xref: /freebsd/sys/dev/glxiic/glxiic.c (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011 Henrik Brix Andersen <brix@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 /*
31  * AMD Geode LX CS5536 System Management Bus controller.
32  *
33  * Although AMD refers to this device as an SMBus controller, it
34  * really is an I2C controller (It lacks SMBus ALERT# and Alert
35  * Response support).
36  *
37  * The driver is implemented as an interrupt-driven state machine,
38  * supporting both master and slave mode.
39  */
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/bus.h>
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/sysctl.h>
48 #ifdef GLXIIC_DEBUG
49 #include <sys/syslog.h>
50 #endif
51 
52 #include <dev/pci/pcireg.h>
53 #include <dev/pci/pcivar.h>
54 
55 #include <machine/bus.h>
56 #include <sys/rman.h>
57 #include <machine/resource.h>
58 
59 #include <dev/iicbus/iiconf.h>
60 #include <dev/iicbus/iicbus.h>
61 
62 #include "iicbus_if.h"
63 
64 /* CS5536 PCI-ISA ID. */
65 #define	GLXIIC_CS5536_DEV_ID		0x20901022
66 
67 /* MSRs. */
68 #define	GLXIIC_MSR_PIC_YSEL_HIGH	0x51400021
69 
70 /* Bus speeds. */
71 #define	GLXIIC_SLOW	0x0258	/*  10 kHz. */
72 #define	GLXIIC_FAST	0x0078	/*  50 kHz. */
73 #define	GLXIIC_FASTEST	0x003c	/* 100 kHz. */
74 
75 /* Default bus activity timeout in milliseconds. */
76 #define GLXIIC_DEFAULT_TIMEOUT	35
77 
78 /* GPIO register offsets. */
79 #define	GLXIIC_GPIOL_OUT_AUX1_SEL	0x10
80 #define	GLXIIC_GPIOL_IN_AUX1_SEL	0x34
81 
82 /* GPIO 14 (SMB_CLK) and 15 (SMB_DATA) bitmasks. */
83 #define	GLXIIC_GPIO_14_15_ENABLE	0x0000c000
84 #define	GLXIIC_GPIO_14_15_DISABLE	0xc0000000
85 
86 /* SMB register offsets. */
87 #define	GLXIIC_SMB_SDA				0x00
88 #define	GLXIIC_SMB_STS				0x01
89 #define		GLXIIC_SMB_STS_SLVSTP_BIT	(1 << 7)
90 #define		GLXIIC_SMB_STS_SDAST_BIT	(1 << 6)
91 #define		GLXIIC_SMB_STS_BER_BIT		(1 << 5)
92 #define		GLXIIC_SMB_STS_NEGACK_BIT	(1 << 4)
93 #define		GLXIIC_SMB_STS_STASTR_BIT	(1 << 3)
94 #define		GLXIIC_SMB_STS_NMATCH_BIT	(1 << 2)
95 #define		GLXIIC_SMB_STS_MASTER_BIT	(1 << 1)
96 #define		GLXIIC_SMB_STS_XMIT_BIT		(1 << 0)
97 #define	GLXIIC_SMB_CTRL_STS			0x02
98 #define		GLXIIC_SMB_CTRL_STS_TGSCL_BIT	(1 << 5)
99 #define		GLXIIC_SMB_CTRL_STS_TSDA_BIT	(1 << 4)
100 #define		GLXIIC_SMB_CTRL_STS_GCMTCH_BIT	(1 << 3)
101 #define		GLXIIC_SMB_CTRL_STS_MATCH_BIT	(1 << 2)
102 #define		GLXIIC_SMB_CTRL_STS_BB_BIT	(1 << 1)
103 #define		GLXIIC_SMB_CTRL_STS_BUSY_BIT	(1 << 0)
104 #define	GLXIIC_SMB_CTRL1			0x03
105 #define		GLXIIC_SMB_CTRL1_STASTRE_BIT	(1 << 7)
106 #define		GLXIIC_SMB_CTRL1_NMINTE_BIT	(1 << 6)
107 #define		GLXIIC_SMB_CTRL1_GCMEN_BIT	(1 << 5)
108 #define		GLXIIC_SMB_CTRL1_ACK_BIT	(1 << 4)
109 #define		GLXIIC_SMB_CTRL1_INTEN_BIT	(1 << 2)
110 #define		GLXIIC_SMB_CTRL1_STOP_BIT	(1 << 1)
111 #define		GLXIIC_SMB_CTRL1_START_BIT	(1 << 0)
112 #define	GLXIIC_SMB_ADDR				0x04
113 #define		GLXIIC_SMB_ADDR_SAEN_BIT	(1 << 7)
114 #define	GLXIIC_SMB_CTRL2			0x05
115 #define		GLXIIC_SMB_CTRL2_EN_BIT		(1 << 0)
116 #define	GLXIIC_SMB_CTRL3			0x06
117 
118 typedef enum {
119 	GLXIIC_STATE_IDLE,
120 	GLXIIC_STATE_SLAVE_TX,
121 	GLXIIC_STATE_SLAVE_RX,
122 	GLXIIC_STATE_MASTER_ADDR,
123 	GLXIIC_STATE_MASTER_TX,
124 	GLXIIC_STATE_MASTER_RX,
125 	GLXIIC_STATE_MASTER_STOP,
126 	GLXIIC_STATE_MAX,
127 } glxiic_state_t;
128 
129 struct glxiic_softc {
130 	device_t	 dev;		/* Myself. */
131 	device_t	 iicbus;	/* IIC bus. */
132 	struct mtx	 mtx;		/* Lock. */
133 	glxiic_state_t	 state;		/* Driver state. */
134 	struct callout	 callout;	/* Driver state timeout callout. */
135 	int		 timeout;	/* Driver state timeout (ms). */
136 
137 	int		 smb_rid;	/* SMB controller resource ID. */
138 	struct resource *smb_res;	/* SMB controller resource. */
139 	int		 gpio_rid;	/* GPIO resource ID. */
140 	struct resource *gpio_res;	/* GPIO resource. */
141 
142 	int		 irq_rid;	/* IRQ resource ID. */
143 	struct resource *irq_res;	/* IRQ resource. */
144 	void		*irq_handler;	/* IRQ handler cookie. */
145 	int		 old_irq;	/* IRQ mapped by board firmware. */
146 
147 	struct iic_msg	*msg;		/* Current master mode message. */
148 	uint32_t	 nmsgs;		/* Number of messages remaining. */
149 	uint8_t		*data;		/* Current master mode data byte. */
150 	uint16_t	 ndata;		/* Number of data bytes remaining. */
151 	int		 error;		/* Last master mode error. */
152 
153 	uint8_t		 addr;		/* Own address. */
154 	uint16_t	 sclfrq;	/* Bus frequency. */
155 };
156 
157 #ifdef GLXIIC_DEBUG
158 #define GLXIIC_DEBUG_LOG(fmt, args...)	\
159 	log(LOG_DEBUG, "%s: " fmt "\n" , __func__ , ## args)
160 #else
161 #define GLXIIC_DEBUG_LOG(fmt, args...)
162 #endif
163 
164 #define	GLXIIC_SCLFRQ(n)		((n << 1))
165 #define	GLXIIC_SMBADDR(n)		((n >> 1))
166 #define	GLXIIC_SMB_IRQ_TO_MAP(n)	((n << 16))
167 #define	GLXIIC_MAP_TO_SMB_IRQ(n)	((n >> 16) & 0xf)
168 
169 #define	GLXIIC_LOCK(_sc)		mtx_lock(&_sc->mtx)
170 #define	GLXIIC_UNLOCK(_sc)		mtx_unlock(&_sc->mtx)
171 #define	GLXIIC_LOCK_INIT(_sc)		\
172 	mtx_init(&_sc->mtx, device_get_nameunit(_sc->dev), "glxiic", MTX_DEF)
173 #define	GLXIIC_SLEEP(_sc)		\
174 	mtx_sleep(_sc, &_sc->mtx, IICPRI, "glxiic", 0)
175 #define	GLXIIC_WAKEUP(_sc)		wakeup(_sc);
176 #define	GLXIIC_LOCK_DESTROY(_sc)	mtx_destroy(&_sc->mtx);
177 #define	GLXIIC_ASSERT_LOCKED(_sc)	mtx_assert(&_sc->mtx, MA_OWNED);
178 
179 typedef	int (glxiic_state_callback_t)(struct glxiic_softc *sc,
180     uint8_t status);
181 
182 static glxiic_state_callback_t	glxiic_state_idle_callback;
183 static glxiic_state_callback_t	glxiic_state_slave_tx_callback;
184 static glxiic_state_callback_t	glxiic_state_slave_rx_callback;
185 static glxiic_state_callback_t	glxiic_state_master_addr_callback;
186 static glxiic_state_callback_t	glxiic_state_master_tx_callback;
187 static glxiic_state_callback_t	glxiic_state_master_rx_callback;
188 static glxiic_state_callback_t	glxiic_state_master_stop_callback;
189 
190 struct glxiic_state_table_entry {
191 	glxiic_state_callback_t *callback;
192 	boolean_t master;
193 };
194 typedef struct glxiic_state_table_entry glxiic_state_table_entry_t;
195 
196 static glxiic_state_table_entry_t glxiic_state_table[GLXIIC_STATE_MAX] = {
197 	[GLXIIC_STATE_IDLE] = {
198 		.callback = &glxiic_state_idle_callback,
199 		.master = FALSE,
200 	},
201 
202 	[GLXIIC_STATE_SLAVE_TX] = {
203 		.callback = &glxiic_state_slave_tx_callback,
204 		.master = FALSE,
205 	},
206 
207 	[GLXIIC_STATE_SLAVE_RX] = {
208 		.callback = &glxiic_state_slave_rx_callback,
209 		.master = FALSE,
210 	},
211 
212 	[GLXIIC_STATE_MASTER_ADDR] = {
213 		.callback = &glxiic_state_master_addr_callback,
214 		.master = TRUE,
215 	},
216 
217 	[GLXIIC_STATE_MASTER_TX] = {
218 		.callback = &glxiic_state_master_tx_callback,
219 		.master = TRUE,
220 	},
221 
222 	[GLXIIC_STATE_MASTER_RX] = {
223 		.callback = &glxiic_state_master_rx_callback,
224 		.master = TRUE,
225 	},
226 
227 	[GLXIIC_STATE_MASTER_STOP] = {
228 		.callback = &glxiic_state_master_stop_callback,
229 		.master = TRUE,
230 	},
231 };
232 
233 static void	glxiic_identify(driver_t *driver, device_t parent);
234 static int	glxiic_probe(device_t dev);
235 static int	glxiic_attach(device_t dev);
236 static int	glxiic_detach(device_t dev);
237 
238 static uint8_t	glxiic_read_status_locked(struct glxiic_softc *sc);
239 static void	glxiic_stop_locked(struct glxiic_softc *sc);
240 static void	glxiic_timeout(void *arg);
241 static void	glxiic_start_timeout_locked(struct glxiic_softc *sc);
242 static void	glxiic_set_state_locked(struct glxiic_softc *sc,
243     glxiic_state_t state);
244 static int	glxiic_handle_slave_match_locked(struct glxiic_softc *sc,
245     uint8_t status);
246 static void	glxiic_intr(void *arg);
247 
248 static int	glxiic_reset(device_t dev, u_char speed, u_char addr,
249     u_char *oldaddr);
250 static int	glxiic_transfer(device_t dev, struct iic_msg *msgs,
251     uint32_t nmsgs);
252 
253 static void	glxiic_smb_map_interrupt(int irq);
254 static void 	glxiic_gpio_enable(struct glxiic_softc *sc);
255 static void 	glxiic_gpio_disable(struct glxiic_softc *sc);
256 static void	glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed,
257     uint8_t addr);
258 static void	glxiic_smb_disable(struct glxiic_softc *sc);
259 
260 static device_method_t glxiic_methods[] = {
261 	DEVMETHOD(device_identify,	glxiic_identify),
262 	DEVMETHOD(device_probe,		glxiic_probe),
263 	DEVMETHOD(device_attach,	glxiic_attach),
264 	DEVMETHOD(device_detach,	glxiic_detach),
265 
266 	DEVMETHOD(iicbus_reset,		glxiic_reset),
267 	DEVMETHOD(iicbus_transfer,	glxiic_transfer),
268 	DEVMETHOD(iicbus_callback,	iicbus_null_callback),
269 
270 	{ 0, 0 }
271 };
272 
273 static driver_t glxiic_driver = {
274 	"glxiic",
275 	glxiic_methods,
276 	sizeof(struct glxiic_softc),
277 };
278 
279 DRIVER_MODULE(glxiic, isab, glxiic_driver, 0, 0);
280 DRIVER_MODULE(iicbus, glxiic, iicbus_driver, 0, 0);
281 MODULE_DEPEND(glxiic, iicbus, 1, 1, 1);
282 
283 static void
284 glxiic_identify(driver_t *driver, device_t parent)
285 {
286 
287 	/* Prevent child from being added more than once. */
288 	if (device_find_child(parent, driver->name, -1) != NULL)
289 		return;
290 
291 	if (pci_get_devid(parent) == GLXIIC_CS5536_DEV_ID) {
292 		if (device_add_child(parent, driver->name, -1) == NULL)
293 			device_printf(parent, "Could not add glxiic child\n");
294 	}
295 }
296 
297 static int
298 glxiic_probe(device_t dev)
299 {
300 
301 	if (resource_disabled("glxiic", device_get_unit(dev)))
302 		return (ENXIO);
303 
304 	device_set_desc(dev, "AMD Geode CS5536 SMBus controller");
305 
306 	return (BUS_PROBE_DEFAULT);
307 }
308 
309 static int
310 glxiic_attach(device_t dev)
311 {
312 	struct glxiic_softc *sc;
313 	struct sysctl_ctx_list *ctx;
314 	struct sysctl_oid *tree;
315 	int error, irq, unit;
316 	uint32_t irq_map;
317 
318 	sc = device_get_softc(dev);
319 	sc->dev = dev;
320 	sc->state = GLXIIC_STATE_IDLE;
321 	error = 0;
322 
323 	GLXIIC_LOCK_INIT(sc);
324 	callout_init_mtx(&sc->callout, &sc->mtx, 0);
325 
326 	sc->smb_rid = PCIR_BAR(0);
327 	sc->smb_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &sc->smb_rid,
328 	    RF_ACTIVE);
329 	if (sc->smb_res == NULL) {
330 		device_printf(dev, "Could not allocate SMBus I/O port\n");
331 		error = ENXIO;
332 		goto out;
333 	}
334 
335 	sc->gpio_rid = PCIR_BAR(1);
336 	sc->gpio_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
337 	    &sc->gpio_rid, RF_SHAREABLE | RF_ACTIVE);
338 	if (sc->gpio_res == NULL) {
339 		device_printf(dev, "Could not allocate GPIO I/O port\n");
340 		error = ENXIO;
341 		goto out;
342 	}
343 
344 	/* Ensure the controller is not enabled by firmware. */
345 	glxiic_smb_disable(sc);
346 
347 	/* Read the existing IRQ map. */
348 	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
349 	sc->old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
350 
351 	unit = device_get_unit(dev);
352 	if (resource_int_value("glxiic", unit, "irq", &irq) == 0) {
353 		if (irq < 1 || irq > 15) {
354 			device_printf(dev, "Bad value %d for glxiic.%d.irq\n",
355 			    irq, unit);
356 			error = ENXIO;
357 			goto out;
358 		}
359 
360 		if (bootverbose)
361 			device_printf(dev, "Using irq %d set by hint\n", irq);
362 	} else if (sc->old_irq != 0) {
363 		if (bootverbose)
364 			device_printf(dev, "Using irq %d set by firmware\n",
365 			    irq);
366 		irq = sc->old_irq;
367 	} else {
368 		device_printf(dev, "No irq mapped by firmware");
369 		printf(" and no glxiic.%d.irq hint provided\n", unit);
370 		error = ENXIO;
371 		goto out;
372 	}
373 
374 	/* Map the SMBus interrupt to the requested legacy IRQ. */
375 	glxiic_smb_map_interrupt(irq);
376 
377 	sc->irq_rid = 0;
378 	sc->irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &sc->irq_rid,
379 	    irq, irq, 1, RF_SHAREABLE | RF_ACTIVE);
380 	if (sc->irq_res == NULL) {
381 		device_printf(dev, "Could not allocate IRQ %d\n", irq);
382 		error = ENXIO;
383 		goto out;
384 	}
385 
386 	error = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
387 	    NULL, glxiic_intr, sc, &(sc->irq_handler));
388 	if (error != 0) {
389 		device_printf(dev, "Could not setup IRQ handler\n");
390 		error = ENXIO;
391 		goto out;
392 	}
393 
394 	if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) {
395 		device_printf(dev, "Could not allocate iicbus instance\n");
396 		error = ENXIO;
397 		goto out;
398 	}
399 
400 	ctx = device_get_sysctl_ctx(dev);
401 	tree = device_get_sysctl_tree(dev);
402 
403 	sc->timeout = GLXIIC_DEFAULT_TIMEOUT;
404 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
405 	    "timeout", CTLFLAG_RWTUN, &sc->timeout, 0,
406 	    "activity timeout in ms");
407 
408 	glxiic_gpio_enable(sc);
409 	glxiic_smb_enable(sc, IIC_FASTEST, 0);
410 
411 	/* Probe and attach the iicbus when interrupts are available. */
412 	error = bus_delayed_attach_children(dev);
413 
414 out:
415 	if (error != 0) {
416 		callout_drain(&sc->callout);
417 
418 		if (sc->iicbus != NULL)
419 			device_delete_child(dev, sc->iicbus);
420 		if (sc->smb_res != NULL) {
421 			glxiic_smb_disable(sc);
422 			bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
423 			    sc->smb_res);
424 		}
425 		if (sc->gpio_res != NULL) {
426 			glxiic_gpio_disable(sc);
427 			bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
428 			    sc->gpio_res);
429 		}
430 		if (sc->irq_handler != NULL)
431 			bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
432 		if (sc->irq_res != NULL)
433 			bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
434 			    sc->irq_res);
435 
436 		/* Restore the old SMBus interrupt mapping. */
437 		glxiic_smb_map_interrupt(sc->old_irq);
438 
439 		GLXIIC_LOCK_DESTROY(sc);
440 	}
441 
442 	return (error);
443 }
444 
445 static int
446 glxiic_detach(device_t dev)
447 {
448 	struct glxiic_softc *sc;
449 	int error;
450 
451 	sc = device_get_softc(dev);
452 
453 	error = bus_generic_detach(dev);
454 	if (error != 0)
455 		goto out;
456 	if (sc->iicbus != NULL)
457 		error = device_delete_child(dev, sc->iicbus);
458 
459 out:
460 	callout_drain(&sc->callout);
461 
462 	if (sc->smb_res != NULL) {
463 		glxiic_smb_disable(sc);
464 		bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
465 		    sc->smb_res);
466 	}
467 	if (sc->gpio_res != NULL) {
468 		glxiic_gpio_disable(sc);
469 		bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
470 		    sc->gpio_res);
471 	}
472 	if (sc->irq_handler != NULL)
473 		bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
474 	if (sc->irq_res != NULL)
475 		bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
476 		    sc->irq_res);
477 
478 	/* Restore the old SMBus interrupt mapping. */
479 	glxiic_smb_map_interrupt(sc->old_irq);
480 
481 	GLXIIC_LOCK_DESTROY(sc);
482 
483 	return (error);
484 }
485 
486 static uint8_t
487 glxiic_read_status_locked(struct glxiic_softc *sc)
488 {
489 	uint8_t status;
490 
491 	GLXIIC_ASSERT_LOCKED(sc);
492 
493 	status = bus_read_1(sc->smb_res, GLXIIC_SMB_STS);
494 
495 	/* Clear all status flags except SDAST and STASTR after reading. */
496 	bus_write_1(sc->smb_res, GLXIIC_SMB_STS, (GLXIIC_SMB_STS_SLVSTP_BIT |
497 		GLXIIC_SMB_STS_BER_BIT | GLXIIC_SMB_STS_NEGACK_BIT |
498 		GLXIIC_SMB_STS_NMATCH_BIT));
499 
500 	return (status);
501 }
502 
503 static void
504 glxiic_stop_locked(struct glxiic_softc *sc)
505 {
506 	uint8_t status, ctrl1;
507 
508 	GLXIIC_ASSERT_LOCKED(sc);
509 
510 	status = glxiic_read_status_locked(sc);
511 
512 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
513 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
514 	    ctrl1 | GLXIIC_SMB_CTRL1_STOP_BIT);
515 
516 	/*
517 	 * Perform a dummy read of SDA in master receive mode to clear
518 	 * SDAST if set.
519 	 */
520 	if ((status & GLXIIC_SMB_STS_XMIT_BIT) == 0 &&
521 	    (status & GLXIIC_SMB_STS_SDAST_BIT) != 0)
522 	 	bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
523 
524 	/* Check stall after start bit and clear if needed */
525 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
526 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
527 		    GLXIIC_SMB_STS_STASTR_BIT);
528 	}
529 }
530 
531 static void
532 glxiic_timeout(void *arg)
533 {
534 	struct glxiic_softc *sc;
535 	uint8_t error;
536 
537 	sc = (struct glxiic_softc *)arg;
538 
539 	GLXIIC_DEBUG_LOG("timeout in state %d", sc->state);
540 
541 	if (glxiic_state_table[sc->state].master) {
542 		sc->error = IIC_ETIMEOUT;
543 		GLXIIC_WAKEUP(sc);
544 	} else {
545 		error = IIC_ETIMEOUT;
546 		iicbus_intr(sc->iicbus, INTR_ERROR, &error);
547 	}
548 
549 	glxiic_smb_disable(sc);
550 	glxiic_smb_enable(sc, IIC_UNKNOWN, sc->addr);
551 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
552 }
553 
554 static void
555 glxiic_start_timeout_locked(struct glxiic_softc *sc)
556 {
557 
558 	GLXIIC_ASSERT_LOCKED(sc);
559 
560 	callout_reset_sbt(&sc->callout, SBT_1MS * sc->timeout, 0,
561 	    glxiic_timeout, sc, 0);
562 }
563 
564 static void
565 glxiic_set_state_locked(struct glxiic_softc *sc, glxiic_state_t state)
566 {
567 
568 	GLXIIC_ASSERT_LOCKED(sc);
569 
570 	if (state == GLXIIC_STATE_IDLE)
571 		callout_stop(&sc->callout);
572 	else if (sc->timeout > 0)
573 		glxiic_start_timeout_locked(sc);
574 
575 	sc->state = state;
576 }
577 
578 static int
579 glxiic_handle_slave_match_locked(struct glxiic_softc *sc, uint8_t status)
580 {
581 	uint8_t ctrl_sts, addr;
582 
583 	GLXIIC_ASSERT_LOCKED(sc);
584 
585 	ctrl_sts = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL_STS);
586 
587 	if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_MATCH_BIT) != 0) {
588 		if ((status & GLXIIC_SMB_STS_XMIT_BIT) != 0) {
589 			addr = sc->addr | LSB;
590 			glxiic_set_state_locked(sc,
591 			    GLXIIC_STATE_SLAVE_TX);
592 		} else {
593 			addr = sc->addr & ~LSB;
594 			glxiic_set_state_locked(sc,
595 			    GLXIIC_STATE_SLAVE_RX);
596 		}
597 		iicbus_intr(sc->iicbus, INTR_START, &addr);
598 	} else if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_GCMTCH_BIT) != 0) {
599 		addr = 0;
600 		glxiic_set_state_locked(sc, GLXIIC_STATE_SLAVE_RX);
601 		iicbus_intr(sc->iicbus, INTR_GENERAL, &addr);
602 	} else {
603 		GLXIIC_DEBUG_LOG("unknown slave match");
604 		return (IIC_ESTATUS);
605 	}
606 
607 	return (IIC_NOERR);
608 }
609 
610 static int
611 glxiic_state_idle_callback(struct glxiic_softc *sc, uint8_t status)
612 {
613 
614 	GLXIIC_ASSERT_LOCKED(sc);
615 
616 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
617 		GLXIIC_DEBUG_LOG("bus error in idle");
618 		return (IIC_EBUSERR);
619 	}
620 
621 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
622 		return (glxiic_handle_slave_match_locked(sc, status));
623 	}
624 
625 	return (IIC_NOERR);
626 }
627 
628 static int
629 glxiic_state_slave_tx_callback(struct glxiic_softc *sc, uint8_t status)
630 {
631 	uint8_t data;
632 
633 	GLXIIC_ASSERT_LOCKED(sc);
634 
635 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
636 		GLXIIC_DEBUG_LOG("bus error in slave tx");
637 		return (IIC_EBUSERR);
638 	}
639 
640 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
641 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
642 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
643 		return (IIC_NOERR);
644 	}
645 
646 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
647 		iicbus_intr(sc->iicbus, INTR_NOACK, NULL);
648 		return (IIC_NOERR);
649 	}
650 
651 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
652 		/* Handle repeated start in slave mode. */
653 		return (glxiic_handle_slave_match_locked(sc, status));
654 	}
655 
656 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
657 		GLXIIC_DEBUG_LOG("not awaiting data in slave tx");
658 		return (IIC_ESTATUS);
659 	}
660 
661 	iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
662 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, data);
663 
664 	glxiic_start_timeout_locked(sc);
665 
666 	return (IIC_NOERR);
667 }
668 
669 static int
670 glxiic_state_slave_rx_callback(struct glxiic_softc *sc, uint8_t status)
671 {
672 	uint8_t data;
673 
674 	GLXIIC_ASSERT_LOCKED(sc);
675 
676 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
677 		GLXIIC_DEBUG_LOG("bus error in slave rx");
678 		return (IIC_EBUSERR);
679 	}
680 
681 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
682 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
683 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
684 		return (IIC_NOERR);
685 	}
686 
687 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
688 		/* Handle repeated start in slave mode. */
689 		return (glxiic_handle_slave_match_locked(sc, status));
690 	}
691 
692 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
693 		GLXIIC_DEBUG_LOG("no pending data in slave rx");
694 		return (IIC_ESTATUS);
695 	}
696 
697 	data = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
698 	iicbus_intr(sc->iicbus, INTR_RECEIVE, &data);
699 
700 	glxiic_start_timeout_locked(sc);
701 
702 	return (IIC_NOERR);
703 }
704 
705 static int
706 glxiic_state_master_addr_callback(struct glxiic_softc *sc, uint8_t status)
707 {
708 	uint8_t slave;
709 	uint8_t ctrl1;
710 
711 	GLXIIC_ASSERT_LOCKED(sc);
712 
713 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
714 		GLXIIC_DEBUG_LOG("bus error after master start");
715 		return (IIC_EBUSERR);
716 	}
717 
718 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
719 		GLXIIC_DEBUG_LOG("not bus master after master start");
720 		return (IIC_ESTATUS);
721 	}
722 
723 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
724 		GLXIIC_DEBUG_LOG("not awaiting address in master addr");
725 		return (IIC_ESTATUS);
726 	}
727 
728 	if ((sc->msg->flags & IIC_M_RD) != 0) {
729 		slave = sc->msg->slave | LSB;
730 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_RX);
731 	} else {
732 		slave = sc->msg->slave & ~LSB;
733 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_TX);
734 	}
735 
736 	sc->data = sc->msg->buf;
737 	sc->ndata = sc->msg->len;
738 
739 	/* Handle address-only transfer. */
740 	if (sc->ndata == 0)
741 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
742 
743 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, slave);
744 
745 	if ((sc->msg->flags & IIC_M_RD) != 0 && sc->ndata == 1) {
746 		/* Last byte from slave, set NACK. */
747 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
748 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
749 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
750 	}
751 
752 	return (IIC_NOERR);
753 }
754 
755 static int
756 glxiic_state_master_tx_callback(struct glxiic_softc *sc, uint8_t status)
757 {
758 
759 	GLXIIC_ASSERT_LOCKED(sc);
760 
761 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
762 		GLXIIC_DEBUG_LOG("bus error in master tx");
763 		return (IIC_EBUSERR);
764 	}
765 
766 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
767 		GLXIIC_DEBUG_LOG("not bus master in master tx");
768 		return (IIC_ESTATUS);
769 	}
770 
771 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
772 		GLXIIC_DEBUG_LOG("slave nack in master tx");
773 		return (IIC_ENOACK);
774 	}
775 
776 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
777 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
778 		    GLXIIC_SMB_STS_STASTR_BIT);
779 	}
780 
781 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
782 		GLXIIC_DEBUG_LOG("not awaiting data in master tx");
783 		return (IIC_ESTATUS);
784 	}
785 
786 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, *sc->data++);
787 	if (--sc->ndata == 0)
788 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
789 	else
790 		glxiic_start_timeout_locked(sc);
791 
792 	return (IIC_NOERR);
793 }
794 
795 static int
796 glxiic_state_master_rx_callback(struct glxiic_softc *sc, uint8_t status)
797 {
798 	uint8_t ctrl1;
799 
800 	GLXIIC_ASSERT_LOCKED(sc);
801 
802 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
803 		GLXIIC_DEBUG_LOG("bus error in master rx");
804 		return (IIC_EBUSERR);
805 	}
806 
807 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
808 		GLXIIC_DEBUG_LOG("not bus master in master rx");
809 		return (IIC_ESTATUS);
810 	}
811 
812 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
813 		GLXIIC_DEBUG_LOG("slave nack in rx");
814 		return (IIC_ENOACK);
815 	}
816 
817 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
818 		/* Bus is stalled, clear and wait for data. */
819 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
820 		    GLXIIC_SMB_STS_STASTR_BIT);
821 		return (IIC_NOERR);
822 	}
823 
824 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
825 		GLXIIC_DEBUG_LOG("no pending data in master rx");
826 		return (IIC_ESTATUS);
827 	}
828 
829 	*sc->data++ = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
830 	if (--sc->ndata == 0) {
831 		/* Proceed with stop on reading last byte. */
832 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
833 		return (glxiic_state_table[sc->state].callback(sc, status));
834 	}
835 
836 	if (sc->ndata == 1) {
837 		/* Last byte from slave, set NACK. */
838 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
839 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
840 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
841 	}
842 
843 	glxiic_start_timeout_locked(sc);
844 
845 	return (IIC_NOERR);
846 }
847 
848 static int
849 glxiic_state_master_stop_callback(struct glxiic_softc *sc, uint8_t status)
850 {
851 	uint8_t ctrl1;
852 
853 	GLXIIC_ASSERT_LOCKED(sc);
854 
855 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
856 		GLXIIC_DEBUG_LOG("bus error in master stop");
857 		return (IIC_EBUSERR);
858 	}
859 
860 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
861 		GLXIIC_DEBUG_LOG("not bus master in master stop");
862 		return (IIC_ESTATUS);
863 	}
864 
865 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
866 		GLXIIC_DEBUG_LOG("slave nack in master stop");
867 		return (IIC_ENOACK);
868 	}
869 
870 	if (--sc->nmsgs > 0) {
871 		/* Start transfer of next message. */
872 		if ((sc->msg->flags & IIC_M_NOSTOP) == 0) {
873 			glxiic_stop_locked(sc);
874 		}
875 
876 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
877 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
878 		    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
879 
880 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
881 		sc->msg++;
882 	} else {
883 		/* Last message. */
884 		glxiic_stop_locked(sc);
885 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
886 		sc->error = IIC_NOERR;
887 		GLXIIC_WAKEUP(sc);
888 	}
889 
890 	return (IIC_NOERR);
891 }
892 
893 static void
894 glxiic_intr(void *arg)
895 {
896 	struct glxiic_softc *sc;
897 	int error;
898 	uint8_t status, data;
899 
900 	sc = (struct glxiic_softc *)arg;
901 
902 	GLXIIC_LOCK(sc);
903 
904 	status = glxiic_read_status_locked(sc);
905 
906 	/* Check if this interrupt originated from the SMBus. */
907 	if ((status &
908 		~(GLXIIC_SMB_STS_MASTER_BIT | GLXIIC_SMB_STS_XMIT_BIT)) != 0) {
909 
910 		error = glxiic_state_table[sc->state].callback(sc, status);
911 
912 		if (error != IIC_NOERR) {
913 			if (glxiic_state_table[sc->state].master) {
914 				glxiic_stop_locked(sc);
915 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
916 				sc->error = error;
917 				GLXIIC_WAKEUP(sc);
918 			} else {
919 				data = error & 0xff;
920 				iicbus_intr(sc->iicbus, INTR_ERROR, &data);
921 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
922 			}
923 		}
924 	}
925 
926 	GLXIIC_UNLOCK(sc);
927 }
928 
929 static int
930 glxiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
931 {
932 	struct glxiic_softc *sc;
933 
934 	sc = device_get_softc(dev);
935 
936 	GLXIIC_LOCK(sc);
937 
938 	if (oldaddr != NULL)
939 		*oldaddr = sc->addr;
940 	sc->addr = addr;
941 
942 	/* A disable/enable cycle resets the controller. */
943 	glxiic_smb_disable(sc);
944 	glxiic_smb_enable(sc, speed, addr);
945 
946 	if (glxiic_state_table[sc->state].master) {
947 		sc->error = IIC_ESTATUS;
948 		GLXIIC_WAKEUP(sc);
949 	}
950 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
951 
952 	GLXIIC_UNLOCK(sc);
953 
954 	return (IIC_NOERR);
955 }
956 
957 static int
958 glxiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
959 {
960 	struct glxiic_softc *sc;
961 	int error;
962 	uint8_t ctrl1;
963 
964 	sc = device_get_softc(dev);
965 
966 	GLXIIC_LOCK(sc);
967 
968 	if (sc->state != GLXIIC_STATE_IDLE) {
969 		error = IIC_EBUSBSY;
970 		goto out;
971 	}
972 
973 	sc->msg = msgs;
974 	sc->nmsgs = nmsgs;
975 	glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
976 
977 	/* Set start bit and let glxiic_intr() handle the transfer. */
978 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
979 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
980 	    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
981 
982 	GLXIIC_SLEEP(sc);
983 	error = sc->error;
984 out:
985 	GLXIIC_UNLOCK(sc);
986 
987 	return (error);
988 }
989 
990 static void
991 glxiic_smb_map_interrupt(int irq)
992 {
993 	uint32_t irq_map;
994 	int old_irq;
995 
996 	/* Protect the read-modify-write operation. */
997 	critical_enter();
998 
999 	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
1000 	old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
1001 
1002 	if (irq != old_irq) {
1003 		irq_map &= ~GLXIIC_SMB_IRQ_TO_MAP(old_irq);
1004 		irq_map |= GLXIIC_SMB_IRQ_TO_MAP(irq);
1005 		wrmsr(GLXIIC_MSR_PIC_YSEL_HIGH, irq_map);
1006 	}
1007 
1008 	critical_exit();
1009 }
1010 
1011 static void
1012 glxiic_gpio_enable(struct glxiic_softc *sc)
1013 {
1014 
1015 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1016 	    GLXIIC_GPIO_14_15_ENABLE);
1017 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1018 	    GLXIIC_GPIO_14_15_ENABLE);
1019 }
1020 
1021 static void
1022 glxiic_gpio_disable(struct glxiic_softc *sc)
1023 {
1024 
1025 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1026 	    GLXIIC_GPIO_14_15_DISABLE);
1027 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1028 	    GLXIIC_GPIO_14_15_DISABLE);
1029 }
1030 
1031 static void
1032 glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed, uint8_t addr)
1033 {
1034 	uint8_t ctrl1;
1035 
1036 	ctrl1 = 0;
1037 
1038 	switch (speed) {
1039 	case IIC_SLOW:
1040 		sc->sclfrq = GLXIIC_SLOW;
1041 		break;
1042 	case IIC_FAST:
1043 		sc->sclfrq = GLXIIC_FAST;
1044 		break;
1045 	case IIC_FASTEST:
1046 		sc->sclfrq = GLXIIC_FASTEST;
1047 		break;
1048 	case IIC_UNKNOWN:
1049 	default:
1050 		/* Reuse last frequency. */
1051 		break;
1052 	}
1053 
1054 	/* Set bus speed and enable controller. */
1055 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1056 	    GLXIIC_SCLFRQ(sc->sclfrq) | GLXIIC_SMB_CTRL2_EN_BIT);
1057 
1058 	if (addr != 0) {
1059 		/* Enable new match and global call match interrupts. */
1060 		ctrl1 |= GLXIIC_SMB_CTRL1_NMINTE_BIT |
1061 			GLXIIC_SMB_CTRL1_GCMEN_BIT;
1062 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR,
1063 		    GLXIIC_SMB_ADDR_SAEN_BIT | GLXIIC_SMBADDR(addr));
1064 	} else {
1065 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR, 0);
1066 	}
1067 
1068 	/* Enable stall after start and interrupt. */
1069 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
1070 	    ctrl1 | GLXIIC_SMB_CTRL1_STASTRE_BIT | GLXIIC_SMB_CTRL1_INTEN_BIT);
1071 }
1072 
1073 static void
1074 glxiic_smb_disable(struct glxiic_softc *sc)
1075 {
1076 	uint16_t sclfrq;
1077 
1078 	sclfrq = bus_read_2(sc->smb_res, GLXIIC_SMB_CTRL2);
1079 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1080 	    sclfrq & ~GLXIIC_SMB_CTRL2_EN_BIT);
1081 }
1082