xref: /openbmc/qemu/hw/gpio/imx_gpio.c (revision 9c4218e9)
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 
23 #ifndef DEBUG_IMX_GPIO
24 #define DEBUG_IMX_GPIO 0
25 #endif
26 
27 typedef enum IMXGPIOLevel {
28     IMX_GPIO_LEVEL_LOW = 0,
29     IMX_GPIO_LEVEL_HIGH = 1,
30 } IMXGPIOLevel;
31 
32 #define DPRINTF(fmt, args...) \
33     do { \
34         if (DEBUG_IMX_GPIO) { \
35             fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_GPIO, \
36                                              __func__, ##args); \
37         } \
38     } while (0)
39 
40 static const char *imx_gpio_reg_name(uint32_t reg)
41 {
42     switch (reg) {
43     case DR_ADDR:
44         return "DR";
45     case GDIR_ADDR:
46         return "GDIR";
47     case PSR_ADDR:
48         return "PSR";
49     case ICR1_ADDR:
50         return "ICR1";
51     case ICR2_ADDR:
52         return "ICR2";
53     case IMR_ADDR:
54         return "IMR";
55     case ISR_ADDR:
56         return "ISR";
57     case EDGE_SEL_ADDR:
58         return "EDGE_SEL";
59     default:
60         return "[?]";
61     }
62 }
63 
64 static void imx_gpio_update_int(IMXGPIOState *s)
65 {
66     if (s->has_upper_pin_irq) {
67         qemu_set_irq(s->irq[0], (s->isr & s->imr & 0x0000FFFF) ? 1 : 0);
68         qemu_set_irq(s->irq[1], (s->isr & s->imr & 0xFFFF0000) ? 1 : 0);
69     } else {
70         qemu_set_irq(s->irq[0], (s->isr & s->imr) ? 1 : 0);
71     }
72 }
73 
74 static void imx_gpio_set_int_line(IMXGPIOState *s, int line, IMXGPIOLevel level)
75 {
76     /* if this signal isn't configured as an input signal, nothing to do */
77     if (!extract32(s->gdir, line, 1)) {
78         return;
79     }
80 
81     /* When set, EDGE_SEL overrides the ICR config */
82     if (extract32(s->edge_sel, line, 1)) {
83         /* we detect interrupt on rising and falling edge */
84         if (extract32(s->psr, line, 1) != level) {
85             /* level changed */
86             s->isr = deposit32(s->isr, line, 1, 1);
87         }
88     } else if (extract64(s->icr, 2*line + 1, 1)) {
89         /* interrupt is edge sensitive */
90         if (extract32(s->psr, line, 1) != level) {
91             /* level changed */
92             if (extract64(s->icr, 2*line, 1) != level) {
93                 s->isr = deposit32(s->isr, line, 1, 1);
94             }
95         }
96     } else {
97         /* interrupt is level sensitive */
98         if (extract64(s->icr, 2*line, 1) == level) {
99             s->isr = deposit32(s->isr, line, 1, 1);
100         }
101     }
102 }
103 
104 static void imx_gpio_set(void *opaque, int line, int level)
105 {
106     IMXGPIOState *s = IMX_GPIO(opaque);
107     IMXGPIOLevel imx_level = level ? IMX_GPIO_LEVEL_HIGH : IMX_GPIO_LEVEL_LOW;
108 
109     imx_gpio_set_int_line(s, line, imx_level);
110 
111     /* this is an input signal, so set PSR */
112     s->psr = deposit32(s->psr, line, 1, imx_level);
113 
114     imx_gpio_update_int(s);
115 }
116 
117 static void imx_gpio_set_all_int_lines(IMXGPIOState *s)
118 {
119     int i;
120 
121     for (i = 0; i < IMX_GPIO_PIN_COUNT; i++) {
122         IMXGPIOLevel imx_level = extract32(s->psr, i, 1);
123         imx_gpio_set_int_line(s, i, imx_level);
124     }
125 
126     imx_gpio_update_int(s);
127 }
128 
129 static inline void imx_gpio_set_all_output_lines(IMXGPIOState *s)
130 {
131     int i;
132 
133     for (i = 0; i < IMX_GPIO_PIN_COUNT; i++) {
134         /*
135          * if the line is set as output, then forward the line
136          * level to its user.
137          */
138         if (extract32(s->gdir, i, 1) && s->output[i]) {
139             qemu_set_irq(s->output[i], extract32(s->dr, i, 1));
140         }
141     }
142 }
143 
144 static uint64_t imx_gpio_read(void *opaque, hwaddr offset, unsigned size)
145 {
146     IMXGPIOState *s = IMX_GPIO(opaque);
147     uint32_t reg_value = 0;
148 
149     switch (offset) {
150     case DR_ADDR:
151         /*
152          * depending on the "line" configuration, the bit values
153          * are coming either from DR or PSR
154          */
155         reg_value = (s->dr & s->gdir) | (s->psr & ~s->gdir);
156         break;
157 
158     case GDIR_ADDR:
159         reg_value = s->gdir;
160         break;
161 
162     case PSR_ADDR:
163         reg_value = s->psr & ~s->gdir;
164         break;
165 
166     case ICR1_ADDR:
167         reg_value = extract64(s->icr, 0, 32);
168         break;
169 
170     case ICR2_ADDR:
171         reg_value = extract64(s->icr, 32, 32);
172         break;
173 
174     case IMR_ADDR:
175         reg_value = s->imr;
176         break;
177 
178     case ISR_ADDR:
179         reg_value = s->isr;
180         break;
181 
182     case EDGE_SEL_ADDR:
183         if (s->has_edge_sel) {
184             reg_value = s->edge_sel;
185         } else {
186             qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: EDGE_SEL register not "
187                           "present on this version of GPIO device\n",
188                           TYPE_IMX_GPIO, __func__);
189         }
190         break;
191 
192     default:
193         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
194                       HWADDR_PRIx "\n", TYPE_IMX_GPIO, __func__, offset);
195         break;
196     }
197 
198     DPRINTF("(%s) = 0x%" PRIx32 "\n", imx_gpio_reg_name(offset), reg_value);
199 
200     return reg_value;
201 }
202 
203 static void imx_gpio_write(void *opaque, hwaddr offset, uint64_t value,
204                            unsigned size)
205 {
206     IMXGPIOState *s = IMX_GPIO(opaque);
207 
208     DPRINTF("(%s, value = 0x%" PRIx32 ")\n", imx_gpio_reg_name(offset),
209             (uint32_t)value);
210 
211     switch (offset) {
212     case DR_ADDR:
213         s->dr = value;
214         imx_gpio_set_all_output_lines(s);
215         break;
216 
217     case GDIR_ADDR:
218         s->gdir = value;
219         imx_gpio_set_all_output_lines(s);
220         imx_gpio_set_all_int_lines(s);
221         break;
222 
223     case ICR1_ADDR:
224         s->icr = deposit64(s->icr, 0, 32, value);
225         imx_gpio_set_all_int_lines(s);
226         break;
227 
228     case ICR2_ADDR:
229         s->icr = deposit64(s->icr, 32, 32, value);
230         imx_gpio_set_all_int_lines(s);
231         break;
232 
233     case IMR_ADDR:
234         s->imr = value;
235         imx_gpio_update_int(s);
236         break;
237 
238     case ISR_ADDR:
239         s->isr |= ~value;
240         imx_gpio_set_all_int_lines(s);
241         break;
242 
243     case EDGE_SEL_ADDR:
244         if (s->has_edge_sel) {
245             s->edge_sel = value;
246             imx_gpio_set_all_int_lines(s);
247         } else {
248             qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: EDGE_SEL register not "
249                           "present on this version of GPIO device\n",
250                           TYPE_IMX_GPIO, __func__);
251         }
252         break;
253 
254     default:
255         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
256                       HWADDR_PRIx "\n", TYPE_IMX_GPIO, __func__, offset);
257         break;
258     }
259 
260     return;
261 }
262 
263 static const MemoryRegionOps imx_gpio_ops = {
264     .read = imx_gpio_read,
265     .write = imx_gpio_write,
266     .valid.min_access_size = 4,
267     .valid.max_access_size = 4,
268     .endianness = DEVICE_NATIVE_ENDIAN,
269 };
270 
271 static const VMStateDescription vmstate_imx_gpio = {
272     .name = TYPE_IMX_GPIO,
273     .version_id = 1,
274     .minimum_version_id = 1,
275     .minimum_version_id_old = 1,
276     .fields = (VMStateField[]) {
277         VMSTATE_UINT32(dr, IMXGPIOState),
278         VMSTATE_UINT32(gdir, IMXGPIOState),
279         VMSTATE_UINT32(psr, IMXGPIOState),
280         VMSTATE_UINT64(icr, IMXGPIOState),
281         VMSTATE_UINT32(imr, IMXGPIOState),
282         VMSTATE_UINT32(isr, IMXGPIOState),
283         VMSTATE_BOOL(has_edge_sel, IMXGPIOState),
284         VMSTATE_UINT32(edge_sel, IMXGPIOState),
285         VMSTATE_END_OF_LIST()
286     }
287 };
288 
289 static Property imx_gpio_properties[] = {
290     DEFINE_PROP_BOOL("has-edge-sel", IMXGPIOState, has_edge_sel, true),
291     DEFINE_PROP_BOOL("has-upper-pin-irq", IMXGPIOState, has_upper_pin_irq,
292                      false),
293     DEFINE_PROP_END_OF_LIST(),
294 };
295 
296 static void imx_gpio_reset(DeviceState *dev)
297 {
298     IMXGPIOState *s = IMX_GPIO(dev);
299 
300     s->dr       = 0;
301     s->gdir     = 0;
302     s->psr      = 0;
303     s->icr      = 0;
304     s->imr      = 0;
305     s->isr      = 0;
306     s->edge_sel = 0;
307 
308     imx_gpio_set_all_output_lines(s);
309     imx_gpio_update_int(s);
310 }
311 
312 static void imx_gpio_realize(DeviceState *dev, Error **errp)
313 {
314     IMXGPIOState *s = IMX_GPIO(dev);
315 
316     memory_region_init_io(&s->iomem, OBJECT(s), &imx_gpio_ops, s,
317                           TYPE_IMX_GPIO, IMX_GPIO_MEM_SIZE);
318 
319     qdev_init_gpio_in(DEVICE(s), imx_gpio_set, IMX_GPIO_PIN_COUNT);
320     qdev_init_gpio_out(DEVICE(s), s->output, IMX_GPIO_PIN_COUNT);
321 
322     sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq[0]);
323     sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq[1]);
324     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
325 }
326 
327 static void imx_gpio_class_init(ObjectClass *klass, void *data)
328 {
329     DeviceClass *dc = DEVICE_CLASS(klass);
330 
331     dc->realize = imx_gpio_realize;
332     dc->reset = imx_gpio_reset;
333     dc->props = imx_gpio_properties;
334     dc->vmsd = &vmstate_imx_gpio;
335     dc->desc = "i.MX GPIO controller";
336 }
337 
338 static const TypeInfo imx_gpio_info = {
339     .name = TYPE_IMX_GPIO,
340     .parent = TYPE_SYS_BUS_DEVICE,
341     .instance_size = sizeof(IMXGPIOState),
342     .class_init = imx_gpio_class_init,
343 };
344 
345 static void imx_gpio_register_types(void)
346 {
347     type_register_static(&imx_gpio_info);
348 }
349 
350 type_init(imx_gpio_register_types)
351