/*- * Copyright (c) 2012 Oleksandr Tymoshenko * Copyright (c) 2013 Luiz Otavio O Souza * 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: stable/10/sys/arm/broadcom/bcm2835/bcm2835_spi.c 259325 2013-12-13 19:27:23Z ian $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "spibus_if.h" static void bcm_spi_intr(void *); #ifdef BCM_SPI_DEBUG static void bcm_spi_printr(device_t dev) { struct bcm_spi_softc *sc; uint32_t reg; sc = device_get_softc(dev); reg = BCM_SPI_READ(sc, SPI_CS); device_printf(dev, "CS=%b\n", reg, "\20\1CS0\2CS1\3CPHA\4CPOL\7CSPOL" "\10TA\11DMAEN\12INTD\13INTR\14ADCS\15REN\16LEN" "\21DONE\22RXD\23TXD\24RXR\25RXF\26CSPOL0\27CSPOL1" "\30CSPOL2\31DMA_LEN\32LEN_LONG"); reg = BCM_SPI_READ(sc, SPI_CLK) & SPI_CLK_MASK; if (reg % 2) reg--; if (reg == 0) reg = 65536; device_printf(dev, "CLK=%uMhz/%d=%luhz\n", SPI_CORE_CLK / 1000000, reg, SPI_CORE_CLK / reg); reg = BCM_SPI_READ(sc, SPI_DLEN) & SPI_DLEN_MASK; device_printf(dev, "DLEN=%d\n", reg); reg = BCM_SPI_READ(sc, SPI_LTOH) & SPI_LTOH_MASK; device_printf(dev, "LTOH=%d\n", reg); reg = BCM_SPI_READ(sc, SPI_DC); device_printf(dev, "DC=RPANIC=%#x RDREQ=%#x TPANIC=%#x TDREQ=%#x\n", (reg & SPI_DC_RPANIC_MASK) >> SPI_DC_RPANIC_SHIFT, (reg & SPI_DC_RDREQ_MASK) >> SPI_DC_RDREQ_SHIFT, (reg & SPI_DC_TPANIC_MASK) >> SPI_DC_TPANIC_SHIFT, (reg & SPI_DC_TDREQ_MASK) >> SPI_DC_TDREQ_SHIFT); } #endif static void bcm_spi_modifyreg(struct bcm_spi_softc *sc, uint32_t off, uint32_t mask, uint32_t value) { uint32_t reg; mtx_assert(&sc->sc_mtx, MA_OWNED); reg = BCM_SPI_READ(sc, off); reg &= ~mask; reg |= value; BCM_SPI_WRITE(sc, off, reg); } static int bcm_spi_clock_proc(SYSCTL_HANDLER_ARGS) { struct bcm_spi_softc *sc; uint32_t clk; int error; sc = (struct bcm_spi_softc *)arg1; BCM_SPI_LOCK(sc); clk = BCM_SPI_READ(sc, SPI_CLK); BCM_SPI_UNLOCK(sc); clk &= 0xffff; if (clk == 0) clk = 65536; clk = SPI_CORE_CLK / clk; error = sysctl_handle_int(oidp, &clk, sizeof(clk), req); if (error != 0 || req->newptr == NULL) return (error); clk = SPI_CORE_CLK / clk; if (clk <= 1) clk = 2; else if (clk % 2) clk--; if (clk > 0xffff) clk = 0; BCM_SPI_LOCK(sc); BCM_SPI_WRITE(sc, SPI_CLK, clk); BCM_SPI_UNLOCK(sc); return (0); } static int bcm_spi_cs_bit_proc(SYSCTL_HANDLER_ARGS, uint32_t bit) { struct bcm_spi_softc *sc; uint32_t reg; int error; sc = (struct bcm_spi_softc *)arg1; BCM_SPI_LOCK(sc); reg = BCM_SPI_READ(sc, SPI_CS); BCM_SPI_UNLOCK(sc); reg = (reg & bit) ? 1 : 0; error = sysctl_handle_int(oidp, ®, sizeof(reg), req); if (error != 0 || req->newptr == NULL) return (error); if (reg) reg = bit; BCM_SPI_LOCK(sc); bcm_spi_modifyreg(sc, SPI_CS, bit, reg); BCM_SPI_UNLOCK(sc); return (0); } static int bcm_spi_cpol_proc(SYSCTL_HANDLER_ARGS) { return (bcm_spi_cs_bit_proc(oidp, arg1, arg2, req, SPI_CS_CPOL)); } static int bcm_spi_cpha_proc(SYSCTL_HANDLER_ARGS) { return (bcm_spi_cs_bit_proc(oidp, arg1, arg2, req, SPI_CS_CPHA)); } static int bcm_spi_cspol0_proc(SYSCTL_HANDLER_ARGS) { return (bcm_spi_cs_bit_proc(oidp, arg1, arg2, req, SPI_CS_CSPOL0)); } static int bcm_spi_cspol1_proc(SYSCTL_HANDLER_ARGS) { return (bcm_spi_cs_bit_proc(oidp, arg1, arg2, req, SPI_CS_CSPOL1)); } static void bcm_spi_sysctl_init(struct bcm_spi_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, "clock", CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc), bcm_spi_clock_proc, "IU", "SPI BUS clock frequency"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "cpol", CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc), bcm_spi_cpol_proc, "IU", "SPI BUS clock polarity"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "cpha", CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc), bcm_spi_cpha_proc, "IU", "SPI BUS clock phase"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "cspol0", CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc), bcm_spi_cspol0_proc, "IU", "SPI BUS chip select 0 polarity"); SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "cspol1", CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc), bcm_spi_cspol1_proc, "IU", "SPI BUS chip select 1 polarity"); } static int bcm_spi_probe(device_t dev) { if (!ofw_bus_is_compatible(dev, "broadcom,bcm2835-spi")) return (ENXIO); device_set_desc(dev, "BCM2708/2835 SPI controller"); return (BUS_PROBE_DEFAULT); } static int bcm_spi_attach(device_t dev) { struct bcm_spi_softc *sc; device_t gpio; int i, rid; if (device_get_unit(dev) != 0) { device_printf(dev, "only one SPI controller supported\n"); return (ENXIO); } sc = device_get_softc(dev); sc->sc_dev = dev; /* Configure the GPIO pins to ALT0 function to enable SPI the pins. */ gpio = devclass_get_device(devclass_find("gpio"), 0); if (!gpio) { device_printf(dev, "cannot find gpio0\n"); return (ENXIO); } for (i = 0; i < nitems(bcm_spi_pins); i++) bcm_gpio_set_alternate(gpio, bcm_spi_pins[i], BCM_GPIO_ALT0); 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); rid = 0; sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE); 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_spi_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_spi", NULL, MTX_DEF); /* Add sysctl nodes. */ bcm_spi_sysctl_init(sc); #ifdef BCM_SPI_DEBUG bcm_spi_printr(dev); #endif /* * Enable the SPI controller. Clear the rx and tx FIFO. * Defaults to SPI mode 0. */ BCM_SPI_WRITE(sc, SPI_CS, SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO); /* Set the SPI clock to 500Khz. */ BCM_SPI_WRITE(sc, SPI_CLK, SPI_CORE_CLK / 500000); #ifdef BCM_SPI_DEBUG bcm_spi_printr(dev); #endif device_add_child(dev, "spibus", -1); return (bus_generic_attach(dev)); } static int bcm_spi_detach(device_t dev) { struct bcm_spi_softc *sc; bus_generic_detach(dev); sc = device_get_softc(dev); 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_spi_fill_fifo(struct bcm_spi_softc *sc) { struct spi_command *cmd; uint32_t cs, written; uint8_t *data; cmd = sc->sc_cmd; cs = BCM_SPI_READ(sc, SPI_CS) & (SPI_CS_TA | SPI_CS_TXD); while (sc->sc_written < sc->sc_len && cs == (SPI_CS_TA | SPI_CS_TXD)) { data = (uint8_t *)cmd->tx_cmd; written = sc->sc_written++; if (written >= cmd->tx_cmd_sz) { data = (uint8_t *)cmd->tx_data; written -= cmd->tx_cmd_sz; } BCM_SPI_WRITE(sc, SPI_FIFO, data[written]); cs = BCM_SPI_READ(sc, SPI_CS) & (SPI_CS_TA | SPI_CS_TXD); } } static void bcm_spi_drain_fifo(struct bcm_spi_softc *sc) { struct spi_command *cmd; uint32_t cs, read; uint8_t *data; cmd = sc->sc_cmd; cs = BCM_SPI_READ(sc, SPI_CS) & SPI_CS_RXD; while (sc->sc_read < sc->sc_len && cs == SPI_CS_RXD) { data = (uint8_t *)cmd->rx_cmd; read = sc->sc_read++; if (read >= cmd->rx_cmd_sz) { data = (uint8_t *)cmd->rx_data; read -= cmd->rx_cmd_sz; } data[read] = BCM_SPI_READ(sc, SPI_FIFO) & 0xff; cs = BCM_SPI_READ(sc, SPI_CS) & SPI_CS_RXD; } } static void bcm_spi_intr(void *arg) { struct bcm_spi_softc *sc; sc = (struct bcm_spi_softc *)arg; BCM_SPI_LOCK(sc); /* Filter stray interrupts. */ if ((sc->sc_flags & BCM_SPI_BUSY) == 0) { BCM_SPI_UNLOCK(sc); return; } /* TX - Fill up the FIFO. */ bcm_spi_fill_fifo(sc); /* RX - Drain the FIFO. */ bcm_spi_drain_fifo(sc); /* Check for end of transfer. */ if (sc->sc_written == sc->sc_len && sc->sc_read == sc->sc_len) { /* Disable interrupts and the SPI engine. */ bcm_spi_modifyreg(sc, SPI_CS, SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD, 0); wakeup(sc->sc_dev); } BCM_SPI_UNLOCK(sc); } static int bcm_spi_transfer(device_t dev, device_t child, struct spi_command *cmd) { struct bcm_spi_softc *sc; int cs, err; sc = device_get_softc(dev); KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz, ("TX/RX command sizes should be equal")); KASSERT(cmd->tx_data_sz == cmd->rx_data_sz, ("TX/RX data sizes should be equal")); BCM_SPI_LOCK(sc); /* If the controller is in use wait until it is available. */ while (sc->sc_flags & BCM_SPI_BUSY) mtx_sleep(dev, &sc->sc_mtx, 0, "bcm_spi", 0); /* Now we have control over SPI controller. */ sc->sc_flags = BCM_SPI_BUSY; /* Clear the FIFO. */ bcm_spi_modifyreg(sc, SPI_CS, SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO, SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO); /* Get the proper chip select for this child. */ spibus_get_cs(child, &cs); if (cs < 0 || cs > 2) { device_printf(dev, "Invalid chip select %d requested by %s\n", cs, device_get_nameunit(child)); BCM_SPI_UNLOCK(sc); return (EINVAL); } /* Save a pointer to the SPI command. */ sc->sc_cmd = cmd; sc->sc_read = 0; sc->sc_written = 0; sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz; /* * Set the CS for this transaction, enable interrupts and announce * we're ready to tx. This will kick off the first interrupt. */ bcm_spi_modifyreg(sc, SPI_CS, SPI_CS_MASK | SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD, cs | SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD); /* Wait for the transaction to complete. */ err = mtx_sleep(dev, &sc->sc_mtx, 0, "bcm_spi", hz * 2); /* Make sure the SPI engine and interrupts are disabled. */ bcm_spi_modifyreg(sc, SPI_CS, SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD, 0); /* Clear the controller flags. */ sc->sc_flags = 0; /* * Check for transfer timeout. The SPI controller doesn't * return errors. */ if (err == EWOULDBLOCK) { device_printf(sc->sc_dev, "SPI error\n"); err = EIO; } BCM_SPI_UNLOCK(sc); return (err); } static phandle_t bcm_spi_get_node(device_t bus, device_t dev) { /* We only have one child, the SPI bus, which needs our own node. */ return (ofw_bus_get_node(bus)); } static device_method_t bcm_spi_methods[] = { /* Device interface */ DEVMETHOD(device_probe, bcm_spi_probe), DEVMETHOD(device_attach, bcm_spi_attach), DEVMETHOD(device_detach, bcm_spi_detach), /* SPI interface */ DEVMETHOD(spibus_transfer, bcm_spi_transfer), /* ofw_bus interface */ DEVMETHOD(ofw_bus_get_node, bcm_spi_get_node), DEVMETHOD_END }; static devclass_t bcm_spi_devclass; static driver_t bcm_spi_driver = { "spi", bcm_spi_methods, sizeof(struct bcm_spi_softc), }; DRIVER_MODULE(bcm2835_spi, simplebus, bcm_spi_driver, bcm_spi_devclass, 0, 0);