Index: head/sys/arm/broadcom/bcm2835/bcm2835_bsc.c =================================================================== --- head/sys/arm/broadcom/bcm2835/bcm2835_bsc.c (revision 326924) +++ head/sys/arm/broadcom/bcm2835/bcm2835_bsc.c (revision 326925) @@ -1,753 +1,753 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2001 Tsubai Masanari. * Copyright (c) 2012 Oleksandr Tymoshenko * Copyright (c) 2013 Luiz Otavio O Souza * Copyright (c) 2017 Ian Lepore * 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 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 THE 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 __FBSDID("$FreeBSD$"); /* * Driver for bcm2835 i2c-compatible two-wire bus, named 'BSC' on this SoC. * * This controller can only perform complete transfers, it does not provide * low-level control over sending start/repeat-start/stop sequences on the bus. * In addition, bugs in the silicon make it somewhat difficult to perform a * repeat-start, and limit the repeat-start to a read following a write on * the same slave device. (The i2c protocol allows a repeat start to change * direction or not, and change slave address or not at any time.) * * The repeat-start bug and workaround are described in a problem report at * https://github.com/raspberrypi/linux/issues/254 with the crucial part being * in a comment block from a fragment of a GPU i2c driver, containing this: * * ----------------------------------------------------------------------------- * - See i2c.v: The I2C peripheral samples the values for rw_bit and xfer_count * - in the IDLE state if start is set. * - * - We want to generate a ReSTART not a STOP at the end of the TX phase. In * - order to do that we must ensure the state machine goes RACK1 -> RACK2 -> * - SRSTRT1 (not RACK1 -> RACK2 -> SSTOP1). * - * - So, in the RACK2 state when (TX) xfer_count==0 we must therefore have * - already set, ready to be sampled: * - READ ; rw_bit <= I2CC bit 0 -- must be "read" * - ST; start <= I2CC bit 7 -- must be "Go" in order to not issue STOP * - DLEN; xfer_count <= I2CDLEN -- must be equal to our read amount * - * - The plan to do this is: * - 1. Start the sub-address write, but don't let it finish * - (keep xfer_count > 0) * - 2. Populate READ, DLEN and ST in preparation for ReSTART read sequence * - 3. Let TX finish (write the rest of the data) * - 4. Read back data as it arrives * ----------------------------------------------------------------------------- * * The transfer function below scans the list of messages passed to it, looking * for a read following a write to the same slave. When it finds that, it * starts the write without prefilling the tx fifo, which holds xfer_count>0, * then presets the direction, length, and start command for the following read, * as described above. Then the tx fifo is filled and the rest of the transfer * proceeds as normal, with the controller automatically supplying a * repeat-start on the bus when the write operation finishes. * * XXX I suspect the controller may be able to do a repeat-start on any * write->read or write->write transition, even when the slave addresses differ. * It's unclear whether the slave address can be prestaged along with the * direction and length while the write xfer_count is being held at zero. In * fact, if it can't do this, then it couldn't be used to read EDID data. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "iicbus_if.h" static struct ofw_compat_data compat_data[] = { {"broadcom,bcm2835-bsc", 1}, {"brcm,bcm2708-i2c", 1}, {"brcm,bcm2835-i2c", 1}, {NULL, 0} }; #define DEVICE_DEBUGF(sc, lvl, fmt, args...) \ if ((lvl) <= (sc)->sc_debug) \ device_printf((sc)->sc_dev, fmt, ##args) #define DEBUGF(sc, lvl, fmt, args...) \ if ((lvl) <= (sc)->sc_debug) \ printf(fmt, ##args) static void bcm_bsc_intr(void *); static int bcm_bsc_detach(device_t); static void bcm_bsc_modifyreg(struct bcm_bsc_softc *sc, uint32_t off, uint32_t mask, uint32_t value) { uint32_t reg; mtx_assert(&sc->sc_mtx, MA_OWNED); reg = BCM_BSC_READ(sc, off); reg &= ~mask; reg |= value; BCM_BSC_WRITE(sc, off, reg); } static int bcm_bsc_clock_proc(SYSCTL_HANDLER_ARGS) { struct bcm_bsc_softc *sc; uint32_t clk; sc = (struct bcm_bsc_softc *)arg1; BCM_BSC_LOCK(sc); clk = BCM_BSC_READ(sc, BCM_BSC_CLOCK); BCM_BSC_UNLOCK(sc); clk &= 0xffff; if (clk == 0) clk = 32768; clk = BCM_BSC_CORE_CLK / clk; return (sysctl_handle_int(oidp, &clk, 0, req)); } static int bcm_bsc_clkt_proc(SYSCTL_HANDLER_ARGS) { struct bcm_bsc_softc *sc; uint32_t clkt; int error; sc = (struct bcm_bsc_softc *)arg1; BCM_BSC_LOCK(sc); clkt = BCM_BSC_READ(sc, BCM_BSC_CLKT); BCM_BSC_UNLOCK(sc); clkt &= 0xffff; error = sysctl_handle_int(oidp, &clkt, sizeof(clkt), req); if (error != 0 || req->newptr == NULL) return (error); BCM_BSC_LOCK(sc); BCM_BSC_WRITE(sc, BCM_BSC_CLKT, clkt & 0xffff); BCM_BSC_UNLOCK(sc); return (0); } static int bcm_bsc_fall_proc(SYSCTL_HANDLER_ARGS) { struct bcm_bsc_softc *sc; uint32_t clk, reg; int error; sc = (struct bcm_bsc_softc *)arg1; BCM_BSC_LOCK(sc); reg = BCM_BSC_READ(sc, BCM_BSC_DELAY); BCM_BSC_UNLOCK(sc); reg >>= 16; error = sysctl_handle_int(oidp, ®, sizeof(reg), req); if (error != 0 || req->newptr == NULL) return (error); BCM_BSC_LOCK(sc); clk = BCM_BSC_READ(sc, BCM_BSC_CLOCK); clk = BCM_BSC_CORE_CLK / clk; if (reg > clk / 2) reg = clk / 2 - 1; bcm_bsc_modifyreg(sc, BCM_BSC_DELAY, 0xffff0000, reg << 16); BCM_BSC_UNLOCK(sc); return (0); } static int bcm_bsc_rise_proc(SYSCTL_HANDLER_ARGS) { struct bcm_bsc_softc *sc; uint32_t clk, reg; int error; sc = (struct bcm_bsc_softc *)arg1; BCM_BSC_LOCK(sc); reg = BCM_BSC_READ(sc, BCM_BSC_DELAY); BCM_BSC_UNLOCK(sc); reg &= 0xffff; error = sysctl_handle_int(oidp, ®, sizeof(reg), req); if (error != 0 || req->newptr == NULL) return (error); BCM_BSC_LOCK(sc); clk = BCM_BSC_READ(sc, BCM_BSC_CLOCK); clk = BCM_BSC_CORE_CLK / clk; if (reg > clk / 2) reg = clk / 2 - 1; bcm_bsc_modifyreg(sc, BCM_BSC_DELAY, 0xffff, reg); BCM_BSC_UNLOCK(sc); return (0); } static void bcm_bsc_sysctl_init(struct bcm_bsc_softc *sc) { struct sysctl_ctx_list *ctx; struct sysctl_oid *tree_node; struct sysctl_oid_list *tree; /* * Add system sysctl tree/handlers. */ ctx = device_get_sysctl_ctx(sc->sc_dev); tree_node = device_get_sysctl_tree(sc->sc_dev); tree = SYSCTL_CHILDREN(tree_node); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "frequency", CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc), bcm_bsc_clock_proc, "IU", "I2C BUS clock frequency"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "clock_stretch", CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc), bcm_bsc_clkt_proc, "IU", "I2C BUS clock stretch timeout"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "fall_edge_delay", CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc), bcm_bsc_fall_proc, "IU", "I2C BUS falling edge delay"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "rise_edge_delay", CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc), bcm_bsc_rise_proc, "IU", "I2C BUS rising edge delay"); SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "debug", CTLFLAG_RWTUN, &sc->sc_debug, 0, "Enable debug; 1=reads/writes, 2=add starts/stops"); } static void bcm_bsc_reset(struct bcm_bsc_softc *sc) { /* Enable the BSC Controller, disable interrupts. */ BCM_BSC_WRITE(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_I2CEN); /* Clear pending interrupts. */ BCM_BSC_WRITE(sc, BCM_BSC_STATUS, BCM_BSC_STATUS_CLKT | BCM_BSC_STATUS_ERR | BCM_BSC_STATUS_DONE); /* Clear the FIFO. */ bcm_bsc_modifyreg(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_CLEAR0, BCM_BSC_CTRL_CLEAR0); } static int bcm_bsc_probe(device_t dev) { if (!ofw_bus_status_okay(dev)) return (ENXIO); if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) return (ENXIO); device_set_desc(dev, "BCM2708/2835 BSC controller"); return (BUS_PROBE_DEFAULT); } static int bcm_bsc_attach(device_t dev) { struct bcm_bsc_softc *sc; unsigned long start; device_t gpio; int i, rid; sc = device_get_softc(dev); sc->sc_dev = dev; rid = 0; sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); if (!sc->sc_mem_res) { device_printf(dev, "cannot allocate memory window\n"); return (ENXIO); } sc->sc_bst = rman_get_bustag(sc->sc_mem_res); sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res); /* Check the unit we are attaching by its base address. */ start = rman_get_start(sc->sc_mem_res); for (i = 0; i < nitems(bcm_bsc_pins); i++) { if (bcm_bsc_pins[i].start == (start & BCM_BSC_BASE_MASK)) break; } if (i == nitems(bcm_bsc_pins)) { device_printf(dev, "only bsc0 and bsc1 are supported\n"); bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res); return (ENXIO); } /* * Configure the GPIO pins to ALT0 function to enable BSC control * over the pins. */ gpio = devclass_get_device(devclass_find("gpio"), 0); if (!gpio) { device_printf(dev, "cannot find gpio0\n"); bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res); return (ENXIO); } bcm_gpio_set_alternate(gpio, bcm_bsc_pins[i].sda, BCM_GPIO_ALT0); bcm_gpio_set_alternate(gpio, bcm_bsc_pins[i].scl, BCM_GPIO_ALT0); rid = 0; sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE | RF_SHAREABLE); if (!sc->sc_irq_res) { bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res); device_printf(dev, "cannot allocate interrupt\n"); return (ENXIO); } /* Hook up our interrupt handler. */ if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE, NULL, bcm_bsc_intr, sc, &sc->sc_intrhand)) { bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res); bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res); device_printf(dev, "cannot setup the interrupt handler\n"); return (ENXIO); } mtx_init(&sc->sc_mtx, "bcm_bsc", NULL, MTX_DEF); bcm_bsc_sysctl_init(sc); /* Enable the BSC controller. Flush the FIFO. */ BCM_BSC_LOCK(sc); bcm_bsc_reset(sc); BCM_BSC_UNLOCK(sc); sc->sc_iicbus = device_add_child(dev, "iicbus", -1); if (sc->sc_iicbus == NULL) { bcm_bsc_detach(dev); return (ENXIO); } /* Probe and attach the iicbus when interrupts are available. */ config_intrhook_oneshot((ich_func_t)bus_generic_attach, dev); return (0); } static int bcm_bsc_detach(device_t dev) { struct bcm_bsc_softc *sc; bus_generic_detach(dev); sc = device_get_softc(dev); if (sc->sc_iicbus != NULL) device_delete_child(dev, sc->sc_iicbus); mtx_destroy(&sc->sc_mtx); if (sc->sc_intrhand) bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand); if (sc->sc_irq_res) bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res); if (sc->sc_mem_res) bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res); return (0); } static void bcm_bsc_empty_rx_fifo(struct bcm_bsc_softc *sc) { uint32_t status; /* Assumes sc_totlen > 0 and BCM_BSC_STATUS_RXD is asserted on entry. */ do { if (sc->sc_resid == 0) { sc->sc_data = sc->sc_curmsg->buf; sc->sc_dlen = sc->sc_curmsg->len; sc->sc_resid = sc->sc_dlen; ++sc->sc_curmsg; } do { *sc->sc_data = BCM_BSC_READ(sc, BCM_BSC_DATA); DEBUGF(sc, 1, "0x%02x ", *sc->sc_data); ++sc->sc_data; --sc->sc_resid; --sc->sc_totlen; status = BCM_BSC_READ(sc, BCM_BSC_STATUS); } while (sc->sc_resid > 0 && (status & BCM_BSC_STATUS_RXD)); } while (sc->sc_totlen > 0 && (status & BCM_BSC_STATUS_RXD)); } static void bcm_bsc_fill_tx_fifo(struct bcm_bsc_softc *sc) { uint32_t status; /* Assumes sc_totlen > 0 and BCM_BSC_STATUS_TXD is asserted on entry. */ do { if (sc->sc_resid == 0) { sc->sc_data = sc->sc_curmsg->buf; sc->sc_dlen = sc->sc_curmsg->len; sc->sc_resid = sc->sc_dlen; ++sc->sc_curmsg; } do { BCM_BSC_WRITE(sc, BCM_BSC_DATA, *sc->sc_data); DEBUGF(sc, 1, "0x%02x ", *sc->sc_data); ++sc->sc_data; --sc->sc_resid; --sc->sc_totlen; status = BCM_BSC_READ(sc, BCM_BSC_STATUS); } while (sc->sc_resid > 0 && (status & BCM_BSC_STATUS_TXD)); /* * If a repeat-start was pending and we just hit the end of a tx * buffer, see if it's also the end of the writes that preceeded * the repeat-start. If so, log the repeat-start and the start * of the following read, and return because we're not writing * anymore (and TXD will be true because there's room to write * in the fifo). */ if (sc->sc_replen > 0 && sc->sc_resid == 0) { sc->sc_replen -= sc->sc_dlen; if (sc->sc_replen == 0) { DEBUGF(sc, 1, " err=0\n"); DEVICE_DEBUGF(sc, 2, "rstart 0x%02x\n", sc->sc_curmsg->slave | 0x01); DEVICE_DEBUGF(sc, 1, "read 0x%02x len %d: ", sc->sc_curmsg->slave | 0x01, sc->sc_totlen); sc->sc_flags |= BCM_I2C_READ; return; } } } while (sc->sc_totlen > 0 && (status & BCM_BSC_STATUS_TXD)); } static void bcm_bsc_intr(void *arg) { struct bcm_bsc_softc *sc; uint32_t status; sc = (struct bcm_bsc_softc *)arg; BCM_BSC_LOCK(sc); /* The I2C interrupt is shared among all the BSC controllers. */ if ((sc->sc_flags & BCM_I2C_BUSY) == 0) { BCM_BSC_UNLOCK(sc); return; } status = BCM_BSC_READ(sc, BCM_BSC_STATUS); DEBUGF(sc, 4, " ", status); /* RXD and DONE can assert together, empty fifo before checking done. */ if ((sc->sc_flags & BCM_I2C_READ) && (status & BCM_BSC_STATUS_RXD)) bcm_bsc_empty_rx_fifo(sc); /* Check for completion. */ if (status & (BCM_BSC_STATUS_ERRBITS | BCM_BSC_STATUS_DONE)) { sc->sc_flags |= BCM_I2C_DONE; if (status & BCM_BSC_STATUS_ERRBITS) sc->sc_flags |= BCM_I2C_ERROR; /* Disable interrupts. */ bcm_bsc_reset(sc); wakeup(sc); } else if (!(sc->sc_flags & BCM_I2C_READ)) { /* * Don't check for TXD until after determining whether the * transfer is complete; TXD will be asserted along with ERR or * DONE if there is room in the fifo. */ - if (status & BCM_BSC_STATUS_TXD) + if ((status & BCM_BSC_STATUS_TXD) && sc->sc_totlen > 0) bcm_bsc_fill_tx_fifo(sc); } BCM_BSC_UNLOCK(sc); } static int bcm_bsc_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs) { struct bcm_bsc_softc *sc; struct iic_msg *endmsgs, *nxtmsg; uint32_t readctl, status; int err; uint16_t curlen; uint8_t curisread, curslave, nxtisread, nxtslave; sc = device_get_softc(dev); BCM_BSC_LOCK(sc); /* If the controller is busy wait until it is available. */ while (sc->sc_flags & BCM_I2C_BUSY) mtx_sleep(dev, &sc->sc_mtx, 0, "bscbusw", 0); /* Now we have control over the BSC controller. */ sc->sc_flags = BCM_I2C_BUSY; DEVICE_DEBUGF(sc, 3, "Transfer %d msgs\n", nmsgs); /* Clear the FIFO and the pending interrupts. */ bcm_bsc_reset(sc); /* * Perform all the transfers requested in the array of msgs. Note that * it is bcm_bsc_empty_rx_fifo() and bcm_bsc_fill_tx_fifo() that advance * sc->sc_curmsg through the array of messages, as the data from each * message is fully consumed, but it is this loop that notices when we * have no more messages to process. */ err = 0; sc->sc_resid = 0; sc->sc_curmsg = msgs; endmsgs = &msgs[nmsgs]; while (sc->sc_curmsg < endmsgs) { readctl = 0; curslave = sc->sc_curmsg->slave >> 1; curisread = sc->sc_curmsg->flags & IIC_M_RD; sc->sc_replen = 0; sc->sc_totlen = sc->sc_curmsg->len; /* * Scan for scatter/gather IO (same slave and direction) or * repeat-start (read following write for the same slave). */ for (nxtmsg = sc->sc_curmsg + 1; nxtmsg < endmsgs; ++nxtmsg) { nxtslave = nxtmsg->slave >> 1; if (curslave == nxtslave) { nxtisread = nxtmsg->flags & IIC_M_RD; if (curisread == nxtisread) { /* * Same slave and direction, this * message will be part of the same * transfer as the previous one. */ sc->sc_totlen += nxtmsg->len; continue; } else if (curisread == IIC_M_WR) { /* * Read after write to same slave means * repeat-start, remember how many bytes * come before the repeat-start, switch * the direction to IIC_M_RD, and gather * up following reads to the same slave. */ curisread = IIC_M_RD; sc->sc_replen = sc->sc_totlen; sc->sc_totlen += nxtmsg->len; continue; } } break; } /* * curslave and curisread temporaries from above may refer to * the after-repstart msg, reset them to reflect sc_curmsg. */ curisread = (sc->sc_curmsg->flags & IIC_M_RD) ? 1 : 0; curslave = sc->sc_curmsg->slave | curisread; /* Write the slave address. */ BCM_BSC_WRITE(sc, BCM_BSC_SLAVE, curslave >> 1); DEVICE_DEBUGF(sc, 2, "start 0x%02x\n", curslave); /* * Either set up read length and direction variables for a * simple transfer or get the hardware started on the first * piece of a transfer that involves a repeat-start and set up * the read length and direction vars for the second piece. */ if (sc->sc_replen == 0) { DEVICE_DEBUGF(sc, 1, "%-6s 0x%02x len %d: ", (curisread) ? "read" : "write", curslave, sc->sc_totlen); curlen = sc->sc_totlen; if (curisread) { readctl = BCM_BSC_CTRL_READ; sc->sc_flags |= BCM_I2C_READ; } else { readctl = 0; sc->sc_flags &= ~BCM_I2C_READ; } } else { DEVICE_DEBUGF(sc, 1, "%-6s 0x%02x len %d: ", (curisread) ? "read" : "write", curslave, sc->sc_replen); /* * Start the write transfer with an empty fifo and wait * for the 'transfer active' status bit to light up; * that indicates that the hardware has latched the * direction and length for the write, and we can safely * reload those registers and issue the start for the * following read; interrupts are not enabled here. */ BCM_BSC_WRITE(sc, BCM_BSC_DLEN, sc->sc_replen); BCM_BSC_WRITE(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_I2CEN | BCM_BSC_CTRL_ST); do { status = BCM_BSC_READ(sc, BCM_BSC_STATUS); if (status & BCM_BSC_STATUS_ERR) { /* no ACK on slave addr */ err = EIO; goto xfer_done; } } while ((status & BCM_BSC_STATUS_TA) == 0); /* * Set curlen and readctl for the repeat-start read that * we need to set up below, but set sc_flags to write, * because that is the operation in progress right now. */ curlen = sc->sc_totlen - sc->sc_replen; readctl = BCM_BSC_CTRL_READ; sc->sc_flags &= ~BCM_I2C_READ; } /* * Start the transfer with interrupts enabled, then if doing a * write, fill the tx fifo. Not prefilling the fifo until after * this start command is the key workaround for making * repeat-start work, and it's harmless to do it in this order * for a regular write too. */ BCM_BSC_WRITE(sc, BCM_BSC_DLEN, curlen); BCM_BSC_WRITE(sc, BCM_BSC_CTRL, readctl | BCM_BSC_CTRL_I2CEN | BCM_BSC_CTRL_ST | BCM_BSC_CTRL_INT_ALL); if (!(sc->sc_curmsg->flags & IIC_M_RD)) { bcm_bsc_fill_tx_fifo(sc); } /* Wait for the transaction to complete. */ while (err == 0 && !(sc->sc_flags & BCM_I2C_DONE)) { err = mtx_sleep(sc, &sc->sc_mtx, 0, "bsciow", hz); } /* Check for errors. */ if (err == 0 && (sc->sc_flags & BCM_I2C_ERROR)) err = EIO; xfer_done: DEBUGF(sc, 1, " err=%d\n", err); DEVICE_DEBUGF(sc, 2, "stop\n"); if (err != 0) break; } /* Disable interrupts, clean fifo, etc. */ bcm_bsc_reset(sc); /* Clean the controller flags. */ sc->sc_flags = 0; /* Wake up the threads waiting for bus. */ wakeup(dev); BCM_BSC_UNLOCK(sc); return (err); } static int bcm_bsc_iicbus_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr) { struct bcm_bsc_softc *sc; uint32_t busfreq; sc = device_get_softc(dev); BCM_BSC_LOCK(sc); bcm_bsc_reset(sc); if (sc->sc_iicbus == NULL) busfreq = 100000; else busfreq = IICBUS_GET_FREQUENCY(sc->sc_iicbus, speed); BCM_BSC_WRITE(sc, BCM_BSC_CLOCK, BCM_BSC_CORE_CLK / busfreq); BCM_BSC_UNLOCK(sc); return (IIC_ENOADDR); } static phandle_t bcm_bsc_get_node(device_t bus, device_t dev) { /* We only have one child, the I2C bus, which needs our own node. */ return (ofw_bus_get_node(bus)); } static device_method_t bcm_bsc_methods[] = { /* Device interface */ DEVMETHOD(device_probe, bcm_bsc_probe), DEVMETHOD(device_attach, bcm_bsc_attach), DEVMETHOD(device_detach, bcm_bsc_detach), /* iicbus interface */ DEVMETHOD(iicbus_reset, bcm_bsc_iicbus_reset), DEVMETHOD(iicbus_callback, iicbus_null_callback), DEVMETHOD(iicbus_transfer, bcm_bsc_transfer), /* ofw_bus interface */ DEVMETHOD(ofw_bus_get_node, bcm_bsc_get_node), DEVMETHOD_END }; static devclass_t bcm_bsc_devclass; static driver_t bcm_bsc_driver = { "iichb", bcm_bsc_methods, sizeof(struct bcm_bsc_softc), }; DRIVER_MODULE(iicbus, bcm2835_bsc, iicbus_driver, iicbus_devclass, 0, 0); DRIVER_MODULE(bcm2835_bsc, simplebus, bcm_bsc_driver, bcm_bsc_devclass, 0, 0);