icee.c revision 331722 
1/*-
2 * Copyright (c) 2006 Warner Losh.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include <sys/cdefs.h>
26__FBSDID("$FreeBSD: stable/11/sys/dev/iicbus/icee.c 331722 2018-03-29 02:50:57Z eadler $");
27/*
28 * Generic IIC eeprom support, modeled after the AT24C family of products.
29 */
30
31#include "opt_platform.h"
32
33#include <sys/param.h>
34#include <sys/systm.h>
35#include <sys/bus.h>
36#include <sys/conf.h>
37#include <sys/kernel.h>
38#include <sys/module.h>
39#include <sys/resource.h>
40#include <sys/sx.h>
41#include <sys/uio.h>
42#include <machine/bus.h>
43
44#ifdef FDT
45#include <dev/ofw/ofw_bus.h>
46#include <dev/ofw/ofw_bus_subr.h>
47#endif
48
49#include <dev/iicbus/iiconf.h>
50#include <dev/iicbus/iicbus.h>
51
52#include "iicbus_if.h"
53
54/*
55 * AT24 parts have a "write page size" that differs per-device, and a "read page
56 * size" that is always equal to the full device size.  We define maximum values
57 * here to limit how long we occupy the bus with a single transfer, and because
58 * there are temporary buffers of these sizes allocated on the stack.
59 */
60#define	MAX_RD_SZ	256	/* Largest read size we support */
61#define	MAX_WR_SZ	256	/* Largest write size we support */
62
63struct icee_softc {
64	device_t	dev;		/* Myself */
65	struct cdev	*cdev;		/* user interface */
66	int		addr;		/* Slave address on the bus */
67	int		size;		/* How big am I? */
68	int		type;		/* What address type 8 or 16 bit? */
69	int		wr_sz;		/* What's the write page size */
70};
71
72#ifdef FDT
73struct eeprom_desc {
74	int	    type;
75	int	    size;
76	int	    wr_sz;
77	const char *name;
78};
79
80static struct eeprom_desc type_desc[] = {
81	{ 8,        128,   8, "AT24C01"},
82	{ 8,        256,   8, "AT24C02"},
83	{ 8,        512,  16, "AT24C04"},
84	{ 8,       1024,  16, "AT24C08"},
85	{ 8,   2 * 1024,  16, "AT24C16"},
86	{16,   4 * 1024,  32, "AT24C32"},
87	{16,   8 * 1024,  32, "AT24C64"},
88	{16,  16 * 1024,  64, "AT24C128"},
89	{16,  32 * 1024,  64, "AT24C256"},
90	{16,  64 * 1024, 128, "AT24C512"},
91	{16, 128 * 1024, 256, "AT24CM01"},
92};
93
94static struct ofw_compat_data compat_data[] = {
95	{"atmel,24c01",	  (uintptr_t)(&type_desc[0])},
96	{"atmel,24c02",	  (uintptr_t)(&type_desc[1])},
97	{"atmel,24c04",	  (uintptr_t)(&type_desc[2])},
98	{"atmel,24c08",	  (uintptr_t)(&type_desc[3])},
99	{"atmel,24c16",	  (uintptr_t)(&type_desc[4])},
100	{"atmel,24c32",	  (uintptr_t)(&type_desc[5])},
101	{"atmel,24c64",	  (uintptr_t)(&type_desc[6])},
102	{"atmel,24c128",  (uintptr_t)(&type_desc[7])},
103	{"atmel,24c256",  (uintptr_t)(&type_desc[8])},
104	{"atmel,24c512",  (uintptr_t)(&type_desc[9])},
105	{"atmel,24c1024", (uintptr_t)(&type_desc[10])},
106	{NULL,		  (uintptr_t)NULL},
107};
108#endif
109
110#define CDEV2SOFTC(dev)		((dev)->si_drv1)
111
112/* cdev routines */
113static d_open_t icee_open;
114static d_close_t icee_close;
115static d_read_t icee_read;
116static d_write_t icee_write;
117
118static struct cdevsw icee_cdevsw =
119{
120	.d_version = D_VERSION,
121	.d_flags = D_TRACKCLOSE,
122	.d_open = icee_open,
123	.d_close = icee_close,
124	.d_read = icee_read,
125	.d_write = icee_write
126};
127
128#ifdef FDT
129static int
130icee_probe(device_t dev)
131{
132	struct eeprom_desc *d;
133
134	if (!ofw_bus_status_okay(dev))
135		return (ENXIO);
136
137	d = (struct eeprom_desc *)
138	    ofw_bus_search_compatible(dev, compat_data)->ocd_data;
139	if (d == NULL)
140		return (ENXIO);
141
142	device_set_desc(dev, d->name);
143	return (BUS_PROBE_DEFAULT);
144}
145
146static void
147icee_init(struct icee_softc *sc)
148{
149	struct eeprom_desc *d;
150
151	d = (struct eeprom_desc *)
152	    ofw_bus_search_compatible(sc->dev, compat_data)->ocd_data;
153	if (d == NULL)
154		return; /* attach will see sc->size == 0 and return error */
155
156	sc->size  = d->size;
157	sc->type  = d->type;
158	sc->wr_sz = d->wr_sz;
159}
160#else /* !FDT */
161static int
162icee_probe(device_t dev)
163{
164
165	device_set_desc(dev, "I2C EEPROM");
166	return (BUS_PROBE_NOWILDCARD);
167}
168
169static void
170icee_init(struct icee_softc *sc)
171{
172	const char *dname;
173	int dunit;
174
175	dname = device_get_name(sc->dev);
176	dunit = device_get_unit(sc->dev);
177	resource_int_value(dname, dunit, "size", &sc->size);
178	resource_int_value(dname, dunit, "type", &sc->type);
179	resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz);
180}
181#endif /* FDT */
182
183static int
184icee_attach(device_t dev)
185{
186	struct icee_softc *sc = device_get_softc(dev);
187
188	sc->dev = dev;
189	sc->addr = iicbus_get_addr(dev);
190	icee_init(sc);
191	if (sc->size == 0 || sc->type == 0 || sc->wr_sz == 0) {
192		device_printf(sc->dev, "Missing config data, "
193		    "these cannot be zero: size %d type %d wr_sz %d\n",
194		    sc->size, sc->type, sc->wr_sz);
195		return (EINVAL);
196	}
197	if (bootverbose)
198		device_printf(dev, "size: %d bytes, addressing: %d-bits\n",
199		    sc->size, sc->type);
200	sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT,
201	    GID_WHEEL, 0600, "icee%d", device_get_unit(dev));
202	if (sc->cdev == NULL) {
203		return (ENOMEM);
204	}
205	sc->cdev->si_drv1 = sc;
206	return (0);
207}
208
209static int
210icee_detach(device_t dev)
211{
212	struct icee_softc *sc = device_get_softc(dev);
213
214	destroy_dev(sc->cdev);
215	return (0);
216}
217
218static int
219icee_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
220{
221	struct icee_softc *sc;
222
223	sc = CDEV2SOFTC(dev);
224	if (device_get_state(sc->dev) < DS_BUSY)
225		device_busy(sc->dev);
226
227	return (0);
228}
229
230static int
231icee_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
232{
233	struct icee_softc *sc;
234
235	sc = CDEV2SOFTC(dev);
236	device_unbusy(sc->dev);
237	return (0);
238}
239
240static int
241icee_read(struct cdev *dev, struct uio *uio, int ioflag)
242{
243	struct icee_softc *sc;
244	uint8_t addr[2];
245	uint8_t data[MAX_RD_SZ];
246	int error, i, len, slave;
247	struct iic_msg msgs[2] = {
248	     { 0, IIC_M_WR, 1, addr },
249	     { 0, IIC_M_RD, 0, data },
250	};
251
252	sc = CDEV2SOFTC(dev);
253	if (uio->uio_offset == sc->size)
254		return (0);
255	if (uio->uio_offset > sc->size)
256		return (EIO);
257	if (sc->type != 8 && sc->type != 16)
258		return (EINVAL);
259	slave = error = 0;
260	while (uio->uio_resid > 0) {
261		if (uio->uio_offset >= sc->size)
262			break;
263		len = MIN(MAX_RD_SZ - (uio->uio_offset & (MAX_RD_SZ - 1)),
264		    uio->uio_resid);
265		switch (sc->type) {
266		case 8:
267			slave = (uio->uio_offset >> 7) | sc->addr;
268			msgs[0].len = 1;
269			msgs[1].len = len;
270			addr[0] = uio->uio_offset & 0xff;
271			break;
272		case 16:
273			slave = sc->addr | (uio->uio_offset >> 15);
274			msgs[0].len = 2;
275			msgs[1].len = len;
276			addr[0] = (uio->uio_offset >> 8) & 0xff;
277			addr[1] = uio->uio_offset & 0xff;
278			break;
279		}
280		for (i = 0; i < 2; i++)
281			msgs[i].slave = slave;
282		error = iicbus_transfer_excl(sc->dev, msgs, 2, IIC_INTRWAIT);
283		if (error) {
284			error = iic2errno(error);
285			break;
286		}
287		error = uiomove(data, len, uio);
288		if (error)
289			break;
290	}
291	return (error);
292}
293
294/*
295 * Write to the part.  We use three transfers here since we're actually
296 * doing a write followed by a read to make sure that the write finished.
297 * It is easier to encode the dummy read here than to break things up
298 * into smaller chunks...
299 */
300static int
301icee_write(struct cdev *dev, struct uio *uio, int ioflag)
302{
303	struct icee_softc *sc;
304	int error, len, slave, waitlimit;
305	uint8_t data[MAX_WR_SZ + 2];
306	struct iic_msg wr[1] = {
307	     { 0, IIC_M_WR, 0, data },
308	};
309	struct iic_msg rd[1] = {
310	     { 0, IIC_M_RD, 1, data },
311	};
312
313	sc = CDEV2SOFTC(dev);
314	if (uio->uio_offset >= sc->size)
315		return (EIO);
316	if (sc->type != 8 && sc->type != 16)
317		return (EINVAL);
318
319	slave = error = 0;
320	while (uio->uio_resid > 0) {
321		if (uio->uio_offset >= sc->size)
322			break;
323		len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)),
324		    uio->uio_resid);
325		switch (sc->type) {
326		case 8:
327			slave = (uio->uio_offset >> 7) | sc->addr;
328			wr[0].len = 1 + len;
329			data[0] = uio->uio_offset & 0xff;
330			break;
331		case 16:
332			slave = sc->addr | (uio->uio_offset >> 15);
333			wr[0].len = 2 + len;
334			data[0] = (uio->uio_offset >> 8) & 0xff;
335			data[1] = uio->uio_offset & 0xff;
336			break;
337		}
338		wr[0].slave = slave;
339		error = uiomove(data + sc->type / 8, len, uio);
340		if (error)
341			break;
342		error = iicbus_transfer_excl(sc->dev, wr, 1, IIC_INTRWAIT);
343		if (error) {
344			error = iic2errno(error);
345			break;
346		}
347		/* Read after write to wait for write-done. */
348		waitlimit = 10000;
349		rd[0].slave = slave;
350		do {
351			error = iicbus_transfer_excl(sc->dev, rd, 1,
352			    IIC_INTRWAIT);
353		} while (waitlimit-- > 0 && error != 0);
354		if (error) {
355			error = iic2errno(error);
356			break;
357		}
358	}
359	return error;
360}
361
362static device_method_t icee_methods[] = {
363	DEVMETHOD(device_probe,		icee_probe),
364	DEVMETHOD(device_attach,	icee_attach),
365	DEVMETHOD(device_detach,	icee_detach),
366
367	DEVMETHOD_END
368};
369
370static driver_t icee_driver = {
371	"icee",
372	icee_methods,
373	sizeof(struct icee_softc),
374};
375static devclass_t icee_devclass;
376
377DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0);
378MODULE_VERSION(icee, 1);
379MODULE_DEPEND(icee, iicbus, 1, 1, 1);
380