diff options
Diffstat (limited to 'sys/arm/samsung/exynos/exynos5_spi.c')
| -rw-r--r-- | sys/arm/samsung/exynos/exynos5_spi.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/sys/arm/samsung/exynos/exynos5_spi.c b/sys/arm/samsung/exynos/exynos5_spi.c new file mode 100644 index 0000000..9cbdc4b --- /dev/null +++ b/sys/arm/samsung/exynos/exynos5_spi.c @@ -0,0 +1,236 @@ +/*- + * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com> + * 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. + */ + +/* + * Exynos 5 Serial Peripheral Interface (SPI) + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/bus.h> +#include <sys/kernel.h> +#include <sys/module.h> +#include <sys/malloc.h> +#include <sys/rman.h> +#include <sys/timeet.h> +#include <sys/timetc.h> +#include <sys/watchdog.h> + +#include <dev/spibus/spi.h> +#include <dev/spibus/spibusvar.h> + +#include "spibus_if.h" + +#include <dev/fdt/fdt_common.h> +#include <dev/ofw/openfirm.h> +#include <dev/ofw/ofw_bus.h> +#include <dev/ofw/ofw_bus_subr.h> + +#include <machine/bus.h> +#include <machine/fdt.h> +#include <machine/cpu.h> +#include <machine/intr.h> + +#include <arm/samsung/exynos/exynos5_common.h> + +#define CH_CFG 0x00 /* SPI configuration */ +#define SW_RST (1 << 5) /* Reset */ +#define RX_CH_ON (1 << 1) /* SPI Rx Channel On */ +#define TX_CH_ON (1 << 0) /* SPI Tx Channel On */ +#define MODE_CFG 0x08 /* FIFO control */ +#define CS_REG 0x0C /* slave selection control */ +#define NSSOUT (1 << 0) +#define SPI_INT_EN 0x10 /* interrupt enable */ +#define SPI_STATUS 0x14 /* SPI status */ +#define TX_FIFO_LVL_S 6 +#define TX_FIFO_LVL_M 0x1ff +#define RX_FIFO_LVL_S 15 +#define RX_FIFO_LVL_M 0x1ff +#define SPI_TX_DATA 0x18 /* Tx data */ +#define SPI_RX_DATA 0x1C /* Rx data */ +#define PACKET_CNT_REG 0x20 /* packet count */ +#define PENDING_CLR_REG 0x24 /* interrupt pending clear */ +#define SWAP_CFG 0x28 /* swap configuration */ +#define FB_CLK_SEL 0x2C /* feedback clock selection */ +#define FB_CLK_180 0x2 /* 180 degree phase lagging */ + +struct spi_softc { + struct resource *res[2]; + bus_space_tag_t bst; + bus_space_handle_t bsh; + device_t dev; +}; + +struct spi_softc *spi_sc; + +static struct resource_spec spi_spec[] = { + { SYS_RES_MEMORY, 0, RF_ACTIVE }, + { SYS_RES_IRQ, 0, RF_ACTIVE }, + { -1, 0 } +}; + +static int +spi_probe(device_t dev) +{ + + if (!ofw_bus_status_okay(dev)) + return (ENXIO); + + if (!ofw_bus_is_compatible(dev, "samsung,exynos5-spi")) + return (ENXIO); + + device_set_desc(dev, "Exynos 5 Serial Peripheral Interface (SPI)"); + return (BUS_PROBE_DEFAULT); +} + +static int +spi_attach(device_t dev) +{ + struct spi_softc *sc; + int reg; + + sc = device_get_softc(dev); + sc->dev = dev; + + if (bus_alloc_resources(dev, spi_spec, sc->res)) { + device_printf(dev, "could not allocate resources\n"); + return (ENXIO); + } + + /* Memory interface */ + sc->bst = rman_get_bustag(sc->res[0]); + sc->bsh = rman_get_bushandle(sc->res[0]); + + spi_sc = sc; + + WRITE4(sc, FB_CLK_SEL, FB_CLK_180); + + reg = READ4(sc, CH_CFG); + reg |= (RX_CH_ON | TX_CH_ON); + WRITE4(sc, CH_CFG, reg); + + device_add_child(dev, "spibus", 0); + return (bus_generic_attach(dev)); +} + +static int +spi_txrx(struct spi_softc *sc, uint8_t *out_buf, + uint8_t *in_buf, int bufsz, int cs) +{ + uint32_t reg; + uint32_t i; + + if (bufsz == 0) { + /* Nothing to transfer */ + return (0); + } + + /* Reset registers */ + reg = READ4(sc, CH_CFG); + reg |= SW_RST; + WRITE4(sc, CH_CFG, reg); + reg &= ~SW_RST; + WRITE4(sc, CH_CFG, reg); + + /* Assert CS */ + reg = READ4(sc, CS_REG); + reg &= ~NSSOUT; + WRITE4(sc, CS_REG, reg); + + for (i = 0; i < bufsz; i++) { + + /* TODO: Implement FIFO operation */ + + /* Wait all the data shifted out */ + while (READ4(sc, SPI_STATUS) & \ + (TX_FIFO_LVL_M << TX_FIFO_LVL_S)) + continue; + + WRITE1(sc, SPI_TX_DATA, out_buf[i]); + + /* Wait until no data available */ + while ((READ4(sc, SPI_STATUS) & \ + (RX_FIFO_LVL_M << RX_FIFO_LVL_S)) == 0) + continue; + + in_buf[i] = READ1(sc, SPI_RX_DATA); + } + + /* Deassert CS */ + reg = READ4(sc, CS_REG); + reg |= NSSOUT; + WRITE4(sc, CS_REG, reg); + + return (0); +} + +static int +spi_transfer(device_t dev, device_t child, struct spi_command *cmd) +{ + struct spi_softc *sc; + uint32_t cs; + + sc = device_get_softc(dev); + + KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz, + ("%s: TX/RX command sizes should be equal", __func__)); + KASSERT(cmd->tx_data_sz == cmd->rx_data_sz, + ("%s: TX/RX data sizes should be equal", __func__)); + + /* get the proper chip select */ + spibus_get_cs(child, &cs); + + /* Command */ + spi_txrx(sc, cmd->tx_cmd, cmd->rx_cmd, cmd->tx_cmd_sz, cs); + + /* Data */ + spi_txrx(sc, cmd->tx_data, cmd->rx_data, cmd->tx_data_sz, cs); + + return (0); +} + +static device_method_t spi_methods[] = { + DEVMETHOD(device_probe, spi_probe), + DEVMETHOD(device_attach, spi_attach), + + /* SPI interface */ + DEVMETHOD(spibus_transfer, spi_transfer), + + { 0, 0 } +}; + +static driver_t spi_driver = { + "spi", + spi_methods, + sizeof(struct spi_softc), +}; + +static devclass_t spi_devclass; + +DRIVER_MODULE(spi, simplebus, spi_driver, spi_devclass, 0, 0); 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