xref: /openbmc/qemu/hw/gpio/imx_gpio.c (revision 500eb6db)
1 /*
2  * i.MX processors GPIO emulation.
3  *
4  * Copyright (C) 2015 Jean-Christophe Dubois <jcd@tribudubois.net>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 or
9  * (at your option) version 3 of the License.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "hw/gpio/imx_gpio.h"
22 #include "qemu/log.h"
23 #include "qemu/module.h"
24 
25 #ifndef DEBUG_IMX_GPIO
26 #define DEBUG_IMX_GPIO 0
27 #endif
28 
29 typedef enum IMXGPIOLevel {
30     IMX_GPIO_LEVEL_LOW = 0,
31     IMX_GPIO_LEVEL_HIGH = 1,
32 } IMXGPIOLevel;
33 
34 #define DPRINTF(fmt, args...) \
35     do { \
36         if (DEBUG_IMX_GPIO) { \
37             fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_GPIO, \
38                                              __func__, ##args); \
39         } \
40     } while (0)
41 
42 static const char *imx_gpio_reg_name(uint32_t reg)
43 {
44     switch (reg) {
45     case DR_ADDR:
46         return "DR";
47     case GDIR_ADDR:
48         return "GDIR";
49     case PSR_ADDR:
50         return "PSR";
51     case ICR1_ADDR:
52         return "ICR1";
53     case ICR2_ADDR:
54         return "ICR2";
55     case IMR_ADDR:
56         return "IMR";
57     case ISR_ADDR:
58         return "ISR";
59     case EDGE_SEL_ADDR:
60         return "EDGE_SEL";
61     default:
62         return "[?]";
63     }
64 }
65 
66 static void imx_gpio_update_int(IMXGPIOState *s)
67 {
68     if (s->has_upper_pin_irq) {
69         qemu_set_irq(s->irq[0], (s->isr & s->imr & 0x0000FFFF) ? 1 : 0);
70         qemu_set_irq(s->irq[1], (s->isr & s->imr & 0xFFFF0000) ? 1 : 0);
71     } else {
72         qemu_set_irq(s->irq[0], (s->isr & s->imr) ? 1 : 0);
73     }
74 }
75 
76 static void imx_gpio_set_int_line(IMXGPIOState *s, int line, IMXGPIOLevel level)
77 {
78     /* if this signal isn't configured as an input signal, nothing to do */
79     if (!extract32(s->gdir, line, 1)) {
80         return;
81     }
82 
83     /* When set, EDGE_SEL overrides the ICR config */
84     if (extract32(s->edge_sel, line, 1)) {
85         /* we detect interrupt on rising and falling edge */
86         if (extract32(s->psr, line, 1) != level) {
87             /* level changed */
88             s->isr = deposit32(s->isr, line, 1, 1);
89         }
90     } else if (extract64(s->icr, 2*line + 1, 1)) {
91         /* interrupt is edge sensitive */
92         if (extract32(s->psr, line, 1) != level) {
93             /* level changed */
94             if (extract64(s->icr, 2*line, 1) != level) {
95                 s->isr = deposit32(s->isr, line, 1, 1);
96             }
97         }
98     } else {
99         /* interrupt is level sensitive */
100         if (extract64(s->icr, 2*line, 1) == level) {
101             s->isr = deposit32(s->isr, line, 1, 1);
102         }
103     }
104 }
105 
106 static void imx_gpio_set(void *opaque, int line, int level)
107 {
108     IMXGPIOState *s = IMX_GPIO(opaque);
109     IMXGPIOLevel imx_level = level ? IMX_GPIO_LEVEL_HIGH : IMX_GPIO_LEVEL_LOW;
110 
111     imx_gpio_set_int_line(s, line, imx_level);
112 
113     /* this is an input signal, so set PSR */
114     s->psr = deposit32(s->psr, line, 1, imx_level);
115 
116     imx_gpio_update_int(s);
117 }
118 
119 static void imx_gpio_set_all_int_lines(IMXGPIOState *s)
120 {
121     int i;
122 
123     for (i = 0; i < IMX_GPIO_PIN_COUNT; i++) {
124         IMXGPIOLevel imx_level = extract32(s->psr, i, 1);
125         imx_gpio_set_int_line(s, i, imx_level);
126     }
127 
128     imx_gpio_update_int(s);
129 }
130 
131 static inline void imx_gpio_set_all_output_lines(IMXGPIOState *s)
132 {
133     int i;
134 
135     for (i = 0; i < IMX_GPIO_PIN_COUNT; i++) {
136         /*
137          * if the line is set as output, then forward the line
138          * level to its user.
139          */
140         if (extract32(s->gdir, i, 1) && s->output[i]) {
141             qemu_set_irq(s->output[i], extract32(s->dr, i, 1));
142         }
143     }
144 }
145 
146 static uint64_t imx_gpio_read(void *opaque, hwaddr offset, unsigned size)
147 {
148     IMXGPIOState *s = IMX_GPIO(opaque);
149     uint32_t reg_value = 0;
150 
151     switch (offset) {
152     case DR_ADDR:
153         /*
154          * depending on the "line" configuration, the bit values
155          * are coming either from DR or PSR
156          */
157         reg_value = (s->dr & s->gdir) | (s->psr & ~s->gdir);
158         break;
159 
160     case GDIR_ADDR:
161         reg_value = s->gdir;
162         break;
163 
164     case PSR_ADDR:
165         reg_value = s->psr & ~s->gdir;
166         break;
167 
168     case ICR1_ADDR:
169         reg_value = extract64(s->icr, 0, 32);
170         break;
171 
172     case ICR2_ADDR:
173         reg_value = extract64(s->icr, 32, 32);
174         break;
175 
176     case IMR_ADDR:
177         reg_value = s->imr;
178         break;
179 
180     case ISR_ADDR:
181         reg_value = s->isr;
182         break;
183 
184     case EDGE_SEL_ADDR:
185         if (s->has_edge_sel) {
186             reg_value = s->edge_sel;
187         } else {
188             qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: EDGE_SEL register not "
189                           "present on this version of GPIO device\n",
190                           TYPE_IMX_GPIO, __func__);
191         }
192         break;
193 
194     default:
195         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
196                       HWADDR_PRIx "\n", TYPE_IMX_GPIO, __func__, offset);
197         break;
198     }
199 
200     DPRINTF("(%s) = 0x%" PRIx32 "\n", imx_gpio_reg_name(offset), reg_value);
201 
202     return reg_value;
203 }
204 
205 static void imx_gpio_write(void *opaque, hwaddr offset, uint64_t value,
206                            unsigned size)
207 {
208     IMXGPIOState *s = IMX_GPIO(opaque);
209 
210     DPRINTF("(%s, value = 0x%" PRIx32 ")\n", imx_gpio_reg_name(offset),
211             (uint32_t)value);
212 
213     switch (offset) {
214     case DR_ADDR:
215         s->dr = value;
216         imx_gpio_set_all_output_lines(s);
217         break;
218 
219     case GDIR_ADDR:
220         s->gdir = value;
221         imx_gpio_set_all_output_lines(s);
222         imx_gpio_set_all_int_lines(s);
223         break;
224 
225     case ICR1_ADDR:
226         s->icr = deposit64(s->icr, 0, 32, value);
227         imx_gpio_set_all_int_lines(s);
228         break;
229 
230     case ICR2_ADDR:
231         s->icr = deposit64(s->icr, 32, 32, value);
232         imx_gpio_set_all_int_lines(s);
233         break;
234 
235     case IMR_ADDR:
236         s->imr = value;
237         imx_gpio_update_int(s);
238         break;
239 
240     case ISR_ADDR:
241         s->isr &= ~value;
242         imx_gpio_set_all_int_lines(s);
243         break;
244 
245     case EDGE_SEL_ADDR:
246         if (s->has_edge_sel) {
247             s->edge_sel = value;
248             imx_gpio_set_all_int_lines(s);
249         } else {
250             qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: EDGE_SEL register not "
251                           "present on this version of GPIO device\n",
252                           TYPE_IMX_GPIO, __func__);
253         }
254         break;
255 
256     default:
257         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
258                       HWADDR_PRIx "\n", TYPE_IMX_GPIO, __func__, offset);
259         break;
260     }
261 
262     return;
263 }
264 
265 static const MemoryRegionOps imx_gpio_ops = {
266     .read = imx_gpio_read,
267     .write = imx_gpio_write,
268     .valid.min_access_size = 4,
269     .valid.max_access_size = 4,
270     .endianness = DEVICE_NATIVE_ENDIAN,
271 };
272 
273 static const VMStateDescription vmstate_imx_gpio = {
274     .name = TYPE_IMX_GPIO,
275     .version_id = 1,
276     .minimum_version_id = 1,
277     .minimum_version_id_old = 1,
278     .fields = (VMStateField[]) {
279         VMSTATE_UINT32(dr, IMXGPIOState),
280         VMSTATE_UINT32(gdir, IMXGPIOState),
281         VMSTATE_UINT32(psr, IMXGPIOState),
282         VMSTATE_UINT64(icr, IMXGPIOState),
283         VMSTATE_UINT32(imr, IMXGPIOState),
284         VMSTATE_UINT32(isr, IMXGPIOState),
285         VMSTATE_BOOL(has_edge_sel, IMXGPIOState),
286         VMSTATE_UINT32(edge_sel, IMXGPIOState),
287         VMSTATE_END_OF_LIST()
288     }
289 };
290 
291 static Property imx_gpio_properties[] = {
292     DEFINE_PROP_BOOL("has-edge-sel", IMXGPIOState, has_edge_sel, true),
293     DEFINE_PROP_BOOL("has-upper-pin-irq", IMXGPIOState, has_upper_pin_irq,
294                      false),
295     DEFINE_PROP_END_OF_LIST(),
296 };
297 
298 static void imx_gpio_reset(DeviceState *dev)
299 {
300     IMXGPIOState *s = IMX_GPIO(dev);
301 
302     s->dr       = 0;
303     s->gdir     = 0;
304     s->psr      = 0;
305     s->icr      = 0;
306     s->imr      = 0;
307     s->isr      = 0;
308     s->edge_sel = 0;
309 
310     imx_gpio_set_all_output_lines(s);
311     imx_gpio_update_int(s);
312 }
313 
314 static void imx_gpio_realize(DeviceState *dev, Error **errp)
315 {
316     IMXGPIOState *s = IMX_GPIO(dev);
317 
318     memory_region_init_io(&s->iomem, OBJECT(s), &imx_gpio_ops, s,
319                           TYPE_IMX_GPIO, IMX_GPIO_MEM_SIZE);
320 
321     qdev_init_gpio_in(DEVICE(s), imx_gpio_set, IMX_GPIO_PIN_COUNT);
322     qdev_init_gpio_out(DEVICE(s), s->output, IMX_GPIO_PIN_COUNT);
323 
324     sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq[0]);
325     sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq[1]);
326     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
327 }
328 
329 static void imx_gpio_class_init(ObjectClass *klass, void *data)
330 {
331     DeviceClass *dc = DEVICE_CLASS(klass);
332 
333     dc->realize = imx_gpio_realize;
334     dc->reset = imx_gpio_reset;
335     dc->props = imx_gpio_properties;
336     dc->vmsd = &vmstate_imx_gpio;
337     dc->desc = "i.MX GPIO controller";
338 }
339 
340 static const TypeInfo imx_gpio_info = {
341     .name = TYPE_IMX_GPIO,
342     .parent = TYPE_SYS_BUS_DEVICE,
343     .instance_size = sizeof(IMXGPIOState),
344     .class_init = imx_gpio_class_init,
345 };
346 
347 static void imx_gpio_register_types(void)
348 {
349     type_register_static(&imx_gpio_info);
350 }
351 
352 type_init(imx_gpio_register_types)
353