435 lines
10 KiB
C
435 lines
10 KiB
C
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/*-
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* Copyright (c) 2006 M. Warner Losh. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/bus.h>
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#include <sys/conf.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mbuf.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/mutex.h>
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#include <sys/rman.h>
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#include <machine/bus.h>
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#include <arm/at91/at91rm92reg.h>
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#include <arm/at91/at91_twireg.h>
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#include <arm/at91/at91_twiio.h>
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struct at91_twi_softc
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{
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device_t dev; /* Myself */
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void *intrhand; /* Interrupt handle */
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struct resource *irq_res; /* IRQ resource */
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struct resource *mem_res; /* Memory resource */
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struct mtx sc_mtx; /* basically a perimeter lock */
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int flags;
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#define XFER_PENDING 1 /* true when transfer taking place */
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#define OPENED 2 /* Device opened */
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#define RXRDY 4
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#define TXCOMP 8
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#define TXRDY 0x10
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struct cdev *cdev;
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uint32_t cwgr;
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};
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static inline uint32_t
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RD4(struct at91_twi_softc *sc, bus_size_t off)
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{
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return bus_read_4(sc->mem_res, off);
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}
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static inline void
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WR4(struct at91_twi_softc *sc, bus_size_t off, uint32_t val)
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{
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bus_write_4(sc->mem_res, off, val);
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}
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#define AT91_TWI_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx)
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#define AT91_TWI_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx)
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#define AT91_TWI_LOCK_INIT(_sc) \
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mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->dev), \
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"twi", MTX_DEF)
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#define AT91_TWI_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx);
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#define AT91_TWI_ASSERT_LOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_OWNED);
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#define AT91_TWI_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_NOTOWNED);
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#define CDEV2SOFTC(dev) ((dev)->si_drv1)
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#define TWI_DEF_CLK 100000
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static devclass_t at91_twi_devclass;
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/* bus entry points */
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static int at91_twi_probe(device_t dev);
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static int at91_twi_attach(device_t dev);
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static int at91_twi_detach(device_t dev);
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static void at91_twi_intr(void *);
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/* helper routines */
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static int at91_twi_activate(device_t dev);
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static void at91_twi_deactivate(device_t dev);
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/* cdev routines */
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static d_open_t at91_twi_open;
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static d_close_t at91_twi_close;
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static d_ioctl_t at91_twi_ioctl;
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static struct cdevsw at91_twi_cdevsw =
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{
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.d_version = D_VERSION,
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.d_open = at91_twi_open,
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.d_close = at91_twi_close,
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.d_ioctl = at91_twi_ioctl
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};
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static int
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at91_twi_probe(device_t dev)
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{
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device_set_desc(dev, "TWI");
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return (0);
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}
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static int
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at91_twi_attach(device_t dev)
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{
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struct at91_twi_softc *sc = device_get_softc(dev);
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int err;
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sc->dev = dev;
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err = at91_twi_activate(dev);
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if (err)
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goto out;
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AT91_TWI_LOCK_INIT(sc);
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/*
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* Activate the interrupt
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*/
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err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
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at91_twi_intr, sc, &sc->intrhand);
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if (err) {
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AT91_TWI_LOCK_DESTROY(sc);
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goto out;
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}
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sc->cdev = make_dev(&at91_twi_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
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"twi%d", device_get_unit(dev));
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if (sc->cdev == NULL) {
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err = ENOMEM;
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goto out;
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}
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sc->cdev->si_drv1 = sc;
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sc->cwgr = TWI_CWGR_CKDIV(1) |
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TWI_CWGR_CHDIV(TWI_CWGR_DIV(TWI_DEF_CLK)) |
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TWI_CWGR_CLDIV(TWI_CWGR_DIV(TWI_DEF_CLK));
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WR4(sc, TWI_CR, TWI_CR_SWRST);
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WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS);
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WR4(sc, TWI_CWGR, sc->cwgr);
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out:;
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if (err)
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at91_twi_deactivate(dev);
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return (err);
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}
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static int
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at91_twi_detach(device_t dev)
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{
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return (EBUSY); /* XXX */
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}
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static int
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at91_twi_activate(device_t dev)
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{
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struct at91_twi_softc *sc;
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int rid;
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sc = device_get_softc(dev);
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rid = 0;
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sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
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RF_ACTIVE);
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if (sc->mem_res == NULL)
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goto errout;
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rid = 0;
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sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
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RF_ACTIVE);
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if (sc->mem_res == NULL)
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goto errout;
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return (0);
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errout:
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at91_twi_deactivate(dev);
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return (ENOMEM);
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}
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static void
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at91_twi_deactivate(device_t dev)
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{
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struct at91_twi_softc *sc;
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sc = device_get_softc(dev);
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if (sc->intrhand)
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bus_teardown_intr(dev, sc->irq_res, sc->intrhand);
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sc->intrhand = 0;
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bus_generic_detach(sc->dev);
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if (sc->mem_res)
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bus_release_resource(dev, SYS_RES_IOPORT,
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rman_get_rid(sc->mem_res), sc->mem_res);
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sc->mem_res = 0;
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if (sc->irq_res)
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bus_release_resource(dev, SYS_RES_IRQ,
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rman_get_rid(sc->irq_res), sc->irq_res);
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sc->irq_res = 0;
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return;
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}
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static void
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at91_twi_intr(void *xsc)
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{
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struct at91_twi_softc *sc = xsc;
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uint32_t status;
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/* Reading the status also clears the interrupt */
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status = RD4(sc, TWI_SR);
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if (status == 0)
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return;
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AT91_TWI_LOCK(sc);
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if (status & TWI_SR_RXRDY)
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sc->flags |= RXRDY;
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if (status & TWI_SR_TXCOMP)
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sc->flags |= TXCOMP;
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if (status & TWI_SR_TXRDY)
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sc->flags |= TXRDY;
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AT91_TWI_UNLOCK(sc);
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wakeup(sc);
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return;
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}
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static int
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at91_twi_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
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{
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struct at91_twi_softc *sc;
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sc = CDEV2SOFTC(dev);
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AT91_TWI_LOCK(sc);
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if (!(sc->flags & OPENED)) {
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sc->flags |= OPENED;
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WR4(sc, TWI_IER, TWI_SR_TXCOMP | TWI_SR_RXRDY | TWI_SR_TXRDY |
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TWI_SR_OVRE | TWI_SR_UNRE | TWI_SR_NACK);
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}
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AT91_TWI_UNLOCK(sc);
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return (0);
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}
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static int
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at91_twi_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
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{
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struct at91_twi_softc *sc;
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sc = CDEV2SOFTC(dev);
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AT91_TWI_LOCK(sc);
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sc->flags &= ~OPENED;
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WR4(sc, TWI_IDR, TWI_SR_TXCOMP | TWI_SR_RXRDY | TWI_SR_TXRDY |
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TWI_SR_OVRE | TWI_SR_UNRE | TWI_SR_NACK);
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AT91_TWI_UNLOCK(sc);
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return (0);
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}
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static int
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at91_twi_read_master(struct at91_twi_softc *sc, struct at91_twi_io *xfr)
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{
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uint8_t *walker;
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uint8_t buffer[256];
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size_t len;
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int err = 0;
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if (xfr->xfer_len > sizeof(buffer))
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return (EINVAL);
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walker = buffer;
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len = xfr->xfer_len;
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RD4(sc, TWI_RHR);
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// Master mode, with the right address and interal addr size
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WR4(sc, TWI_MMR, TWI_MMR_IADRSZ(xfr->iadrsz) | TWI_MMR_MREAD |
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TWI_MMR_DADR(xfr->dadr));
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WR4(sc, TWI_IADR, xfr->iadr);
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WR4(sc, TWI_CR, TWI_CR_START);
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while (len-- > 1) {
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while (!(sc->flags & RXRDY)) {
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err = msleep(sc, &sc->sc_mtx, PZERO | PCATCH, "twird",
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0);
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if (err)
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return (err);
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}
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sc->flags &= ~RXRDY;
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*walker++ = RD4(sc, TWI_RHR) & 0xff;
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}
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WR4(sc, TWI_CR, TWI_CR_STOP);
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while (!(sc->flags & TXCOMP)) {
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err = msleep(sc, &sc->sc_mtx, PZERO | PCATCH, "twird2", 0);
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if (err)
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return (err);
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}
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sc->flags &= ~TXCOMP;
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*walker = RD4(sc, TWI_RHR) & 0xff;
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if (xfr->xfer_buf) {
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AT91_TWI_UNLOCK(sc);
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err = copyout(buffer, xfr->xfer_buf, xfr->xfer_len);
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AT91_TWI_LOCK(sc);
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}
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return (err);
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}
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static int
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at91_twi_write_master(struct at91_twi_softc *sc, struct at91_twi_io *xfr)
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{
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uint8_t *walker;
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uint8_t buffer[256];
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size_t len;
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int err;
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if (xfr->xfer_len > sizeof(buffer))
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return (EINVAL);
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walker = buffer;
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len = xfr->xfer_len;
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AT91_TWI_UNLOCK(sc);
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err = copyin(xfr->xfer_buf, buffer, xfr->xfer_len);
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AT91_TWI_LOCK(sc);
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if (err)
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return (err);
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/* Setup the xfr for later readback */
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xfr->xfer_buf = 0;
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xfr->xfer_len = 1;
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while (len--) {
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WR4(sc, TWI_MMR, TWI_MMR_IADRSZ(xfr->iadrsz) | TWI_MMR_MWRITE |
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TWI_MMR_DADR(xfr->dadr));
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WR4(sc, TWI_IADR, xfr->iadr++);
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WR4(sc, TWI_THR, *walker++);
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WR4(sc, TWI_CR, TWI_CR_START);
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/*
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* If we get signal while waiting for TXRDY, make sure we
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* try to stop this device
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*/
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while (!(sc->flags & TXRDY)) {
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err = msleep(sc, &sc->sc_mtx, PZERO | PCATCH, "twiwr",
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0);
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if (err)
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break;
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}
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WR4(sc, TWI_CR, TWI_CR_STOP);
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if (err)
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return (err);
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while (!(sc->flags & TXCOMP)) {
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err = msleep(sc, &sc->sc_mtx, PZERO | PCATCH, "twiwr2",
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0);
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if (err)
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return (err);
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}
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/* Readback */
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at91_twi_read_master(sc, xfr);
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|
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}
|
||
|
|
return (err);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int
|
||
|
|
at91_twi_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
|
||
|
|
struct thread *td)
|
||
|
|
{
|
||
|
|
int err = 0;
|
||
|
|
struct at91_twi_softc *sc;
|
||
|
|
|
||
|
|
sc = CDEV2SOFTC(dev);
|
||
|
|
AT91_TWI_LOCK(sc);
|
||
|
|
while (sc->flags & XFER_PENDING) {
|
||
|
|
err = msleep(sc, &sc->sc_mtx, PZERO | PCATCH,
|
||
|
|
"twiwait", 0);
|
||
|
|
if (err) {
|
||
|
|
AT91_TWI_UNLOCK(sc);
|
||
|
|
return (err);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
sc->flags |= XFER_PENDING;
|
||
|
|
|
||
|
|
switch (cmd)
|
||
|
|
{
|
||
|
|
case TWIIOCXFER:
|
||
|
|
{
|
||
|
|
struct at91_twi_io *xfr = (struct at91_twi_io *)data;
|
||
|
|
switch (xfr->type)
|
||
|
|
{
|
||
|
|
case TWI_IO_READ_MASTER:
|
||
|
|
err = at91_twi_read_master(sc, xfr);
|
||
|
|
break;
|
||
|
|
case TWI_IO_WRITE_MASTER:
|
||
|
|
err = at91_twi_write_master(sc, xfr);
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
err = EINVAL;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
case TWIIOCSETCLOCK:
|
||
|
|
{
|
||
|
|
struct at91_twi_clock *twick = (struct at91_twi_clock *)data;
|
||
|
|
|
||
|
|
sc->cwgr = TWI_CWGR_CKDIV(twick->ckdiv) |
|
||
|
|
TWI_CWGR_CHDIV(TWI_CWGR_DIV(twick->high_rate)) |
|
||
|
|
TWI_CWGR_CLDIV(TWI_CWGR_DIV(twick->low_rate));
|
||
|
|
WR4(sc, TWI_CR, TWI_CR_SWRST);
|
||
|
|
WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS);
|
||
|
|
WR4(sc, TWI_CWGR, sc->cwgr);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
default:
|
||
|
|
err = ENOTTY;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
sc->flags &= ~XFER_PENDING;
|
||
|
|
AT91_TWI_UNLOCK(sc);
|
||
|
|
wakeup(sc);
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
static device_method_t at91_twi_methods[] = {
|
||
|
|
/* Device interface */
|
||
|
|
DEVMETHOD(device_probe, at91_twi_probe),
|
||
|
|
DEVMETHOD(device_attach, at91_twi_attach),
|
||
|
|
DEVMETHOD(device_detach, at91_twi_detach),
|
||
|
|
|
||
|
|
{ 0, 0 }
|
||
|
|
};
|
||
|
|
|
||
|
|
static driver_t at91_twi_driver = {
|
||
|
|
"at91_twi",
|
||
|
|
at91_twi_methods,
|
||
|
|
sizeof(struct at91_twi_softc),
|
||
|
|
};
|
||
|
|
|
||
|
|
DRIVER_MODULE(at91_twi, atmelarm, at91_twi_driver, at91_twi_devclass, 0, 0);
|