summaryrefslogtreecommitdiffstats
path: root/sys/dev/iicbus/icee.c
blob: 93c03ad3bbb0b22349de2b14782f9a3b1a7e45ae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
/*-
 * Copyright (c) 2006 Warner Losh.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
 * Generic IIC eeprom support, modeled after the AT24C family of products.
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/resource.h>
#include <sys/sx.h>
#include <sys/uio.h>
#include <machine/bus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>

#include "iicbus_if.h"

#define	IIC_M_WR	0	/* write operation */
#define	MAX_RD_SZ	256	/* Largest read size we support */
#define MAX_WR_SZ	256	/* Largest write size we support */

struct icee_softc {
	device_t	sc_dev;		/* Myself */
	struct sx	sc_lock;	/* basically a perimeter lock */
	struct cdev	*cdev;		/* user interface */
	int		addr;
	int		size;		/* How big am I? */
	int		type;		/* What type 8 or 16 bit? */
	int		rd_sz;		/* What's the read page size */
	int		wr_sz;		/* What's the write page size */
};

#define ICEE_LOCK(_sc)		sx_xlock(&(_sc)->sc_lock)
#define	ICEE_UNLOCK(_sc)	sx_xunlock(&(_sc)->sc_lock)
#define ICEE_LOCK_INIT(_sc)	sx_init(&_sc->sc_lock, "icee")
#define ICEE_LOCK_DESTROY(_sc)	sx_destroy(&_sc->sc_lock);
#define ICEE_ASSERT_LOCKED(_sc)	sx_assert(&_sc->sc_lock, SA_XLOCKED);
#define ICEE_ASSERT_UNLOCKED(_sc) sx_assert(&_sc->sc_lock, SA_UNLOCKED);
#define CDEV2SOFTC(dev)		((dev)->si_drv1)

/* cdev routines */
static d_open_t icee_open;
static d_close_t icee_close;
static d_read_t icee_read;
static d_write_t icee_write;

static struct cdevsw icee_cdevsw =
{
	.d_version = D_VERSION,
	.d_flags = D_TRACKCLOSE,
	.d_open = icee_open,
	.d_close = icee_close,
	.d_read = icee_read,
	.d_write = icee_write
};

static int
icee_probe(device_t dev)
{
	/* XXX really probe? -- not until we know the size... */
	device_set_desc(dev, "I2C EEPROM");
	return (BUS_PROBE_NOWILDCARD);
}

static int
icee_attach(device_t dev)
{
	struct icee_softc *sc = device_get_softc(dev);
	const char *dname;
	int dunit, err;

	sc->sc_dev = dev;
	sc->addr = iicbus_get_addr(dev);
	err = 0;
	dname = device_get_name(dev);
	dunit = device_get_unit(dev);
	resource_int_value(dname, dunit, "size", &sc->size);
	resource_int_value(dname, dunit, "type", &sc->type);
	resource_int_value(dname, dunit, "rd_sz", &sc->rd_sz);
	if (sc->rd_sz > MAX_RD_SZ)
		sc->rd_sz = MAX_RD_SZ;
	resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz);
	if (bootverbose)
		device_printf(dev, "size: %d bytes bus_width: %d-bits\n",
		    sc->size, sc->type);
	sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT,
	    GID_WHEEL, 0600, "icee%d", device_get_unit(dev));
	if (sc->cdev == NULL) {
		err = ENOMEM;
		goto out;
	}
	sc->cdev->si_drv1 = sc;
	ICEE_LOCK_INIT(sc);
out:;
	return (err);
}

static int 
icee_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{

    	return (0);
}

static int
icee_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
{

	return (0);
}

static int
icee_read(struct cdev *dev, struct uio *uio, int ioflag)
{
	struct icee_softc *sc;
	uint8_t addr[2];
	uint8_t data[MAX_RD_SZ];
	int error, i, len, slave;
	struct iic_msg msgs[2] = {
	     { 0, IIC_M_WR, 1, addr },
	     { 0, IIC_M_RD, 0, data },
	};

	sc = CDEV2SOFTC(dev);
	if (uio->uio_offset == sc->size)
		return (0);
	if (uio->uio_offset > sc->size)
		return (EIO);
	if (sc->type != 8 && sc->type != 16)
		return (EINVAL);
	ICEE_LOCK(sc);
	slave = error = 0;
	while (uio->uio_resid > 0) {
		if (uio->uio_offset >= sc->size)
			break;
		len = MIN(sc->rd_sz - (uio->uio_offset & (sc->rd_sz - 1)),
		    uio->uio_resid);
		switch (sc->type) {
		case 8:
			slave = (uio->uio_offset >> 7) | sc->addr;
			msgs[0].len = 1;
			msgs[1].len = len;
			addr[0] = uio->uio_offset & 0xff;
			break;
		case 16:
			slave = sc->addr | (uio->uio_offset >> 15);
			msgs[0].len = 2;
			msgs[1].len = len;
			addr[0] = (uio->uio_offset >> 8) & 0xff;
			addr[1] = uio->uio_offset & 0xff;
			break;
		}
		for (i = 0; i < 2; i++)
			msgs[i].slave = slave;
		error = iicbus_transfer(sc->sc_dev, msgs, 2);
		if (error)
			break;
		error = uiomove(data, len, uio);
		if (error)
			break;
	}
	ICEE_UNLOCK(sc);
	return (error);
}

/*
 * Write to the part.  We use three transfers here since we're actually
 * doing a write followed by a read to make sure that the write finished.
 * It is easier to encode the dummy read here than to break things up
 * into smaller chunks...
 */
static int
icee_write(struct cdev *dev, struct uio *uio, int ioflag)
{
	struct icee_softc *sc;
	int error, len, slave, waitlimit;
	uint8_t data[MAX_WR_SZ + 2];
	struct iic_msg wr[1] = {
	     { 0, IIC_M_WR, 0, data },
	};
	struct iic_msg rd[1] = {
	     { 0, IIC_M_RD, 1, data },
	};

	sc = CDEV2SOFTC(dev);
	if (uio->uio_offset >= sc->size)
		return (EIO);
	if (sc->type != 8 && sc->type != 16)
		return (EINVAL);
	ICEE_LOCK(sc);
	slave = error = 0;
	while (uio->uio_resid > 0) {
		if (uio->uio_offset >= sc->size)
			break;
		len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)),
		    uio->uio_resid);
		switch (sc->type) {
		case 8:
			slave = (uio->uio_offset >> 7) | sc->addr;
			wr[0].len = 1 + len;
			data[0] = uio->uio_offset & 0xff;
			break;
		case 16:
			slave = sc->addr | (uio->uio_offset >> 15);
			wr[0].len = 2 + len;
			data[0] = (uio->uio_offset >> 8) & 0xff;
			data[1] = uio->uio_offset & 0xff;
			break;
		}
		wr[0].slave = slave;
		error = uiomove(data + sc->type / 8, len, uio);
		if (error)
			break;
		error = iicbus_transfer(sc->sc_dev, wr, 1);
		if (error)
			break;
		// Now wait for the write to be done by trying to read
		// the part.
		waitlimit = 10000;
		rd[0].slave = slave;
		do 
		{
		    error = iicbus_transfer(sc->sc_dev, rd, 1);
		} while (waitlimit-- > 0 && error != 0);
		if (error) {
		    printf("waiting for write failed %d\n", error);
		    break;
		}
	}
	ICEE_UNLOCK(sc);
	return error;
}

static device_method_t icee_methods[] = {
	DEVMETHOD(device_probe,		icee_probe),
	DEVMETHOD(device_attach,	icee_attach),

	{0, 0},
};

static driver_t icee_driver = {
	"icee",
	icee_methods,
	sizeof(struct icee_softc),
};
static devclass_t icee_devclass;

DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0);
MODULE_VERSION(icee, 1);
MODULE_DEPEND(icee, iicbus, 1, 1, 1);
OpenPOWER on IntegriCloud