/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2009, Oleksandr Tymoshenko * 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 unmodified, 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "spibus_if.h" #include #undef AR71XX_SPI_DEBUG #ifdef AR71XX_SPI_DEBUG #define dprintf printf #else #define dprintf(x, arg...) #endif /* * register space access macros */ #define SPI_BARRIER_WRITE(sc) bus_barrier((sc)->sc_mem_res, 0, 0, \ BUS_SPACE_BARRIER_WRITE) #define SPI_BARRIER_READ(sc) bus_barrier((sc)->sc_mem_res, 0, 0, \ BUS_SPACE_BARRIER_READ) #define SPI_BARRIER_RW(sc) bus_barrier((sc)->sc_mem_res, 0, 0, \ BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE) #define SPI_WRITE(sc, reg, val) do { \ bus_write_4(sc->sc_mem_res, (reg), (val)); \ } while (0) #define SPI_READ(sc, reg) bus_read_4(sc->sc_mem_res, (reg)) #define SPI_SET_BITS(sc, reg, bits) \ SPI_WRITE(sc, reg, SPI_READ(sc, (reg)) | (bits)) #define SPI_CLEAR_BITS(sc, reg, bits) \ SPI_WRITE(sc, reg, SPI_READ(sc, (reg)) & ~(bits)) struct ar71xx_spi_softc { device_t sc_dev; struct resource *sc_mem_res; uint32_t sc_reg_ctrl; }; static int ar71xx_spi_probe(device_t dev) { device_set_desc(dev, "AR71XX SPI"); return (BUS_PROBE_NOWILDCARD); } static int ar71xx_spi_attach(device_t dev) { struct ar71xx_spi_softc *sc = device_get_softc(dev); int rid; 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, "Could not map memory\n"); return (ENXIO); } SPI_WRITE(sc, AR71XX_SPI_FS, 1); /* Flush out read before reading the control register */ SPI_BARRIER_WRITE(sc); sc->sc_reg_ctrl = SPI_READ(sc, AR71XX_SPI_CTRL); /* * XXX TODO: document what the SPI control register does. */ SPI_WRITE(sc, AR71XX_SPI_CTRL, 0x43); /* * Ensure the config register write has gone out before configuring * the chip select mask. */ SPI_BARRIER_WRITE(sc); SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, SPI_IO_CTRL_CSMASK); /* * .. and ensure the write has gone out before continuing. */ SPI_BARRIER_WRITE(sc); device_add_child(dev, "spibus", -1); return (bus_generic_attach(dev)); } static void ar71xx_spi_chip_activate(struct ar71xx_spi_softc *sc, int cs) { uint32_t ioctrl = SPI_IO_CTRL_CSMASK; /* * Put respective CSx to low */ ioctrl &= ~(SPI_IO_CTRL_CS0 << cs); /* * Make sure any other writes have gone out to the * device before changing the chip select line; * then ensure that it has made it out to the device * before continuing. */ SPI_BARRIER_WRITE(sc); SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, ioctrl); SPI_BARRIER_WRITE(sc); } static void ar71xx_spi_chip_deactivate(struct ar71xx_spi_softc *sc, int cs) { /* * Put all CSx to high */ SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, SPI_IO_CTRL_CSMASK); } static uint8_t ar71xx_spi_txrx(struct ar71xx_spi_softc *sc, int cs, uint8_t data) { int bit; /* CS0 */ uint32_t ioctrl = SPI_IO_CTRL_CSMASK; /* * low-level for selected CS */ ioctrl &= ~(SPI_IO_CTRL_CS0 << cs); uint32_t iod, rds; for (bit = 7; bit >=0; bit--) { if (data & (1 << bit)) iod = ioctrl | SPI_IO_CTRL_DO; else iod = ioctrl & ~SPI_IO_CTRL_DO; SPI_BARRIER_WRITE(sc); SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, iod); SPI_BARRIER_WRITE(sc); SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, iod | SPI_IO_CTRL_CLK); } /* * Provide falling edge for connected device by clear clock bit. */ SPI_BARRIER_WRITE(sc); SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, iod); SPI_BARRIER_WRITE(sc); rds = SPI_READ(sc, AR71XX_SPI_RDS); return (rds & 0xff); } static int ar71xx_spi_transfer(device_t dev, device_t child, struct spi_command *cmd) { struct ar71xx_spi_softc *sc; uint32_t cs; uint8_t *buf_in, *buf_out; int i; sc = device_get_softc(dev); spibus_get_cs(child, &cs); cs &= ~SPIBUS_CS_HIGH; ar71xx_spi_chip_activate(sc, cs); 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")); /* * Transfer command */ buf_out = (uint8_t *)cmd->tx_cmd; buf_in = (uint8_t *)cmd->rx_cmd; for (i = 0; i < cmd->tx_cmd_sz; i++) buf_in[i] = ar71xx_spi_txrx(sc, cs, buf_out[i]); /* * Receive/transmit data (depends on command) */ buf_out = (uint8_t *)cmd->tx_data; buf_in = (uint8_t *)cmd->rx_data; for (i = 0; i < cmd->tx_data_sz; i++) buf_in[i] = ar71xx_spi_txrx(sc, cs, buf_out[i]); ar71xx_spi_chip_deactivate(sc, cs); return (0); } static int ar71xx_spi_detach(device_t dev) { struct ar71xx_spi_softc *sc = device_get_softc(dev); /* * Ensure any other writes to the device are finished * before we tear down the SPI device. */ SPI_BARRIER_WRITE(sc); /* * Restore the control register; ensure it has hit the * hardware before continuing. */ SPI_WRITE(sc, AR71XX_SPI_CTRL, sc->sc_reg_ctrl); SPI_BARRIER_WRITE(sc); /* * And now, put the flash back into mapped IO mode and * ensure _that_ has completed before we finish up. */ SPI_WRITE(sc, AR71XX_SPI_FS, 0); SPI_BARRIER_WRITE(sc); if (sc->sc_mem_res) bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res); return (0); } static device_method_t ar71xx_spi_methods[] = { /* Device interface */ DEVMETHOD(device_probe, ar71xx_spi_probe), DEVMETHOD(device_attach, ar71xx_spi_attach), DEVMETHOD(device_detach, ar71xx_spi_detach), DEVMETHOD(spibus_transfer, ar71xx_spi_transfer), {0, 0} }; static driver_t ar71xx_spi_driver = { "spi", ar71xx_spi_methods, sizeof(struct ar71xx_spi_softc), }; static devclass_t ar71xx_spi_devclass; DRIVER_MODULE(ar71xx_spi, nexus, ar71xx_spi_driver, ar71xx_spi_devclass, 0, 0);