New device: icee. Generic i2c eeprom driver.

1 files changed, 291 insertions, 0 deletions

diff --git a/sys/dev/iicbus/icee.c b/sys/dev/iicbus/icee.c
new file mode 100644
index 0000000..6d9d40d
--- /dev/null
+++ b/sys/dev/iicbus/icee.c
@@ -0,0 +1,291 @@
+/*-
+ * 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/mutex.h>
+#include <sys/resource.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 mtx	sc_mtx;		/* basically a perimeter lock */
+	struct cdev	*cdev;		/* user interface */
+	int		addr;
+	int		flags;
+#define	OPENED	1
+	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)		mtx_lock_spin(&(_sc)->sc_mtx)
+#define	ICEE_UNLOCK(_sc)	mtx_unlock_spin(&(_sc)->sc_mtx)
+#define ICEE_LOCK_INIT(_sc) \
+	mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), "icee", MTX_SPIN)
+#define ICEE_LOCK_DESTROY(_sc)	mtx_destroy(&_sc->sc_mtx);
+#define ICEE_ASSERT_LOCKED(_sc)	mtx_assert(&_sc->sc_mtx, MA_OWNED);
+#define ICEE_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_NOTOWNED);
+#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_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 (0);
+}
+
+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;
+	iicbus_get_addr(dev, &sc->addr);
+	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)
+{
+	struct icee_softc *sc;
+
+	sc = CDEV2SOFTC(dev);
+	ICEE_LOCK(sc);
+	if (!(sc->flags & OPENED)) {
+		sc->flags |= OPENED;
+	}
+	ICEE_UNLOCK(sc);
+    	return (0);
+}
+
+static int
+icee_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
+{
+	struct icee_softc *sc;
+
+	sc = CDEV2SOFTC(dev);
+	ICEE_LOCK(sc);
+	sc->flags &= ~OPENED;
+	ICEE_UNLOCK(sc);
+	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);