xref: /freebsd/sys/dev/glxiic/glxiic.c (revision b670c9bafc0e31c7609969bf374b2e80bdc00211)
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
glxiic_identify(driver_t * driver,device_t parent)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, DEVICE_UNIT_ANY) != NULL)
288 		return;
289 
290 	if (pci_get_devid(parent) == GLXIIC_CS5536_DEV_ID) {
291 		if (device_add_child(parent, driver->name, DEVICE_UNIT_ANY) == NULL)
292 			device_printf(parent, "Could not add glxiic child\n");
293 	}
294 }
295 
296 static int
glxiic_probe(device_t dev)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
glxiic_attach(device_t dev)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",
394 	    DEVICE_UNIT_ANY)) == 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 	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
glxiic_detach(device_t dev)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 		return (error);
456 
457 	callout_drain(&sc->callout);
458 
459 	if (sc->smb_res != NULL) {
460 		glxiic_smb_disable(sc);
461 		bus_release_resource(dev, SYS_RES_IOPORT, sc->smb_rid,
462 		    sc->smb_res);
463 	}
464 	if (sc->gpio_res != NULL) {
465 		glxiic_gpio_disable(sc);
466 		bus_release_resource(dev, SYS_RES_IOPORT, sc->gpio_rid,
467 		    sc->gpio_res);
468 	}
469 	if (sc->irq_handler != NULL)
470 		bus_teardown_intr(dev, sc->irq_res, sc->irq_handler);
471 	if (sc->irq_res != NULL)
472 		bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
473 		    sc->irq_res);
474 
475 	/* Restore the old SMBus interrupt mapping. */
476 	glxiic_smb_map_interrupt(sc->old_irq);
477 
478 	GLXIIC_LOCK_DESTROY(sc);
479 
480 	return (0);
481 }
482 
483 static uint8_t
glxiic_read_status_locked(struct glxiic_softc * sc)484 glxiic_read_status_locked(struct glxiic_softc *sc)
485 {
486 	uint8_t status;
487 
488 	GLXIIC_ASSERT_LOCKED(sc);
489 
490 	status = bus_read_1(sc->smb_res, GLXIIC_SMB_STS);
491 
492 	/* Clear all status flags except SDAST and STASTR after reading. */
493 	bus_write_1(sc->smb_res, GLXIIC_SMB_STS, (GLXIIC_SMB_STS_SLVSTP_BIT |
494 		GLXIIC_SMB_STS_BER_BIT | GLXIIC_SMB_STS_NEGACK_BIT |
495 		GLXIIC_SMB_STS_NMATCH_BIT));
496 
497 	return (status);
498 }
499 
500 static void
glxiic_stop_locked(struct glxiic_softc * sc)501 glxiic_stop_locked(struct glxiic_softc *sc)
502 {
503 	uint8_t status, ctrl1;
504 
505 	GLXIIC_ASSERT_LOCKED(sc);
506 
507 	status = glxiic_read_status_locked(sc);
508 
509 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
510 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
511 	    ctrl1 | GLXIIC_SMB_CTRL1_STOP_BIT);
512 
513 	/*
514 	 * Perform a dummy read of SDA in master receive mode to clear
515 	 * SDAST if set.
516 	 */
517 	if ((status & GLXIIC_SMB_STS_XMIT_BIT) == 0 &&
518 	    (status & GLXIIC_SMB_STS_SDAST_BIT) != 0)
519 	 	bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
520 
521 	/* Check stall after start bit and clear if needed */
522 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
523 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
524 		    GLXIIC_SMB_STS_STASTR_BIT);
525 	}
526 }
527 
528 static void
glxiic_timeout(void * arg)529 glxiic_timeout(void *arg)
530 {
531 	struct glxiic_softc *sc;
532 	uint8_t error;
533 
534 	sc = (struct glxiic_softc *)arg;
535 
536 	GLXIIC_DEBUG_LOG("timeout in state %d", sc->state);
537 
538 	if (glxiic_state_table[sc->state].master) {
539 		sc->error = IIC_ETIMEOUT;
540 		GLXIIC_WAKEUP(sc);
541 	} else {
542 		error = IIC_ETIMEOUT;
543 		iicbus_intr(sc->iicbus, INTR_ERROR, &error);
544 	}
545 
546 	glxiic_smb_disable(sc);
547 	glxiic_smb_enable(sc, IIC_UNKNOWN, sc->addr);
548 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
549 }
550 
551 static void
glxiic_start_timeout_locked(struct glxiic_softc * sc)552 glxiic_start_timeout_locked(struct glxiic_softc *sc)
553 {
554 
555 	GLXIIC_ASSERT_LOCKED(sc);
556 
557 	callout_reset_sbt(&sc->callout, SBT_1MS * sc->timeout, 0,
558 	    glxiic_timeout, sc, 0);
559 }
560 
561 static void
glxiic_set_state_locked(struct glxiic_softc * sc,glxiic_state_t state)562 glxiic_set_state_locked(struct glxiic_softc *sc, glxiic_state_t state)
563 {
564 
565 	GLXIIC_ASSERT_LOCKED(sc);
566 
567 	if (state == GLXIIC_STATE_IDLE)
568 		callout_stop(&sc->callout);
569 	else if (sc->timeout > 0)
570 		glxiic_start_timeout_locked(sc);
571 
572 	sc->state = state;
573 }
574 
575 static int
glxiic_handle_slave_match_locked(struct glxiic_softc * sc,uint8_t status)576 glxiic_handle_slave_match_locked(struct glxiic_softc *sc, uint8_t status)
577 {
578 	uint8_t ctrl_sts, addr;
579 
580 	GLXIIC_ASSERT_LOCKED(sc);
581 
582 	ctrl_sts = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL_STS);
583 
584 	if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_MATCH_BIT) != 0) {
585 		if ((status & GLXIIC_SMB_STS_XMIT_BIT) != 0) {
586 			addr = sc->addr | LSB;
587 			glxiic_set_state_locked(sc,
588 			    GLXIIC_STATE_SLAVE_TX);
589 		} else {
590 			addr = sc->addr & ~LSB;
591 			glxiic_set_state_locked(sc,
592 			    GLXIIC_STATE_SLAVE_RX);
593 		}
594 		iicbus_intr(sc->iicbus, INTR_START, &addr);
595 	} else if ((ctrl_sts & GLXIIC_SMB_CTRL_STS_GCMTCH_BIT) != 0) {
596 		addr = 0;
597 		glxiic_set_state_locked(sc, GLXIIC_STATE_SLAVE_RX);
598 		iicbus_intr(sc->iicbus, INTR_GENERAL, &addr);
599 	} else {
600 		GLXIIC_DEBUG_LOG("unknown slave match");
601 		return (IIC_ESTATUS);
602 	}
603 
604 	return (IIC_NOERR);
605 }
606 
607 static int
glxiic_state_idle_callback(struct glxiic_softc * sc,uint8_t status)608 glxiic_state_idle_callback(struct glxiic_softc *sc, uint8_t status)
609 {
610 
611 	GLXIIC_ASSERT_LOCKED(sc);
612 
613 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
614 		GLXIIC_DEBUG_LOG("bus error in idle");
615 		return (IIC_EBUSERR);
616 	}
617 
618 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
619 		return (glxiic_handle_slave_match_locked(sc, status));
620 	}
621 
622 	return (IIC_NOERR);
623 }
624 
625 static int
glxiic_state_slave_tx_callback(struct glxiic_softc * sc,uint8_t status)626 glxiic_state_slave_tx_callback(struct glxiic_softc *sc, uint8_t status)
627 {
628 	uint8_t data;
629 
630 	GLXIIC_ASSERT_LOCKED(sc);
631 
632 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
633 		GLXIIC_DEBUG_LOG("bus error in slave tx");
634 		return (IIC_EBUSERR);
635 	}
636 
637 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
638 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
639 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
640 		return (IIC_NOERR);
641 	}
642 
643 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
644 		iicbus_intr(sc->iicbus, INTR_NOACK, NULL);
645 		return (IIC_NOERR);
646 	}
647 
648 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
649 		/* Handle repeated start in slave mode. */
650 		return (glxiic_handle_slave_match_locked(sc, status));
651 	}
652 
653 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
654 		GLXIIC_DEBUG_LOG("not awaiting data in slave tx");
655 		return (IIC_ESTATUS);
656 	}
657 
658 	iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
659 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, data);
660 
661 	glxiic_start_timeout_locked(sc);
662 
663 	return (IIC_NOERR);
664 }
665 
666 static int
glxiic_state_slave_rx_callback(struct glxiic_softc * sc,uint8_t status)667 glxiic_state_slave_rx_callback(struct glxiic_softc *sc, uint8_t status)
668 {
669 	uint8_t data;
670 
671 	GLXIIC_ASSERT_LOCKED(sc);
672 
673 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
674 		GLXIIC_DEBUG_LOG("bus error in slave rx");
675 		return (IIC_EBUSERR);
676 	}
677 
678 	if ((status & GLXIIC_SMB_STS_SLVSTP_BIT) != 0) {
679 		iicbus_intr(sc->iicbus, INTR_STOP, NULL);
680 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
681 		return (IIC_NOERR);
682 	}
683 
684 	if ((status & GLXIIC_SMB_STS_NMATCH_BIT) != 0) {
685 		/* Handle repeated start in slave mode. */
686 		return (glxiic_handle_slave_match_locked(sc, status));
687 	}
688 
689 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
690 		GLXIIC_DEBUG_LOG("no pending data in slave rx");
691 		return (IIC_ESTATUS);
692 	}
693 
694 	data = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
695 	iicbus_intr(sc->iicbus, INTR_RECEIVE, &data);
696 
697 	glxiic_start_timeout_locked(sc);
698 
699 	return (IIC_NOERR);
700 }
701 
702 static int
glxiic_state_master_addr_callback(struct glxiic_softc * sc,uint8_t status)703 glxiic_state_master_addr_callback(struct glxiic_softc *sc, uint8_t status)
704 {
705 	uint8_t slave;
706 	uint8_t ctrl1;
707 
708 	GLXIIC_ASSERT_LOCKED(sc);
709 
710 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
711 		GLXIIC_DEBUG_LOG("bus error after master start");
712 		return (IIC_EBUSERR);
713 	}
714 
715 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
716 		GLXIIC_DEBUG_LOG("not bus master after master start");
717 		return (IIC_ESTATUS);
718 	}
719 
720 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
721 		GLXIIC_DEBUG_LOG("not awaiting address in master addr");
722 		return (IIC_ESTATUS);
723 	}
724 
725 	if ((sc->msg->flags & IIC_M_RD) != 0) {
726 		slave = sc->msg->slave | LSB;
727 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_RX);
728 	} else {
729 		slave = sc->msg->slave & ~LSB;
730 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_TX);
731 	}
732 
733 	sc->data = sc->msg->buf;
734 	sc->ndata = sc->msg->len;
735 
736 	/* Handle address-only transfer. */
737 	if (sc->ndata == 0)
738 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
739 
740 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, slave);
741 
742 	if ((sc->msg->flags & IIC_M_RD) != 0 && sc->ndata == 1) {
743 		/* Last byte from slave, set NACK. */
744 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
745 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
746 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
747 	}
748 
749 	return (IIC_NOERR);
750 }
751 
752 static int
glxiic_state_master_tx_callback(struct glxiic_softc * sc,uint8_t status)753 glxiic_state_master_tx_callback(struct glxiic_softc *sc, uint8_t status)
754 {
755 
756 	GLXIIC_ASSERT_LOCKED(sc);
757 
758 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
759 		GLXIIC_DEBUG_LOG("bus error in master tx");
760 		return (IIC_EBUSERR);
761 	}
762 
763 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
764 		GLXIIC_DEBUG_LOG("not bus master in master tx");
765 		return (IIC_ESTATUS);
766 	}
767 
768 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
769 		GLXIIC_DEBUG_LOG("slave nack in master tx");
770 		return (IIC_ENOACK);
771 	}
772 
773 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
774 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
775 		    GLXIIC_SMB_STS_STASTR_BIT);
776 	}
777 
778 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
779 		GLXIIC_DEBUG_LOG("not awaiting data in master tx");
780 		return (IIC_ESTATUS);
781 	}
782 
783 	bus_write_1(sc->smb_res, GLXIIC_SMB_SDA, *sc->data++);
784 	if (--sc->ndata == 0)
785 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
786 	else
787 		glxiic_start_timeout_locked(sc);
788 
789 	return (IIC_NOERR);
790 }
791 
792 static int
glxiic_state_master_rx_callback(struct glxiic_softc * sc,uint8_t status)793 glxiic_state_master_rx_callback(struct glxiic_softc *sc, uint8_t status)
794 {
795 	uint8_t ctrl1;
796 
797 	GLXIIC_ASSERT_LOCKED(sc);
798 
799 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
800 		GLXIIC_DEBUG_LOG("bus error in master rx");
801 		return (IIC_EBUSERR);
802 	}
803 
804 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
805 		GLXIIC_DEBUG_LOG("not bus master in master rx");
806 		return (IIC_ESTATUS);
807 	}
808 
809 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
810 		GLXIIC_DEBUG_LOG("slave nack in rx");
811 		return (IIC_ENOACK);
812 	}
813 
814 	if ((status & GLXIIC_SMB_STS_STASTR_BIT) != 0) {
815 		/* Bus is stalled, clear and wait for data. */
816 		bus_write_1(sc->smb_res, GLXIIC_SMB_STS,
817 		    GLXIIC_SMB_STS_STASTR_BIT);
818 		return (IIC_NOERR);
819 	}
820 
821 	if ((status & GLXIIC_SMB_STS_SDAST_BIT) == 0) {
822 		GLXIIC_DEBUG_LOG("no pending data in master rx");
823 		return (IIC_ESTATUS);
824 	}
825 
826 	*sc->data++ = bus_read_1(sc->smb_res, GLXIIC_SMB_SDA);
827 	if (--sc->ndata == 0) {
828 		/* Proceed with stop on reading last byte. */
829 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_STOP);
830 		return (glxiic_state_table[sc->state].callback(sc, status));
831 	}
832 
833 	if (sc->ndata == 1) {
834 		/* Last byte from slave, set NACK. */
835 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
836 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
837 		    ctrl1 | GLXIIC_SMB_CTRL1_ACK_BIT);
838 	}
839 
840 	glxiic_start_timeout_locked(sc);
841 
842 	return (IIC_NOERR);
843 }
844 
845 static int
glxiic_state_master_stop_callback(struct glxiic_softc * sc,uint8_t status)846 glxiic_state_master_stop_callback(struct glxiic_softc *sc, uint8_t status)
847 {
848 	uint8_t ctrl1;
849 
850 	GLXIIC_ASSERT_LOCKED(sc);
851 
852 	if ((status & GLXIIC_SMB_STS_BER_BIT) != 0) {
853 		GLXIIC_DEBUG_LOG("bus error in master stop");
854 		return (IIC_EBUSERR);
855 	}
856 
857 	if ((status & GLXIIC_SMB_STS_MASTER_BIT) == 0) {
858 		GLXIIC_DEBUG_LOG("not bus master in master stop");
859 		return (IIC_ESTATUS);
860 	}
861 
862 	if ((status & GLXIIC_SMB_STS_NEGACK_BIT) != 0) {
863 		GLXIIC_DEBUG_LOG("slave nack in master stop");
864 		return (IIC_ENOACK);
865 	}
866 
867 	if (--sc->nmsgs > 0) {
868 		/* Start transfer of next message. */
869 		if ((sc->msg->flags & IIC_M_NOSTOP) == 0) {
870 			glxiic_stop_locked(sc);
871 		}
872 
873 		ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
874 		bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
875 		    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
876 
877 		glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
878 		sc->msg++;
879 	} else {
880 		/* Last message. */
881 		glxiic_stop_locked(sc);
882 		glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
883 		sc->error = IIC_NOERR;
884 		GLXIIC_WAKEUP(sc);
885 	}
886 
887 	return (IIC_NOERR);
888 }
889 
890 static void
glxiic_intr(void * arg)891 glxiic_intr(void *arg)
892 {
893 	struct glxiic_softc *sc;
894 	int error;
895 	uint8_t status, data;
896 
897 	sc = (struct glxiic_softc *)arg;
898 
899 	GLXIIC_LOCK(sc);
900 
901 	status = glxiic_read_status_locked(sc);
902 
903 	/* Check if this interrupt originated from the SMBus. */
904 	if ((status &
905 		~(GLXIIC_SMB_STS_MASTER_BIT | GLXIIC_SMB_STS_XMIT_BIT)) != 0) {
906 
907 		error = glxiic_state_table[sc->state].callback(sc, status);
908 
909 		if (error != IIC_NOERR) {
910 			if (glxiic_state_table[sc->state].master) {
911 				glxiic_stop_locked(sc);
912 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
913 				sc->error = error;
914 				GLXIIC_WAKEUP(sc);
915 			} else {
916 				data = error & 0xff;
917 				iicbus_intr(sc->iicbus, INTR_ERROR, &data);
918 				glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
919 			}
920 		}
921 	}
922 
923 	GLXIIC_UNLOCK(sc);
924 }
925 
926 static int
glxiic_reset(device_t dev,u_char speed,u_char addr,u_char * oldaddr)927 glxiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
928 {
929 	struct glxiic_softc *sc;
930 
931 	sc = device_get_softc(dev);
932 
933 	GLXIIC_LOCK(sc);
934 
935 	if (oldaddr != NULL)
936 		*oldaddr = sc->addr;
937 	sc->addr = addr;
938 
939 	/* A disable/enable cycle resets the controller. */
940 	glxiic_smb_disable(sc);
941 	glxiic_smb_enable(sc, speed, addr);
942 
943 	if (glxiic_state_table[sc->state].master) {
944 		sc->error = IIC_ESTATUS;
945 		GLXIIC_WAKEUP(sc);
946 	}
947 	glxiic_set_state_locked(sc, GLXIIC_STATE_IDLE);
948 
949 	GLXIIC_UNLOCK(sc);
950 
951 	return (IIC_NOERR);
952 }
953 
954 static int
glxiic_transfer(device_t dev,struct iic_msg * msgs,uint32_t nmsgs)955 glxiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
956 {
957 	struct glxiic_softc *sc;
958 	int error;
959 	uint8_t ctrl1;
960 
961 	sc = device_get_softc(dev);
962 
963 	GLXIIC_LOCK(sc);
964 
965 	if (sc->state != GLXIIC_STATE_IDLE) {
966 		error = IIC_EBUSBSY;
967 		goto out;
968 	}
969 
970 	sc->msg = msgs;
971 	sc->nmsgs = nmsgs;
972 	glxiic_set_state_locked(sc, GLXIIC_STATE_MASTER_ADDR);
973 
974 	/* Set start bit and let glxiic_intr() handle the transfer. */
975 	ctrl1 = bus_read_1(sc->smb_res, GLXIIC_SMB_CTRL1);
976 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
977 	    ctrl1 | GLXIIC_SMB_CTRL1_START_BIT);
978 
979 	GLXIIC_SLEEP(sc);
980 	error = sc->error;
981 out:
982 	GLXIIC_UNLOCK(sc);
983 
984 	return (error);
985 }
986 
987 static void
glxiic_smb_map_interrupt(int irq)988 glxiic_smb_map_interrupt(int irq)
989 {
990 	uint32_t irq_map;
991 	int old_irq;
992 
993 	/* Protect the read-modify-write operation. */
994 	critical_enter();
995 
996 	irq_map = rdmsr(GLXIIC_MSR_PIC_YSEL_HIGH);
997 	old_irq = GLXIIC_MAP_TO_SMB_IRQ(irq_map);
998 
999 	if (irq != old_irq) {
1000 		irq_map &= ~GLXIIC_SMB_IRQ_TO_MAP(old_irq);
1001 		irq_map |= GLXIIC_SMB_IRQ_TO_MAP(irq);
1002 		wrmsr(GLXIIC_MSR_PIC_YSEL_HIGH, irq_map);
1003 	}
1004 
1005 	critical_exit();
1006 }
1007 
1008 static void
glxiic_gpio_enable(struct glxiic_softc * sc)1009 glxiic_gpio_enable(struct glxiic_softc *sc)
1010 {
1011 
1012 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1013 	    GLXIIC_GPIO_14_15_ENABLE);
1014 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1015 	    GLXIIC_GPIO_14_15_ENABLE);
1016 }
1017 
1018 static void
glxiic_gpio_disable(struct glxiic_softc * sc)1019 glxiic_gpio_disable(struct glxiic_softc *sc)
1020 {
1021 
1022 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_OUT_AUX1_SEL,
1023 	    GLXIIC_GPIO_14_15_DISABLE);
1024 	bus_write_4(sc->gpio_res, GLXIIC_GPIOL_IN_AUX1_SEL,
1025 	    GLXIIC_GPIO_14_15_DISABLE);
1026 }
1027 
1028 static void
glxiic_smb_enable(struct glxiic_softc * sc,uint8_t speed,uint8_t addr)1029 glxiic_smb_enable(struct glxiic_softc *sc, uint8_t speed, uint8_t addr)
1030 {
1031 	uint8_t ctrl1;
1032 
1033 	ctrl1 = 0;
1034 
1035 	switch (speed) {
1036 	case IIC_SLOW:
1037 		sc->sclfrq = GLXIIC_SLOW;
1038 		break;
1039 	case IIC_FAST:
1040 		sc->sclfrq = GLXIIC_FAST;
1041 		break;
1042 	case IIC_FASTEST:
1043 		sc->sclfrq = GLXIIC_FASTEST;
1044 		break;
1045 	case IIC_UNKNOWN:
1046 	default:
1047 		/* Reuse last frequency. */
1048 		break;
1049 	}
1050 
1051 	/* Set bus speed and enable controller. */
1052 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1053 	    GLXIIC_SCLFRQ(sc->sclfrq) | GLXIIC_SMB_CTRL2_EN_BIT);
1054 
1055 	if (addr != 0) {
1056 		/* Enable new match and global call match interrupts. */
1057 		ctrl1 |= GLXIIC_SMB_CTRL1_NMINTE_BIT |
1058 			GLXIIC_SMB_CTRL1_GCMEN_BIT;
1059 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR,
1060 		    GLXIIC_SMB_ADDR_SAEN_BIT | GLXIIC_SMBADDR(addr));
1061 	} else {
1062 		bus_write_1(sc->smb_res, GLXIIC_SMB_ADDR, 0);
1063 	}
1064 
1065 	/* Enable stall after start and interrupt. */
1066 	bus_write_1(sc->smb_res, GLXIIC_SMB_CTRL1,
1067 	    ctrl1 | GLXIIC_SMB_CTRL1_STASTRE_BIT | GLXIIC_SMB_CTRL1_INTEN_BIT);
1068 }
1069 
1070 static void
glxiic_smb_disable(struct glxiic_softc * sc)1071 glxiic_smb_disable(struct glxiic_softc *sc)
1072 {
1073 	uint16_t sclfrq;
1074 
1075 	sclfrq = bus_read_2(sc->smb_res, GLXIIC_SMB_CTRL2);
1076 	bus_write_2(sc->smb_res, GLXIIC_SMB_CTRL2,
1077 	    sclfrq & ~GLXIIC_SMB_CTRL2_EN_BIT);
1078 }
1079