FreeBSD/Linux Kernel Cross Reference
sys/dev/uart/uart_bus_fdt.c

     /*-
      * Copyright (c) 2009-2010 The FreeBSD Foundation
      * All rights reserved.
      *
      * This software was developed by Semihalf under sponsorship from
      * the FreeBSD Foundation.
      *
      * 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("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    
    #include <machine/bus.h>
    #include <machine/fdt.h>
    
    #include <dev/fdt/fdt_common.h>
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    #include <dev/uart/uart.h>
    #include <dev/uart/uart_bus.h>
    #include <dev/uart/uart_cpu.h>
    
    static int uart_fdt_probe(device_t);
    
    static device_method_t uart_fdt_methods[] = {
            /* Device interface */
            DEVMETHOD(device_probe,         uart_fdt_probe),
            DEVMETHOD(device_attach,        uart_bus_attach),
            DEVMETHOD(device_detach,        uart_bus_detach),
            { 0, 0 }
    };
    
    static driver_t uart_fdt_driver = {
            uart_driver_name,
            uart_fdt_methods,
            sizeof(struct uart_softc),
    };
    
    static int
    uart_fdt_get_clock(phandle_t node, pcell_t *cell)
    {
            pcell_t clock;
    
            if ((OF_getprop(node, "clock-frequency", &clock,
                sizeof(clock))) <= 0)
                    return (ENXIO);
    
            if (clock == 0)
                    /* Try to retrieve parent 'bus-frequency' */
                    /* XXX this should go to simple-bus fixup or so */
                    if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
                        sizeof(clock))) <= 0)
                            clock = 0;
    
            *cell = fdt32_to_cpu(clock);
            return (0);
    }
    
    static int
    uart_fdt_get_shift(phandle_t node, pcell_t *cell)
    {
            pcell_t shift;
    
            if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
                    shift = 0;
            *cell = fdt32_to_cpu(shift);
            return (0);
    }
    
    static int
    uart_fdt_probe(device_t dev)
    {
            struct uart_softc *sc;
            phandle_t node;
           pcell_t clock, shift;
           int err;
   
           if (!ofw_bus_is_compatible(dev, "ns16550"))
                   return (ENXIO);
   
           sc = device_get_softc(dev);
           sc->sc_class = &uart_ns8250_class;
   
           node = ofw_bus_get_node(dev);
   
           if ((err = uart_fdt_get_clock(node, &clock)) != 0)
                   return (err);
           uart_fdt_get_shift(node, &shift);
   
           return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
   }
   
   DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
   
   /*
    * UART console routines.
    */
   bus_space_tag_t uart_bus_space_io;
   bus_space_tag_t uart_bus_space_mem;
   
   int
   uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
   {
   
           return ((b1->bsh == b2->bsh && b1->bst == b2->bst) ? 1 : 0);
   }
   
   int
   uart_cpu_getdev(int devtype, struct uart_devinfo *di)
   {
           char buf[64];
           struct uart_class *class;
           phandle_t node, chosen;
           pcell_t shift, br, rclk;
           u_long start, size;
           int err;
   
           uart_bus_space_mem = fdtbus_bs_tag;
           uart_bus_space_io = NULL;
   
           /* Allow overriding the FDT uning the environment. */
           class = &uart_ns8250_class;
           err = uart_getenv(devtype, di, class);
           if (!err)
                   return (0);
   
           if (devtype != UART_DEV_CONSOLE)
                   return (ENXIO);
   
           /*
            * Retrieve /chosen/std{in,out}.
            */
           if ((chosen = OF_finddevice("/chosen")) == 0)
                   return (ENXIO);
           if (OF_getprop(chosen, "stdin", buf, sizeof(buf)) <= 0)
                   return (ENXIO);
           if ((node = OF_finddevice(buf)) == 0)
                   return (ENXIO);
           if (OF_getprop(chosen, "stdout", buf, sizeof(buf)) <= 0)
                   return (ENXIO);
           if (OF_finddevice(buf) != node)
                   /* Only stdin == stdout is supported. */
                   return (ENXIO);
           /*
            * Retrieve serial attributes.
            */
           uart_fdt_get_shift(node, &shift);
   
           if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
                   br = 0;
           br = fdt32_to_cpu(br);
   
           if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
                   return (err);
           /*
            * Finalize configuration.
            */
           class = &uart_quicc_class;
           if (fdt_is_compatible(node, "ns16550"))
                   class = &uart_ns8250_class;
   
           di->bas.chan = 0;
           di->bas.regshft = (u_int)shift;
           di->baudrate = 0;
           di->bas.rclk = (u_int)rclk;
           di->ops = uart_getops(class);
           di->databits = 8;
           di->stopbits = 1;
           di->parity = UART_PARITY_NONE;
           di->bas.bst = uart_bus_space_mem;
   
           err = fdt_regsize(node, &start, &size);
           if (err)
                   return (ENXIO);
           start += fdt_immr_va;
   
           return (bus_space_map(di->bas.bst, start, size, 0, &di->bas.bsh));
   }

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