FreeBSD/Linux Kernel Cross Reference
sys/arm/lpc/lpc_spi.c

     /*-
      * Copyright (c) 2011 Jakub Wojciech Klama <jceel@FreeBSD.org>
      * 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 <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/10.0/sys/arm/lpc/lpc_spi.c 239278 2012-08-15 05:37:10Z gonzo $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bio.h>
    #include <sys/bus.h>
    #include <sys/conf.h>
    #include <sys/endian.h>
    #include <sys/kernel.h>
    #include <sys/kthread.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/module.h>
    #include <sys/mutex.h>
    #include <sys/queue.h>
    #include <sys/resource.h>
    #include <sys/rman.h>
    #include <sys/time.h>
    #include <sys/timetc.h>
    #include <sys/watchdog.h>
    
    #include <machine/bus.h>
    #include <machine/cpu.h>
    #include <machine/cpufunc.h>
    #include <machine/resource.h>
    #include <machine/frame.h>
    #include <machine/intr.h>
    
    #include <dev/spibus/spi.h>
    #include <dev/spibus/spibusvar.h>
    
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    
    #include <arm/lpc/lpcreg.h>
    #include <arm/lpc/lpcvar.h>
    
    #include "spibus_if.h"
    
    struct lpc_spi_softc
    {
            device_t                ls_dev;
            struct resource *       ls_mem_res;
            struct resource *       ls_irq_res;
            bus_space_tag_t         ls_bst;
            bus_space_handle_t      ls_bsh;
    };
    
    static int lpc_spi_probe(device_t);
    static int lpc_spi_attach(device_t);
    static int lpc_spi_detach(device_t);
    static int lpc_spi_transfer(device_t, device_t, struct spi_command *);
    
    #define lpc_spi_read_4(_sc, _reg)               \
        bus_space_read_4(_sc->ls_bst, _sc->ls_bsh, _reg)
    #define lpc_spi_write_4(_sc, _reg, _val)        \
        bus_space_write_4(_sc->ls_bst, _sc->ls_bsh, _reg, _val)
    
    static int
    lpc_spi_probe(device_t dev)
    {
            if (!ofw_bus_is_compatible(dev, "lpc,spi"))
                    return (ENXIO);
    
            device_set_desc(dev, "LPC32x0 PL022 SPI/SSP controller");
            return (BUS_PROBE_DEFAULT);
    }
    
    static int
    lpc_spi_attach(device_t dev)
    {
            struct lpc_spi_softc *sc = device_get_softc(dev);
           int rid;
   
           sc->ls_dev = dev;
   
           rid = 0;
           sc->ls_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
               RF_ACTIVE);
           if (!sc->ls_mem_res) {
                   device_printf(dev, "cannot allocate memory window\n");
                   return (ENXIO);
           }
   
           sc->ls_bst = rman_get_bustag(sc->ls_mem_res);
           sc->ls_bsh = rman_get_bushandle(sc->ls_mem_res);
   
           rid = 0;
           sc->ls_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
               RF_ACTIVE);
           if (!sc->ls_irq_res) {
                   device_printf(dev, "cannot allocate interrupt\n");
                   return (ENXIO);
           }
   
           bus_space_write_4(sc->ls_bst, 0xd0028100, 0, (1<<12)|(1<<10)|(1<<9)|(1<<8)|(1<<6)|(1<<5)); 
           lpc_pwr_write(dev, LPC_CLKPWR_SSP_CTRL, LPC_CLKPWR_SSP_CTRL_SSP0EN);
           lpc_spi_write_4(sc, LPC_SSP_CR0, LPC_SSP_CR0_DSS(8));
           lpc_spi_write_4(sc, LPC_SSP_CR1, LPC_SSP_CR1_SSE);
           lpc_spi_write_4(sc, LPC_SSP_CPSR, 128);
   
           device_add_child(dev, "spibus", 0);
           return (bus_generic_attach(dev));
   }
   
   static int
   lpc_spi_detach(device_t dev)
   {
           return (EBUSY);
   }
   
   static int
   lpc_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
   {
           struct lpc_spi_softc *sc = device_get_softc(dev);
           struct spibus_ivar *devi = SPIBUS_IVAR(child);
           uint8_t *in_buf, *out_buf;
           int i;
   
           /* Set CS active */
           lpc_gpio_set_state(child, devi->cs, 0);
   
           /* Wait for FIFO to be ready */
           while ((lpc_spi_read_4(sc, LPC_SSP_SR) & LPC_SSP_SR_TNF) == 0);
   
           /* Command */
           in_buf = cmd->rx_cmd;
           out_buf = cmd->tx_cmd;
           for (i = 0; i < cmd->tx_cmd_sz; i++) {
                   lpc_spi_write_4(sc, LPC_SSP_DR, out_buf[i]);
                   in_buf[i] = lpc_spi_read_4(sc, LPC_SSP_DR);
           }
   
           /* Data */
           in_buf = cmd->rx_data;
           out_buf = cmd->tx_data;
           for (i = 0; i < cmd->tx_data_sz; i++) {
                   lpc_spi_write_4(sc, LPC_SSP_DR, out_buf[i]);
                   in_buf[i] = lpc_spi_read_4(sc, LPC_SSP_DR);
           }
   
           /* Set CS inactive */
           lpc_gpio_set_state(child, devi->cs, 1);
   
           return (0);
   }
   
   static device_method_t lpc_spi_methods[] = {
           /* Device interface */
           DEVMETHOD(device_probe,         lpc_spi_probe),
           DEVMETHOD(device_attach,        lpc_spi_attach),
           DEVMETHOD(device_detach,        lpc_spi_detach),
   
           /* SPI interface */
           DEVMETHOD(spibus_transfer,      lpc_spi_transfer),
   
           { 0, 0 }
   };
   
   static devclass_t lpc_spi_devclass;
   
   static driver_t lpc_spi_driver = {
           "spi",
           lpc_spi_methods,
           sizeof(struct lpc_spi_softc),
   };
   
   DRIVER_MODULE(lpcspi, simplebus, lpc_spi_driver, lpc_spi_devclass, 0, 0);

Cache object: de3586a2d7c7028322878b381a11454e