1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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
118typedef 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
129struct 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
179typedef	int (glxiic_state_callback_t)(struct glxiic_softc *sc,
180    uint8_t status);
181
182static glxiic_state_callback_t	glxiic_state_idle_callback;
183static glxiic_state_callback_t	glxiic_state_slave_tx_callback;
184static glxiic_state_callback_t	glxiic_state_slave_rx_callback;
185static glxiic_state_callback_t	glxiic_state_master_addr_callback;
186static glxiic_state_callback_t	glxiic_state_master_tx_callback;
187static glxiic_state_callback_t	glxiic_state_master_rx_callback;
188static glxiic_state_callback_t	glxiic_state_master_stop_callback;
189
190struct glxiic_state_table_entry {
191	glxiic_state_callback_t *callback;
192	boolean_t master;
193};
194typedef struct glxiic_state_table_entry glxiic_state_table_entry_t;
195
196static 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
233static void	glxiic_identify(driver_t *driver, device_t parent);
234static int	glxiic_probe(device_t dev);
235static int	glxiic_attach(device_t dev);
236static int	glxiic_detach(device_t dev);
237
238static uint8_t	glxiic_read_status_locked(struct glxiic_softc *sc);
239static void	glxiic_stop_locked(struct glxiic_softc *sc);
240static void	glxiic_timeout(void *arg);
241static void	glxiic_start_timeout_locked(struct glxiic_softc *sc);
242static void	glxiic_set_state_locked(struct glxiic_softc *sc,
243    glxiic_state_t state);
244static int	glxiic_handle_slave_match_locked(struct glxiic_softc *sc,
245    uint8_t status);
246static void	glxiic_intr(void *arg);
247
248static int	glxiic_reset(device_t dev, u_char speed, u_char addr,
249    u_char *oldaddr);
250static int	glxiic_transfer(device_t dev, struct iic_msg *msgs,
251    uint32_t nmsgs);
252
253static void	glxiic_smb_map_interrupt(int irq);
254static void 	glxiic_gpio_enable(struct glxiic_softc *sc);
255static void 	glxiic_gpio_disable(struct glxiic_softc *sc);
256static void	glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed,
257    uint8_t addr);
258static void	glxiic_smb_disable(struct glxiic_softc *sc);
259
260static 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
273static driver_t glxiic_driver = {
274	"glxiic",
275	glxiic_methods,
276	sizeof(struct glxiic_softc),
277};
278
279static devclass_t glxiic_devclass;
280
281DRIVER_MODULE(glxiic, isab, glxiic_driver, glxiic_devclass, 0, 0);
282DRIVER_MODULE(iicbus, glxiic, iicbus_driver, iicbus_devclass, 0, 0);
283MODULE_DEPEND(glxiic, iicbus, 1, 1, 1);
284
285static void
286glxiic_identify(driver_t *driver, device_t parent)
287{
288
289	/* Prevent child from being added more than once. */
290	if (device_find_child(parent, driver->name, -1) != NULL)
291		return;
292
293	if (pci_get_devid(parent) == GLXIIC_CS5536_DEV_ID) {
294		if (device_add_child(parent, driver->name, -1) == NULL)
295			device_printf(parent, "Could not add glxiic child\n");
296	}
297}
298
299static int
300glxiic_probe(device_t dev)
301{
302
303	if (resource_disabled("glxiic", device_get_unit(dev)))
304		return (ENXIO);
305
306	device_set_desc(dev, "AMD Geode CS5536 SMBus controller");
307
308	return (BUS_PROBE_DEFAULT);
309}
310
311static int
312glxiic_attach(device_t dev)
313{
314	struct glxiic_softc *sc;
315	struct sysctl_ctx_list *ctx;
316	struct sysctl_oid *tree;
317	int error, irq, unit;
318	uint32_t irq_map;
319
320	sc = device_get_softc(dev);
321	sc->dev = dev;
322	sc->state = GLXIIC_STATE_IDLE;
323	error = 0;
324
325	GLXIIC_LOCK_INIT(sc);
326	callout_init_mtx(&sc->callout, &sc->mtx, 0);
327
328	sc->smb_rid = PCIR_BAR(0);
329	sc->smb_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &sc->smb_rid,
330	    RF_ACTIVE);
331	if (sc->smb_res == NULL) {
332		device_printf(dev, "Could not allocate SMBus I/O port\n");
333		error = ENXIO;
334		goto out;
335	}
336
337	sc->gpio_rid = PCIR_BAR(1);
338	sc->gpio_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
339	    &sc->gpio_rid, RF_SHAREABLE | RF_ACTIVE);
340	if (sc->gpio_res == NULL) {
341		device_printf(dev, "Could not allocate GPIO I/O port\n");
342		error = ENXIO;
343		goto out;
344	}
345
346	/* Ensure the controller is not enabled by firmware. */
347	glxiic_smb_disable(sc);
348
349	/* Read the existing IRQ map. */
350	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
351	sc->old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
352
353	unit = device_get_unit(dev);
354	if (resource_int_value("glxiic", unit, "irq", &irq) == 0) {
355		if (irq < 1 || irq > 15) {
356			device_printf(dev, "Bad value %d for glxiic.%d.irq\n",
357			    irq, unit);
358			error = ENXIO;
359			goto out;
360		}
361
362		if (bootverbose)
363			device_printf(dev, "Using irq %d set by hint\n", irq);
364	} else if (sc->old_irq != 0) {
365		if (bootverbose)
366			device_printf(dev, "Using irq %d set by firmware\n",
367			    irq);
368		irq = sc->old_irq;
369	} else {
370		device_printf(dev, "No irq mapped by firmware");
371		printf(" and no glxiic.%d.irq hint provided\n", unit);
372		error = ENXIO;
373		goto out;
374	}
375
376	/* Map the SMBus interrupt to the requested legacy IRQ. */
377	glxiic_smb_map_interrupt(irq);
378
379	sc->irq_rid = 0;
380	sc->irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &sc->irq_rid,
381	    irq, irq, 1, RF_SHAREABLE | RF_ACTIVE);
382	if (sc->irq_res == NULL) {
383		device_printf(dev, "Could not allocate IRQ %d\n", irq);
384		error = ENXIO;
385		goto out;
386	}
387
388	error = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
389	    NULL, glxiic_intr, sc, &(sc->irq_handler));
390	if (error != 0) {
391		device_printf(dev, "Could not setup IRQ handler\n");
392		error = ENXIO;
393		goto out;
394	}
395
396	if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) {
397		device_printf(dev, "Could not allocate iicbus instance\n");
398		error = ENXIO;
399		goto out;
400	}
401
402	ctx = device_get_sysctl_ctx(dev);
403	tree = device_get_sysctl_tree(dev);
404
405	sc->timeout = GLXIIC_DEFAULT_TIMEOUT;
406	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
407	    "timeout", CTLFLAG_RWTUN, &sc->timeout, 0,
408	    "activity timeout in ms");
409
410	glxiic_gpio_enable(sc);
411	glxiic_smb_enable(sc, IIC_FASTEST, 0);
412
413	/* Probe and attach the iicbus when interrupts are available. */
414	error = bus_delayed_attach_children(dev);
415
416out:
417	if (error != 0) {
418		callout_drain(&sc->callout);
419
420		if (sc->iicbus != NULL)
421			device_delete_child(dev, sc->iicbus);
422		if (sc->smb_res != NULL) {
423			glxiic_smb_disable(sc);
424			bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
425			    sc->smb_res);
426		}
427		if (sc->gpio_res != NULL) {
428			glxiic_gpio_disable(sc);
429			bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
430			    sc->gpio_res);
431		}
432		if (sc->irq_handler != NULL)
433			bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
434		if (sc->irq_res != NULL)
435			bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
436			    sc->irq_res);
437
438		/* Restore the old SMBus interrupt mapping. */
439		glxiic_smb_map_interrupt(sc->old_irq);
440
441		GLXIIC_LOCK_DESTROY(sc);
442	}
443
444	return (error);
445}
446
447static int
448glxiic_detach(device_t dev)
449{
450	struct glxiic_softc *sc;
451	int error;
452
453	sc = device_get_softc(dev);
454
455	error = bus_generic_detach(dev);
456	if (error != 0)
457		goto out;
458	if (sc->iicbus != NULL)
459		error = device_delete_child(dev, sc->iicbus);
460
461out:
462	callout_drain(&sc->callout);
463
464	if (sc->smb_res != NULL) {
465		glxiic_smb_disable(sc);
466		bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
467		    sc->smb_res);
468	}
469	if (sc->gpio_res != NULL) {
470		glxiic_gpio_disable(sc);
471		bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
472		    sc->gpio_res);
473	}
474	if (sc->irq_handler != NULL)
475		bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
476	if (sc->irq_res != NULL)
477		bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
478		    sc->irq_res);
479
480	/* Restore the old SMBus interrupt mapping. */
481	glxiic_smb_map_interrupt(sc->old_irq);
482
483	GLXIIC_LOCK_DESTROY(sc);
484
485	return (error);
486}
487
488static uint8_t
489glxiic_read_status_locked(struct glxiic_softc *sc)
490{
491	uint8_t status;
492
493	GLXIIC_ASSERT_LOCKED(sc);
494
495	status = bus_read_1(sc->smb_res, GLXIIC_SMB_STS);
496
497	/* Clear all status flags except SDAST and STASTR after reading. */
498	bus_write_1(sc->smb_res, GLXIIC_SMB_STS, (GLXIIC_SMB_STS_SLVSTP_BIT |
499		GLXIIC_SMB_STS_BER_BIT | GLXIIC_SMB_STS_NEGACK_BIT |
500		GLXIIC_SMB_STS_NMATCH_BIT));
501
502	return (status);
503}
504
505static void
506glxiic_stop_locked(struct glxiic_softc *sc)
507{
508	uint8_t status, ctrl1;
509
510	GLXIIC_ASSERT_LOCKED(sc);
511
512	status = glxiic_read_status_locked(sc);
513
514	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
515	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
516	    ctrl1 | GLXIIC_SMB_CTRL1_STOP_BIT);
517
518	/*
519	 * Perform a dummy read of SDA in master receive mode to clear
520	 * SDAST if set.
521	 */
522	if ((status & GLXIIC_SMB_STS_XMIT_BIT) == 0 &&
523	    (status & GLXIIC_SMB_STS_SDAST_BIT) != 0)
524	 	bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
525
526	/* Check stall after start bit and clear if needed */
527	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
528		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
529		    GLXIIC_SMB_STS_STASTR_BIT);
530	}
531}
532
533static void
534glxiic_timeout(void *arg)
535{
536	struct glxiic_softc *sc;
537	uint8_t error;
538
539	sc = (struct glxiic_softc *)arg;
540
541	GLXIIC_DEBUG_LOG("timeout in state %d", sc->state);
542
543	if (glxiic_state_table[sc->state].master) {
544		sc->error = IIC_ETIMEOUT;
545		GLXIIC_WAKEUP(sc);
546	} else {
547		error = IIC_ETIMEOUT;
548		iicbus_intr(sc->iicbus, INTR_ERROR, &error);
549	}
550
551	glxiic_smb_disable(sc);
552	glxiic_smb_enable(sc, IIC_UNKNOWN, sc->addr);
553	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
554}
555
556static void
557glxiic_start_timeout_locked(struct glxiic_softc *sc)
558{
559
560	GLXIIC_ASSERT_LOCKED(sc);
561
562	callout_reset_sbt(&sc->callout, SBT_1MS * sc->timeout, 0,
563	    glxiic_timeout, sc, 0);
564}
565
566static void
567glxiic_set_state_locked(struct glxiic_softc *sc, glxiic_state_t state)
568{
569
570	GLXIIC_ASSERT_LOCKED(sc);
571
572	if (state == GLXIIC_STATE_IDLE)
573		callout_stop(&sc->callout);
574	else if (sc->timeout > 0)
575		glxiic_start_timeout_locked(sc);
576
577	sc->state = state;
578}
579
580static int
581glxiic_handle_slave_match_locked(struct glxiic_softc *sc, uint8_t status)
582{
583	uint8_t ctrl_sts, addr;
584
585	GLXIIC_ASSERT_LOCKED(sc);
586
587	ctrl_sts = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL_STS);
588
589	if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_MATCH_BIT) != 0) {
590		if ((status & GLXIIC_SMB_STS_XMIT_BIT) != 0) {
591			addr = sc->addr | LSB;
592			glxiic_set_state_locked(sc,
593			    GLXIIC_STATE_SLAVE_TX);
594		} else {
595			addr = sc->addr & ~LSB;
596			glxiic_set_state_locked(sc,
597			    GLXIIC_STATE_SLAVE_RX);
598		}
599		iicbus_intr(sc->iicbus, INTR_START, &addr);
600	} else if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_GCMTCH_BIT) != 0) {
601		addr = 0;
602		glxiic_set_state_locked(sc, GLXIIC_STATE_SLAVE_RX);
603		iicbus_intr(sc->iicbus, INTR_GENERAL, &addr);
604	} else {
605		GLXIIC_DEBUG_LOG("unknown slave match");
606		return (IIC_ESTATUS);
607	}
608
609	return (IIC_NOERR);
610}
611
612static int
613glxiic_state_idle_callback(struct glxiic_softc *sc, uint8_t status)
614{
615
616	GLXIIC_ASSERT_LOCKED(sc);
617
618	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
619		GLXIIC_DEBUG_LOG("bus error in idle");
620		return (IIC_EBUSERR);
621	}
622
623	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
624		return (glxiic_handle_slave_match_locked(sc, status));
625	}
626
627	return (IIC_NOERR);
628}
629
630static int
631glxiic_state_slave_tx_callback(struct glxiic_softc *sc, uint8_t status)
632{
633	uint8_t data;
634
635	GLXIIC_ASSERT_LOCKED(sc);
636
637	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
638		GLXIIC_DEBUG_LOG("bus error in slave tx");
639		return (IIC_EBUSERR);
640	}
641
642	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
643		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
644		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
645		return (IIC_NOERR);
646	}
647
648	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
649		iicbus_intr(sc->iicbus, INTR_NOACK, NULL);
650		return (IIC_NOERR);
651	}
652
653	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
654		/* Handle repeated start in slave mode. */
655		return (glxiic_handle_slave_match_locked(sc, status));
656	}
657
658	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
659		GLXIIC_DEBUG_LOG("not awaiting data in slave tx");
660		return (IIC_ESTATUS);
661	}
662
663	iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
664	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, data);
665
666	glxiic_start_timeout_locked(sc);
667
668	return (IIC_NOERR);
669}
670
671static int
672glxiic_state_slave_rx_callback(struct glxiic_softc *sc, uint8_t status)
673{
674	uint8_t data;
675
676	GLXIIC_ASSERT_LOCKED(sc);
677
678	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
679		GLXIIC_DEBUG_LOG("bus error in slave rx");
680		return (IIC_EBUSERR);
681	}
682
683	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
684		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
685		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
686		return (IIC_NOERR);
687	}
688
689	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
690		/* Handle repeated start in slave mode. */
691		return (glxiic_handle_slave_match_locked(sc, status));
692	}
693
694	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
695		GLXIIC_DEBUG_LOG("no pending data in slave rx");
696		return (IIC_ESTATUS);
697	}
698
699	data = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
700	iicbus_intr(sc->iicbus, INTR_RECEIVE, &data);
701
702	glxiic_start_timeout_locked(sc);
703
704	return (IIC_NOERR);
705}
706
707static int
708glxiic_state_master_addr_callback(struct glxiic_softc *sc, uint8_t status)
709{
710	uint8_t slave;
711	uint8_t ctrl1;
712
713	GLXIIC_ASSERT_LOCKED(sc);
714
715	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
716		GLXIIC_DEBUG_LOG("bus error after master start");
717		return (IIC_EBUSERR);
718	}
719
720	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
721		GLXIIC_DEBUG_LOG("not bus master after master start");
722		return (IIC_ESTATUS);
723	}
724
725	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
726		GLXIIC_DEBUG_LOG("not awaiting address in master addr");
727		return (IIC_ESTATUS);
728	}
729
730	if ((sc->msg->flags & IIC_M_RD) != 0) {
731		slave = sc->msg->slave | LSB;
732		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_RX);
733	} else {
734		slave = sc->msg->slave & ~LSB;
735		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_TX);
736	}
737
738	sc->data = sc->msg->buf;
739	sc->ndata = sc->msg->len;
740
741	/* Handle address-only transfer. */
742	if (sc->ndata == 0)
743		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
744
745	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, slave);
746
747	if ((sc->msg->flags & IIC_M_RD) != 0 && sc->ndata == 1) {
748		/* Last byte from slave, set NACK. */
749		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
750		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
751		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
752	}
753
754	return (IIC_NOERR);
755}
756
757static int
758glxiic_state_master_tx_callback(struct glxiic_softc *sc, uint8_t status)
759{
760
761	GLXIIC_ASSERT_LOCKED(sc);
762
763	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
764		GLXIIC_DEBUG_LOG("bus error in master tx");
765		return (IIC_EBUSERR);
766	}
767
768	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
769		GLXIIC_DEBUG_LOG("not bus master in master tx");
770		return (IIC_ESTATUS);
771	}
772
773	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
774		GLXIIC_DEBUG_LOG("slave nack in master tx");
775		return (IIC_ENOACK);
776	}
777
778	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
779		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
780		    GLXIIC_SMB_STS_STASTR_BIT);
781	}
782
783	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
784		GLXIIC_DEBUG_LOG("not awaiting data in master tx");
785		return (IIC_ESTATUS);
786	}
787
788	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, *sc->data++);
789	if (--sc->ndata == 0)
790		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
791	else
792		glxiic_start_timeout_locked(sc);
793
794	return (IIC_NOERR);
795}
796
797static int
798glxiic_state_master_rx_callback(struct glxiic_softc *sc, uint8_t status)
799{
800	uint8_t ctrl1;
801
802	GLXIIC_ASSERT_LOCKED(sc);
803
804	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
805		GLXIIC_DEBUG_LOG("bus error in master rx");
806		return (IIC_EBUSERR);
807	}
808
809	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
810		GLXIIC_DEBUG_LOG("not bus master in master rx");
811		return (IIC_ESTATUS);
812	}
813
814	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
815		GLXIIC_DEBUG_LOG("slave nack in rx");
816		return (IIC_ENOACK);
817	}
818
819	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
820		/* Bus is stalled, clear and wait for data. */
821		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
822		    GLXIIC_SMB_STS_STASTR_BIT);
823		return (IIC_NOERR);
824	}
825
826	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
827		GLXIIC_DEBUG_LOG("no pending data in master rx");
828		return (IIC_ESTATUS);
829	}
830
831	*sc->data++ = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
832	if (--sc->ndata == 0) {
833		/* Proceed with stop on reading last byte. */
834		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
835		return (glxiic_state_table[sc->state].callback(sc, status));
836	}
837
838	if (sc->ndata == 1) {
839		/* Last byte from slave, set NACK. */
840		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
841		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
842		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
843	}
844
845	glxiic_start_timeout_locked(sc);
846
847	return (IIC_NOERR);
848}
849
850static int
851glxiic_state_master_stop_callback(struct glxiic_softc *sc, uint8_t status)
852{
853	uint8_t ctrl1;
854
855	GLXIIC_ASSERT_LOCKED(sc);
856
857	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
858		GLXIIC_DEBUG_LOG("bus error in master stop");
859		return (IIC_EBUSERR);
860	}
861
862	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
863		GLXIIC_DEBUG_LOG("not bus master in master stop");
864		return (IIC_ESTATUS);
865	}
866
867	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
868		GLXIIC_DEBUG_LOG("slave nack in master stop");
869		return (IIC_ENOACK);
870	}
871
872	if (--sc->nmsgs > 0) {
873		/* Start transfer of next message. */
874		if ((sc->msg->flags & IIC_M_NOSTOP) == 0) {
875			glxiic_stop_locked(sc);
876		}
877
878		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
879		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
880		    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
881
882		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
883		sc->msg++;
884	} else {
885		/* Last message. */
886		glxiic_stop_locked(sc);
887		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
888		sc->error = IIC_NOERR;
889		GLXIIC_WAKEUP(sc);
890	}
891
892	return (IIC_NOERR);
893}
894
895static void
896glxiic_intr(void *arg)
897{
898	struct glxiic_softc *sc;
899	int error;
900	uint8_t status, data;
901
902	sc = (struct glxiic_softc *)arg;
903
904	GLXIIC_LOCK(sc);
905
906	status = glxiic_read_status_locked(sc);
907
908	/* Check if this interrupt originated from the SMBus. */
909	if ((status &
910		~(GLXIIC_SMB_STS_MASTER_BIT | GLXIIC_SMB_STS_XMIT_BIT)) != 0) {
911
912		error = glxiic_state_table[sc->state].callback(sc, status);
913
914		if (error != IIC_NOERR) {
915			if (glxiic_state_table[sc->state].master) {
916				glxiic_stop_locked(sc);
917				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
918				sc->error = error;
919				GLXIIC_WAKEUP(sc);
920			} else {
921				data = error & 0xff;
922				iicbus_intr(sc->iicbus, INTR_ERROR, &data);
923				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
924			}
925		}
926	}
927
928	GLXIIC_UNLOCK(sc);
929}
930
931static int
932glxiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
933{
934	struct glxiic_softc *sc;
935
936	sc = device_get_softc(dev);
937
938	GLXIIC_LOCK(sc);
939
940	if (oldaddr != NULL)
941		*oldaddr = sc->addr;
942	sc->addr = addr;
943
944	/* A disable/enable cycle resets the controller. */
945	glxiic_smb_disable(sc);
946	glxiic_smb_enable(sc, speed, addr);
947
948	if (glxiic_state_table[sc->state].master) {
949		sc->error = IIC_ESTATUS;
950		GLXIIC_WAKEUP(sc);
951	}
952	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
953
954	GLXIIC_UNLOCK(sc);
955
956	return (IIC_NOERR);
957}
958
959static int
960glxiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
961{
962	struct glxiic_softc *sc;
963	int error;
964	uint8_t ctrl1;
965
966	sc = device_get_softc(dev);
967
968	GLXIIC_LOCK(sc);
969
970	if (sc->state != GLXIIC_STATE_IDLE) {
971		error = IIC_EBUSBSY;
972		goto out;
973	}
974
975	sc->msg = msgs;
976	sc->nmsgs = nmsgs;
977	glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
978
979	/* Set start bit and let glxiic_intr() handle the transfer. */
980	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
981	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
982	    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
983
984	GLXIIC_SLEEP(sc);
985	error = sc->error;
986out:
987	GLXIIC_UNLOCK(sc);
988
989	return (error);
990}
991
992static void
993glxiic_smb_map_interrupt(int irq)
994{
995	uint32_t irq_map;
996	int old_irq;
997
998	/* Protect the read-modify-write operation. */
999	critical_enter();
1000
1001	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
1002	old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
1003
1004	if (irq != old_irq) {
1005		irq_map &= ~GLXIIC_SMB_IRQ_TO_MAP(old_irq);
1006		irq_map |= GLXIIC_SMB_IRQ_TO_MAP(irq);
1007		wrmsr(GLXIIC_MSR_PIC_YSEL_HIGH, irq_map);
1008	}
1009
1010	critical_exit();
1011}
1012
1013static void
1014glxiic_gpio_enable(struct glxiic_softc *sc)
1015{
1016
1017	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1018	    GLXIIC_GPIO_14_15_ENABLE);
1019	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1020	    GLXIIC_GPIO_14_15_ENABLE);
1021}
1022
1023static void
1024glxiic_gpio_disable(struct glxiic_softc *sc)
1025{
1026
1027	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1028	    GLXIIC_GPIO_14_15_DISABLE);
1029	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1030	    GLXIIC_GPIO_14_15_DISABLE);
1031}
1032
1033static void
1034glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed, uint8_t addr)
1035{
1036	uint8_t ctrl1;
1037
1038	ctrl1 = 0;
1039
1040	switch (speed) {
1041	case IIC_SLOW:
1042		sc->sclfrq = GLXIIC_SLOW;
1043		break;
1044	case IIC_FAST:
1045		sc->sclfrq = GLXIIC_FAST;
1046		break;
1047	case IIC_FASTEST:
1048		sc->sclfrq = GLXIIC_FASTEST;
1049		break;
1050	case IIC_UNKNOWN:
1051	default:
1052		/* Reuse last frequency. */
1053		break;
1054	}
1055
1056	/* Set bus speed and enable controller. */
1057	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1058	    GLXIIC_SCLFRQ(sc->sclfrq) | GLXIIC_SMB_CTRL2_EN_BIT);
1059
1060	if (addr != 0) {
1061		/* Enable new match and global call match interrupts. */
1062		ctrl1 |= GLXIIC_SMB_CTRL1_NMINTE_BIT |
1063			GLXIIC_SMB_CTRL1_GCMEN_BIT;
1064		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR,
1065		    GLXIIC_SMB_ADDR_SAEN_BIT | GLXIIC_SMBADDR(addr));
1066	} else {
1067		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR, 0);
1068	}
1069
1070	/* Enable stall after start and interrupt. */
1071	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
1072	    ctrl1 | GLXIIC_SMB_CTRL1_STASTRE_BIT | GLXIIC_SMB_CTRL1_INTEN_BIT);
1073}
1074
1075static void
1076glxiic_smb_disable(struct glxiic_softc *sc)
1077{
1078	uint16_t sclfrq;
1079
1080	sclfrq = bus_read_2(sc->smb_res, GLXIIC_SMB_CTRL2);
1081	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1082	    sclfrq & ~GLXIIC_SMB_CTRL2_EN_BIT);
1083}
1084