xref: /freebsd/sys/dev/ismt/ismt.c (revision 7447ca0eb235974642312b9555caec00b57d8fc1)
1 /*-
2  * Copyright (C) 2014 Intel Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of Intel Corporation nor the names of its
14  *    contributors may be used to endorse or promote products derived from
15  *    this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/errno.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/module.h>
40 #include <sys/priority.h>
41 #include <sys/proc.h>
42 #include <sys/syslog.h>
43 
44 #include <machine/bus.h>
45 #include <sys/rman.h>
46 #include <machine/resource.h>
47 
48 #include <dev/pci/pcireg.h>
49 #include <dev/pci/pcivar.h>
50 #include <dev/smbus/smbconf.h>
51 
52 #include "smbus_if.h"
53 
54 #define ISMT_DESC_ENTRIES	32
55 
56 /* Hardware Descriptor Constants - Control Field */
57 #define ISMT_DESC_CWRL	0x01	/* Command/Write Length */
58 #define ISMT_DESC_BLK	0X04	/* Perform Block Transaction */
59 #define ISMT_DESC_FAIR	0x08	/* Set fairness flag upon successful arbit. */
60 #define ISMT_DESC_PEC	0x10	/* Packet Error Code */
61 #define ISMT_DESC_I2C	0x20	/* I2C Enable */
62 #define ISMT_DESC_INT	0x40	/* Interrupt */
63 #define ISMT_DESC_SOE	0x80	/* Stop On Error */
64 
65 /* Hardware Descriptor Constants - Status Field */
66 #define ISMT_DESC_SCS	0x01	/* Success */
67 #define ISMT_DESC_DLTO	0x04	/* Data Low Time Out */
68 #define ISMT_DESC_NAK	0x08	/* NAK Received */
69 #define ISMT_DESC_CRC	0x10	/* CRC Error */
70 #define ISMT_DESC_CLTO	0x20	/* Clock Low Time Out */
71 #define ISMT_DESC_COL	0x40	/* Collisions */
72 #define ISMT_DESC_LPR	0x80	/* Large Packet Received */
73 
74 /* Macros */
75 #define ISMT_DESC_ADDR_RW(addr, is_read) ((addr << 1) | (is_read))
76 
77 /* iSMT General Register address offsets (SMBBAR + <addr>) */
78 #define ISMT_GR_GCTRL		0x000	/* General Control */
79 #define ISMT_GR_SMTICL		0x008	/* SMT Interrupt Cause Location */
80 #define ISMT_GR_ERRINTMSK	0x010	/* Error Interrupt Mask */
81 #define ISMT_GR_ERRAERMSK	0x014	/* Error AER Mask */
82 #define ISMT_GR_ERRSTS		0x018	/* Error Status */
83 #define ISMT_GR_ERRINFO		0x01c	/* Error Information */
84 
85 /* iSMT Master Registers */
86 #define ISMT_MSTR_MDBA		0x100	/* Master Descriptor Base Address */
87 #define ISMT_MSTR_MCTRL		0x108	/* Master Control */
88 #define ISMT_MSTR_MSTS		0x10c	/* Master Status */
89 #define ISMT_MSTR_MDS		0x110	/* Master Descriptor Size */
90 #define ISMT_MSTR_RPOLICY	0x114	/* Retry Policy */
91 
92 /* iSMT Miscellaneous Registers */
93 #define ISMT_SPGT	0x300	/* SMBus PHY Global Timing */
94 
95 /* General Control Register (GCTRL) bit definitions */
96 #define ISMT_GCTRL_TRST	0x04	/* Target Reset */
97 #define ISMT_GCTRL_KILL	0x08	/* Kill */
98 #define ISMT_GCTRL_SRST	0x40	/* Soft Reset */
99 
100 /* Master Control Register (MCTRL) bit definitions */
101 #define ISMT_MCTRL_SS	0x01		/* Start/Stop */
102 #define ISMT_MCTRL_MEIE	0x10		/* Master Error Interrupt Enable */
103 #define ISMT_MCTRL_FMHP	0x00ff0000	/* Firmware Master Head Ptr (FMHP) */
104 
105 /* Master Status Register (MSTS) bit definitions */
106 #define ISMT_MSTS_HMTP	0xff0000	/* HW Master Tail Pointer (HMTP) */
107 #define ISMT_MSTS_MIS	0x20		/* Master Interrupt Status (MIS) */
108 #define ISMT_MSTS_MEIS	0x10		/* Master Error Int Status (MEIS) */
109 #define ISMT_MSTS_IP	0x01		/* In Progress */
110 
111 /* Master Descriptor Size (MDS) bit definitions */
112 #define ISMT_MDS_MASK	0xff	/* Master Descriptor Size mask (MDS) */
113 
114 /* SMBus PHY Global Timing Register (SPGT) bit definitions */
115 #define ISMT_SPGT_SPD_MASK	0xc0000000	/* SMBus Speed mask */
116 #define ISMT_SPGT_SPD_80K	0x00		/* 80 kHz */
117 #define ISMT_SPGT_SPD_100K	(0x1 << 30)	/* 100 kHz */
118 #define ISMT_SPGT_SPD_400K	(0x2 << 30)	/* 400 kHz */
119 #define ISMT_SPGT_SPD_1M	(0x3 << 30)	/* 1 MHz */
120 
121 /* MSI Control Register (MSICTL) bit definitions */
122 #define ISMT_MSICTL_MSIE	0x01	/* MSI Enable */
123 
124 #define ISMT_MAX_BLOCK_SIZE	32 /* per SMBus spec */
125 
126 //#define ISMT_DEBUG	device_printf
127 #ifndef ISMT_DEBUG
128 #define ISMT_DEBUG(...)
129 #endif
130 
131 /* iSMT Hardware Descriptor */
132 struct ismt_desc {
133 	uint8_t tgtaddr_rw;	/* target address & r/w bit */
134 	uint8_t wr_len_cmd;	/* write length in bytes or a command */
135 	uint8_t rd_len;		/* read length */
136 	uint8_t control;	/* control bits */
137 	uint8_t status;		/* status bits */
138 	uint8_t retry;		/* collision retry and retry count */
139 	uint8_t rxbytes;	/* received bytes */
140 	uint8_t txbytes;	/* transmitted bytes */
141 	uint32_t dptr_low;	/* lower 32 bit of the data pointer */
142 	uint32_t dptr_high;	/* upper 32 bit of the data pointer */
143 } __packed;
144 
145 #define DESC_SIZE	(ISMT_DESC_ENTRIES * sizeof(struct ismt_desc))
146 
147 #define DMA_BUFFER_SIZE	64
148 
149 struct ismt_softc {
150 	device_t		pcidev;
151 	device_t		smbdev;
152 
153 	struct thread		*bus_reserved;
154 
155 	int			intr_rid;
156 	struct resource		*intr_res;
157 	void			*intr_handle;
158 
159 	bus_space_tag_t		mmio_tag;
160 	bus_space_handle_t	mmio_handle;
161 	int			mmio_rid;
162 	struct resource		*mmio_res;
163 
164 	uint8_t			head;
165 
166 	struct ismt_desc	*desc;
167 	bus_dma_tag_t		desc_dma_tag;
168 	bus_dmamap_t		desc_dma_map;
169 	uint64_t		desc_bus_addr;
170 
171 	uint8_t			*dma_buffer;
172 	bus_dma_tag_t		dma_buffer_dma_tag;
173 	bus_dmamap_t		dma_buffer_dma_map;
174 	uint64_t		dma_buffer_bus_addr;
175 
176 	uint8_t			using_msi;
177 };
178 
179 static void
180 ismt_intr(void *arg)
181 {
182 	struct ismt_softc *sc = arg;
183 	uint32_t val;
184 
185 	val = bus_read_4(sc->mmio_res, ISMT_MSTR_MSTS);
186 	ISMT_DEBUG(sc->pcidev, "%s MSTS=0x%x\n", __func__, val);
187 
188 	val |= (ISMT_MSTS_MIS | ISMT_MSTS_MEIS);
189 	bus_write_4(sc->mmio_res, ISMT_MSTR_MSTS, val);
190 
191 	wakeup(sc);
192 }
193 
194 static int
195 ismt_callback(device_t dev, int index, void *data)
196 {
197 	struct ismt_softc	*sc;
198 	int			acquired, err;
199 
200 	sc = device_get_softc(dev);
201 
202 	switch (index) {
203 	case SMB_REQUEST_BUS:
204 		acquired = atomic_cmpset_ptr(
205 		    (uintptr_t *)&sc->bus_reserved,
206 		    (uintptr_t)NULL, (uintptr_t)curthread);
207 		ISMT_DEBUG(dev, "SMB_REQUEST_BUS acquired=%d\n", acquired);
208 		if (acquired)
209 			err = 0;
210 		else
211 			err = EWOULDBLOCK;
212 		break;
213 	case SMB_RELEASE_BUS:
214 		KASSERT(sc->bus_reserved == curthread,
215 		    ("SMB_RELEASE_BUS called by wrong thread\n"));
216 		ISMT_DEBUG(dev, "SMB_RELEASE_BUS\n");
217 		atomic_store_rel_ptr((uintptr_t *)&sc->bus_reserved,
218 		    (uintptr_t)NULL);
219 		err = 0;
220 		break;
221 	default:
222 		err = SMB_EABORT;
223 		break;
224 	}
225 
226 	return (err);
227 }
228 
229 static struct ismt_desc *
230 ismt_alloc_desc(struct ismt_softc *sc)
231 {
232 	struct ismt_desc *desc;
233 
234 	KASSERT(sc->bus_reserved == curthread,
235 	    ("curthread %p did not request bus (%p has reserved)\n",
236 	    curthread, sc->bus_reserved));
237 
238 	desc = &sc->desc[sc->head++];
239 	if (sc->head == ISMT_DESC_ENTRIES)
240 		sc->head = 0;
241 
242 	memset(desc, 0, sizeof(*desc));
243 
244 	return (desc);
245 }
246 
247 static int
248 ismt_submit(struct ismt_softc *sc, struct ismt_desc *desc, uint8_t slave,
249     uint8_t is_read)
250 {
251 	uint32_t err, fmhp, val;
252 
253 	desc->control |= ISMT_DESC_FAIR;
254 	if (sc->using_msi)
255 		desc->control |= ISMT_DESC_INT;
256 
257 	desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(slave, is_read);
258 	desc->dptr_low = (sc->dma_buffer_bus_addr & 0xFFFFFFFFLL);
259 	desc->dptr_high = (sc->dma_buffer_bus_addr >> 32);
260 
261 	wmb();
262 
263 	fmhp = sc->head << 16;
264 	val = bus_read_4(sc->mmio_res, ISMT_MSTR_MCTRL);
265 	val &= ~ISMT_MCTRL_FMHP;
266 	val |= fmhp;
267 	bus_write_4(sc->mmio_res, ISMT_MSTR_MCTRL, val);
268 
269 	/* set the start bit */
270 	val = bus_read_4(sc->mmio_res, ISMT_MSTR_MCTRL);
271 	val |= ISMT_MCTRL_SS;
272 	bus_write_4(sc->mmio_res, ISMT_MSTR_MCTRL, val);
273 
274 	err = tsleep(sc, PWAIT, "ismt_wait", 5 * hz);
275 
276 	if (err != 0) {
277 		ISMT_DEBUG(sc->pcidev, "%s timeout\n", __func__);
278 		return (SMB_ETIMEOUT);
279 	}
280 
281 	ISMT_DEBUG(sc->pcidev, "%s status=0x%x\n", __func__, desc->status);
282 
283 	if (desc->status & ISMT_DESC_SCS)
284 		return (SMB_ENOERR);
285 
286 	if (desc->status & ISMT_DESC_NAK)
287 		return (SMB_ENOACK);
288 
289 	if (desc->status & ISMT_DESC_CRC)
290 		return (SMB_EBUSERR);
291 
292 	if (desc->status & ISMT_DESC_COL)
293 		return (SMB_ECOLLI);
294 
295 	if (desc->status & ISMT_DESC_LPR)
296 		return (SMB_EINVAL);
297 
298 	if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
299 		return (SMB_ETIMEOUT);
300 
301 	return (SMB_EBUSERR);
302 }
303 
304 
305 static int
306 ismt_quick(device_t dev, u_char slave, int how)
307 {
308 	struct ismt_desc	*desc;
309 	struct ismt_softc	*sc;
310 	int			is_read;
311 
312 	ISMT_DEBUG(dev, "%s\n", __func__);
313 
314 	if (how != SMB_QREAD && how != SMB_QWRITE) {
315 		return (SMB_ENOTSUPP);
316 	}
317 
318 	sc = device_get_softc(dev);
319 	desc = ismt_alloc_desc(sc);
320 	is_read = (how == SMB_QREAD ? 1 : 0);
321 	return (ismt_submit(sc, desc, slave, is_read));
322 }
323 
324 static int
325 ismt_sendb(device_t dev, u_char slave, char byte)
326 {
327 	struct ismt_desc	*desc;
328 	struct ismt_softc	*sc;
329 
330 	ISMT_DEBUG(dev, "%s\n", __func__);
331 
332 	sc = device_get_softc(dev);
333 	desc = ismt_alloc_desc(sc);
334 	desc->control = ISMT_DESC_CWRL;
335 	desc->wr_len_cmd = byte;
336 
337 	return (ismt_submit(sc, desc, slave, 0));
338 }
339 
340 static int
341 ismt_recvb(device_t dev, u_char slave, char *byte)
342 {
343 	struct ismt_desc	*desc;
344 	struct ismt_softc	*sc;
345 	int			err;
346 
347 	ISMT_DEBUG(dev, "%s\n", __func__);
348 
349 	sc = device_get_softc(dev);
350 	desc = ismt_alloc_desc(sc);
351 	desc->rd_len = 1;
352 
353 	err = ismt_submit(sc, desc, slave, 1);
354 
355 	if (err != SMB_ENOERR)
356 		return (err);
357 
358 	*byte = sc->dma_buffer[0];
359 
360 	return (err);
361 }
362 
363 static int
364 ismt_writeb(device_t dev, u_char slave, char cmd, char byte)
365 {
366 	struct ismt_desc	*desc;
367 	struct ismt_softc	*sc;
368 
369 	ISMT_DEBUG(dev, "%s\n", __func__);
370 
371 	sc = device_get_softc(dev);
372 	desc = ismt_alloc_desc(sc);
373 	desc->wr_len_cmd = 2;
374 	sc->dma_buffer[0] = cmd;
375 	sc->dma_buffer[1] = byte;
376 
377 	return (ismt_submit(sc, desc, slave, 0));
378 }
379 
380 static int
381 ismt_writew(device_t dev, u_char slave, char cmd, short word)
382 {
383 	struct ismt_desc	*desc;
384 	struct ismt_softc	*sc;
385 
386 	ISMT_DEBUG(dev, "%s\n", __func__);
387 
388 	sc = device_get_softc(dev);
389 	desc = ismt_alloc_desc(sc);
390 	desc->wr_len_cmd = 3;
391 	sc->dma_buffer[0] = cmd;
392 	sc->dma_buffer[1] = word & 0xFF;
393 	sc->dma_buffer[2] = word >> 8;
394 
395 	return (ismt_submit(sc, desc, slave, 0));
396 }
397 
398 static int
399 ismt_readb(device_t dev, u_char slave, char cmd, char *byte)
400 {
401 	struct ismt_desc	*desc;
402 	struct ismt_softc	*sc;
403 	int			err;
404 
405 	ISMT_DEBUG(dev, "%s\n", __func__);
406 
407 	sc = device_get_softc(dev);
408 	desc = ismt_alloc_desc(sc);
409 	desc->control = ISMT_DESC_CWRL;
410 	desc->wr_len_cmd = cmd;
411 	desc->rd_len = 1;
412 
413 	err = ismt_submit(sc, desc, slave, 1);
414 
415 	if (err != SMB_ENOERR)
416 		return (err);
417 
418 	*byte = sc->dma_buffer[0];
419 
420 	return (err);
421 }
422 
423 static int
424 ismt_readw(device_t dev, u_char slave, char cmd, short *word)
425 {
426 	struct ismt_desc	*desc;
427 	struct ismt_softc	*sc;
428 	int			err;
429 
430 	ISMT_DEBUG(dev, "%s\n", __func__);
431 
432 	sc = device_get_softc(dev);
433 	desc = ismt_alloc_desc(sc);
434 	desc->control = ISMT_DESC_CWRL;
435 	desc->wr_len_cmd = cmd;
436 	desc->rd_len = 2;
437 
438 	err = ismt_submit(sc, desc, slave, 1);
439 
440 	if (err != SMB_ENOERR)
441 		return (err);
442 
443 	*word = sc->dma_buffer[0] | (sc->dma_buffer[1] << 8);
444 
445 	return (err);
446 }
447 
448 static int
449 ismt_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata)
450 {
451 	struct ismt_desc	*desc;
452 	struct ismt_softc	*sc;
453 	int			err;
454 
455 	ISMT_DEBUG(dev, "%s\n", __func__);
456 
457 	sc = device_get_softc(dev);
458 	desc = ismt_alloc_desc(sc);
459 	desc->wr_len_cmd = 3;
460 	desc->rd_len = 2;
461 	sc->dma_buffer[0] = cmd;
462 	sc->dma_buffer[1] = sdata & 0xff;
463 	sc->dma_buffer[2] = sdata >> 8;
464 
465 	err = ismt_submit(sc, desc, slave, 0);
466 
467 	if (err != SMB_ENOERR)
468 		return (err);
469 
470 	*rdata = sc->dma_buffer[0] | (sc->dma_buffer[1] << 8);
471 
472 	return (err);
473 }
474 
475 static int
476 ismt_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf)
477 {
478 	struct ismt_desc	*desc;
479 	struct ismt_softc	*sc;
480 
481 	ISMT_DEBUG(dev, "%s\n", __func__);
482 
483 	if (count == 0 || count > ISMT_MAX_BLOCK_SIZE)
484 		return (SMB_EINVAL);
485 
486 	sc = device_get_softc(dev);
487 	desc = ismt_alloc_desc(sc);
488 	desc->control = ISMT_DESC_I2C;
489 	desc->wr_len_cmd = count + 1;
490 	sc->dma_buffer[0] = cmd;
491 	memcpy(&sc->dma_buffer[1], buf, count);
492 
493 	return (ismt_submit(sc, desc, slave, 0));
494 }
495 
496 static int
497 ismt_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf)
498 {
499 	struct ismt_desc	*desc;
500 	struct ismt_softc	*sc;
501 	int			err;
502 
503 	ISMT_DEBUG(dev, "%s\n", __func__);
504 
505 	if (*count == 0 || *count > ISMT_MAX_BLOCK_SIZE)
506 		return (SMB_EINVAL);
507 
508 	sc = device_get_softc(dev);
509 	desc = ismt_alloc_desc(sc);
510 	desc->control = ISMT_DESC_I2C | ISMT_DESC_CWRL;
511 	desc->wr_len_cmd = cmd;
512 	desc->rd_len = *count;
513 
514 	err = ismt_submit(sc, desc, slave, 0);
515 
516 	if (err != SMB_ENOERR)
517 		return (err);
518 
519 	memcpy(buf, sc->dma_buffer, desc->rxbytes);
520 	*count = desc->rxbytes;
521 
522 	return (err);
523 }
524 
525 static int
526 ismt_detach(device_t dev)
527 {
528 	struct ismt_softc	*sc;
529 	int			error;
530 
531 	ISMT_DEBUG(dev, "%s\n", __func__);
532 	sc = device_get_softc(dev);
533 
534 	error = bus_generic_detach(dev);
535 	if (error)
536 		return (error);
537 
538 	device_delete_child(dev, sc->smbdev);
539 
540 	if (sc->intr_handle != NULL) {
541 		bus_teardown_intr(dev, sc->intr_res, sc->intr_handle);
542 		sc->intr_handle = NULL;
543 	}
544 	if (sc->intr_res != NULL) {
545 		bus_release_resource(dev,
546 		    SYS_RES_IRQ, sc->intr_rid, sc->intr_res);
547 		sc->intr_res = NULL;
548 	}
549 	if (sc->using_msi == 1)
550 		pci_release_msi(dev);
551 
552 	if (sc->mmio_res != NULL) {
553 		bus_release_resource(dev,
554 		    SYS_RES_MEMORY, sc->mmio_rid, sc->mmio_res);
555 		sc->mmio_res = NULL;
556 	}
557 
558 	bus_dmamap_unload(sc->desc_dma_tag, sc->desc_dma_map);
559 	bus_dmamap_unload(sc->dma_buffer_dma_tag, sc->dma_buffer_dma_map);
560 
561 	bus_dmamem_free(sc->desc_dma_tag, sc->desc,
562 	    sc->desc_dma_map);
563 	bus_dmamem_free(sc->dma_buffer_dma_tag, sc->dma_buffer,
564 	    sc->dma_buffer_dma_map);
565 
566 	bus_dma_tag_destroy(sc->desc_dma_tag);
567 	bus_dma_tag_destroy(sc->dma_buffer_dma_tag);
568 
569 	pci_disable_busmaster(dev);
570 
571 	return 0;
572 }
573 
574 static void
575 ismt_single_map(void *arg, bus_dma_segment_t *seg, int nseg, int error)
576 {
577 	uint64_t *bus_addr = (uint64_t *)arg;
578 
579 	KASSERT(error == 0, ("%s: error=%d\n", __func__, error));
580 	KASSERT(nseg == 1, ("%s: nseg=%d\n", __func__, nseg));
581 
582 	*bus_addr = seg[0].ds_addr;
583 }
584 
585 static int
586 ismt_attach(device_t dev)
587 {
588 	struct ismt_softc *sc = device_get_softc(dev);
589 	int err, num_vectors, val;
590 
591 	sc->pcidev = dev;
592 	pci_enable_busmaster(dev);
593 
594 	if ((sc->smbdev = device_add_child(dev, "smbus", -1)) == NULL) {
595 		device_printf(dev, "no smbus child found\n");
596 		err = ENXIO;
597 		goto fail;
598 	}
599 
600 	sc->mmio_rid = PCIR_BAR(0);
601 	sc->mmio_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
602 	    &sc->mmio_rid, RF_ACTIVE);
603 	if (sc->mmio_res == NULL) {
604 		device_printf(dev, "cannot allocate mmio region\n");
605 		err = ENOMEM;
606 		goto fail;
607 	}
608 
609 	sc->mmio_tag = rman_get_bustag(sc->mmio_res);
610 	sc->mmio_handle = rman_get_bushandle(sc->mmio_res);
611 
612 	/* Attach "smbus" child */
613 	if ((err = bus_generic_attach(dev)) != 0) {
614 		device_printf(dev, "failed to attach child: %d\n", err);
615 		err = ENXIO;
616 		goto fail;
617 	}
618 
619 	bus_dma_tag_create(bus_get_dma_tag(dev), 4, PAGE_SIZE,
620 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
621 	    DESC_SIZE, 1, DESC_SIZE,
622 	    0, NULL, NULL, &sc->desc_dma_tag);
623 
624 	bus_dma_tag_create(bus_get_dma_tag(dev), 4, PAGE_SIZE,
625 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
626 	    DMA_BUFFER_SIZE, 1, DMA_BUFFER_SIZE,
627 	    0, NULL, NULL, &sc->dma_buffer_dma_tag);
628 
629 	bus_dmamap_create(sc->desc_dma_tag, 0,
630 	    &sc->desc_dma_map);
631 	bus_dmamap_create(sc->dma_buffer_dma_tag, 0,
632 	    &sc->dma_buffer_dma_map);
633 
634 	bus_dmamem_alloc(sc->desc_dma_tag,
635 	    (void **)&sc->desc, BUS_DMA_WAITOK,
636 	    &sc->desc_dma_map);
637 	bus_dmamem_alloc(sc->dma_buffer_dma_tag,
638 	    (void **)&sc->dma_buffer, BUS_DMA_WAITOK,
639 	    &sc->dma_buffer_dma_map);
640 
641 	bus_dmamap_load(sc->desc_dma_tag,
642 	    sc->desc_dma_map, sc->desc, DESC_SIZE,
643 	    ismt_single_map, &sc->desc_bus_addr, 0);
644 	bus_dmamap_load(sc->dma_buffer_dma_tag,
645 	    sc->dma_buffer_dma_map, sc->dma_buffer, DMA_BUFFER_SIZE,
646 	    ismt_single_map, &sc->dma_buffer_bus_addr, 0);
647 
648 	bus_write_4(sc->mmio_res, ISMT_MSTR_MDBA,
649 	    (sc->desc_bus_addr & 0xFFFFFFFFLL));
650 	bus_write_4(sc->mmio_res, ISMT_MSTR_MDBA + 4,
651 	    (sc->desc_bus_addr >> 32));
652 
653 	/* initialize the Master Control Register (MCTRL) */
654 	bus_write_4(sc->mmio_res, ISMT_MSTR_MCTRL, ISMT_MCTRL_MEIE);
655 
656 	/* initialize the Master Status Register (MSTS) */
657 	bus_write_4(sc->mmio_res, ISMT_MSTR_MSTS, 0);
658 
659 	/* initialize the Master Descriptor Size (MDS) */
660 	val = bus_read_4(sc->mmio_res, ISMT_MSTR_MDS);
661 	val &= ~ISMT_MDS_MASK;
662 	val |= (ISMT_DESC_ENTRIES - 1);
663 	bus_write_4(sc->mmio_res, ISMT_MSTR_MDS, val);
664 
665 	sc->using_msi = 1;
666 
667 	if (pci_msi_count(dev) == 0) {
668 		sc->using_msi = 0;
669 		goto intx;
670 	}
671 
672 	num_vectors = 1;
673 	if (pci_alloc_msi(dev, &num_vectors) != 0) {
674 		sc->using_msi = 0;
675 		goto intx;
676 	}
677 
678 	sc->intr_rid = 1;
679 	sc->intr_res = bus_alloc_resource_any(dev, SYS_RES_IRQ,
680 	    &sc->intr_rid, RF_ACTIVE);
681 
682 	if (sc->intr_res == NULL) {
683 		sc->using_msi = 0;
684 		pci_release_msi(dev);
685 	}
686 
687 intx:
688 	if (sc->using_msi == 0) {
689 		sc->intr_rid = 0;
690 		sc->intr_res = bus_alloc_resource_any(dev, SYS_RES_IRQ,
691 		    &sc->intr_rid, RF_SHAREABLE | RF_ACTIVE);
692 		if (sc->intr_res == NULL) {
693 			device_printf(dev, "cannot allocate irq\n");
694 			err = ENXIO;
695 			goto fail;
696 		}
697 	}
698 
699 	ISMT_DEBUG(dev, "using_msi = %d\n", sc->using_msi);
700 
701 	err = bus_setup_intr(dev, sc->intr_res,
702 	    INTR_TYPE_MISC | INTR_MPSAFE, NULL, ismt_intr, sc,
703 	    &sc->intr_handle);
704 	if (err != 0) {
705 		device_printf(dev, "cannot setup interrupt\n");
706 		err = ENXIO;
707 		goto fail;
708 	}
709 
710 	return (0);
711 
712 fail:
713 	ismt_detach(dev);
714 	return (err);
715 }
716 
717 #define ID_INTEL_S1200_SMT0		0x0c598086
718 #define ID_INTEL_S1200_SMT1		0x0c5a8086
719 #define ID_INTEL_C2000_SMT		0x1f158086
720 
721 static int
722 ismt_probe(device_t dev)
723 {
724 	const char *desc;
725 
726 	switch (pci_get_devid(dev)) {
727 	case ID_INTEL_S1200_SMT0:
728 		desc = "Atom Processor S1200 SMBus 2.0 Controller 0";
729 		break;
730 	case ID_INTEL_S1200_SMT1:
731 		desc = "Atom Processor S1200 SMBus 2.0 Controller 1";
732 		break;
733 	case ID_INTEL_C2000_SMT:
734 		desc = "Atom Processor C2000 SMBus 2.0";
735 		break;
736 	default:
737 		return (ENXIO);
738 	}
739 
740 	device_set_desc(dev, desc);
741 	return (BUS_PROBE_DEFAULT);
742 }
743 
744 /* Device methods */
745 static device_method_t ismt_pci_methods[] = {
746         DEVMETHOD(device_probe,		ismt_probe),
747         DEVMETHOD(device_attach,	ismt_attach),
748         DEVMETHOD(device_detach,	ismt_detach),
749 
750         DEVMETHOD(smbus_callback,	ismt_callback),
751         DEVMETHOD(smbus_quick,		ismt_quick),
752         DEVMETHOD(smbus_sendb,		ismt_sendb),
753         DEVMETHOD(smbus_recvb,		ismt_recvb),
754         DEVMETHOD(smbus_writeb,		ismt_writeb),
755         DEVMETHOD(smbus_writew,		ismt_writew),
756         DEVMETHOD(smbus_readb,		ismt_readb),
757         DEVMETHOD(smbus_readw,		ismt_readw),
758         DEVMETHOD(smbus_pcall,		ismt_pcall),
759         DEVMETHOD(smbus_bwrite,		ismt_bwrite),
760         DEVMETHOD(smbus_bread,		ismt_bread),
761 
762 	DEVMETHOD_END
763 };
764 
765 static driver_t ismt_pci_driver = {
766 	"ismt",
767 	ismt_pci_methods,
768 	sizeof(struct ismt_softc)
769 };
770 
771 static devclass_t ismt_pci_devclass;
772 
773 DRIVER_MODULE(ismt, pci, ismt_pci_driver, ismt_pci_devclass, 0, 0);
774 DRIVER_MODULE(smbus, ismt, smbus_driver, smbus_devclass, 0, 0);
775 
776 MODULE_DEPEND(ismt, pci, 1, 1, 1);
777 MODULE_DEPEND(ismt, smbus, SMBUS_MINVER, SMBUS_PREFVER, SMBUS_MAXVER);
778 MODULE_VERSION(ismt, 1);
779