xref: /netbsd-src/sys/arch/arm/ti/ti_iic.c (revision d90047b5d07facf36e6c01dcc0bded8997ce9cc2)
1 /* $NetBSD: ti_iic.c,v 1.6 2020/06/03 16:00:00 jmcneill Exp $ */
2 
3 /*
4  * Copyright (c) 2013 Manuel Bouyer.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /*-
28  * Copyright (c) 2012 Jared D. McNeill <jmcneill@invisible.ca>
29  * All rights reserved.
30  *
31  * Redistribution and use in source and binary forms, with or without
32  * modification, are permitted provided that the following conditions
33  * are met:
34  * 1. Redistributions of source code must retain the above copyright
35  *    notice, this list of conditions and the following disclaimer.
36  * 2. The name of the author may not be used to endorse or promote products
37  *    derived from this software without specific prior written permission.
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
40  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
41  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
42  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
43  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
44  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
46  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
47  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
48  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
49  * SUCH DAMAGE.
50  */
51 
52 #include <sys/cdefs.h>
53 __KERNEL_RCSID(0, "$NetBSD: ti_iic.c,v 1.6 2020/06/03 16:00:00 jmcneill Exp $");
54 
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/device.h>
58 #include <sys/conf.h>
59 #include <sys/bus.h>
60 #include <sys/proc.h>
61 #include <sys/kernel.h>
62 #include <sys/mutex.h>
63 #include <sys/condvar.h>
64 
65 #include <dev/i2c/i2cvar.h>
66 
67 #include <dev/fdt/fdtvar.h>
68 
69 #include <arm/ti/ti_prcm.h>
70 #include <arm/ti/ti_iicreg.h>
71 
72 #ifndef OMAP2_I2C_SLAVE_ADDR
73 #define OMAP2_I2C_SLAVE_ADDR	0x01
74 #endif
75 
76 #define OMAP2_I2C_FIFOBYTES(fd)	(8 << (fd))
77 
78 #ifdef I2CDEBUG
79 #define DPRINTF(args)	printf args
80 #else
81 #define DPRINTF(args)
82 #endif
83 
84 enum ti_iic_type {
85 	TI_IIC_OMAP3,
86 	TI_IIC_OMAP4,
87 	TI_NTYPES
88 };
89 
90 enum {
91 	I2C_SYSC,
92 	I2C_IRQSTATUS_RAW,
93 	I2C_IRQSTATUS,
94 	I2C_IRQENABLE,		/* OMAP3 */
95 	I2C_IRQENABLE_SET,	/* OMAP4 */
96 	I2C_IRQENABLE_CLR,	/* OMAP4 */
97 	I2C_SYSS,
98 	I2C_BUF,
99 	I2C_CNT,
100 	I2C_DATA,
101 	I2C_CON,
102 	I2C_OA,
103 	I2C_SA,
104 	I2C_PSC,
105 	I2C_SCLL,
106 	I2C_SCLH,
107 	I2C_BUFSTAT,
108 	TI_NREGS
109 };
110 
111 static const u_int ti_iic_regmap[TI_NTYPES][TI_NREGS] = {
112 	[TI_IIC_OMAP3] = {
113 		[I2C_SYSC] = 0x20,
114 		[I2C_IRQSTATUS_RAW] = 0x08,
115 		[I2C_IRQSTATUS] = 0x08,
116 		[I2C_IRQENABLE] = 0x04,
117 		[I2C_SYSS] = 0x10,
118 		[I2C_BUF] = 0x14,
119 		[I2C_CNT] = 0x18,
120 		[I2C_DATA] = 0x1c,
121 		[I2C_CON] = 0x24,
122 		[I2C_OA] = 0x28,
123 		[I2C_SA] = 0x2c,
124 		[I2C_PSC] = 0x30,
125 		[I2C_SCLL] = 0x34,
126 		[I2C_SCLH] = 0x38,
127 		[I2C_BUFSTAT] = 0x40,
128 	},
129 	[TI_IIC_OMAP4] = {
130 		[I2C_SYSC] = 0x10,
131 		[I2C_IRQSTATUS_RAW] = 0x24,
132 		[I2C_IRQSTATUS] = 0x28,
133 		[I2C_IRQENABLE_SET] = 0x2c,
134 		[I2C_IRQENABLE_CLR] = 0x30,
135 		[I2C_SYSS] = 0x90,
136 		[I2C_BUF] = 0x94,
137 		[I2C_CNT] = 0x98,
138 		[I2C_DATA] = 0x9c,
139 		[I2C_CON] = 0xa4,
140 		[I2C_OA] = 0xa8,
141 		[I2C_SA] = 0xac,
142 		[I2C_PSC] = 0xb0,
143 		[I2C_SCLL] = 0xb4,
144 		[I2C_SCLH] = 0xb8,
145 		[I2C_BUFSTAT] = 0xc0,
146 	},
147 };
148 
149 static const struct of_compat_data compat_data[] = {
150 	/* compatible		type */
151 	{ "ti,omap3-i2c",	TI_IIC_OMAP3 },
152 	{ "ti,omap4-i2c",	TI_IIC_OMAP4 },
153 	{ NULL }
154 };
155 
156 /* operation in progress */
157 typedef enum {
158 	TI_I2CREAD,
159 	TI_I2CWRITE,
160 	TI_I2CDONE,
161 	TI_I2CERROR
162 } ti_i2cop_t;
163 
164 struct ti_iic_softc {
165 	device_t		sc_dev;
166 	struct i2c_controller	sc_ic;
167 	kmutex_t		sc_lock;
168 	device_t		sc_i2cdev;
169 
170 	bus_space_tag_t		sc_iot;
171 	bus_space_handle_t	sc_ioh;
172 
173 	enum ti_iic_type	sc_type;
174 
175 	void			*sc_ih;
176 	kmutex_t		sc_mtx;
177 	kcondvar_t		sc_cv;
178 	ti_i2cop_t		sc_op;
179 	int			sc_opflags;
180 	int			sc_buflen;
181 	int			sc_bufidx;
182 	char			*sc_buf;
183 
184 	bool			sc_busy;
185 
186 	int			sc_rxthres;
187 	int			sc_txthres;
188 };
189 
190 #define I2C_READ_REG(sc, reg)		\
191 	bus_space_read_2((sc)->sc_iot, (sc)->sc_ioh, ti_iic_regmap[(sc)->sc_type][(reg)])
192 #define I2C_READ_DATA(sc)		\
193 	bus_space_read_1((sc)->sc_iot, (sc)->sc_ioh, ti_iic_regmap[(sc)->sc_type][I2C_DATA])
194 #define I2C_WRITE_REG(sc, reg, val)	\
195 	bus_space_write_2((sc)->sc_iot, (sc)->sc_ioh, ti_iic_regmap[(sc)->sc_type][(reg)], (val))
196 #define I2C_WRITE_DATA(sc, val)		\
197 	bus_space_write_1((sc)->sc_iot, (sc)->sc_ioh, ti_iic_regmap[(sc)->sc_type][I2C_DATA], (val))
198 
199 static int	ti_iic_match(device_t, cfdata_t, void *);
200 static void	ti_iic_attach(device_t, device_t, void *);
201 
202 static int	ti_iic_intr(void *);
203 
204 static int	ti_iic_acquire_bus(void *, int);
205 static void	ti_iic_release_bus(void *, int);
206 static int	ti_iic_exec(void *, i2c_op_t, i2c_addr_t, const void *,
207 			       size_t, void *, size_t, int);
208 
209 static int	ti_iic_reset(struct ti_iic_softc *);
210 static int	ti_iic_op(struct ti_iic_softc *, i2c_addr_t, ti_i2cop_t,
211 			       uint8_t *, size_t, int);
212 static void	ti_iic_handle_intr(struct ti_iic_softc *, uint32_t);
213 static void	ti_iic_do_read(struct ti_iic_softc *, uint32_t);
214 static void	ti_iic_do_write(struct ti_iic_softc *, uint32_t);
215 
216 static int	ti_iic_wait(struct ti_iic_softc *, uint16_t, uint16_t, int);
217 static uint32_t	ti_iic_stat(struct ti_iic_softc *, uint32_t);
218 static int	ti_iic_flush(struct ti_iic_softc *);
219 
220 static i2c_tag_t ti_iic_get_tag(device_t);
221 
222 static const struct fdtbus_i2c_controller_func ti_iic_funcs = {
223 	.get_tag = ti_iic_get_tag,
224 };
225 
226 CFATTACH_DECL_NEW(ti_iic, sizeof(struct ti_iic_softc),
227     ti_iic_match, ti_iic_attach, NULL, NULL);
228 
229 static int
230 ti_iic_match(device_t parent, cfdata_t match, void *opaque)
231 {
232 	struct fdt_attach_args * const faa = opaque;
233 
234 	return of_match_compat_data(faa->faa_phandle, compat_data);
235 }
236 
237 static void
238 ti_iic_attach(device_t parent, device_t self, void *opaque)
239 {
240 	struct ti_iic_softc *sc = device_private(self);
241 	struct fdt_attach_args * const faa = opaque;
242 	const int phandle = faa->faa_phandle;
243 	int fifodepth, fifo;
244 	const char *modname;
245 	char intrstr[128];
246 	bus_addr_t addr;
247 	bus_size_t size;
248 
249 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
250 		aprint_error(": couldn't get registers\n");
251 		return;
252 	}
253 	if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
254 		aprint_error(": couldn't decode interrupt\n");
255 		return;
256 	}
257 
258 	if (ti_prcm_enable_hwmod(phandle, 0) != 0) {
259 		aprint_error(": couldn't enable module\n");
260 		return;
261 	}
262 
263 	sc->sc_dev = self;
264 	sc->sc_iot = faa->faa_bst;
265 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE);
266 	mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NET);
267 	cv_init(&sc->sc_cv, "tiiic");
268 	sc->sc_ic.ic_cookie = sc;
269 	sc->sc_ic.ic_acquire_bus = ti_iic_acquire_bus;
270 	sc->sc_ic.ic_release_bus = ti_iic_release_bus;
271 	sc->sc_ic.ic_exec = ti_iic_exec;
272 
273 	if (bus_space_map(sc->sc_iot, addr, size, 0, &sc->sc_ioh) != 0) {
274 		aprint_error(": couldn't map registers\n");
275 		return;
276 	}
277 	sc->sc_type = of_search_compatible(phandle, compat_data)->data;
278 
279 	sc->sc_ih = fdtbus_intr_establish(phandle, 0, IPL_NET, 0,
280 	    ti_iic_intr, sc);
281 	if (sc->sc_ih == NULL) {
282 		aprint_error(": couldn't establish interrupt\n");
283 		return;
284 	}
285 
286 	modname = fdtbus_get_string(phandle, "ti,hwmods");
287 	if (modname == NULL)
288 		modname = fdtbus_get_string(OF_parent(phandle), "ti,hwmods");
289 
290 	fifodepth = I2C_BUFSTAT_FIFODEPTH(I2C_READ_REG(sc, I2C_BUFSTAT));
291 	fifo = OMAP2_I2C_FIFOBYTES(fifodepth);
292 	sc->sc_rxthres = sc->sc_txthres = fifo >> 1;
293 
294 	aprint_naive("\n");
295 	if (modname != NULL)
296 		aprint_normal(": I2C controller (%s), %d-bytes FIFO\n", modname, fifo);
297 	else
298 		aprint_normal(": I2C controller (i2c@%" PRIxBUSADDR "), %d-bytes FIFO\n",
299 		    addr, fifo);
300 
301 	ti_iic_reset(sc);
302 	ti_iic_flush(sc);
303 
304 	fdtbus_register_i2c_controller(self, phandle, &ti_iic_funcs);
305 
306 	fdtbus_attach_i2cbus(self, phandle, &sc->sc_ic, iicbus_print);
307 }
308 
309 static int
310 ti_iic_intr(void *arg)
311 {
312 	struct ti_iic_softc *sc = arg;
313 	uint32_t stat;
314 
315 	mutex_enter(&sc->sc_mtx);
316 	DPRINTF(("ti_iic_intr opflags=%#x\n", sc->sc_opflags));
317 	if ((sc->sc_opflags & I2C_F_POLL) == 0) {
318 		stat = I2C_READ_REG(sc, I2C_IRQSTATUS);
319 		DPRINTF(("ti_iic_intr pre handle sc->sc_op eq %#x\n", sc->sc_op));
320 		ti_iic_handle_intr(sc, stat);
321 		I2C_WRITE_REG(sc, I2C_IRQSTATUS, stat);
322 		if (sc->sc_op == TI_I2CERROR || sc->sc_op == TI_I2CDONE) {
323 			DPRINTF(("ti_iic_intr post handle sc->sc_op %#x\n", sc->sc_op));
324 			cv_broadcast(&sc->sc_cv);
325 		}
326 	}
327 	mutex_exit(&sc->sc_mtx);
328 	DPRINTF(("ti_iic_intr status 0x%x\n", stat));
329 	return 1;
330 }
331 
332 static int
333 ti_iic_acquire_bus(void *opaque, int flags)
334 {
335 	struct ti_iic_softc *sc = opaque;
336 
337 	mutex_enter(&sc->sc_lock);
338 	while (sc->sc_busy)
339 		cv_wait(&sc->sc_cv, &sc->sc_lock);
340 	sc->sc_busy = true;
341 	mutex_exit(&sc->sc_lock);
342 
343 	return 0;
344 }
345 
346 static void
347 ti_iic_release_bus(void *opaque, int flags)
348 {
349 	struct ti_iic_softc *sc = opaque;
350 
351 	mutex_enter(&sc->sc_lock);
352 	sc->sc_busy = false;
353 	cv_broadcast(&sc->sc_cv);
354 	mutex_exit(&sc->sc_lock);
355 }
356 
357 static int
358 ti_iic_exec(void *opaque, i2c_op_t op, i2c_addr_t addr,
359     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
360 {
361 	struct ti_iic_softc *sc = opaque;
362 	int err;
363 
364 	DPRINTF(("ti_iic_exec: op 0x%x cmdlen %zd len %zd flags 0x%x\n",
365 	    op, cmdlen, len, flags));
366 
367 	if (cmdlen > 0) {
368 		err = ti_iic_op(sc, addr, TI_I2CWRITE,
369 		    __UNCONST(cmdbuf), cmdlen,
370 		    (I2C_OP_READ_P(op) ? 0 : I2C_F_STOP) | flags);
371 		if (err)
372 			goto done;
373 	}
374 
375 	if (I2C_OP_STOP_P(op))
376 		flags |= I2C_F_STOP;
377 
378 	/*
379 	 * I2C controller doesn't allow for zero-byte transfers.
380 	 */
381 	if (len == 0) {
382 		err = EINVAL;
383 		goto done;
384 	}
385 
386 	if (I2C_OP_READ_P(op)) {
387 		err = ti_iic_op(sc, addr, TI_I2CREAD, buf, len, flags);
388 	} else {
389 		err = ti_iic_op(sc, addr, TI_I2CWRITE, buf, len, flags);
390 	}
391 
392 done:
393 	if (err)
394 		ti_iic_reset(sc);
395 
396 	ti_iic_flush(sc);
397 
398 	DPRINTF(("ti_iic_exec: done %d\n", err));
399 	return err;
400 }
401 
402 static int
403 ti_iic_reset(struct ti_iic_softc *sc)
404 {
405 	uint32_t psc, scll, sclh;
406 	int i;
407 
408 	DPRINTF(("ti_iic_reset\n"));
409 
410 	/* Disable */
411 	I2C_WRITE_REG(sc, I2C_CON, 0);
412 	/* Soft reset */
413 	I2C_WRITE_REG(sc, I2C_SYSC, I2C_SYSC_SRST);
414 	delay(1000);
415 	/* enable so that we can check for reset complete */
416 	I2C_WRITE_REG(sc, I2C_CON, I2C_CON_EN);
417 	delay(1000);
418 	for (i = 0; i < 1000; i++) { /* 1s delay for reset */
419 		if (I2C_READ_REG(sc, I2C_SYSS) & I2C_SYSS_RDONE)
420 			break;
421 	}
422 	/* Disable again */
423 	I2C_WRITE_REG(sc, I2C_CON, 0);
424 	delay(50000);
425 
426 	if (i >= 1000) {
427 		aprint_error_dev(sc->sc_dev, ": couldn't reset module\n");
428 		return 1;
429 	}
430 
431 
432 	/* XXX standard speed only */
433 	if (sc->sc_type == TI_IIC_OMAP3) {
434 		psc = (96000000 / 19200000) - 1;
435 		scll = sclh = (19200000 / (2 * 100000)) - 6;
436 	} else {
437 		psc = 3;
438 		scll = 53;
439 		sclh = 55;
440 	}
441 
442 	/* Clocks */
443 	I2C_WRITE_REG(sc, I2C_PSC, psc);
444 	I2C_WRITE_REG(sc, I2C_SCLL, scll);
445 	I2C_WRITE_REG(sc, I2C_SCLH, sclh);
446 
447 	/* Own I2C address */
448 	I2C_WRITE_REG(sc, I2C_OA, OMAP2_I2C_SLAVE_ADDR);
449 
450 	/* 5 bytes fifo */
451 	I2C_WRITE_REG(sc, I2C_BUF,
452 	    I2C_BUF_RXTRSH(sc->sc_rxthres) | I2C_BUF_TXTRSH(sc->sc_txthres));
453 
454 	/* Enable */
455 	I2C_WRITE_REG(sc, I2C_CON, I2C_CON_EN);
456 
457 	return 0;
458 }
459 
460 static int
461 ti_iic_op(struct ti_iic_softc *sc, i2c_addr_t addr, ti_i2cop_t op,
462     uint8_t *buf, size_t buflen, int flags)
463 {
464 	uint16_t con, stat, mask;
465 	int err, retry;
466 
467 	KASSERT(op == TI_I2CREAD || op == TI_I2CWRITE);
468 	DPRINTF(("ti_iic_op: addr %#x op %#x buf %p buflen %#x flags %#x\n",
469 	    addr, op, buf, (unsigned int) buflen, flags));
470 
471 	mask = I2C_IRQSTATUS_ARDY | I2C_IRQSTATUS_NACK | I2C_IRQSTATUS_AL;
472 	if (op == TI_I2CREAD) {
473 		mask |= I2C_IRQSTATUS_RDR | I2C_IRQSTATUS_RRDY;
474 	} else {
475 		mask |= I2C_IRQSTATUS_XDR | I2C_IRQSTATUS_XRDY;
476 	}
477 
478 	err = ti_iic_wait(sc, I2C_IRQSTATUS_BB, 0, flags);
479 	if (err) {
480 		DPRINTF(("ti_iic_op: wait error %d\n", err));
481 		return err;
482 	}
483 
484 	con = I2C_CON_EN;
485 	con |= I2C_CON_MST;
486 	con |= I2C_CON_STT;
487 	if (flags & I2C_F_STOP)
488 		con |= I2C_CON_STP;
489 	if (addr & ~0x7f)
490 		con |= I2C_CON_XSA;
491 	if (op == TI_I2CWRITE)
492 		con |= I2C_CON_TRX;
493 
494 	mutex_enter(&sc->sc_mtx);
495 	sc->sc_op = op;
496 	sc->sc_opflags = flags;
497 	sc->sc_buf = buf;
498 	sc->sc_buflen = buflen;
499 	sc->sc_bufidx = 0;
500 
501 	I2C_WRITE_REG(sc, I2C_CON, I2C_CON_EN | I2C_CON_MST | I2C_CON_STP);
502 	DPRINTF(("ti_iic_op: op %d con 0x%x ", op, con));
503 	I2C_WRITE_REG(sc, I2C_CNT, buflen);
504 	I2C_WRITE_REG(sc, I2C_SA, (addr & I2C_SA_MASK));
505 	DPRINTF(("SA 0x%x len %d\n", I2C_READ_REG(sc, I2C_SA), I2C_READ_REG(sc, I2C_CNT)));
506 
507 	if ((flags & I2C_F_POLL) == 0 || sc->sc_type == TI_IIC_OMAP3) {
508 		/* clear any pending interrupt */
509 		I2C_WRITE_REG(sc, I2C_IRQSTATUS,
510 		    I2C_READ_REG(sc, I2C_IRQSTATUS));
511 		/* and enable */
512 		if (sc->sc_type == TI_IIC_OMAP4) {
513 			I2C_WRITE_REG(sc, I2C_IRQENABLE_SET, mask);
514 		} else {
515 			I2C_WRITE_REG(sc, I2C_IRQENABLE, mask);
516 		}
517 	}
518 	/* start transfer */
519 	I2C_WRITE_REG(sc, I2C_CON, con);
520 
521 	if ((flags & I2C_F_POLL) == 0) {
522 		/* and wait for completion */
523 		DPRINTF(("ti_iic_op waiting, op %#x\n", sc->sc_op));
524 		while (sc->sc_op == op) {
525 			if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx,
526 			    mstohz(5000)) == EWOULDBLOCK) {
527 				/* timeout */
528 				op = TI_I2CERROR;
529 			}
530 		}
531 		DPRINTF(("ti_iic_op waiting done, op %#x\n", sc->sc_op));
532 
533 		/* disable interrupts */
534 		if (sc->sc_type == TI_IIC_OMAP4) {
535 			I2C_WRITE_REG(sc, I2C_IRQENABLE_CLR, 0xffff);
536 		} else {
537 			I2C_WRITE_REG(sc, I2C_IRQENABLE, 0);
538 		}
539 	} else {
540 		/* poll for completion */
541 		DPRINTF(("ti_iic_op polling, op %x\n", sc->sc_op));
542 		while (sc->sc_op == op) {
543 			stat = ti_iic_stat(sc, mask);
544 			DPRINTF(("ti_iic_op stat 0x%x\n", stat));
545 			if (stat == 0) {
546 				/* timeout */
547 				sc->sc_op = TI_I2CERROR;
548 			} else {
549 				ti_iic_handle_intr(sc, stat);
550 			}
551 			I2C_WRITE_REG(sc, I2C_IRQSTATUS, stat);
552 		}
553 		DPRINTF(("ti_iic_op polling done, op now %x\n", sc->sc_op));
554 	}
555 	mutex_exit(&sc->sc_mtx);
556 	retry = 10000;
557 	I2C_WRITE_REG(sc, I2C_CON, 0);
558 	while (I2C_READ_REG(sc, I2C_CON) & I2C_CON_MST) {
559 		delay(100);
560 		if (--retry == 0)
561 			break;
562 	}
563 	return (sc->sc_op == TI_I2CDONE) ? 0 : EIO;
564 }
565 
566 static void
567 ti_iic_handle_intr(struct ti_iic_softc *sc, uint32_t stat)
568 {
569 	KASSERT(mutex_owned(&sc->sc_mtx));
570 	KASSERT(stat != 0);
571 	DPRINTF(("ti_iic_handle_intr stat %#x\n", stat));
572 
573 	if (stat &
574 	    (I2C_IRQSTATUS_NACK|I2C_IRQSTATUS_AL)) {
575 		sc->sc_op = TI_I2CERROR;
576 		return;
577 	}
578 	if (stat & I2C_IRQSTATUS_ARDY) {
579 		sc->sc_op = TI_I2CDONE;
580 		return;
581 	}
582 	if (sc->sc_op == TI_I2CREAD)
583 		ti_iic_do_read(sc, stat);
584 	else if (sc->sc_op == TI_I2CWRITE)
585 		ti_iic_do_write(sc, stat);
586 	else
587 		return;
588 }
589 void
590 ti_iic_do_read(struct ti_iic_softc *sc, uint32_t stat)
591 {
592 	int len = 0;
593 
594 	KASSERT(mutex_owned(&sc->sc_mtx));
595 	DPRINTF(("ti_iic_do_read stat %#x\n", stat));
596 	if (stat & I2C_IRQSTATUS_RDR) {
597 		len = I2C_READ_REG(sc, I2C_BUFSTAT);
598 		len = I2C_BUFSTAT_RXSTAT(len);
599 		DPRINTF(("ti_iic_do_read receive drain len %d left %d\n",
600 		    len, I2C_READ_REG(sc, I2C_CNT)));
601 	} else if (stat & I2C_IRQSTATUS_RRDY) {
602 		len = sc->sc_rxthres + 1;
603 		DPRINTF(("ti_iic_do_read receive len %d left %d\n",
604 		    len, I2C_READ_REG(sc, I2C_CNT)));
605 	}
606 	for (;
607 	    sc->sc_bufidx < sc->sc_buflen && len > 0;
608 	    sc->sc_bufidx++, len--) {
609 		sc->sc_buf[sc->sc_bufidx] = I2C_READ_DATA(sc);
610 		DPRINTF(("ti_iic_do_read got b[%d]=0x%x\n", sc->sc_bufidx,
611 		    sc->sc_buf[sc->sc_bufidx]));
612 	}
613 	DPRINTF(("ti_iic_do_read done\n"));
614 }
615 
616 void
617 ti_iic_do_write(struct ti_iic_softc *sc, uint32_t stat)
618 {
619 	int len = 0;
620 
621 	DPRINTF(("ti_iic_do_write stat %#x\n", stat));
622 	KASSERT(mutex_owned(&sc->sc_mtx));
623 	if (stat & I2C_IRQSTATUS_XDR) {
624 		len = I2C_READ_REG(sc, I2C_BUFSTAT);
625 		len = I2C_BUFSTAT_TXSTAT(len);
626 		DPRINTF(("ti_iic_do_write xmit drain len %d left %d\n",
627 		    len, I2C_READ_REG(sc, I2C_CNT)));
628 	} else if (stat & I2C_IRQSTATUS_XRDY) {
629 		len = sc->sc_txthres + 1;
630 		DPRINTF(("ti_iic_do_write xmit len %d left %d\n",
631 		    len, I2C_READ_REG(sc, I2C_CNT)));
632 	}
633 	for (;
634 	    sc->sc_bufidx < sc->sc_buflen && len > 0;
635 	    sc->sc_bufidx++, len--) {
636 		DPRINTF(("ti_iic_do_write send b[%d]=0x%x\n",
637 		    sc->sc_bufidx, sc->sc_buf[sc->sc_bufidx]));
638 		I2C_WRITE_DATA(sc, sc->sc_buf[sc->sc_bufidx]);
639 	}
640 	DPRINTF(("ti_iic_do_write done\n"));
641 }
642 
643 static int
644 ti_iic_wait(struct ti_iic_softc *sc, uint16_t mask, uint16_t val, int flags)
645 {
646 	int retry = 10;
647 	uint16_t v;
648 	DPRINTF(("ti_iic_wait mask %#x val %#x flags %#x\n", mask, val, flags));
649 
650 	while (((v = I2C_READ_REG(sc, I2C_IRQSTATUS_RAW)) & mask) != val) {
651 		--retry;
652 		if (retry == 0) {
653 			aprint_error_dev(sc->sc_dev, ": wait timeout, "
654 			    "mask = %#x val = %#x stat = %#x\n",
655 			    mask, val, v);
656 			return EBUSY;
657 		}
658 		if (flags & I2C_F_POLL) {
659 			delay(50000);
660 		} else {
661 			kpause("tiiic", false, mstohz(50), NULL);
662 		}
663 	}
664 	DPRINTF(("ti_iic_wait done retry %#x\n", retry));
665 
666 	return 0;
667 }
668 
669 static uint32_t
670 ti_iic_stat(struct ti_iic_softc *sc, uint32_t mask)
671 {
672 	uint32_t v;
673 	int retry = 500;
674 	DPRINTF(("ti_iic_wait mask %#x\n", mask));
675 	while (--retry > 0) {
676 		v = I2C_READ_REG(sc, I2C_IRQSTATUS_RAW) & mask;
677 		if (v != 0)
678 			break;
679 		delay(100);
680 	}
681 	DPRINTF(("ti_iic_wait done retry %#x\n", retry));
682 	return v;
683 }
684 
685 static int
686 ti_iic_flush(struct ti_iic_softc *sc)
687 {
688 	DPRINTF(("ti_iic_flush\n"));
689 #if 0
690 	int retry = 1000;
691 	uint16_t v;
692 
693 	while ((v = I2C_READ_REG(sc, I2C_IRQSTATUS_RAW)) & I2C_IRQSTATUS_RRDY) {
694 		if (--retry == 0) {
695 			aprint_error_dev(sc->sc_dev,
696 			    ": flush timeout, stat = %#x\n", v);
697 			return EBUSY;
698 		}
699 		(void)I2C_READ_DATA(sc);
700 		delay(1000);
701 	}
702 #endif
703 
704 	I2C_WRITE_REG(sc, I2C_CNT, 0);
705 	return 0;
706 }
707 
708 static i2c_tag_t
709 ti_iic_get_tag(device_t dev)
710 {
711 	struct ti_iic_softc * const sc = device_private(dev);
712 
713 	return &sc->sc_ic;
714 }
715