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author | imp <imp@FreeBSD.org> | 2007-03-23 23:10:35 +0000 |
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committer | imp <imp@FreeBSD.org> | 2007-03-23 23:10:35 +0000 |
commit | 8c61b1c8ef52085026e7535536ce18cb69a98af0 (patch) | |
tree | eed15e06ce698b512541a5c1a95d48dedcfe07e2 /sys/dev | |
parent | 88cdc2595dd63fcb79c3d9b0ed4b9f0481772e8f (diff) | |
download | FreeBSD-src-8c61b1c8ef52085026e7535536ce18cb69a98af0.zip FreeBSD-src-8c61b1c8ef52085026e7535536ce18cb69a98af0.tar.gz |
New device: icee. Generic i2c eeprom driver.
Diffstat (limited to 'sys/dev')
-rw-r--r-- | sys/dev/iicbus/icee.c | 291 |
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); |