xref: /netbsd-src/sys/arch/arm/ti/ti_iic.c (revision 6e54367a22fbc89a1139d033e95bec0c0cf0975b)
1 /* $NetBSD: ti_iic.c,v 1.13 2021/01/27 03:10:20 thorpej 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 1.13 2021/01/27 03:10:20 thorpej 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 device_compatible_entry compat_data[] = {
150 	/* compatible			type */
151 	{ .compat = "ti,omap3-i2c",	.value = TI_IIC_OMAP3 },
152 	{ .compat = "ti,omap4-i2c",	.value = TI_IIC_OMAP4 },
153 	DEVICE_COMPAT_EOL
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 CFATTACH_DECL_NEW(ti_iic, sizeof(struct ti_iic_softc),
221     ti_iic_match, ti_iic_attach, NULL, NULL);
222 
223 static int
ti_iic_match(device_t parent,cfdata_t match,void * opaque)224 ti_iic_match(device_t parent, cfdata_t match, void *opaque)
225 {
226 	struct fdt_attach_args * const faa = opaque;
227 
228 	return of_compatible_match(faa->faa_phandle, compat_data);
229 }
230 
231 static void
ti_iic_attach(device_t parent,device_t self,void * opaque)232 ti_iic_attach(device_t parent, device_t self, void *opaque)
233 {
234 	struct ti_iic_softc *sc = device_private(self);
235 	struct fdt_attach_args * const faa = opaque;
236 	const int phandle = faa->faa_phandle;
237 	int fifodepth, fifo;
238 	const char *modname;
239 	char intrstr[128];
240 	bus_addr_t addr;
241 	bus_size_t size;
242 
243 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
244 		aprint_error(": couldn't get registers\n");
245 		return;
246 	}
247 	if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
248 		aprint_error(": couldn't decode interrupt\n");
249 		return;
250 	}
251 
252 	if (ti_prcm_enable_hwmod(phandle, 0) != 0) {
253 		aprint_error(": couldn't enable module\n");
254 		return;
255 	}
256 
257 	sc->sc_dev = self;
258 	sc->sc_iot = faa->faa_bst;
259 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE);
260 	mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NET);
261 	cv_init(&sc->sc_cv, "tiiic");
262 	iic_tag_init(&sc->sc_ic);
263 	sc->sc_ic.ic_cookie = sc;
264 	sc->sc_ic.ic_acquire_bus = ti_iic_acquire_bus;
265 	sc->sc_ic.ic_release_bus = ti_iic_release_bus;
266 	sc->sc_ic.ic_exec = ti_iic_exec;
267 
268 	if (bus_space_map(sc->sc_iot, addr, size, 0, &sc->sc_ioh) != 0) {
269 		aprint_error(": couldn't map registers\n");
270 		return;
271 	}
272 	sc->sc_type = of_compatible_lookup(phandle, compat_data)->value;
273 
274 	sc->sc_ih = fdtbus_intr_establish_xname(phandle, 0, IPL_NET, 0,
275 	    ti_iic_intr, sc, device_xname(self));
276 	if (sc->sc_ih == NULL) {
277 		aprint_error(": couldn't establish interrupt\n");
278 		return;
279 	}
280 
281 	modname = fdtbus_get_string(phandle, "ti,hwmods");
282 	if (modname == NULL)
283 		modname = fdtbus_get_string(OF_parent(phandle), "ti,hwmods");
284 
285 	fifodepth = I2C_BUFSTAT_FIFODEPTH(I2C_READ_REG(sc, I2C_BUFSTAT));
286 	fifo = OMAP2_I2C_FIFOBYTES(fifodepth);
287 	sc->sc_rxthres = sc->sc_txthres = fifo >> 1;
288 
289 	aprint_naive("\n");
290 	if (modname != NULL)
291 		aprint_normal(": I2C controller (%s), %d-bytes FIFO\n", modname, fifo);
292 	else
293 		aprint_normal(": I2C controller (i2c@%" PRIxBUSADDR "), %d-bytes FIFO\n",
294 		    addr, fifo);
295 
296 	ti_iic_reset(sc);
297 	ti_iic_flush(sc);
298 
299 	fdtbus_register_i2c_controller(&sc->sc_ic, phandle);
300 
301 	fdtbus_attach_i2cbus(self, phandle, &sc->sc_ic, iicbus_print);
302 }
303 
304 static int
ti_iic_intr(void * arg)305 ti_iic_intr(void *arg)
306 {
307 	struct ti_iic_softc *sc = arg;
308 	uint32_t stat;
309 
310 	mutex_enter(&sc->sc_mtx);
311 	DPRINTF(("ti_iic_intr opflags=%#x\n", sc->sc_opflags));
312 	if ((sc->sc_opflags & I2C_F_POLL) == 0) {
313 		stat = I2C_READ_REG(sc, I2C_IRQSTATUS);
314 		DPRINTF(("ti_iic_intr pre handle sc->sc_op eq %#x\n", sc->sc_op));
315 		ti_iic_handle_intr(sc, stat);
316 		I2C_WRITE_REG(sc, I2C_IRQSTATUS, stat);
317 		if (sc->sc_op == TI_I2CERROR || sc->sc_op == TI_I2CDONE) {
318 			DPRINTF(("ti_iic_intr post handle sc->sc_op %#x\n", sc->sc_op));
319 			cv_broadcast(&sc->sc_cv);
320 		}
321 	}
322 	mutex_exit(&sc->sc_mtx);
323 	DPRINTF(("ti_iic_intr status 0x%x\n", stat));
324 	return 1;
325 }
326 
327 static int
ti_iic_acquire_bus(void * opaque,int flags)328 ti_iic_acquire_bus(void *opaque, int flags)
329 {
330 	struct ti_iic_softc *sc = opaque;
331 
332 	mutex_enter(&sc->sc_lock);
333 	while (sc->sc_busy)
334 		cv_wait(&sc->sc_cv, &sc->sc_lock);
335 	sc->sc_busy = true;
336 	mutex_exit(&sc->sc_lock);
337 
338 	return 0;
339 }
340 
341 static void
ti_iic_release_bus(void * opaque,int flags)342 ti_iic_release_bus(void *opaque, int flags)
343 {
344 	struct ti_iic_softc *sc = opaque;
345 
346 	mutex_enter(&sc->sc_lock);
347 	sc->sc_busy = false;
348 	cv_broadcast(&sc->sc_cv);
349 	mutex_exit(&sc->sc_lock);
350 }
351 
352 static int
ti_iic_exec(void * opaque,i2c_op_t op,i2c_addr_t addr,const void * cmdbuf,size_t cmdlen,void * buf,size_t len,int flags)353 ti_iic_exec(void *opaque, i2c_op_t op, i2c_addr_t addr,
354     const void *cmdbuf, size_t cmdlen, void *buf, size_t len, int flags)
355 {
356 	struct ti_iic_softc *sc = opaque;
357 	int err;
358 
359 	DPRINTF(("ti_iic_exec: op 0x%x cmdlen %zd len %zd flags 0x%x\n",
360 	    op, cmdlen, len, flags));
361 
362 	if (cmdlen > 0) {
363 		err = ti_iic_op(sc, addr, TI_I2CWRITE,
364 		    __UNCONST(cmdbuf), cmdlen,
365 		    (I2C_OP_READ_P(op) ? 0 : I2C_F_STOP) | flags);
366 		if (err)
367 			goto done;
368 	}
369 
370 	if (I2C_OP_STOP_P(op))
371 		flags |= I2C_F_STOP;
372 
373 	/*
374 	 * I2C controller doesn't allow for zero-byte transfers.
375 	 */
376 	if (len == 0) {
377 		err = EINVAL;
378 		goto done;
379 	}
380 
381 	if (I2C_OP_READ_P(op)) {
382 		err = ti_iic_op(sc, addr, TI_I2CREAD, buf, len, flags);
383 	} else {
384 		err = ti_iic_op(sc, addr, TI_I2CWRITE, buf, len, flags);
385 	}
386 
387 done:
388 	if (err)
389 		ti_iic_reset(sc);
390 
391 	ti_iic_flush(sc);
392 
393 	DPRINTF(("ti_iic_exec: done %d\n", err));
394 	return err;
395 }
396 
397 static int
ti_iic_reset(struct ti_iic_softc * sc)398 ti_iic_reset(struct ti_iic_softc *sc)
399 {
400 	uint32_t psc, scll, sclh;
401 	int i;
402 
403 	DPRINTF(("ti_iic_reset\n"));
404 
405 	/* Disable */
406 	I2C_WRITE_REG(sc, I2C_CON, 0);
407 	/* Soft reset */
408 	I2C_WRITE_REG(sc, I2C_SYSC, I2C_SYSC_SRST);
409 	delay(1000);
410 	/* enable so that we can check for reset complete */
411 	I2C_WRITE_REG(sc, I2C_CON, I2C_CON_EN);
412 	delay(1000);
413 	for (i = 0; i < 1000; i++) { /* 1s delay for reset */
414 		if (I2C_READ_REG(sc, I2C_SYSS) & I2C_SYSS_RDONE)
415 			break;
416 	}
417 	/* Disable again */
418 	I2C_WRITE_REG(sc, I2C_CON, 0);
419 	delay(50000);
420 
421 	if (i >= 1000) {
422 		aprint_error_dev(sc->sc_dev, ": couldn't reset module\n");
423 		return 1;
424 	}
425 
426 
427 	/* XXX standard speed only */
428 	if (sc->sc_type == TI_IIC_OMAP3) {
429 		psc = (96000000 / 19200000) - 1;
430 		scll = sclh = (19200000 / (2 * 100000)) - 6;
431 	} else {
432 		psc = 3;
433 		scll = 53;
434 		sclh = 55;
435 	}
436 
437 	/* Clocks */
438 	I2C_WRITE_REG(sc, I2C_PSC, psc);
439 	I2C_WRITE_REG(sc, I2C_SCLL, scll);
440 	I2C_WRITE_REG(sc, I2C_SCLH, sclh);
441 
442 	/* Own I2C address */
443 	I2C_WRITE_REG(sc, I2C_OA, OMAP2_I2C_SLAVE_ADDR);
444 
445 	/* 5 bytes fifo */
446 	I2C_WRITE_REG(sc, I2C_BUF,
447 	    I2C_BUF_RXTRSH(sc->sc_rxthres) | I2C_BUF_TXTRSH(sc->sc_txthres));
448 
449 	/* Enable */
450 	I2C_WRITE_REG(sc, I2C_CON, I2C_CON_EN);
451 
452 	return 0;
453 }
454 
455 static int
ti_iic_op(struct ti_iic_softc * sc,i2c_addr_t addr,ti_i2cop_t op,uint8_t * buf,size_t buflen,int flags)456 ti_iic_op(struct ti_iic_softc *sc, i2c_addr_t addr, ti_i2cop_t op,
457     uint8_t *buf, size_t buflen, int flags)
458 {
459 	uint16_t con, stat, mask;
460 	int err, retry;
461 
462 	KASSERT(op == TI_I2CREAD || op == TI_I2CWRITE);
463 	DPRINTF(("ti_iic_op: addr %#x op %#x buf %p buflen %#x flags %#x\n",
464 	    addr, op, buf, (unsigned int) buflen, flags));
465 
466 	mask = I2C_IRQSTATUS_ARDY | I2C_IRQSTATUS_NACK | I2C_IRQSTATUS_AL;
467 	if (op == TI_I2CREAD) {
468 		mask |= I2C_IRQSTATUS_RDR | I2C_IRQSTATUS_RRDY;
469 	} else {
470 		mask |= I2C_IRQSTATUS_XDR | I2C_IRQSTATUS_XRDY;
471 	}
472 
473 	err = ti_iic_wait(sc, I2C_IRQSTATUS_BB, 0, flags);
474 	if (err) {
475 		DPRINTF(("ti_iic_op: wait error %d\n", err));
476 		return err;
477 	}
478 
479 	con = I2C_CON_EN;
480 	con |= I2C_CON_MST;
481 	con |= I2C_CON_STT;
482 	if (flags & I2C_F_STOP)
483 		con |= I2C_CON_STP;
484 	if (addr & ~0x7f)
485 		con |= I2C_CON_XSA;
486 	if (op == TI_I2CWRITE)
487 		con |= I2C_CON_TRX;
488 
489 	mutex_enter(&sc->sc_mtx);
490 	sc->sc_op = op;
491 	sc->sc_opflags = flags;
492 	sc->sc_buf = buf;
493 	sc->sc_buflen = buflen;
494 	sc->sc_bufidx = 0;
495 
496 	I2C_WRITE_REG(sc, I2C_CON, I2C_CON_EN | I2C_CON_MST | I2C_CON_STP);
497 	DPRINTF(("ti_iic_op: op %d con 0x%x ", op, con));
498 	I2C_WRITE_REG(sc, I2C_CNT, buflen);
499 	I2C_WRITE_REG(sc, I2C_SA, (addr & I2C_SA_MASK));
500 	DPRINTF(("SA 0x%x len %d\n", I2C_READ_REG(sc, I2C_SA), I2C_READ_REG(sc, I2C_CNT)));
501 
502 	if ((flags & I2C_F_POLL) == 0 || sc->sc_type == TI_IIC_OMAP3) {
503 		/* clear any pending interrupt */
504 		I2C_WRITE_REG(sc, I2C_IRQSTATUS,
505 		    I2C_READ_REG(sc, I2C_IRQSTATUS));
506 		/* and enable */
507 		if (sc->sc_type == TI_IIC_OMAP4) {
508 			I2C_WRITE_REG(sc, I2C_IRQENABLE_SET, mask);
509 		} else {
510 			I2C_WRITE_REG(sc, I2C_IRQENABLE, mask);
511 		}
512 	}
513 	/* start transfer */
514 	I2C_WRITE_REG(sc, I2C_CON, con);
515 
516 	if ((flags & I2C_F_POLL) == 0) {
517 		/* and wait for completion */
518 		DPRINTF(("ti_iic_op waiting, op %#x\n", sc->sc_op));
519 		while (sc->sc_op == op) {
520 			if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx,
521 			    mstohz(5000)) == EWOULDBLOCK) {
522 				/* timeout */
523 				op = TI_I2CERROR;
524 			}
525 		}
526 		DPRINTF(("ti_iic_op waiting done, op %#x\n", sc->sc_op));
527 
528 		/* disable interrupts */
529 		if (sc->sc_type == TI_IIC_OMAP4) {
530 			I2C_WRITE_REG(sc, I2C_IRQENABLE_CLR, 0xffff);
531 		} else {
532 			I2C_WRITE_REG(sc, I2C_IRQENABLE, 0);
533 		}
534 	} else {
535 		/* poll for completion */
536 		DPRINTF(("ti_iic_op polling, op %x\n", sc->sc_op));
537 		while (sc->sc_op == op) {
538 			stat = ti_iic_stat(sc, mask);
539 			DPRINTF(("ti_iic_op stat 0x%x\n", stat));
540 			if (stat == 0) {
541 				/* timeout */
542 				sc->sc_op = TI_I2CERROR;
543 			} else {
544 				ti_iic_handle_intr(sc, stat);
545 			}
546 			I2C_WRITE_REG(sc, I2C_IRQSTATUS, stat);
547 		}
548 		DPRINTF(("ti_iic_op polling done, op now %x\n", sc->sc_op));
549 	}
550 	mutex_exit(&sc->sc_mtx);
551 	retry = 10000;
552 	I2C_WRITE_REG(sc, I2C_CON, 0);
553 	while (I2C_READ_REG(sc, I2C_CON) & I2C_CON_MST) {
554 		delay(100);
555 		if (--retry == 0)
556 			break;
557 	}
558 	return (sc->sc_op == TI_I2CDONE) ? 0 : EIO;
559 }
560 
561 static void
ti_iic_handle_intr(struct ti_iic_softc * sc,uint32_t stat)562 ti_iic_handle_intr(struct ti_iic_softc *sc, uint32_t stat)
563 {
564 	KASSERT(mutex_owned(&sc->sc_mtx));
565 	KASSERT(stat != 0);
566 	DPRINTF(("ti_iic_handle_intr stat %#x\n", stat));
567 
568 	if (stat &
569 	    (I2C_IRQSTATUS_NACK|I2C_IRQSTATUS_AL)) {
570 		sc->sc_op = TI_I2CERROR;
571 		return;
572 	}
573 	if (stat & I2C_IRQSTATUS_ARDY) {
574 		sc->sc_op = TI_I2CDONE;
575 		return;
576 	}
577 	if (sc->sc_op == TI_I2CREAD)
578 		ti_iic_do_read(sc, stat);
579 	else if (sc->sc_op == TI_I2CWRITE)
580 		ti_iic_do_write(sc, stat);
581 	else
582 		return;
583 }
584 void
ti_iic_do_read(struct ti_iic_softc * sc,uint32_t stat)585 ti_iic_do_read(struct ti_iic_softc *sc, uint32_t stat)
586 {
587 	int len = 0;
588 
589 	KASSERT(mutex_owned(&sc->sc_mtx));
590 	DPRINTF(("ti_iic_do_read stat %#x\n", stat));
591 	if (stat & I2C_IRQSTATUS_RDR) {
592 		len = I2C_READ_REG(sc, I2C_BUFSTAT);
593 		len = I2C_BUFSTAT_RXSTAT(len);
594 		DPRINTF(("ti_iic_do_read receive drain len %d left %d\n",
595 		    len, I2C_READ_REG(sc, I2C_CNT)));
596 	} else if (stat & I2C_IRQSTATUS_RRDY) {
597 		len = sc->sc_rxthres + 1;
598 		DPRINTF(("ti_iic_do_read receive len %d left %d\n",
599 		    len, I2C_READ_REG(sc, I2C_CNT)));
600 	}
601 	for (;
602 	    sc->sc_bufidx < sc->sc_buflen && len > 0;
603 	    sc->sc_bufidx++, len--) {
604 		sc->sc_buf[sc->sc_bufidx] = I2C_READ_DATA(sc);
605 		DPRINTF(("ti_iic_do_read got b[%d]=0x%x\n", sc->sc_bufidx,
606 		    sc->sc_buf[sc->sc_bufidx]));
607 	}
608 	DPRINTF(("ti_iic_do_read done\n"));
609 }
610 
611 void
ti_iic_do_write(struct ti_iic_softc * sc,uint32_t stat)612 ti_iic_do_write(struct ti_iic_softc *sc, uint32_t stat)
613 {
614 	int len = 0;
615 
616 	DPRINTF(("ti_iic_do_write stat %#x\n", stat));
617 	KASSERT(mutex_owned(&sc->sc_mtx));
618 	if (stat & I2C_IRQSTATUS_XDR) {
619 		len = I2C_READ_REG(sc, I2C_BUFSTAT);
620 		len = I2C_BUFSTAT_TXSTAT(len);
621 		DPRINTF(("ti_iic_do_write xmit drain len %d left %d\n",
622 		    len, I2C_READ_REG(sc, I2C_CNT)));
623 	} else if (stat & I2C_IRQSTATUS_XRDY) {
624 		len = sc->sc_txthres + 1;
625 		DPRINTF(("ti_iic_do_write xmit len %d left %d\n",
626 		    len, I2C_READ_REG(sc, I2C_CNT)));
627 	}
628 	for (;
629 	    sc->sc_bufidx < sc->sc_buflen && len > 0;
630 	    sc->sc_bufidx++, len--) {
631 		DPRINTF(("ti_iic_do_write send b[%d]=0x%x\n",
632 		    sc->sc_bufidx, sc->sc_buf[sc->sc_bufidx]));
633 		I2C_WRITE_DATA(sc, sc->sc_buf[sc->sc_bufidx]);
634 	}
635 	DPRINTF(("ti_iic_do_write done\n"));
636 }
637 
638 static int
ti_iic_wait(struct ti_iic_softc * sc,uint16_t mask,uint16_t val,int flags)639 ti_iic_wait(struct ti_iic_softc *sc, uint16_t mask, uint16_t val, int flags)
640 {
641 	int retry = 10;
642 	uint16_t v;
643 	DPRINTF(("ti_iic_wait mask %#x val %#x flags %#x\n", mask, val, flags));
644 
645 	while (((v = I2C_READ_REG(sc, I2C_IRQSTATUS_RAW)) & mask) != val) {
646 		--retry;
647 		if (retry == 0) {
648 			aprint_error_dev(sc->sc_dev, ": wait timeout, "
649 			    "mask = %#x val = %#x stat = %#x\n",
650 			    mask, val, v);
651 			return EBUSY;
652 		}
653 		if (flags & I2C_F_POLL) {
654 			delay(50000);
655 		} else {
656 			kpause("tiiic", false, mstohz(50), NULL);
657 		}
658 	}
659 	DPRINTF(("ti_iic_wait done retry %#x\n", retry));
660 
661 	return 0;
662 }
663 
664 static uint32_t
ti_iic_stat(struct ti_iic_softc * sc,uint32_t mask)665 ti_iic_stat(struct ti_iic_softc *sc, uint32_t mask)
666 {
667 	uint32_t v;
668 	int retry = 500;
669 	DPRINTF(("ti_iic_wait mask %#x\n", mask));
670 	while (--retry > 0) {
671 		v = I2C_READ_REG(sc, I2C_IRQSTATUS_RAW) & mask;
672 		if (v != 0)
673 			break;
674 		delay(100);
675 	}
676 	DPRINTF(("ti_iic_wait done retry %#x\n", retry));
677 	return v;
678 }
679 
680 static int
ti_iic_flush(struct ti_iic_softc * sc)681 ti_iic_flush(struct ti_iic_softc *sc)
682 {
683 	DPRINTF(("ti_iic_flush\n"));
684 #if 0
685 	int retry = 1000;
686 	uint16_t v;
687 
688 	while ((v = I2C_READ_REG(sc, I2C_IRQSTATUS_RAW)) & I2C_IRQSTATUS_RRDY) {
689 		if (--retry == 0) {
690 			aprint_error_dev(sc->sc_dev,
691 			    ": flush timeout, stat = %#x\n", v);
692 			return EBUSY;
693 		}
694 		(void)I2C_READ_DATA(sc);
695 		delay(1000);
696 	}
697 #endif
698 
699 	I2C_WRITE_REG(sc, I2C_CNT, 0);
700 	return 0;
701 }
702