xref: /openbmc/qemu/hw/gpio/imx_gpio.c (revision 27c7275a)
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 "hw/gpio/imx_gpio.h"
21 
22 #ifndef DEBUG_IMX_GPIO
23 #define DEBUG_IMX_GPIO 0
24 #endif
25 
26 typedef enum IMXGPIOLevel {
27     IMX_GPIO_LEVEL_LOW = 0,
28     IMX_GPIO_LEVEL_HIGH = 1,
29 } IMXGPIOLevel;
30 
31 #define DPRINTF(fmt, args...) \
32           do { \
33               if (DEBUG_IMX_GPIO) { \
34                   fprintf(stderr, "%s: " fmt , __func__, ##args); \
35               } \
36           } while (0)
37 
38 static const char *imx_gpio_reg_name(uint32_t reg)
39 {
40     switch (reg) {
41     case DR_ADDR:
42         return "DR";
43     case GDIR_ADDR:
44         return "GDIR";
45     case PSR_ADDR:
46         return "PSR";
47     case ICR1_ADDR:
48         return "ICR1";
49     case ICR2_ADDR:
50         return "ICR2";
51     case IMR_ADDR:
52         return "IMR";
53     case ISR_ADDR:
54         return "ISR";
55     case EDGE_SEL_ADDR:
56         return "EDGE_SEL";
57     default:
58         return "[?]";
59     }
60 }
61 
62 static void imx_gpio_update_int(IMXGPIOState *s)
63 {
64     qemu_set_irq(s->irq, (s->isr & s->imr) ? 1 : 0);
65 }
66 
67 static void imx_gpio_set_int_line(IMXGPIOState *s, int line, IMXGPIOLevel level)
68 {
69     /* if this signal isn't configured as an input signal, nothing to do */
70     if (!extract32(s->gdir, line, 1)) {
71         return;
72     }
73 
74     /* When set, EDGE_SEL overrides the ICR config */
75     if (extract32(s->edge_sel, line, 1)) {
76         /* we detect interrupt on rising and falling edge */
77         if (extract32(s->psr, line, 1) != level) {
78             /* level changed */
79             s->isr = deposit32(s->isr, line, 1, 1);
80         }
81     } else if (extract64(s->icr, 2*line + 1, 1)) {
82         /* interrupt is edge sensitive */
83         if (extract32(s->psr, line, 1) != level) {
84             /* level changed */
85             if (extract64(s->icr, 2*line, 1) != level) {
86                 s->isr = deposit32(s->isr, line, 1, 1);
87             }
88         }
89     } else {
90         /* interrupt is level sensitive */
91         if (extract64(s->icr, 2*line, 1) == level) {
92             s->isr = deposit32(s->isr, line, 1, 1);
93         }
94     }
95 }
96 
97 static void imx_gpio_set(void *opaque, int line, int level)
98 {
99     IMXGPIOState *s = IMX_GPIO(opaque);
100     IMXGPIOLevel imx_level = level ? IMX_GPIO_LEVEL_HIGH : IMX_GPIO_LEVEL_LOW;
101 
102     imx_gpio_set_int_line(s, line, imx_level);
103 
104     /* this is an input signal, so set PSR */
105     s->psr = deposit32(s->psr, line, 1, imx_level);
106 
107     imx_gpio_update_int(s);
108 }
109 
110 static void imx_gpio_set_all_int_lines(IMXGPIOState *s)
111 {
112     int i;
113 
114     for (i = 0; i < IMX_GPIO_PIN_COUNT; i++) {
115         IMXGPIOLevel imx_level = extract32(s->psr, i, 1);
116         imx_gpio_set_int_line(s, i, imx_level);
117     }
118 
119     imx_gpio_update_int(s);
120 }
121 
122 static inline void imx_gpio_set_all_output_lines(IMXGPIOState *s)
123 {
124     int i;
125 
126     for (i = 0; i < IMX_GPIO_PIN_COUNT; i++) {
127         /*
128          * if the line is set as output, then forward the line
129          * level to its user.
130          */
131         if (extract32(s->gdir, i, 1) && s->output[i]) {
132             qemu_set_irq(s->output[i], extract32(s->dr, i, 1));
133         }
134     }
135 }
136 
137 static uint64_t imx_gpio_read(void *opaque, hwaddr offset, unsigned size)
138 {
139     IMXGPIOState *s = IMX_GPIO(opaque);
140     uint32_t reg_value = 0;
141 
142     switch (offset) {
143     case DR_ADDR:
144         /*
145          * depending on the "line" configuration, the bit values
146          * are coming either from DR or PSR
147          */
148         reg_value = (s->dr & s->gdir) | (s->psr & ~s->gdir);
149         break;
150 
151     case GDIR_ADDR:
152         reg_value = s->gdir;
153         break;
154 
155     case PSR_ADDR:
156         reg_value = s->psr & ~s->gdir;
157         break;
158 
159     case ICR1_ADDR:
160         reg_value = extract64(s->icr, 0, 32);
161         break;
162 
163     case ICR2_ADDR:
164         reg_value = extract64(s->icr, 32, 32);
165         break;
166 
167     case IMR_ADDR:
168         reg_value = s->imr;
169         break;
170 
171     case ISR_ADDR:
172         reg_value = s->isr;
173         break;
174 
175     case EDGE_SEL_ADDR:
176         if (s->has_edge_sel) {
177             reg_value = s->edge_sel;
178         } else {
179             qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: EDGE_SEL register not "
180                           "present on this version of GPIO device\n",
181                           TYPE_IMX_GPIO, __func__);
182         }
183         break;
184 
185     default:
186         qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: Bad register at offset %d\n",
187                       TYPE_IMX_GPIO, __func__, (int)offset);
188         break;
189     }
190 
191     DPRINTF("(%s) = 0x%"PRIx32"\n", imx_gpio_reg_name(offset), reg_value);
192 
193     return reg_value;
194 }
195 
196 static void imx_gpio_write(void *opaque, hwaddr offset, uint64_t value,
197                            unsigned size)
198 {
199     IMXGPIOState *s = IMX_GPIO(opaque);
200 
201     DPRINTF("(%s, value = 0x%"PRIx32")\n", imx_gpio_reg_name(offset),
202             (uint32_t)value);
203 
204     switch (offset) {
205     case DR_ADDR:
206         s->dr = value;
207         imx_gpio_set_all_output_lines(s);
208         break;
209 
210     case GDIR_ADDR:
211         s->gdir = value;
212         imx_gpio_set_all_output_lines(s);
213         imx_gpio_set_all_int_lines(s);
214         break;
215 
216     case ICR1_ADDR:
217         s->icr = deposit64(s->icr, 0, 32, value);
218         imx_gpio_set_all_int_lines(s);
219         break;
220 
221     case ICR2_ADDR:
222         s->icr = deposit64(s->icr, 32, 32, value);
223         imx_gpio_set_all_int_lines(s);
224         break;
225 
226     case IMR_ADDR:
227         s->imr = value;
228         imx_gpio_update_int(s);
229         break;
230 
231     case ISR_ADDR:
232         s->isr |= ~value;
233         imx_gpio_set_all_int_lines(s);
234         break;
235 
236     case EDGE_SEL_ADDR:
237         if (s->has_edge_sel) {
238             s->edge_sel = value;
239             imx_gpio_set_all_int_lines(s);
240         } else {
241             qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: EDGE_SEL register not "
242                           "present on this version of GPIO device\n",
243                           TYPE_IMX_GPIO, __func__);
244         }
245         break;
246 
247     default:
248         qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: Bad register at offset %d\n",
249                       TYPE_IMX_GPIO, __func__, (int)offset);
250         break;
251     }
252 
253     return;
254 }
255 
256 static const MemoryRegionOps imx_gpio_ops = {
257     .read = imx_gpio_read,
258     .write = imx_gpio_write,
259     .valid.min_access_size = 4,
260     .valid.max_access_size = 4,
261     .endianness = DEVICE_NATIVE_ENDIAN,
262 };
263 
264 static const VMStateDescription vmstate_imx_gpio = {
265     .name = TYPE_IMX_GPIO,
266     .version_id = 1,
267     .minimum_version_id = 1,
268     .minimum_version_id_old = 1,
269     .fields = (VMStateField[]) {
270         VMSTATE_UINT32(dr, IMXGPIOState),
271         VMSTATE_UINT32(gdir, IMXGPIOState),
272         VMSTATE_UINT32(psr, IMXGPIOState),
273         VMSTATE_UINT64(icr, IMXGPIOState),
274         VMSTATE_UINT32(imr, IMXGPIOState),
275         VMSTATE_UINT32(isr, IMXGPIOState),
276         VMSTATE_BOOL(has_edge_sel, IMXGPIOState),
277         VMSTATE_UINT32(edge_sel, IMXGPIOState),
278         VMSTATE_END_OF_LIST()
279     }
280 };
281 
282 static Property imx_gpio_properties[] = {
283     DEFINE_PROP_BOOL("has-edge-sel", IMXGPIOState, has_edge_sel, true),
284     DEFINE_PROP_END_OF_LIST(),
285 };
286 
287 static void imx_gpio_reset(DeviceState *dev)
288 {
289     IMXGPIOState *s = IMX_GPIO(dev);
290 
291     s->dr       = 0;
292     s->gdir     = 0;
293     s->psr      = 0;
294     s->icr      = 0;
295     s->imr      = 0;
296     s->isr      = 0;
297     s->edge_sel = 0;
298 
299     imx_gpio_set_all_output_lines(s);
300     imx_gpio_update_int(s);
301 }
302 
303 static void imx_gpio_realize(DeviceState *dev, Error **errp)
304 {
305     IMXGPIOState *s = IMX_GPIO(dev);
306 
307     memory_region_init_io(&s->iomem, OBJECT(s), &imx_gpio_ops, s,
308                           TYPE_IMX_GPIO, IMX_GPIO_MEM_SIZE);
309 
310     qdev_init_gpio_in(DEVICE(s), imx_gpio_set, IMX_GPIO_PIN_COUNT);
311     qdev_init_gpio_out(DEVICE(s), s->output, IMX_GPIO_PIN_COUNT);
312 
313     sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq);
314     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
315 }
316 
317 static void imx_gpio_class_init(ObjectClass *klass, void *data)
318 {
319     DeviceClass *dc = DEVICE_CLASS(klass);
320 
321     dc->realize = imx_gpio_realize;
322     dc->reset = imx_gpio_reset;
323     dc->props = imx_gpio_properties;
324     dc->vmsd = &vmstate_imx_gpio;
325     dc->desc = "i.MX GPIO controller";
326 }
327 
328 static const TypeInfo imx_gpio_info = {
329     .name = TYPE_IMX_GPIO,
330     .parent = TYPE_SYS_BUS_DEVICE,
331     .instance_size = sizeof(IMXGPIOState),
332     .class_init = imx_gpio_class_init,
333 };
334 
335 static void imx_gpio_register_types(void)
336 {
337     type_register_static(&imx_gpio_info);
338 }
339 
340 type_init(imx_gpio_register_types)
341