Current Path : /sys/arm/at91/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/arm/at91/at91_twi.c |
/*- * Copyright (c) 2006 M. 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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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: release/9.1.0/sys/arm/at91/at91_twi.c 237093 2012-06-14 20:02:53Z marius $"); #include <sys/param.h> #include <sys/systm.h> #include <sys/bus.h> #include <sys/conf.h> #include <sys/kernel.h> #include <sys/lock.h> #include <sys/mbuf.h> #include <sys/malloc.h> #include <sys/module.h> #include <sys/mutex.h> #include <sys/rman.h> #include <machine/bus.h> #include <arm/at91/at91_twireg.h> #include <arm/at91/at91var.h> #include <dev/iicbus/iiconf.h> #include <dev/iicbus/iicbus.h> #include "iicbus_if.h" #define TWI_SLOW_CLOCK 1500 #define TWI_FAST_CLOCK 45000 #define TWI_FASTEST_CLOCK 90000 struct at91_twi_softc { device_t dev; /* Myself */ void *intrhand; /* Interrupt handle */ struct resource *irq_res; /* IRQ resource */ struct resource *mem_res; /* Memory resource */ struct mtx sc_mtx; /* basically a perimeter lock */ volatile uint32_t flags; uint32_t cwgr; int sc_started; int twi_addr; device_t iicbus; }; static inline uint32_t RD4(struct at91_twi_softc *sc, bus_size_t off) { return bus_read_4(sc->mem_res, off); } static inline void WR4(struct at91_twi_softc *sc, bus_size_t off, uint32_t val) { bus_write_4(sc->mem_res, off, val); } #define AT91_TWI_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx) #define AT91_TWI_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx) #define AT91_TWI_LOCK_INIT(_sc) \ mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->dev), \ "twi", MTX_DEF) #define AT91_TWI_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx); #define AT91_TWI_ASSERT_LOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_OWNED); #define AT91_TWI_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_NOTOWNED); #define TWI_DEF_CLK 100000 static devclass_t at91_twi_devclass; /* bus entry points */ static int at91_twi_probe(device_t dev); static int at91_twi_attach(device_t dev); static int at91_twi_detach(device_t dev); static void at91_twi_intr(void *); /* helper routines */ static int at91_twi_activate(device_t dev); static void at91_twi_deactivate(device_t dev); static int at91_twi_probe(device_t dev) { device_set_desc(dev, "TWI"); return (0); } static int at91_twi_attach(device_t dev) { struct at91_twi_softc *sc = device_get_softc(dev); int err; sc->dev = dev; err = at91_twi_activate(dev); if (err) goto out; AT91_TWI_LOCK_INIT(sc); /* * Activate the interrupt */ err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE, NULL, at91_twi_intr, sc, &sc->intrhand); if (err) { AT91_TWI_LOCK_DESTROY(sc); goto out; } sc->cwgr = TWI_CWGR_CKDIV(8 * at91_master_clock / TWI_FASTEST_CLOCK) | TWI_CWGR_CHDIV(TWI_CWGR_DIV(TWI_DEF_CLK)) | TWI_CWGR_CLDIV(TWI_CWGR_DIV(TWI_DEF_CLK)); WR4(sc, TWI_CR, TWI_CR_SWRST); WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS); WR4(sc, TWI_CWGR, sc->cwgr); if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) device_printf(dev, "could not allocate iicbus instance\n"); /* probe and attach the iicbus */ bus_generic_attach(dev); out: if (err) at91_twi_deactivate(dev); return (err); } static int at91_twi_detach(device_t dev) { struct at91_twi_softc *sc; int rv; sc = device_get_softc(dev); at91_twi_deactivate(dev); if (sc->iicbus && (rv = device_delete_child(dev, sc->iicbus)) != 0) return (rv); AT91_TWI_LOCK_DESTROY(sc); return (0); } static int at91_twi_activate(device_t dev) { struct at91_twi_softc *sc; int rid; sc = device_get_softc(dev); rid = 0; sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); if (sc->mem_res == NULL) goto errout; rid = 0; sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE); if (sc->irq_res == NULL) goto errout; return (0); errout: at91_twi_deactivate(dev); return (ENOMEM); } static void at91_twi_deactivate(device_t dev) { struct at91_twi_softc *sc; sc = device_get_softc(dev); if (sc->intrhand) bus_teardown_intr(dev, sc->irq_res, sc->intrhand); sc->intrhand = 0; bus_generic_detach(sc->dev); if (sc->mem_res) bus_release_resource(dev, SYS_RES_MEMORY, rman_get_rid(sc->mem_res), sc->mem_res); sc->mem_res = 0; if (sc->irq_res) bus_release_resource(dev, SYS_RES_IRQ, rman_get_rid(sc->irq_res), sc->irq_res); sc->irq_res = 0; return; } static void at91_twi_intr(void *xsc) { struct at91_twi_softc *sc = xsc; uint32_t status; status = RD4(sc, TWI_SR); if (status == 0) return; AT91_TWI_LOCK(sc); sc->flags |= status & (TWI_SR_OVRE | TWI_SR_UNRE | TWI_SR_NACK); if (status & TWI_SR_RXRDY) sc->flags |= TWI_SR_RXRDY; if (status & TWI_SR_TXRDY) sc->flags |= TWI_SR_TXRDY; if (status & TWI_SR_TXCOMP) sc->flags |= TWI_SR_TXCOMP; WR4(sc, TWI_IDR, status); wakeup(sc); AT91_TWI_UNLOCK(sc); return; } static int at91_twi_wait(struct at91_twi_softc *sc, uint32_t bit) { int err = 0; int counter = 100000; uint32_t sr; AT91_TWI_ASSERT_LOCKED(sc); while (!((sr = RD4(sc, TWI_SR)) & bit) && counter-- > 0 && !(sr & TWI_SR_NACK)) continue; if (counter <= 0) err = EBUSY; else if (sr & TWI_SR_NACK) err = ENXIO; // iic nack convention return (err); } static int at91_twi_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr) { struct at91_twi_softc *sc; int clk; sc = device_get_softc(dev); AT91_TWI_LOCK(sc); if (oldaddr) *oldaddr = sc->twi_addr; sc->twi_addr = addr; /* * speeds are for 1.5kb/s, 45kb/s and 90kb/s. */ switch (speed) { case IIC_SLOW: clk = TWI_SLOW_CLOCK; break; case IIC_FAST: clk = TWI_FAST_CLOCK; break; case IIC_UNKNOWN: case IIC_FASTEST: default: clk = TWI_FASTEST_CLOCK; break; } sc->cwgr = TWI_CWGR_CKDIV(1) | TWI_CWGR_CHDIV(TWI_CWGR_DIV(clk)) | TWI_CWGR_CLDIV(TWI_CWGR_DIV(clk)); WR4(sc, TWI_CR, TWI_CR_SWRST); WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS); WR4(sc, TWI_CWGR, sc->cwgr); printf("setting cwgr to %#x\n", sc->cwgr); AT91_TWI_UNLOCK(sc); return 0; } static int at91_twi_callback(device_t dev, int index, caddr_t data) { int error = 0; switch (index) { case IIC_REQUEST_BUS: break; case IIC_RELEASE_BUS: break; default: error = EINVAL; } return (error); } static int at91_twi_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs) { struct at91_twi_softc *sc; int i, len, err; uint32_t rdwr; uint8_t *buf; uint32_t sr; sc = device_get_softc(dev); err = 0; AT91_TWI_LOCK(sc); for (i = 0; i < nmsgs; i++) { /* * The linux atmel driver doesn't use the internal device * address feature of twi. A separate i2c message needs to * be written to use this. * See http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2004-September/024411.html * for details. Upon reflection, we could use this as an * optimization, but it is unclear the code bloat will * result in faster/better operations. */ rdwr = (msgs[i].flags & IIC_M_RD) ? TWI_MMR_MREAD : 0; WR4(sc, TWI_MMR, TWI_MMR_DADR(msgs[i].slave) | rdwr); len = msgs[i].len; buf = msgs[i].buf; /* zero byte transfers aren't allowed */ if (len == 0 || buf == NULL) { err = EINVAL; goto out; } if (len == 1 && msgs[i].flags & IIC_M_RD) WR4(sc, TWI_CR, TWI_CR_START | TWI_CR_STOP); else WR4(sc, TWI_CR, TWI_CR_START); if (msgs[i].flags & IIC_M_RD) { sr = RD4(sc, TWI_SR); while (!(sr & TWI_SR_TXCOMP)) { if ((sr = RD4(sc, TWI_SR)) & TWI_SR_RXRDY) { len--; *buf++ = RD4(sc, TWI_RHR) & 0xff; if (len == 1) WR4(sc, TWI_CR, TWI_CR_STOP); } } if (len > 0 || (sr & TWI_SR_NACK)) { err = ENXIO; // iic nack convention goto out; } } else { while (len--) { if ((err = at91_twi_wait(sc, TWI_SR_TXRDY))) goto out; WR4(sc, TWI_THR, *buf++); } WR4(sc, TWI_CR, TWI_CR_STOP); } if ((err = at91_twi_wait(sc, TWI_SR_TXCOMP))) break; } out: if (err) { WR4(sc, TWI_CR, TWI_CR_SWRST); WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS); WR4(sc, TWI_CWGR, sc->cwgr); } AT91_TWI_UNLOCK(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), /* iicbus interface */ DEVMETHOD(iicbus_callback, at91_twi_callback), DEVMETHOD(iicbus_reset, at91_twi_rst_card), DEVMETHOD(iicbus_transfer, at91_twi_transfer), DEVMETHOD_END }; 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, NULL, NULL); DRIVER_MODULE(iicbus, at91_twi, iicbus_driver, iicbus_devclass, NULL, NULL); MODULE_DEPEND(at91_twi, iicbus, 1, 1, 1);