xref: /freebsd/sys/dev/glxiic/glxiic.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
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 /*
30  * AMD Geode LX CS5536 System Management Bus controller.
31  *
32  * Although AMD refers to this device as an SMBus controller, it
33  * really is an I2C controller (It lacks SMBus ALERT# and Alert
34  * Response support).
35  *
36  * The driver is implemented as an interrupt-driven state machine,
37  * supporting both master and slave mode.
38  */
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/bus.h>
42 #include <sys/kernel.h>
43 #include <sys/module.h>
44 #include <sys/lock.h>
45 #include <sys/mutex.h>
46 #include <sys/sysctl.h>
47 #ifdef GLXIIC_DEBUG
48 #include <sys/syslog.h>
49 #endif
50 
51 #include <dev/pci/pcireg.h>
52 #include <dev/pci/pcivar.h>
53 
54 #include <machine/bus.h>
55 #include <sys/rman.h>
56 #include <machine/resource.h>
57 
58 #include <dev/iicbus/iiconf.h>
59 #include <dev/iicbus/iicbus.h>
60 
61 #include "iicbus_if.h"
62 
63 /* CS5536 PCI-ISA ID. */
64 #define	GLXIIC_CS5536_DEV_ID		0x20901022
65 
66 /* MSRs. */
67 #define	GLXIIC_MSR_PIC_YSEL_HIGH	0x51400021
68 
69 /* Bus speeds. */
70 #define	GLXIIC_SLOW	0x0258	/*  10 kHz. */
71 #define	GLXIIC_FAST	0x0078	/*  50 kHz. */
72 #define	GLXIIC_FASTEST	0x003c	/* 100 kHz. */
73 
74 /* Default bus activity timeout in milliseconds. */
75 #define GLXIIC_DEFAULT_TIMEOUT	35
76 
77 /* GPIO register offsets. */
78 #define	GLXIIC_GPIOL_OUT_AUX1_SEL	0x10
79 #define	GLXIIC_GPIOL_IN_AUX1_SEL	0x34
80 
81 /* GPIO 14 (SMB_CLK) and 15 (SMB_DATA) bitmasks. */
82 #define	GLXIIC_GPIO_14_15_ENABLE	0x0000c000
83 #define	GLXIIC_GPIO_14_15_DISABLE	0xc0000000
84 
85 /* SMB register offsets. */
86 #define	GLXIIC_SMB_SDA				0x00
87 #define	GLXIIC_SMB_STS				0x01
88 #define		GLXIIC_SMB_STS_SLVSTP_BIT	(1 << 7)
89 #define		GLXIIC_SMB_STS_SDAST_BIT	(1 << 6)
90 #define		GLXIIC_SMB_STS_BER_BIT		(1 << 5)
91 #define		GLXIIC_SMB_STS_NEGACK_BIT	(1 << 4)
92 #define		GLXIIC_SMB_STS_STASTR_BIT	(1 << 3)
93 #define		GLXIIC_SMB_STS_NMATCH_BIT	(1 << 2)
94 #define		GLXIIC_SMB_STS_MASTER_BIT	(1 << 1)
95 #define		GLXIIC_SMB_STS_XMIT_BIT		(1 << 0)
96 #define	GLXIIC_SMB_CTRL_STS			0x02
97 #define		GLXIIC_SMB_CTRL_STS_TGSCL_BIT	(1 << 5)
98 #define		GLXIIC_SMB_CTRL_STS_TSDA_BIT	(1 << 4)
99 #define		GLXIIC_SMB_CTRL_STS_GCMTCH_BIT	(1 << 3)
100 #define		GLXIIC_SMB_CTRL_STS_MATCH_BIT	(1 << 2)
101 #define		GLXIIC_SMB_CTRL_STS_BB_BIT	(1 << 1)
102 #define		GLXIIC_SMB_CTRL_STS_BUSY_BIT	(1 << 0)
103 #define	GLXIIC_SMB_CTRL1			0x03
104 #define		GLXIIC_SMB_CTRL1_STASTRE_BIT	(1 << 7)
105 #define		GLXIIC_SMB_CTRL1_NMINTE_BIT	(1 << 6)
106 #define		GLXIIC_SMB_CTRL1_GCMEN_BIT	(1 << 5)
107 #define		GLXIIC_SMB_CTRL1_ACK_BIT	(1 << 4)
108 #define		GLXIIC_SMB_CTRL1_INTEN_BIT	(1 << 2)
109 #define		GLXIIC_SMB_CTRL1_STOP_BIT	(1 << 1)
110 #define		GLXIIC_SMB_CTRL1_START_BIT	(1 << 0)
111 #define	GLXIIC_SMB_ADDR				0x04
112 #define		GLXIIC_SMB_ADDR_SAEN_BIT	(1 << 7)
113 #define	GLXIIC_SMB_CTRL2			0x05
114 #define		GLXIIC_SMB_CTRL2_EN_BIT		(1 << 0)
115 #define	GLXIIC_SMB_CTRL3			0x06
116 
117 typedef enum {
118 	GLXIIC_STATE_IDLE,
119 	GLXIIC_STATE_SLAVE_TX,
120 	GLXIIC_STATE_SLAVE_RX,
121 	GLXIIC_STATE_MASTER_ADDR,
122 	GLXIIC_STATE_MASTER_TX,
123 	GLXIIC_STATE_MASTER_RX,
124 	GLXIIC_STATE_MASTER_STOP,
125 	GLXIIC_STATE_MAX,
126 } glxiic_state_t;
127 
128 struct glxiic_softc {
129 	device_t	 dev;		/* Myself. */
130 	device_t	 iicbus;	/* IIC bus. */
131 	struct mtx	 mtx;		/* Lock. */
132 	glxiic_state_t	 state;		/* Driver state. */
133 	struct callout	 callout;	/* Driver state timeout callout. */
134 	int		 timeout;	/* Driver state timeout (ms). */
135 
136 	int		 smb_rid;	/* SMB controller resource ID. */
137 	struct resource *smb_res;	/* SMB controller resource. */
138 	int		 gpio_rid;	/* GPIO resource ID. */
139 	struct resource *gpio_res;	/* GPIO resource. */
140 
141 	int		 irq_rid;	/* IRQ resource ID. */
142 	struct resource *irq_res;	/* IRQ resource. */
143 	void		*irq_handler;	/* IRQ handler cookie. */
144 	int		 old_irq;	/* IRQ mapped by board firmware. */
145 
146 	struct iic_msg	*msg;		/* Current master mode message. */
147 	uint32_t	 nmsgs;		/* Number of messages remaining. */
148 	uint8_t		*data;		/* Current master mode data byte. */
149 	uint16_t	 ndata;		/* Number of data bytes remaining. */
150 	int		 error;		/* Last master mode error. */
151 
152 	uint8_t		 addr;		/* Own address. */
153 	uint16_t	 sclfrq;	/* Bus frequency. */
154 };
155 
156 #ifdef GLXIIC_DEBUG
157 #define GLXIIC_DEBUG_LOG(fmt, args...)	\
158 	log(LOG_DEBUG, "%s: " fmt "\n" , __func__ , ## args)
159 #else
160 #define GLXIIC_DEBUG_LOG(fmt, args...)
161 #endif
162 
163 #define	GLXIIC_SCLFRQ(n)		((n << 1))
164 #define	GLXIIC_SMBADDR(n)		((n >> 1))
165 #define	GLXIIC_SMB_IRQ_TO_MAP(n)	((n << 16))
166 #define	GLXIIC_MAP_TO_SMB_IRQ(n)	((n >> 16) & 0xf)
167 
168 #define	GLXIIC_LOCK(_sc)		mtx_lock(&_sc->mtx)
169 #define	GLXIIC_UNLOCK(_sc)		mtx_unlock(&_sc->mtx)
170 #define	GLXIIC_LOCK_INIT(_sc)		\
171 	mtx_init(&_sc->mtx, device_get_nameunit(_sc->dev), "glxiic", MTX_DEF)
172 #define	GLXIIC_SLEEP(_sc)		\
173 	mtx_sleep(_sc, &_sc->mtx, IICPRI, "glxiic", 0)
174 #define	GLXIIC_WAKEUP(_sc)		wakeup(_sc);
175 #define	GLXIIC_LOCK_DESTROY(_sc)	mtx_destroy(&_sc->mtx);
176 #define	GLXIIC_ASSERT_LOCKED(_sc)	mtx_assert(&_sc->mtx, MA_OWNED);
177 
178 typedef	int (glxiic_state_callback_t)(struct glxiic_softc *sc,
179     uint8_t status);
180 
181 static glxiic_state_callback_t	glxiic_state_idle_callback;
182 static glxiic_state_callback_t	glxiic_state_slave_tx_callback;
183 static glxiic_state_callback_t	glxiic_state_slave_rx_callback;
184 static glxiic_state_callback_t	glxiic_state_master_addr_callback;
185 static glxiic_state_callback_t	glxiic_state_master_tx_callback;
186 static glxiic_state_callback_t	glxiic_state_master_rx_callback;
187 static glxiic_state_callback_t	glxiic_state_master_stop_callback;
188 
189 struct glxiic_state_table_entry {
190 	glxiic_state_callback_t *callback;
191 	boolean_t master;
192 };
193 typedef struct glxiic_state_table_entry glxiic_state_table_entry_t;
194 
195 static glxiic_state_table_entry_t glxiic_state_table[GLXIIC_STATE_MAX] = {
196 	[GLXIIC_STATE_IDLE] = {
197 		.callback = &glxiic_state_idle_callback,
198 		.master = FALSE,
199 	},
200 
201 	[GLXIIC_STATE_SLAVE_TX] = {
202 		.callback = &glxiic_state_slave_tx_callback,
203 		.master = FALSE,
204 	},
205 
206 	[GLXIIC_STATE_SLAVE_RX] = {
207 		.callback = &glxiic_state_slave_rx_callback,
208 		.master = FALSE,
209 	},
210 
211 	[GLXIIC_STATE_MASTER_ADDR] = {
212 		.callback = &glxiic_state_master_addr_callback,
213 		.master = TRUE,
214 	},
215 
216 	[GLXIIC_STATE_MASTER_TX] = {
217 		.callback = &glxiic_state_master_tx_callback,
218 		.master = TRUE,
219 	},
220 
221 	[GLXIIC_STATE_MASTER_RX] = {
222 		.callback = &glxiic_state_master_rx_callback,
223 		.master = TRUE,
224 	},
225 
226 	[GLXIIC_STATE_MASTER_STOP] = {
227 		.callback = &glxiic_state_master_stop_callback,
228 		.master = TRUE,
229 	},
230 };
231 
232 static void	glxiic_identify(driver_t *driver, device_t parent);
233 static int	glxiic_probe(device_t dev);
234 static int	glxiic_attach(device_t dev);
235 static int	glxiic_detach(device_t dev);
236 
237 static uint8_t	glxiic_read_status_locked(struct glxiic_softc *sc);
238 static void	glxiic_stop_locked(struct glxiic_softc *sc);
239 static void	glxiic_timeout(void *arg);
240 static void	glxiic_start_timeout_locked(struct glxiic_softc *sc);
241 static void	glxiic_set_state_locked(struct glxiic_softc *sc,
242     glxiic_state_t state);
243 static int	glxiic_handle_slave_match_locked(struct glxiic_softc *sc,
244     uint8_t status);
245 static void	glxiic_intr(void *arg);
246 
247 static int	glxiic_reset(device_t dev, u_char speed, u_char addr,
248     u_char *oldaddr);
249 static int	glxiic_transfer(device_t dev, struct iic_msg *msgs,
250     uint32_t nmsgs);
251 
252 static void	glxiic_smb_map_interrupt(int irq);
253 static void 	glxiic_gpio_enable(struct glxiic_softc *sc);
254 static void 	glxiic_gpio_disable(struct glxiic_softc *sc);
255 static void	glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed,
256     uint8_t addr);
257 static void	glxiic_smb_disable(struct glxiic_softc *sc);
258 
259 static device_method_t glxiic_methods[] = {
260 	DEVMETHOD(device_identify,	glxiic_identify),
261 	DEVMETHOD(device_probe,		glxiic_probe),
262 	DEVMETHOD(device_attach,	glxiic_attach),
263 	DEVMETHOD(device_detach,	glxiic_detach),
264 
265 	DEVMETHOD(iicbus_reset,		glxiic_reset),
266 	DEVMETHOD(iicbus_transfer,	glxiic_transfer),
267 	DEVMETHOD(iicbus_callback,	iicbus_null_callback),
268 
269 	{ 0, 0 }
270 };
271 
272 static driver_t glxiic_driver = {
273 	"glxiic",
274 	glxiic_methods,
275 	sizeof(struct glxiic_softc),
276 };
277 
278 DRIVER_MODULE(glxiic, isab, glxiic_driver, 0, 0);
279 DRIVER_MODULE(iicbus, glxiic, iicbus_driver, 0, 0);
280 MODULE_DEPEND(glxiic, iicbus, 1, 1, 1);
281 
282 static void
283 glxiic_identify(driver_t *driver, device_t parent)
284 {
285 
286 	/* Prevent child from being added more than once. */
287 	if (device_find_child(parent, driver->name, -1) != NULL)
288 		return;
289 
290 	if (pci_get_devid(parent) == GLXIIC_CS5536_DEV_ID) {
291 		if (device_add_child(parent, driver->name, -1) == NULL)
292 			device_printf(parent, "Could not add glxiic child\n");
293 	}
294 }
295 
296 static int
297 glxiic_probe(device_t dev)
298 {
299 
300 	if (resource_disabled("glxiic", device_get_unit(dev)))
301 		return (ENXIO);
302 
303 	device_set_desc(dev, "AMD Geode CS5536 SMBus controller");
304 
305 	return (BUS_PROBE_DEFAULT);
306 }
307 
308 static int
309 glxiic_attach(device_t dev)
310 {
311 	struct glxiic_softc *sc;
312 	struct sysctl_ctx_list *ctx;
313 	struct sysctl_oid *tree;
314 	int error, irq, unit;
315 	uint32_t irq_map;
316 
317 	sc = device_get_softc(dev);
318 	sc->dev = dev;
319 	sc->state = GLXIIC_STATE_IDLE;
320 	error = 0;
321 
322 	GLXIIC_LOCK_INIT(sc);
323 	callout_init_mtx(&sc->callout, &sc->mtx, 0);
324 
325 	sc->smb_rid = PCIR_BAR(0);
326 	sc->smb_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &sc->smb_rid,
327 	    RF_ACTIVE);
328 	if (sc->smb_res == NULL) {
329 		device_printf(dev, "Could not allocate SMBus I/O port\n");
330 		error = ENXIO;
331 		goto out;
332 	}
333 
334 	sc->gpio_rid = PCIR_BAR(1);
335 	sc->gpio_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
336 	    &sc->gpio_rid, RF_SHAREABLE | RF_ACTIVE);
337 	if (sc->gpio_res == NULL) {
338 		device_printf(dev, "Could not allocate GPIO I/O port\n");
339 		error = ENXIO;
340 		goto out;
341 	}
342 
343 	/* Ensure the controller is not enabled by firmware. */
344 	glxiic_smb_disable(sc);
345 
346 	/* Read the existing IRQ map. */
347 	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
348 	sc->old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
349 
350 	unit = device_get_unit(dev);
351 	if (resource_int_value("glxiic", unit, "irq", &irq) == 0) {
352 		if (irq < 1 || irq > 15) {
353 			device_printf(dev, "Bad value %d for glxiic.%d.irq\n",
354 			    irq, unit);
355 			error = ENXIO;
356 			goto out;
357 		}
358 
359 		if (bootverbose)
360 			device_printf(dev, "Using irq %d set by hint\n", irq);
361 	} else if (sc->old_irq != 0) {
362 		if (bootverbose)
363 			device_printf(dev, "Using irq %d set by firmware\n",
364 			    irq);
365 		irq = sc->old_irq;
366 	} else {
367 		device_printf(dev, "No irq mapped by firmware");
368 		printf(" and no glxiic.%d.irq hint provided\n", unit);
369 		error = ENXIO;
370 		goto out;
371 	}
372 
373 	/* Map the SMBus interrupt to the requested legacy IRQ. */
374 	glxiic_smb_map_interrupt(irq);
375 
376 	sc->irq_rid = 0;
377 	sc->irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &sc->irq_rid,
378 	    irq, irq, 1, RF_SHAREABLE | RF_ACTIVE);
379 	if (sc->irq_res == NULL) {
380 		device_printf(dev, "Could not allocate IRQ %d\n", irq);
381 		error = ENXIO;
382 		goto out;
383 	}
384 
385 	error = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
386 	    NULL, glxiic_intr, sc, &(sc->irq_handler));
387 	if (error != 0) {
388 		device_printf(dev, "Could not setup IRQ handler\n");
389 		error = ENXIO;
390 		goto out;
391 	}
392 
393 	if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) {
394 		device_printf(dev, "Could not allocate iicbus instance\n");
395 		error = ENXIO;
396 		goto out;
397 	}
398 
399 	ctx = device_get_sysctl_ctx(dev);
400 	tree = device_get_sysctl_tree(dev);
401 
402 	sc->timeout = GLXIIC_DEFAULT_TIMEOUT;
403 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
404 	    "timeout", CTLFLAG_RWTUN, &sc->timeout, 0,
405 	    "activity timeout in ms");
406 
407 	glxiic_gpio_enable(sc);
408 	glxiic_smb_enable(sc, IIC_FASTEST, 0);
409 
410 	/* Probe and attach the iicbus when interrupts are available. */
411 	error = bus_delayed_attach_children(dev);
412 
413 out:
414 	if (error != 0) {
415 		callout_drain(&sc->callout);
416 
417 		if (sc->iicbus != NULL)
418 			device_delete_child(dev, sc->iicbus);
419 		if (sc->smb_res != NULL) {
420 			glxiic_smb_disable(sc);
421 			bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
422 			    sc->smb_res);
423 		}
424 		if (sc->gpio_res != NULL) {
425 			glxiic_gpio_disable(sc);
426 			bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
427 			    sc->gpio_res);
428 		}
429 		if (sc->irq_handler != NULL)
430 			bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
431 		if (sc->irq_res != NULL)
432 			bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
433 			    sc->irq_res);
434 
435 		/* Restore the old SMBus interrupt mapping. */
436 		glxiic_smb_map_interrupt(sc->old_irq);
437 
438 		GLXIIC_LOCK_DESTROY(sc);
439 	}
440 
441 	return (error);
442 }
443 
444 static int
445 glxiic_detach(device_t dev)
446 {
447 	struct glxiic_softc *sc;
448 	int error;
449 
450 	sc = device_get_softc(dev);
451 
452 	error = bus_generic_detach(dev);
453 	if (error != 0)
454 		goto out;
455 	if (sc->iicbus != NULL)
456 		error = device_delete_child(dev, sc->iicbus);
457 
458 out:
459 	callout_drain(&sc->callout);
460 
461 	if (sc->smb_res != NULL) {
462 		glxiic_smb_disable(sc);
463 		bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
464 		    sc->smb_res);
465 	}
466 	if (sc->gpio_res != NULL) {
467 		glxiic_gpio_disable(sc);
468 		bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
469 		    sc->gpio_res);
470 	}
471 	if (sc->irq_handler != NULL)
472 		bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
473 	if (sc->irq_res != NULL)
474 		bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
475 		    sc->irq_res);
476 
477 	/* Restore the old SMBus interrupt mapping. */
478 	glxiic_smb_map_interrupt(sc->old_irq);
479 
480 	GLXIIC_LOCK_DESTROY(sc);
481 
482 	return (error);
483 }
484 
485 static uint8_t
486 glxiic_read_status_locked(struct glxiic_softc *sc)
487 {
488 	uint8_t status;
489 
490 	GLXIIC_ASSERT_LOCKED(sc);
491 
492 	status = bus_read_1(sc->smb_res, GLXIIC_SMB_STS);
493 
494 	/* Clear all status flags except SDAST and STASTR after reading. */
495 	bus_write_1(sc->smb_res, GLXIIC_SMB_STS, (GLXIIC_SMB_STS_SLVSTP_BIT |
496 		GLXIIC_SMB_STS_BER_BIT | GLXIIC_SMB_STS_NEGACK_BIT |
497 		GLXIIC_SMB_STS_NMATCH_BIT));
498 
499 	return (status);
500 }
501 
502 static void
503 glxiic_stop_locked(struct glxiic_softc *sc)
504 {
505 	uint8_t status, ctrl1;
506 
507 	GLXIIC_ASSERT_LOCKED(sc);
508 
509 	status = glxiic_read_status_locked(sc);
510 
511 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
512 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
513 	    ctrl1 | GLXIIC_SMB_CTRL1_STOP_BIT);
514 
515 	/*
516 	 * Perform a dummy read of SDA in master receive mode to clear
517 	 * SDAST if set.
518 	 */
519 	if ((status & GLXIIC_SMB_STS_XMIT_BIT) == 0 &&
520 	    (status & GLXIIC_SMB_STS_SDAST_BIT) != 0)
521 	 	bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
522 
523 	/* Check stall after start bit and clear if needed */
524 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
525 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
526 		    GLXIIC_SMB_STS_STASTR_BIT);
527 	}
528 }
529 
530 static void
531 glxiic_timeout(void *arg)
532 {
533 	struct glxiic_softc *sc;
534 	uint8_t error;
535 
536 	sc = (struct glxiic_softc *)arg;
537 
538 	GLXIIC_DEBUG_LOG("timeout in state %d", sc->state);
539 
540 	if (glxiic_state_table[sc->state].master) {
541 		sc->error = IIC_ETIMEOUT;
542 		GLXIIC_WAKEUP(sc);
543 	} else {
544 		error = IIC_ETIMEOUT;
545 		iicbus_intr(sc->iicbus, INTR_ERROR, &error);
546 	}
547 
548 	glxiic_smb_disable(sc);
549 	glxiic_smb_enable(sc, IIC_UNKNOWN, sc->addr);
550 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
551 }
552 
553 static void
554 glxiic_start_timeout_locked(struct glxiic_softc *sc)
555 {
556 
557 	GLXIIC_ASSERT_LOCKED(sc);
558 
559 	callout_reset_sbt(&sc->callout, SBT_1MS * sc->timeout, 0,
560 	    glxiic_timeout, sc, 0);
561 }
562 
563 static void
564 glxiic_set_state_locked(struct glxiic_softc *sc, glxiic_state_t state)
565 {
566 
567 	GLXIIC_ASSERT_LOCKED(sc);
568 
569 	if (state == GLXIIC_STATE_IDLE)
570 		callout_stop(&sc->callout);
571 	else if (sc->timeout > 0)
572 		glxiic_start_timeout_locked(sc);
573 
574 	sc->state = state;
575 }
576 
577 static int
578 glxiic_handle_slave_match_locked(struct glxiic_softc *sc, uint8_t status)
579 {
580 	uint8_t ctrl_sts, addr;
581 
582 	GLXIIC_ASSERT_LOCKED(sc);
583 
584 	ctrl_sts = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL_STS);
585 
586 	if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_MATCH_BIT) != 0) {
587 		if ((status & GLXIIC_SMB_STS_XMIT_BIT) != 0) {
588 			addr = sc->addr | LSB;
589 			glxiic_set_state_locked(sc,
590 			    GLXIIC_STATE_SLAVE_TX);
591 		} else {
592 			addr = sc->addr & ~LSB;
593 			glxiic_set_state_locked(sc,
594 			    GLXIIC_STATE_SLAVE_RX);
595 		}
596 		iicbus_intr(sc->iicbus, INTR_START, &addr);
597 	} else if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_GCMTCH_BIT) != 0) {
598 		addr = 0;
599 		glxiic_set_state_locked(sc, GLXIIC_STATE_SLAVE_RX);
600 		iicbus_intr(sc->iicbus, INTR_GENERAL, &addr);
601 	} else {
602 		GLXIIC_DEBUG_LOG("unknown slave match");
603 		return (IIC_ESTATUS);
604 	}
605 
606 	return (IIC_NOERR);
607 }
608 
609 static int
610 glxiic_state_idle_callback(struct glxiic_softc *sc, uint8_t status)
611 {
612 
613 	GLXIIC_ASSERT_LOCKED(sc);
614 
615 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
616 		GLXIIC_DEBUG_LOG("bus error in idle");
617 		return (IIC_EBUSERR);
618 	}
619 
620 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
621 		return (glxiic_handle_slave_match_locked(sc, status));
622 	}
623 
624 	return (IIC_NOERR);
625 }
626 
627 static int
628 glxiic_state_slave_tx_callback(struct glxiic_softc *sc, uint8_t status)
629 {
630 	uint8_t data;
631 
632 	GLXIIC_ASSERT_LOCKED(sc);
633 
634 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
635 		GLXIIC_DEBUG_LOG("bus error in slave tx");
636 		return (IIC_EBUSERR);
637 	}
638 
639 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
640 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
641 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
642 		return (IIC_NOERR);
643 	}
644 
645 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
646 		iicbus_intr(sc->iicbus, INTR_NOACK, NULL);
647 		return (IIC_NOERR);
648 	}
649 
650 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
651 		/* Handle repeated start in slave mode. */
652 		return (glxiic_handle_slave_match_locked(sc, status));
653 	}
654 
655 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
656 		GLXIIC_DEBUG_LOG("not awaiting data in slave tx");
657 		return (IIC_ESTATUS);
658 	}
659 
660 	iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
661 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, data);
662 
663 	glxiic_start_timeout_locked(sc);
664 
665 	return (IIC_NOERR);
666 }
667 
668 static int
669 glxiic_state_slave_rx_callback(struct glxiic_softc *sc, uint8_t status)
670 {
671 	uint8_t data;
672 
673 	GLXIIC_ASSERT_LOCKED(sc);
674 
675 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
676 		GLXIIC_DEBUG_LOG("bus error in slave rx");
677 		return (IIC_EBUSERR);
678 	}
679 
680 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
681 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
682 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
683 		return (IIC_NOERR);
684 	}
685 
686 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
687 		/* Handle repeated start in slave mode. */
688 		return (glxiic_handle_slave_match_locked(sc, status));
689 	}
690 
691 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
692 		GLXIIC_DEBUG_LOG("no pending data in slave rx");
693 		return (IIC_ESTATUS);
694 	}
695 
696 	data = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
697 	iicbus_intr(sc->iicbus, INTR_RECEIVE, &data);
698 
699 	glxiic_start_timeout_locked(sc);
700 
701 	return (IIC_NOERR);
702 }
703 
704 static int
705 glxiic_state_master_addr_callback(struct glxiic_softc *sc, uint8_t status)
706 {
707 	uint8_t slave;
708 	uint8_t ctrl1;
709 
710 	GLXIIC_ASSERT_LOCKED(sc);
711 
712 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
713 		GLXIIC_DEBUG_LOG("bus error after master start");
714 		return (IIC_EBUSERR);
715 	}
716 
717 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
718 		GLXIIC_DEBUG_LOG("not bus master after master start");
719 		return (IIC_ESTATUS);
720 	}
721 
722 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
723 		GLXIIC_DEBUG_LOG("not awaiting address in master addr");
724 		return (IIC_ESTATUS);
725 	}
726 
727 	if ((sc->msg->flags & IIC_M_RD) != 0) {
728 		slave = sc->msg->slave | LSB;
729 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_RX);
730 	} else {
731 		slave = sc->msg->slave & ~LSB;
732 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_TX);
733 	}
734 
735 	sc->data = sc->msg->buf;
736 	sc->ndata = sc->msg->len;
737 
738 	/* Handle address-only transfer. */
739 	if (sc->ndata == 0)
740 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
741 
742 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, slave);
743 
744 	if ((sc->msg->flags & IIC_M_RD) != 0 && sc->ndata == 1) {
745 		/* Last byte from slave, set NACK. */
746 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
747 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
748 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
749 	}
750 
751 	return (IIC_NOERR);
752 }
753 
754 static int
755 glxiic_state_master_tx_callback(struct glxiic_softc *sc, uint8_t status)
756 {
757 
758 	GLXIIC_ASSERT_LOCKED(sc);
759 
760 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
761 		GLXIIC_DEBUG_LOG("bus error in master tx");
762 		return (IIC_EBUSERR);
763 	}
764 
765 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
766 		GLXIIC_DEBUG_LOG("not bus master in master tx");
767 		return (IIC_ESTATUS);
768 	}
769 
770 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
771 		GLXIIC_DEBUG_LOG("slave nack in master tx");
772 		return (IIC_ENOACK);
773 	}
774 
775 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
776 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
777 		    GLXIIC_SMB_STS_STASTR_BIT);
778 	}
779 
780 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
781 		GLXIIC_DEBUG_LOG("not awaiting data in master tx");
782 		return (IIC_ESTATUS);
783 	}
784 
785 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, *sc->data++);
786 	if (--sc->ndata == 0)
787 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
788 	else
789 		glxiic_start_timeout_locked(sc);
790 
791 	return (IIC_NOERR);
792 }
793 
794 static int
795 glxiic_state_master_rx_callback(struct glxiic_softc *sc, uint8_t status)
796 {
797 	uint8_t ctrl1;
798 
799 	GLXIIC_ASSERT_LOCKED(sc);
800 
801 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
802 		GLXIIC_DEBUG_LOG("bus error in master rx");
803 		return (IIC_EBUSERR);
804 	}
805 
806 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
807 		GLXIIC_DEBUG_LOG("not bus master in master rx");
808 		return (IIC_ESTATUS);
809 	}
810 
811 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
812 		GLXIIC_DEBUG_LOG("slave nack in rx");
813 		return (IIC_ENOACK);
814 	}
815 
816 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
817 		/* Bus is stalled, clear and wait for data. */
818 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
819 		    GLXIIC_SMB_STS_STASTR_BIT);
820 		return (IIC_NOERR);
821 	}
822 
823 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
824 		GLXIIC_DEBUG_LOG("no pending data in master rx");
825 		return (IIC_ESTATUS);
826 	}
827 
828 	*sc->data++ = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
829 	if (--sc->ndata == 0) {
830 		/* Proceed with stop on reading last byte. */
831 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
832 		return (glxiic_state_table[sc->state].callback(sc, status));
833 	}
834 
835 	if (sc->ndata == 1) {
836 		/* Last byte from slave, set NACK. */
837 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
838 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
839 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
840 	}
841 
842 	glxiic_start_timeout_locked(sc);
843 
844 	return (IIC_NOERR);
845 }
846 
847 static int
848 glxiic_state_master_stop_callback(struct glxiic_softc *sc, uint8_t status)
849 {
850 	uint8_t ctrl1;
851 
852 	GLXIIC_ASSERT_LOCKED(sc);
853 
854 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
855 		GLXIIC_DEBUG_LOG("bus error in master stop");
856 		return (IIC_EBUSERR);
857 	}
858 
859 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
860 		GLXIIC_DEBUG_LOG("not bus master in master stop");
861 		return (IIC_ESTATUS);
862 	}
863 
864 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
865 		GLXIIC_DEBUG_LOG("slave nack in master stop");
866 		return (IIC_ENOACK);
867 	}
868 
869 	if (--sc->nmsgs > 0) {
870 		/* Start transfer of next message. */
871 		if ((sc->msg->flags & IIC_M_NOSTOP) == 0) {
872 			glxiic_stop_locked(sc);
873 		}
874 
875 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
876 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
877 		    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
878 
879 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
880 		sc->msg++;
881 	} else {
882 		/* Last message. */
883 		glxiic_stop_locked(sc);
884 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
885 		sc->error = IIC_NOERR;
886 		GLXIIC_WAKEUP(sc);
887 	}
888 
889 	return (IIC_NOERR);
890 }
891 
892 static void
893 glxiic_intr(void *arg)
894 {
895 	struct glxiic_softc *sc;
896 	int error;
897 	uint8_t status, data;
898 
899 	sc = (struct glxiic_softc *)arg;
900 
901 	GLXIIC_LOCK(sc);
902 
903 	status = glxiic_read_status_locked(sc);
904 
905 	/* Check if this interrupt originated from the SMBus. */
906 	if ((status &
907 		~(GLXIIC_SMB_STS_MASTER_BIT | GLXIIC_SMB_STS_XMIT_BIT)) != 0) {
908 
909 		error = glxiic_state_table[sc->state].callback(sc, status);
910 
911 		if (error != IIC_NOERR) {
912 			if (glxiic_state_table[sc->state].master) {
913 				glxiic_stop_locked(sc);
914 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
915 				sc->error = error;
916 				GLXIIC_WAKEUP(sc);
917 			} else {
918 				data = error & 0xff;
919 				iicbus_intr(sc->iicbus, INTR_ERROR, &data);
920 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
921 			}
922 		}
923 	}
924 
925 	GLXIIC_UNLOCK(sc);
926 }
927 
928 static int
929 glxiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
930 {
931 	struct glxiic_softc *sc;
932 
933 	sc = device_get_softc(dev);
934 
935 	GLXIIC_LOCK(sc);
936 
937 	if (oldaddr != NULL)
938 		*oldaddr = sc->addr;
939 	sc->addr = addr;
940 
941 	/* A disable/enable cycle resets the controller. */
942 	glxiic_smb_disable(sc);
943 	glxiic_smb_enable(sc, speed, addr);
944 
945 	if (glxiic_state_table[sc->state].master) {
946 		sc->error = IIC_ESTATUS;
947 		GLXIIC_WAKEUP(sc);
948 	}
949 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
950 
951 	GLXIIC_UNLOCK(sc);
952 
953 	return (IIC_NOERR);
954 }
955 
956 static int
957 glxiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
958 {
959 	struct glxiic_softc *sc;
960 	int error;
961 	uint8_t ctrl1;
962 
963 	sc = device_get_softc(dev);
964 
965 	GLXIIC_LOCK(sc);
966 
967 	if (sc->state != GLXIIC_STATE_IDLE) {
968 		error = IIC_EBUSBSY;
969 		goto out;
970 	}
971 
972 	sc->msg = msgs;
973 	sc->nmsgs = nmsgs;
974 	glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
975 
976 	/* Set start bit and let glxiic_intr() handle the transfer. */
977 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
978 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
979 	    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
980 
981 	GLXIIC_SLEEP(sc);
982 	error = sc->error;
983 out:
984 	GLXIIC_UNLOCK(sc);
985 
986 	return (error);
987 }
988 
989 static void
990 glxiic_smb_map_interrupt(int irq)
991 {
992 	uint32_t irq_map;
993 	int old_irq;
994 
995 	/* Protect the read-modify-write operation. */
996 	critical_enter();
997 
998 	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
999 	old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
1000 
1001 	if (irq != old_irq) {
1002 		irq_map &= ~GLXIIC_SMB_IRQ_TO_MAP(old_irq);
1003 		irq_map |= GLXIIC_SMB_IRQ_TO_MAP(irq);
1004 		wrmsr(GLXIIC_MSR_PIC_YSEL_HIGH, irq_map);
1005 	}
1006 
1007 	critical_exit();
1008 }
1009 
1010 static void
1011 glxiic_gpio_enable(struct glxiic_softc *sc)
1012 {
1013 
1014 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1015 	    GLXIIC_GPIO_14_15_ENABLE);
1016 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1017 	    GLXIIC_GPIO_14_15_ENABLE);
1018 }
1019 
1020 static void
1021 glxiic_gpio_disable(struct glxiic_softc *sc)
1022 {
1023 
1024 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1025 	    GLXIIC_GPIO_14_15_DISABLE);
1026 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1027 	    GLXIIC_GPIO_14_15_DISABLE);
1028 }
1029 
1030 static void
1031 glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed, uint8_t addr)
1032 {
1033 	uint8_t ctrl1;
1034 
1035 	ctrl1 = 0;
1036 
1037 	switch (speed) {
1038 	case IIC_SLOW:
1039 		sc->sclfrq = GLXIIC_SLOW;
1040 		break;
1041 	case IIC_FAST:
1042 		sc->sclfrq = GLXIIC_FAST;
1043 		break;
1044 	case IIC_FASTEST:
1045 		sc->sclfrq = GLXIIC_FASTEST;
1046 		break;
1047 	case IIC_UNKNOWN:
1048 	default:
1049 		/* Reuse last frequency. */
1050 		break;
1051 	}
1052 
1053 	/* Set bus speed and enable controller. */
1054 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1055 	    GLXIIC_SCLFRQ(sc->sclfrq) | GLXIIC_SMB_CTRL2_EN_BIT);
1056 
1057 	if (addr != 0) {
1058 		/* Enable new match and global call match interrupts. */
1059 		ctrl1 |= GLXIIC_SMB_CTRL1_NMINTE_BIT |
1060 			GLXIIC_SMB_CTRL1_GCMEN_BIT;
1061 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR,
1062 		    GLXIIC_SMB_ADDR_SAEN_BIT | GLXIIC_SMBADDR(addr));
1063 	} else {
1064 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR, 0);
1065 	}
1066 
1067 	/* Enable stall after start and interrupt. */
1068 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
1069 	    ctrl1 | GLXIIC_SMB_CTRL1_STASTRE_BIT | GLXIIC_SMB_CTRL1_INTEN_BIT);
1070 }
1071 
1072 static void
1073 glxiic_smb_disable(struct glxiic_softc *sc)
1074 {
1075 	uint16_t sclfrq;
1076 
1077 	sclfrq = bus_read_2(sc->smb_res, GLXIIC_SMB_CTRL2);
1078 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1079 	    sclfrq & ~GLXIIC_SMB_CTRL2_EN_BIT);
1080 }
1081