FreeBSD/Linux Kernel Cross Reference
sys/dev/extres/syscon/syscon.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2017 Kyle Evans <kevans@FreeBSD.org>
      *
      * 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.
     */
    
    /*
     * This is a generic syscon driver, whose purpose is to provide access to
     * various unrelated bits packed in a single register space. It is usually used
     * as a fallback to more specific driver, but works well enough for simple
     * access.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    #include "opt_platform.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/kobj.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/module.h>
    #include <sys/rman.h>
    #include <sys/sx.h>
    #include <sys/queue.h>
    
    #include <machine/bus.h>
    
    #ifdef FDT
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    #endif
    
    #include "syscon_if.h"
    #include "syscon.h"
    
    /*
     * Syscon interface details
     */
    typedef TAILQ_HEAD(syscon_list, syscon) syscon_list_t;
    
    /*
     * Declarations
     */
    static int syscon_method_init(struct syscon *syscon);
    static int syscon_method_uninit(struct syscon *syscon);
    static uint32_t syscon_method_read_4(struct syscon *syscon, bus_size_t offset);
    static int syscon_method_write_4(struct syscon *syscon, bus_size_t offset,
        uint32_t val);
    static int syscon_method_modify_4(struct syscon *syscon, bus_size_t offset,
        uint32_t clear_bits, uint32_t set_bits);
    
    
    MALLOC_DEFINE(M_SYSCON, "syscon", "Syscon driver");
    
    static syscon_list_t syscon_list = TAILQ_HEAD_INITIALIZER(syscon_list);
    static struct sx                syscon_topo_lock;
    SX_SYSINIT(syscon_topology, &syscon_topo_lock, "Syscon topology lock");
    
    /*
     * Syscon methods.
     */
    static syscon_method_t syscon_methods[] = {
            SYSCONMETHOD(syscon_init,       syscon_method_init),
            SYSCONMETHOD(syscon_uninit,     syscon_method_uninit),
            SYSCONMETHOD(syscon_read_4,     syscon_method_read_4),
            SYSCONMETHOD(syscon_write_4,    syscon_method_write_4),
            SYSCONMETHOD(syscon_modify_4,   syscon_method_modify_4),
    
            SYSCONMETHOD_END
    };
    DEFINE_CLASS_0(syscon, syscon_class, syscon_methods, 0);
    
    #define SYSCON_TOPO_SLOCK()     sx_slock(&syscon_topo_lock)
    #define SYSCON_TOPO_XLOCK()     sx_xlock(&syscon_topo_lock)
   #define SYSCON_TOPO_UNLOCK()    sx_unlock(&syscon_topo_lock)
   #define SYSCON_TOPO_ASSERT()    sx_assert(&syscon_topo_lock, SA_LOCKED)
   #define SYSCON_TOPO_XASSERT()   sx_assert(&syscon_topo_lock, SA_XLOCKED)
   
   /*
    * Default syscon methods for base class.
    */
   static int
   syscon_method_init(struct syscon *syscon)
   {
   
           return (0);
   };
   
   static int
   syscon_method_uninit(struct syscon *syscon)
   {
   
           return (0);
   };
   
   void *
   syscon_get_softc(struct syscon *syscon)
   {
   
           return (syscon->softc);
   };
   
   static uint32_t
   syscon_method_read_4(struct syscon *syscon, bus_size_t offset)
   {
           uint32_t val;
   
           SYSCON_DEVICE_LOCK(syscon->pdev);
           val = SYSCON_UNLOCKED_READ_4(syscon, offset);
           SYSCON_DEVICE_UNLOCK(syscon->pdev);
           return(val);
   }
   
   static int
   syscon_method_write_4(struct syscon *syscon, bus_size_t offset, uint32_t val)
   {
           int     rv;
   
           SYSCON_DEVICE_LOCK(syscon->pdev);
           rv = SYSCON_UNLOCKED_WRITE_4(syscon, offset, val);
           SYSCON_DEVICE_UNLOCK(syscon->pdev);
           return(rv);
   }
   
   static int
   syscon_method_modify_4(struct syscon *syscon, bus_size_t offset,
       uint32_t clear_bits, uint32_t set_bits)
   {
           int     rv;
   
           SYSCON_DEVICE_LOCK(syscon->pdev);
           rv = SYSCON_UNLOCKED_MODIFY_4(syscon, offset, clear_bits, set_bits);
           SYSCON_DEVICE_UNLOCK(syscon->pdev);
           return(rv);
   }
   /*
    * Create and initialize syscon object, but do not register it.
    */
   struct syscon *
   syscon_create(device_t pdev, syscon_class_t syscon_class)
   {
           struct syscon *syscon;
   
           /* Create object and initialize it. */
           syscon = malloc(sizeof(struct syscon), M_SYSCON,
               M_WAITOK | M_ZERO);
           kobj_init((kobj_t)syscon, (kobj_class_t)syscon_class);
   
           /* Allocate softc if required. */
           if (syscon_class->size > 0)
                   syscon->softc = malloc(syscon_class->size, M_SYSCON,
                       M_WAITOK | M_ZERO);
   
           /* Rest of init. */
           syscon->pdev = pdev;
           return (syscon);
   }
   
   /* Register syscon object. */
   struct syscon *
   syscon_register(struct syscon *syscon)
   {
           int rv;
   
   #ifdef FDT
           if (syscon->ofw_node <= 0)
                   syscon->ofw_node = ofw_bus_get_node(syscon->pdev);
           if (syscon->ofw_node <= 0)
                   return (NULL);
   #endif
   
           rv = SYSCON_INIT(syscon);
           if (rv != 0) {
                   printf("SYSCON_INIT failed: %d\n", rv);
                   return (NULL);
           }
   
   #ifdef FDT
           OF_device_register_xref(OF_xref_from_node(syscon->ofw_node),
               syscon->pdev);
   #endif
           SYSCON_TOPO_XLOCK();
           TAILQ_INSERT_TAIL(&syscon_list, syscon, syscon_link);
           SYSCON_TOPO_UNLOCK();
           return (syscon);
   }
   
   int
   syscon_unregister(struct syscon *syscon)
   {
   
           SYSCON_TOPO_XLOCK();
           TAILQ_REMOVE(&syscon_list, syscon, syscon_link);
           SYSCON_TOPO_UNLOCK();
   #ifdef FDT
           OF_device_register_xref(OF_xref_from_node(syscon->ofw_node), NULL);
   #endif
           return (SYSCON_UNINIT(syscon));
   }
   
   /**
    * Provider methods
    */
   #ifdef FDT
   static struct syscon *
   syscon_find_by_ofw_node(phandle_t node)
   {
           struct syscon *entry;
   
           SYSCON_TOPO_ASSERT();
   
           TAILQ_FOREACH(entry, &syscon_list, syscon_link) {
                   if (entry->ofw_node == node)
                           return (entry);
           }
   
           return (NULL);
   }
   
   struct syscon *
   syscon_create_ofw_node(device_t pdev, syscon_class_t syscon_class,
       phandle_t node)
   {
           struct syscon *syscon;
   
           syscon = syscon_create(pdev, syscon_class);
           if (syscon == NULL)
                   return (NULL);
           syscon->ofw_node = node;
           if (syscon_register(syscon) == NULL)
                   return (NULL);
           return (syscon);
   }
   
   phandle_t
   syscon_get_ofw_node(struct syscon *syscon)
   {
   
           return (syscon->ofw_node);
   }
   
   int
   syscon_get_by_ofw_node(device_t cdev, phandle_t node, struct syscon **syscon)
   {
   
           SYSCON_TOPO_SLOCK();
           *syscon = syscon_find_by_ofw_node(node);
           if (*syscon == NULL) {
                   SYSCON_TOPO_UNLOCK();
                   device_printf(cdev, "Failed to find syscon node\n");
                   return (ENODEV);
           }
           SYSCON_TOPO_UNLOCK();
           return (0);
   }
   
   int
   syscon_get_by_ofw_property(device_t cdev, phandle_t cnode, char *name,
       struct syscon **syscon)
   {
           pcell_t *cells;
           int ncells;
   
           if (cnode <= 0)
                   cnode = ofw_bus_get_node(cdev);
           if (cnode <= 0) {
                   device_printf(cdev,
                       "%s called on not ofw based device\n", __func__);
                   return (ENXIO);
           }
           ncells = OF_getencprop_alloc_multi(cnode, name, sizeof(pcell_t),
               (void **)&cells);
           if (ncells < 1)
                   return (ENOENT);
   
           /* Translate to syscon node. */
           SYSCON_TOPO_SLOCK();
           *syscon = syscon_find_by_ofw_node(OF_node_from_xref(cells[0]));
           if (*syscon == NULL) {
                   SYSCON_TOPO_UNLOCK();
                   device_printf(cdev, "Failed to find syscon node\n");
                   OF_prop_free(cells);
                   return (ENODEV);
           }
           SYSCON_TOPO_UNLOCK();
           OF_prop_free(cells);
           return (0);
   }
   #endif

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