xref: /openbmc/qemu/hw/i2c/aspeed_i2c.c (revision 4a09d0bb)
1 /*
2  * ARM Aspeed I2C controller
3  *
4  * Copyright (C) 2016 IBM Corp.
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
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
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
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  *
19  */
20 
21 #include "qemu/osdep.h"
22 #include "hw/sysbus.h"
23 #include "qemu/log.h"
24 #include "hw/i2c/aspeed_i2c.h"
25 
26 /* I2C Global Register */
27 
28 #define I2C_CTRL_STATUS         0x00        /* Device Interrupt Status */
29 #define I2C_CTRL_ASSIGN         0x08        /* Device Interrupt Target
30                                                Assignment */
31 
32 /* I2C Device (Bus) Register */
33 
34 #define I2CD_FUN_CTRL_REG       0x00       /* I2CD Function Control  */
35 #define   I2CD_BUFF_SEL_MASK               (0x7 << 20)
36 #define   I2CD_BUFF_SEL(x)                 (x << 20)
37 #define   I2CD_M_SDA_LOCK_EN               (0x1 << 16)
38 #define   I2CD_MULTI_MASTER_DIS            (0x1 << 15)
39 #define   I2CD_M_SCL_DRIVE_EN              (0x1 << 14)
40 #define   I2CD_MSB_STS                     (0x1 << 9)
41 #define   I2CD_SDA_DRIVE_1T_EN             (0x1 << 8)
42 #define   I2CD_M_SDA_DRIVE_1T_EN           (0x1 << 7)
43 #define   I2CD_M_HIGH_SPEED_EN             (0x1 << 6)
44 #define   I2CD_DEF_ADDR_EN                 (0x1 << 5)
45 #define   I2CD_DEF_ALERT_EN                (0x1 << 4)
46 #define   I2CD_DEF_ARP_EN                  (0x1 << 3)
47 #define   I2CD_DEF_GCALL_EN                (0x1 << 2)
48 #define   I2CD_SLAVE_EN                    (0x1 << 1)
49 #define   I2CD_MASTER_EN                   (0x1)
50 
51 #define I2CD_AC_TIMING_REG1     0x04       /* Clock and AC Timing Control #1 */
52 #define I2CD_AC_TIMING_REG2     0x08       /* Clock and AC Timing Control #1 */
53 #define I2CD_INTR_CTRL_REG      0x0c       /* I2CD Interrupt Control */
54 #define I2CD_INTR_STS_REG       0x10       /* I2CD Interrupt Status */
55 #define   I2CD_INTR_SDA_DL_TIMEOUT         (0x1 << 14)
56 #define   I2CD_INTR_BUS_RECOVER_DONE       (0x1 << 13)
57 #define   I2CD_INTR_SMBUS_ALERT            (0x1 << 12) /* Bus [0-3] only */
58 #define   I2CD_INTR_SMBUS_ARP_ADDR         (0x1 << 11) /* Removed */
59 #define   I2CD_INTR_SMBUS_DEV_ALERT_ADDR   (0x1 << 10) /* Removed */
60 #define   I2CD_INTR_SMBUS_DEF_ADDR         (0x1 << 9)  /* Removed */
61 #define   I2CD_INTR_GCALL_ADDR             (0x1 << 8)  /* Removed */
62 #define   I2CD_INTR_SLAVE_MATCH            (0x1 << 7)  /* use RX_DONE */
63 #define   I2CD_INTR_SCL_TIMEOUT            (0x1 << 6)
64 #define   I2CD_INTR_ABNORMAL               (0x1 << 5)
65 #define   I2CD_INTR_NORMAL_STOP            (0x1 << 4)
66 #define   I2CD_INTR_ARBIT_LOSS             (0x1 << 3)
67 #define   I2CD_INTR_RX_DONE                (0x1 << 2)
68 #define   I2CD_INTR_TX_NAK                 (0x1 << 1)
69 #define   I2CD_INTR_TX_ACK                 (0x1 << 0)
70 
71 #define I2CD_CMD_REG            0x14       /* I2CD Command/Status */
72 #define   I2CD_SDA_OE                      (0x1 << 28)
73 #define   I2CD_SDA_O                       (0x1 << 27)
74 #define   I2CD_SCL_OE                      (0x1 << 26)
75 #define   I2CD_SCL_O                       (0x1 << 25)
76 #define   I2CD_TX_TIMING                   (0x1 << 24)
77 #define   I2CD_TX_STATUS                   (0x1 << 23)
78 
79 #define   I2CD_TX_STATE_SHIFT              19 /* Tx State Machine */
80 #define   I2CD_TX_STATE_MASK                  0xf
81 #define     I2CD_IDLE                         0x0
82 #define     I2CD_MACTIVE                      0x8
83 #define     I2CD_MSTART                       0x9
84 #define     I2CD_MSTARTR                      0xa
85 #define     I2CD_MSTOP                        0xb
86 #define     I2CD_MTXD                         0xc
87 #define     I2CD_MRXACK                       0xd
88 #define     I2CD_MRXD                         0xe
89 #define     I2CD_MTXACK                       0xf
90 #define     I2CD_SWAIT                        0x1
91 #define     I2CD_SRXD                         0x4
92 #define     I2CD_STXACK                       0x5
93 #define     I2CD_STXD                         0x6
94 #define     I2CD_SRXACK                       0x7
95 #define     I2CD_RECOVER                      0x3
96 
97 #define   I2CD_SCL_LINE_STS                (0x1 << 18)
98 #define   I2CD_SDA_LINE_STS                (0x1 << 17)
99 #define   I2CD_BUS_BUSY_STS                (0x1 << 16)
100 #define   I2CD_SDA_OE_OUT_DIR              (0x1 << 15)
101 #define   I2CD_SDA_O_OUT_DIR               (0x1 << 14)
102 #define   I2CD_SCL_OE_OUT_DIR              (0x1 << 13)
103 #define   I2CD_SCL_O_OUT_DIR               (0x1 << 12)
104 #define   I2CD_BUS_RECOVER_CMD_EN          (0x1 << 11)
105 #define   I2CD_S_ALT_EN                    (0x1 << 10)
106 #define   I2CD_RX_DMA_ENABLE               (0x1 << 9)
107 #define   I2CD_TX_DMA_ENABLE               (0x1 << 8)
108 
109 /* Command Bit */
110 #define   I2CD_M_STOP_CMD                  (0x1 << 5)
111 #define   I2CD_M_S_RX_CMD_LAST             (0x1 << 4)
112 #define   I2CD_M_RX_CMD                    (0x1 << 3)
113 #define   I2CD_S_TX_CMD                    (0x1 << 2)
114 #define   I2CD_M_TX_CMD                    (0x1 << 1)
115 #define   I2CD_M_START_CMD                 (0x1)
116 
117 #define I2CD_DEV_ADDR_REG       0x18       /* Slave Device Address */
118 #define I2CD_BUF_CTRL_REG       0x1c       /* Pool Buffer Control */
119 #define I2CD_BYTE_BUF_REG       0x20       /* Transmit/Receive Byte Buffer */
120 #define   I2CD_BYTE_BUF_TX_SHIFT           0
121 #define   I2CD_BYTE_BUF_TX_MASK            0xff
122 #define   I2CD_BYTE_BUF_RX_SHIFT           8
123 #define   I2CD_BYTE_BUF_RX_MASK            0xff
124 
125 
126 static inline bool aspeed_i2c_bus_is_master(AspeedI2CBus *bus)
127 {
128     return bus->ctrl & I2CD_MASTER_EN;
129 }
130 
131 static inline bool aspeed_i2c_bus_is_enabled(AspeedI2CBus *bus)
132 {
133     return bus->ctrl & (I2CD_MASTER_EN | I2CD_SLAVE_EN);
134 }
135 
136 static inline void aspeed_i2c_bus_raise_interrupt(AspeedI2CBus *bus)
137 {
138     bus->intr_status &= bus->intr_ctrl;
139     if (bus->intr_status) {
140         bus->controller->intr_status |= 1 << bus->id;
141         qemu_irq_raise(bus->controller->irq);
142     }
143 }
144 
145 static uint64_t aspeed_i2c_bus_read(void *opaque, hwaddr offset,
146                                     unsigned size)
147 {
148     AspeedI2CBus *bus = opaque;
149 
150     switch (offset) {
151     case I2CD_FUN_CTRL_REG:
152         return bus->ctrl;
153     case I2CD_AC_TIMING_REG1:
154         return bus->timing[0];
155     case I2CD_AC_TIMING_REG2:
156         return bus->timing[1];
157     case I2CD_INTR_CTRL_REG:
158         return bus->intr_ctrl;
159     case I2CD_INTR_STS_REG:
160         return bus->intr_status;
161     case I2CD_BYTE_BUF_REG:
162         return bus->buf;
163     case I2CD_CMD_REG:
164         return bus->cmd | (i2c_bus_busy(bus->bus) << 16);
165     default:
166         qemu_log_mask(LOG_GUEST_ERROR,
167                       "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset);
168         return -1;
169     }
170 }
171 
172 static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value)
173 {
174     bus->cmd |= value & 0xFFFF;
175     bus->intr_status = 0;
176 
177     if (bus->cmd & I2CD_M_START_CMD) {
178         if (i2c_start_transfer(bus->bus, extract32(bus->buf, 1, 7),
179                                extract32(bus->buf, 0, 1))) {
180             bus->intr_status |= I2CD_INTR_TX_NAK;
181         } else {
182             bus->intr_status |= I2CD_INTR_TX_ACK;
183         }
184 
185     } else if (bus->cmd & I2CD_M_TX_CMD) {
186         if (i2c_send(bus->bus, bus->buf)) {
187             bus->intr_status |= (I2CD_INTR_TX_NAK | I2CD_INTR_ABNORMAL);
188             i2c_end_transfer(bus->bus);
189         } else {
190             bus->intr_status |= I2CD_INTR_TX_ACK;
191         }
192 
193     } else if (bus->cmd & I2CD_M_RX_CMD) {
194         int ret = i2c_recv(bus->bus);
195         if (ret < 0) {
196             qemu_log_mask(LOG_GUEST_ERROR, "%s: read failed\n", __func__);
197             ret = 0xff;
198         } else {
199             bus->intr_status |= I2CD_INTR_RX_DONE;
200         }
201         bus->buf = (ret & I2CD_BYTE_BUF_RX_MASK) << I2CD_BYTE_BUF_RX_SHIFT;
202     }
203 
204     if (bus->cmd & (I2CD_M_STOP_CMD | I2CD_M_S_RX_CMD_LAST)) {
205         if (!i2c_bus_busy(bus->bus)) {
206             bus->intr_status |= I2CD_INTR_ABNORMAL;
207         } else {
208             i2c_end_transfer(bus->bus);
209             bus->intr_status |= I2CD_INTR_NORMAL_STOP;
210         }
211     }
212 
213     /* command is handled, reset it and check for interrupts  */
214     bus->cmd &= ~0xFFFF;
215     aspeed_i2c_bus_raise_interrupt(bus);
216 }
217 
218 static void aspeed_i2c_bus_write(void *opaque, hwaddr offset,
219                                  uint64_t value, unsigned size)
220 {
221     AspeedI2CBus *bus = opaque;
222 
223     switch (offset) {
224     case I2CD_FUN_CTRL_REG:
225         if (value & I2CD_SLAVE_EN) {
226             qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
227                           __func__);
228             break;
229         }
230         bus->ctrl = value & 0x0071C3FF;
231         break;
232     case I2CD_AC_TIMING_REG1:
233         bus->timing[0] = value & 0xFFFFF0F;
234         break;
235     case I2CD_AC_TIMING_REG2:
236         bus->timing[1] = value & 0x7;
237         break;
238     case I2CD_INTR_CTRL_REG:
239         bus->intr_ctrl = value & 0x7FFF;
240         break;
241     case I2CD_INTR_STS_REG:
242         bus->intr_status &= ~(value & 0x7FFF);
243         bus->controller->intr_status &= ~(1 << bus->id);
244         qemu_irq_lower(bus->controller->irq);
245         break;
246     case I2CD_DEV_ADDR_REG:
247         qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
248                       __func__);
249         break;
250     case I2CD_BYTE_BUF_REG:
251         bus->buf = (value & I2CD_BYTE_BUF_TX_MASK) << I2CD_BYTE_BUF_TX_SHIFT;
252         break;
253     case I2CD_CMD_REG:
254         if (!aspeed_i2c_bus_is_enabled(bus)) {
255             break;
256         }
257 
258         if (!aspeed_i2c_bus_is_master(bus)) {
259             qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
260                           __func__);
261             break;
262         }
263 
264         aspeed_i2c_bus_handle_cmd(bus, value);
265         break;
266 
267     default:
268         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
269                       __func__, offset);
270     }
271 }
272 
273 static uint64_t aspeed_i2c_ctrl_read(void *opaque, hwaddr offset,
274                                    unsigned size)
275 {
276     AspeedI2CState *s = opaque;
277 
278     switch (offset) {
279     case I2C_CTRL_STATUS:
280         return s->intr_status;
281     default:
282         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
283                       __func__, offset);
284         break;
285     }
286 
287     return -1;
288 }
289 
290 static void aspeed_i2c_ctrl_write(void *opaque, hwaddr offset,
291                                   uint64_t value, unsigned size)
292 {
293     switch (offset) {
294     case I2C_CTRL_STATUS:
295     default:
296         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
297                       __func__, offset);
298         break;
299     }
300 }
301 
302 static const MemoryRegionOps aspeed_i2c_bus_ops = {
303     .read = aspeed_i2c_bus_read,
304     .write = aspeed_i2c_bus_write,
305     .endianness = DEVICE_LITTLE_ENDIAN,
306 };
307 
308 static const MemoryRegionOps aspeed_i2c_ctrl_ops = {
309     .read = aspeed_i2c_ctrl_read,
310     .write = aspeed_i2c_ctrl_write,
311     .endianness = DEVICE_LITTLE_ENDIAN,
312 };
313 
314 static const VMStateDescription aspeed_i2c_bus_vmstate = {
315     .name = TYPE_ASPEED_I2C,
316     .version_id = 1,
317     .minimum_version_id = 1,
318     .fields = (VMStateField[]) {
319         VMSTATE_UINT8(id, AspeedI2CBus),
320         VMSTATE_UINT32(ctrl, AspeedI2CBus),
321         VMSTATE_UINT32_ARRAY(timing, AspeedI2CBus, 2),
322         VMSTATE_UINT32(intr_ctrl, AspeedI2CBus),
323         VMSTATE_UINT32(intr_status, AspeedI2CBus),
324         VMSTATE_UINT32(cmd, AspeedI2CBus),
325         VMSTATE_UINT32(buf, AspeedI2CBus),
326         VMSTATE_END_OF_LIST()
327     }
328 };
329 
330 static const VMStateDescription aspeed_i2c_vmstate = {
331     .name = TYPE_ASPEED_I2C,
332     .version_id = 1,
333     .minimum_version_id = 1,
334     .fields = (VMStateField[]) {
335         VMSTATE_UINT32(intr_status, AspeedI2CState),
336         VMSTATE_STRUCT_ARRAY(busses, AspeedI2CState,
337                              ASPEED_I2C_NR_BUSSES, 1, aspeed_i2c_bus_vmstate,
338                              AspeedI2CBus),
339         VMSTATE_END_OF_LIST()
340     }
341 };
342 
343 static void aspeed_i2c_reset(DeviceState *dev)
344 {
345     int i;
346     AspeedI2CState *s = ASPEED_I2C(dev);
347 
348     s->intr_status = 0;
349 
350     for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
351         s->busses[i].intr_ctrl = 0;
352         s->busses[i].intr_status = 0;
353         s->busses[i].cmd = 0;
354         s->busses[i].buf = 0;
355         i2c_end_transfer(s->busses[i].bus);
356     }
357 }
358 
359 /*
360  * Address Definitions
361  *
362  *   0x000 ... 0x03F: Global Register
363  *   0x040 ... 0x07F: Device 1
364  *   0x080 ... 0x0BF: Device 2
365  *   0x0C0 ... 0x0FF: Device 3
366  *   0x100 ... 0x13F: Device 4
367  *   0x140 ... 0x17F: Device 5
368  *   0x180 ... 0x1BF: Device 6
369  *   0x1C0 ... 0x1FF: Device 7
370  *   0x200 ... 0x2FF: Buffer Pool  (unused in linux driver)
371  *   0x300 ... 0x33F: Device 8
372  *   0x340 ... 0x37F: Device 9
373  *   0x380 ... 0x3BF: Device 10
374  *   0x3C0 ... 0x3FF: Device 11
375  *   0x400 ... 0x43F: Device 12
376  *   0x440 ... 0x47F: Device 13
377  *   0x480 ... 0x4BF: Device 14
378  *   0x800 ... 0xFFF: Buffer Pool  (unused in linux driver)
379  */
380 static void aspeed_i2c_realize(DeviceState *dev, Error **errp)
381 {
382     int i;
383     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
384     AspeedI2CState *s = ASPEED_I2C(dev);
385 
386     sysbus_init_irq(sbd, &s->irq);
387     memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_i2c_ctrl_ops, s,
388                           "aspeed.i2c", 0x1000);
389     sysbus_init_mmio(sbd, &s->iomem);
390 
391     for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
392         char name[16];
393         int offset = i < 7 ? 1 : 5;
394         snprintf(name, sizeof(name), "aspeed.i2c.%d", i);
395         s->busses[i].controller = s;
396         s->busses[i].id = i;
397         s->busses[i].bus = i2c_init_bus(dev, name);
398         memory_region_init_io(&s->busses[i].mr, OBJECT(dev),
399                               &aspeed_i2c_bus_ops, &s->busses[i], name, 0x40);
400         memory_region_add_subregion(&s->iomem, 0x40 * (i + offset),
401                                     &s->busses[i].mr);
402     }
403 }
404 
405 static void aspeed_i2c_class_init(ObjectClass *klass, void *data)
406 {
407     DeviceClass *dc = DEVICE_CLASS(klass);
408 
409     dc->vmsd = &aspeed_i2c_vmstate;
410     dc->reset = aspeed_i2c_reset;
411     dc->realize = aspeed_i2c_realize;
412     dc->desc = "Aspeed I2C Controller";
413 }
414 
415 static const TypeInfo aspeed_i2c_info = {
416     .name          = TYPE_ASPEED_I2C,
417     .parent        = TYPE_SYS_BUS_DEVICE,
418     .instance_size = sizeof(AspeedI2CState),
419     .class_init    = aspeed_i2c_class_init,
420 };
421 
422 static void aspeed_i2c_register_types(void)
423 {
424     type_register_static(&aspeed_i2c_info);
425 }
426 
427 type_init(aspeed_i2c_register_types)
428 
429 
430 I2CBus *aspeed_i2c_get_bus(DeviceState *dev, int busnr)
431 {
432     AspeedI2CState *s = ASPEED_I2C(dev);
433     I2CBus *bus = NULL;
434 
435     if (busnr >= 0 && busnr < ASPEED_I2C_NR_BUSSES) {
436         bus = s->busses[busnr].bus;
437     }
438 
439     return bus;
440 }
441