGPIOState *s = SIFIVE_GPIO(opaque);
287 
288     trace_sifive_gpio_set(line, value);
289 
290     assert(line >= 0 && line < SIFIVE_GPIO_PINS);
291 
292     s->in_mask = deposit32(s->in_mask, line, 1, value >= 0);
293     if (value >= 0) {
294         s->in = deposit32(s->in, line, 1, value != 0);
295     }
296 
297     update_state(s);
298 }
299 
300 static void sifive_gpio_reset(DeviceState *dev)
301 {
302     SIFIVEGPIOState *s = SIFIVE_GPIO(dev);
303 
304     s->value = 0;
305     s->input_en = 0;
306     s->output_en = 0;
307     s->port = 0;
308     s->pue = 0;
309     s->ds = 0;
310     s->rise_ie = 0;
311     s->rise_ip = 0;
312     s->fall_ie = 0;
313     s->fall_ip = 0;
314     s->high_ie = 0;
315     s->high_ip = 0;
316     s->low_ie = 0;
317     s->low_ip = 0;
318     s->iof_en = 0;
319     s->iof_sel = 0;
320     s->out_xor = 0;
321     s->in = 0;
322     s->in_mask = 0;
323 }
324 
325 static const VMStateDescription vmstate_sifive_gpio = {
326     .name = TYPE_SIFIVE_GPIO,
327     .version_id = 1,
328     .minimum_version_id = 1,
329     .fields = (const VMStateField[]) {
330         VMSTATE_UINT32(value,     SIFIVEGPIOState),
331         VMSTATE_UINT32(input_en,  SIFIVEGPIOState),
332         VMSTATE_UINT32(output_en, SIFIVEGPIOState),
333         VMSTATE_UINT32(port,      SIFIVEGPIOState),
334         VMSTATE_UINT32(pue,       SIFIVEGPIOState),
335         VMSTATE_UINT32(rise_ie,   SIFIVEGPIOState),
336         VMSTATE_UINT32(rise_ip,   SIFIVEGPIOState),
337         VMSTATE_UINT32(fall_ie,   SIFIVEGPIOState),
338         VMSTATE_UINT32(fall_ip,   SIFIVEGPIOState),
339         VMSTATE_UINT32(high_ie,   SIFIVEGPIOState),
340         VMSTATE_UINT32(high_ip,   SIFIVEGPIOState),
341         VMSTATE_UINT32(low_ie,    SIFIVEGPIOState),
342         VMSTATE_UINT32(low_ip,    SIFIVEGPIOState),
343         VMSTATE_UINT32(iof_en,    SIFIVEGPIOState),
344         VMSTATE_UINT32(iof_sel,   SIFIVEGPIOState),
345         VMSTATE_UINT32(out_xor,   SIFIVEGPIOState),
346         VMSTATE_UINT32(in,        SIFIVEGPIOState),
347         VMSTATE_UINT32(in_mask,   SIFIVEGPIOState),
348         VMSTATE_END_OF_LIST()
349     }
350 };
351 
352 static Property sifive_gpio_properties[] = {
353     DEFINE_PROP_UINT32("ngpio", SIFIVEGPIOState, ngpio, SIFIVE_GPIO_PINS),
354     DEFINE_PROP_END_OF_LIST(),
355 };
356 
357 static void sifive_gpio_realize(DeviceState *dev, Error **errp)
358 {
359     SIFIVEGPIOState *s = SIFIVE_GPIO(dev);
360 
361     memory_region_init_io(&s->mmio, OBJECT(dev), &gpio_ops, s,
362             TYPE_SIFIVE_GPIO, SIFIVE_GPIO_SIZE);
363 
364     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
365 
366     for (int i = 0; i < s->ngpio; i++) {
367         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq[i]);
368     }
369 
370     qdev_init_gpio_in(DEVICE(s), sifive_gpio_set, s->ngpio);
371     qdev_init_gpio_out(DEVICE(s), s->output, s->ngpio);
372 }
373 
374 static void sifive_gpio_class_init(ObjectClass *klass, void *data)
375 {
376     DeviceClass *dc = DEVICE_CLASS(klass);
377 
378     device_class_set_props(dc, sifive_gpio_properties);
379     dc->vmsd = &vmstate_sifive_gpio;
380     dc->realize = sifive_gpio_realize;
381     dc->reset = sifive_gpio_reset;
382     dc->desc = "SiFive GPIO";
383 }
384 
385 static const TypeInfo sifive_gpio_info = {
386     .name = TYPE_SIFIVE_GPIO,
387     .parent = TYPE_SYS_BUS_DEVICE,
388     .instance_size = sizeof(SIFIVEGPIOState),
389     .class_init = sifive_gpio_class_init
390 };
391 
392 static void sifive_gpio_register_types(void)
393 {
394     type_register_static(&sifive_gpio_info);
395 }
396 
397 type_init(sifive_gpio_register_types)
398