FreeBSD/Linux Kernel Cross Reference
sys/dev/acpica/acpi_ec.c

     /*-
      * Copyright (c) 2003-2007 Nate Lawson
      * Copyright (c) 2000 Michael Smith
      * Copyright (c) 2000 BSDi
      * 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/8.1/sys/dev/acpica/acpi_ec.c 207250 2010-04-26 20:55:03Z jkim $");
    
    #include "opt_acpi.h"
    #include <sys/param.h>
    #include <sys/kernel.h>
    #include <sys/bus.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/module.h>
    #include <sys/sx.h>
    
    #include <machine/bus.h>
    #include <machine/resource.h>
    #include <sys/rman.h>
    
    #include <contrib/dev/acpica/include/acpi.h>
    #include <contrib/dev/acpica/include/accommon.h>
    
    #include <dev/acpica/acpivar.h>
    
    /* Hooks for the ACPI CA debugging infrastructure */
    #define _COMPONENT      ACPI_EC
    ACPI_MODULE_NAME("EC")
    
    /*
     * EC_COMMAND:
     * -----------
     */
    typedef UINT8                           EC_COMMAND;
    
    #define EC_COMMAND_UNKNOWN              ((EC_COMMAND) 0x00)
    #define EC_COMMAND_READ                 ((EC_COMMAND) 0x80)
    #define EC_COMMAND_WRITE                ((EC_COMMAND) 0x81)
    #define EC_COMMAND_BURST_ENABLE         ((EC_COMMAND) 0x82)
    #define EC_COMMAND_BURST_DISABLE        ((EC_COMMAND) 0x83)
    #define EC_COMMAND_QUERY                ((EC_COMMAND) 0x84)
    
    /*
     * EC_STATUS:
     * ----------
     * The encoding of the EC status register is illustrated below.
     * Note that a set bit (1) indicates the property is TRUE
     * (e.g. if bit 0 is set then the output buffer is full).
     * +-+-+-+-+-+-+-+-+
     * |7|6|5|4|3|2|1|0|
     * +-+-+-+-+-+-+-+-+
     *  | | | | | | | |
     *  | | | | | | | +- Output Buffer Full?
     *  | | | | | | +--- Input Buffer Full?
     *  | | | | | +----- <reserved>
     *  | | | | +------- Data Register is Command Byte?
     *  | | | +--------- Burst Mode Enabled?
     *  | | +----------- SCI Event?
     *  | +------------- SMI Event?
     *  +--------------- <reserved>
     *
     */
    typedef UINT8                           EC_STATUS;
    
    #define EC_FLAG_OUTPUT_BUFFER           ((EC_STATUS) 0x01)
    #define EC_FLAG_INPUT_BUFFER            ((EC_STATUS) 0x02)
    #define EC_FLAG_DATA_IS_CMD             ((EC_STATUS) 0x08)
    #define EC_FLAG_BURST_MODE              ((EC_STATUS) 0x10)
    
    /*
     * EC_EVENT:
     * ---------
     */
    typedef UINT8                           EC_EVENT;
    
   #define EC_EVENT_UNKNOWN                ((EC_EVENT) 0x00)
   #define EC_EVENT_OUTPUT_BUFFER_FULL     ((EC_EVENT) 0x01)
   #define EC_EVENT_INPUT_BUFFER_EMPTY     ((EC_EVENT) 0x02)
   #define EC_EVENT_SCI                    ((EC_EVENT) 0x20)
   #define EC_EVENT_SMI                    ((EC_EVENT) 0x40)
   
   /* Data byte returned after burst enable indicating it was successful. */
   #define EC_BURST_ACK                    0x90
   
   /*
    * Register access primitives
    */
   #define EC_GET_DATA(sc)                                                 \
           bus_space_read_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0)
   
   #define EC_SET_DATA(sc, v)                                              \
           bus_space_write_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0, (v))
   
   #define EC_GET_CSR(sc)                                                  \
           bus_space_read_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0)
   
   #define EC_SET_CSR(sc, v)                                               \
           bus_space_write_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0, (v))
   
   /* Additional params to pass from the probe routine */
   struct acpi_ec_params {
       int         glk;
       int         gpe_bit;
       ACPI_HANDLE gpe_handle;
       int         uid;
   };
   
   /*
    * Driver softc.
    */
   struct acpi_ec_softc {
       device_t            ec_dev;
       ACPI_HANDLE         ec_handle;
       int                 ec_uid;
       ACPI_HANDLE         ec_gpehandle;
       UINT8               ec_gpebit;
   
       int                 ec_data_rid;
       struct resource     *ec_data_res;
       bus_space_tag_t     ec_data_tag;
       bus_space_handle_t  ec_data_handle;
   
       int                 ec_csr_rid;
       struct resource     *ec_csr_res;
       bus_space_tag_t     ec_csr_tag;
       bus_space_handle_t  ec_csr_handle;
   
       int                 ec_glk;
       int                 ec_glkhandle;
       int                 ec_burstactive;
       int                 ec_sci_pend;
       u_int               ec_gencount;
       int                 ec_suspending;
   };
   
   /*
    * XXX njl
    * I couldn't find it in the spec but other implementations also use a
    * value of 1 ms for the time to acquire global lock.
    */
   #define EC_LOCK_TIMEOUT 1000
   
   /* Default delay in microseconds between each run of the status polling loop. */
   #define EC_POLL_DELAY   5
   
   /* Total time in ms spent waiting for a response from EC. */
   #define EC_TIMEOUT      750
   
   #define EVENT_READY(event, status)                      \
           (((event) == EC_EVENT_OUTPUT_BUFFER_FULL &&     \
            ((status) & EC_FLAG_OUTPUT_BUFFER) != 0) ||    \
            ((event) == EC_EVENT_INPUT_BUFFER_EMPTY &&     \
            ((status) & EC_FLAG_INPUT_BUFFER) == 0))
   
   ACPI_SERIAL_DECL(ec, "ACPI embedded controller");
   
   SYSCTL_DECL(_debug_acpi);
   SYSCTL_NODE(_debug_acpi, OID_AUTO, ec, CTLFLAG_RD, NULL, "EC debugging");
   
   static int      ec_burst_mode;
   TUNABLE_INT("debug.acpi.ec.burst", &ec_burst_mode);
   SYSCTL_INT(_debug_acpi_ec, OID_AUTO, burst, CTLFLAG_RW, &ec_burst_mode, 0,
       "Enable use of burst mode (faster for nearly all systems)");
   static int      ec_polled_mode;
   TUNABLE_INT("debug.acpi.ec.polled", &ec_polled_mode);
   SYSCTL_INT(_debug_acpi_ec, OID_AUTO, polled, CTLFLAG_RW, &ec_polled_mode, 0,
       "Force use of polled mode (only if interrupt mode doesn't work)");
   static int      ec_timeout = EC_TIMEOUT;
   TUNABLE_INT("debug.acpi.ec.timeout", &ec_timeout);
   SYSCTL_INT(_debug_acpi_ec, OID_AUTO, timeout, CTLFLAG_RW, &ec_timeout,
       EC_TIMEOUT, "Total time spent waiting for a response (poll+sleep)");
   
   static ACPI_STATUS
   EcLock(struct acpi_ec_softc *sc)
   {
       ACPI_STATUS status;
   
       /* If _GLK is non-zero, acquire the global lock. */
       status = AE_OK;
       if (sc->ec_glk) {
           status = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->ec_glkhandle);
           if (ACPI_FAILURE(status))
               return (status);
       }
       ACPI_SERIAL_BEGIN(ec);
       return (status);
   }
   
   static void
   EcUnlock(struct acpi_ec_softc *sc)
   {
       ACPI_SERIAL_END(ec);
       if (sc->ec_glk)
           AcpiReleaseGlobalLock(sc->ec_glkhandle);
   }
   
   static uint32_t         EcGpeHandler(void *Context);
   static ACPI_STATUS      EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function,
                                   void *Context, void **return_Context);
   static ACPI_STATUS      EcSpaceHandler(UINT32 Function,
                                   ACPI_PHYSICAL_ADDRESS Address,
                                   UINT32 width, UINT64 *Value,
                                   void *Context, void *RegionContext);
   static ACPI_STATUS      EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event,
                                   u_int gen_count);
   static ACPI_STATUS      EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd);
   static ACPI_STATUS      EcRead(struct acpi_ec_softc *sc, UINT8 Address,
                                   UINT8 *Data);
   static ACPI_STATUS      EcWrite(struct acpi_ec_softc *sc, UINT8 Address,
                                   UINT8 *Data);
   static int              acpi_ec_probe(device_t dev);
   static int              acpi_ec_attach(device_t dev);
   static int              acpi_ec_suspend(device_t dev);
   static int              acpi_ec_resume(device_t dev);
   static int              acpi_ec_shutdown(device_t dev);
   static int              acpi_ec_read_method(device_t dev, u_int addr,
                                   UINT64 *val, int width);
   static int              acpi_ec_write_method(device_t dev, u_int addr,
                                   UINT64 val, int width);
   
   static device_method_t acpi_ec_methods[] = {
       /* Device interface */
       DEVMETHOD(device_probe,     acpi_ec_probe),
       DEVMETHOD(device_attach,    acpi_ec_attach),
       DEVMETHOD(device_suspend,   acpi_ec_suspend),
       DEVMETHOD(device_resume,    acpi_ec_resume),
       DEVMETHOD(device_shutdown,  acpi_ec_shutdown),
   
       /* Embedded controller interface */
       DEVMETHOD(acpi_ec_read,     acpi_ec_read_method),
       DEVMETHOD(acpi_ec_write,    acpi_ec_write_method),
   
       {0, 0}
   };
   
   static driver_t acpi_ec_driver = {
       "acpi_ec",
       acpi_ec_methods,
       sizeof(struct acpi_ec_softc),
   };
   
   static devclass_t acpi_ec_devclass;
   DRIVER_MODULE(acpi_ec, acpi, acpi_ec_driver, acpi_ec_devclass, 0, 0);
   MODULE_DEPEND(acpi_ec, acpi, 1, 1, 1);
   
   /*
    * Look for an ECDT and if we find one, set up default GPE and
    * space handlers to catch attempts to access EC space before
    * we have a real driver instance in place.
    *
    * TODO: Some old Gateway laptops need us to fake up an ECDT or
    * otherwise attach early so that _REG methods can run.
    */
   void
   acpi_ec_ecdt_probe(device_t parent)
   {
       ACPI_TABLE_ECDT *ecdt;
       ACPI_STATUS      status;
       device_t         child;
       ACPI_HANDLE      h;
       struct acpi_ec_params *params;
   
       ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
   
       /* Find and validate the ECDT. */
       status = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
       if (ACPI_FAILURE(status) ||
           ecdt->Control.BitWidth != 8 ||
           ecdt->Data.BitWidth != 8) {
           return;
       }
   
       /* Create the child device with the given unit number. */
       child = BUS_ADD_CHILD(parent, 0, "acpi_ec", ecdt->Uid);
       if (child == NULL) {
           printf("%s: can't add child\n", __func__);
           return;
       }
   
       /* Find and save the ACPI handle for this device. */
       status = AcpiGetHandle(NULL, ecdt->Id, &h);
       if (ACPI_FAILURE(status)) {
           device_delete_child(parent, child);
           printf("%s: can't get handle\n", __func__);
           return;
       }
       acpi_set_handle(child, h);
   
       /* Set the data and CSR register addresses. */
       bus_set_resource(child, SYS_RES_IOPORT, 0, ecdt->Data.Address,
           /*count*/1);
       bus_set_resource(child, SYS_RES_IOPORT, 1, ecdt->Control.Address,
           /*count*/1);
   
       /*
        * Store values for the probe/attach routines to use.  Store the
        * ECDT GPE bit and set the global lock flag according to _GLK.
        * Note that it is not perfectly correct to be evaluating a method
        * before initializing devices, but in practice this function
        * should be safe to call at this point.
        */
       params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
       params->gpe_handle = NULL;
       params->gpe_bit = ecdt->Gpe;
       params->uid = ecdt->Uid;
       acpi_GetInteger(h, "_GLK", &params->glk);
       acpi_set_private(child, params);
   
       /* Finish the attach process. */
       if (device_probe_and_attach(child) != 0)
           device_delete_child(parent, child);
   }
   
   static int
   acpi_ec_probe(device_t dev)
   {
       ACPI_BUFFER buf;
       ACPI_HANDLE h;
       ACPI_OBJECT *obj;
       ACPI_STATUS status;
       device_t    peer;
       char        desc[64];
       int         ecdt;
       int         ret;
       struct acpi_ec_params *params;
       static char *ec_ids[] = { "PNP0C09", NULL };
   
       /* Check that this is a device and that EC is not disabled. */
       if (acpi_get_type(dev) != ACPI_TYPE_DEVICE || acpi_disabled("ec"))
           return (ENXIO);
   
       /*
        * If probed via ECDT, set description and continue.  Otherwise,
        * we can access the namespace and make sure this is not a
        * duplicate probe.
        */
       ret = ENXIO;
       ecdt = 0;
       buf.Pointer = NULL;
       buf.Length = ACPI_ALLOCATE_BUFFER;
       params = acpi_get_private(dev);
       if (params != NULL) {
           ecdt = 1;
           ret = 0;
       } else if (ACPI_ID_PROBE(device_get_parent(dev), dev, ec_ids)) {
           params = malloc(sizeof(struct acpi_ec_params), M_TEMP,
                           M_WAITOK | M_ZERO);
           h = acpi_get_handle(dev);
   
           /*
            * Read the unit ID to check for duplicate attach and the
            * global lock value to see if we should acquire it when
            * accessing the EC.
            */
           status = acpi_GetInteger(h, "_UID", &params->uid);
           if (ACPI_FAILURE(status))
               params->uid = 0;
           status = acpi_GetInteger(h, "_GLK", &params->glk);
           if (ACPI_FAILURE(status))
               params->glk = 0;
   
           /*
            * Evaluate the _GPE method to find the GPE bit used by the EC to
            * signal status (SCI).  If it's a package, it contains a reference
            * and GPE bit, similar to _PRW.
            */
           status = AcpiEvaluateObject(h, "_GPE", NULL, &buf);
           if (ACPI_FAILURE(status)) {
               device_printf(dev, "can't evaluate _GPE - %s\n",
                             AcpiFormatException(status));
               goto out;
           }
           obj = (ACPI_OBJECT *)buf.Pointer;
           if (obj == NULL)
               goto out;
   
           switch (obj->Type) {
           case ACPI_TYPE_INTEGER:
               params->gpe_handle = NULL;
               params->gpe_bit = obj->Integer.Value;
               break;
           case ACPI_TYPE_PACKAGE:
               if (!ACPI_PKG_VALID(obj, 2))
                   goto out;
               params->gpe_handle =
                   acpi_GetReference(NULL, &obj->Package.Elements[0]);
               if (params->gpe_handle == NULL ||
                   acpi_PkgInt32(obj, 1, &params->gpe_bit) != 0)
                   goto out;
               break;
           default:
               device_printf(dev, "_GPE has invalid type %d\n", obj->Type);
               goto out;
           }
   
           /* Store the values we got from the namespace for attach. */
           acpi_set_private(dev, params);
   
           /*
            * Check for a duplicate probe.  This can happen when a probe
            * via ECDT succeeded already.  If this is a duplicate, disable
            * this device.
            */
           peer = devclass_get_device(acpi_ec_devclass, params->uid);
           if (peer == NULL || !device_is_alive(peer))
               ret = 0;
           else
               device_disable(dev);
       }
   
   out:
       if (ret == 0) {
           snprintf(desc, sizeof(desc), "Embedded Controller: GPE %#x%s%s",
                    params->gpe_bit, (params->glk) ? ", GLK" : "",
                    ecdt ? ", ECDT" : "");
           device_set_desc_copy(dev, desc);
       }
   
       if (ret > 0 && params)
           free(params, M_TEMP);
       if (buf.Pointer)
           AcpiOsFree(buf.Pointer);
       return (ret);
   }
   
   static int
   acpi_ec_attach(device_t dev)
   {
       struct acpi_ec_softc        *sc;
       struct acpi_ec_params       *params;
       ACPI_STATUS                 Status;
   
       ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
   
       /* Fetch/initialize softc (assumes softc is pre-zeroed). */
       sc = device_get_softc(dev);
       params = acpi_get_private(dev);
       sc->ec_dev = dev;
       sc->ec_handle = acpi_get_handle(dev);
   
       /* Retrieve previously probed values via device ivars. */
       sc->ec_glk = params->glk;
       sc->ec_gpebit = params->gpe_bit;
       sc->ec_gpehandle = params->gpe_handle;
       sc->ec_uid = params->uid;
       sc->ec_suspending = FALSE;
       acpi_set_private(dev, NULL);
       free(params, M_TEMP);
   
       /* Attach bus resources for data and command/status ports. */
       sc->ec_data_rid = 0;
       sc->ec_data_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
                           &sc->ec_data_rid, RF_ACTIVE);
       if (sc->ec_data_res == NULL) {
           device_printf(dev, "can't allocate data port\n");
           goto error;
       }
       sc->ec_data_tag = rman_get_bustag(sc->ec_data_res);
       sc->ec_data_handle = rman_get_bushandle(sc->ec_data_res);
   
       sc->ec_csr_rid = 1;
       sc->ec_csr_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
                           &sc->ec_csr_rid, RF_ACTIVE);
       if (sc->ec_csr_res == NULL) {
           device_printf(dev, "can't allocate command/status port\n");
           goto error;
       }
       sc->ec_csr_tag = rman_get_bustag(sc->ec_csr_res);
       sc->ec_csr_handle = rman_get_bushandle(sc->ec_csr_res);
   
       /*
        * Install a handler for this EC's GPE bit.  We want edge-triggered
        * behavior.
        */
       ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching GPE handler\n"));
       Status = AcpiInstallGpeHandler(sc->ec_gpehandle, sc->ec_gpebit,
                   ACPI_GPE_EDGE_TRIGGERED, &EcGpeHandler, sc);
       if (ACPI_FAILURE(Status)) {
           device_printf(dev, "can't install GPE handler for %s - %s\n",
                         acpi_name(sc->ec_handle), AcpiFormatException(Status));
           goto error;
       }
   
       /*
        * Install address space handler
        */
       ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching address space handler\n"));
       Status = AcpiInstallAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
                   &EcSpaceHandler, &EcSpaceSetup, sc);
       if (ACPI_FAILURE(Status)) {
           device_printf(dev, "can't install address space handler for %s - %s\n",
                         acpi_name(sc->ec_handle), AcpiFormatException(Status));
           goto error;
       }
   
       /* Enable runtime GPEs for the handler. */
       Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit,
           ACPI_GPE_TYPE_RUNTIME);
       if (ACPI_FAILURE(Status)) {
           device_printf(dev, "AcpiEnableGpe failed: %s\n",
                         AcpiFormatException(Status));
           goto error;
       }
   
       ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "acpi_ec_attach complete\n"));
       return (0);
   
   error:
       AcpiRemoveGpeHandler(sc->ec_gpehandle, sc->ec_gpebit, &EcGpeHandler);
       AcpiRemoveAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
           EcSpaceHandler);
       if (sc->ec_csr_res)
           bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_csr_rid,
                                sc->ec_csr_res);
       if (sc->ec_data_res)
           bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_data_rid,
                                sc->ec_data_res);
       return (ENXIO);
   }
   
   static int
   acpi_ec_suspend(device_t dev)
   {
       struct acpi_ec_softc        *sc;
   
       sc = device_get_softc(dev);
       sc->ec_suspending = TRUE;
       return (0);
   }
   
   static int
   acpi_ec_resume(device_t dev)
   {
       struct acpi_ec_softc        *sc;
   
       sc = device_get_softc(dev);
       sc->ec_suspending = FALSE;
       return (0);
   }
   
   static int
   acpi_ec_shutdown(device_t dev)
   {
       struct acpi_ec_softc        *sc;
   
       /* Disable the GPE so we don't get EC events during shutdown. */
       sc = device_get_softc(dev);
       AcpiDisableGpe(sc->ec_gpehandle, sc->ec_gpebit, ACPI_GPE_TYPE_RUNTIME);
       return (0);
   }
   
   /* Methods to allow other devices (e.g., smbat) to read/write EC space. */
   static int
   acpi_ec_read_method(device_t dev, u_int addr, UINT64 *val, int width)
   {
       struct acpi_ec_softc *sc;
       ACPI_STATUS status;
   
       sc = device_get_softc(dev);
       status = EcSpaceHandler(ACPI_READ, addr, width * 8, val, sc, NULL);
       if (ACPI_FAILURE(status))
           return (ENXIO);
       return (0);
   }
   
   static int
   acpi_ec_write_method(device_t dev, u_int addr, UINT64 val, int width)
   {
       struct acpi_ec_softc *sc;
       ACPI_STATUS status;
   
       sc = device_get_softc(dev);
       status = EcSpaceHandler(ACPI_WRITE, addr, width * 8, &val, sc, NULL);
       if (ACPI_FAILURE(status))
           return (ENXIO);
       return (0);
   }
   
   static void
   EcGpeQueryHandler(void *Context)
   {
       struct acpi_ec_softc        *sc = (struct acpi_ec_softc *)Context;
       UINT8                       Data;
       ACPI_STATUS                 Status;
       char                        qxx[5];
   
       ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
       KASSERT(Context != NULL, ("EcGpeQueryHandler called with NULL"));
   
       /* Serialize user access with EcSpaceHandler(). */
       Status = EcLock(sc);
       if (ACPI_FAILURE(Status)) {
           device_printf(sc->ec_dev, "GpeQuery lock error: %s\n",
               AcpiFormatException(Status));
           return;
       }
   
       /*
        * Send a query command to the EC to find out which _Qxx call it
        * wants to make.  This command clears the SCI bit and also the
        * interrupt source since we are edge-triggered.  To prevent the GPE
        * that may arise from running the query from causing another query
        * to be queued, we clear the pending flag only after running it.
        */
       Status = EcCommand(sc, EC_COMMAND_QUERY);
       sc->ec_sci_pend = FALSE;
       if (ACPI_FAILURE(Status)) {
           EcUnlock(sc);
           device_printf(sc->ec_dev, "GPE query failed: %s\n",
               AcpiFormatException(Status));
           return;
       }
       Data = EC_GET_DATA(sc);
   
       /*
        * We have to unlock before running the _Qxx method below since that
        * method may attempt to read/write from EC address space, causing
        * recursive acquisition of the lock.
        */
       EcUnlock(sc);
   
       /* Ignore the value for "no outstanding event". (13.3.5) */
       CTR2(KTR_ACPI, "ec query ok,%s running _Q%02X", Data ? "" : " not", Data);
       if (Data == 0)
           return;
   
       /* Evaluate _Qxx to respond to the controller. */
       snprintf(qxx, sizeof(qxx), "_Q%02X", Data);
       AcpiUtStrupr(qxx);
       Status = AcpiEvaluateObject(sc->ec_handle, qxx, NULL, NULL);
       if (ACPI_FAILURE(Status) && Status != AE_NOT_FOUND) {
           device_printf(sc->ec_dev, "evaluation of query method %s failed: %s\n",
               qxx, AcpiFormatException(Status));
       }
   }
   
   /*
    * The GPE handler is called when IBE/OBF or SCI events occur.  We are
    * called from an unknown lock context.
    */
   static uint32_t
   EcGpeHandler(void *Context)
   {
       struct acpi_ec_softc *sc = Context;
       ACPI_STATUS                Status;
       EC_STATUS                  EcStatus;
   
       KASSERT(Context != NULL, ("EcGpeHandler called with NULL"));
       CTR0(KTR_ACPI, "ec gpe handler start");
   
       /*
        * Notify EcWaitEvent() that the status register is now fresh.  If we
        * didn't do this, it wouldn't be possible to distinguish an old IBE
        * from a new one, for example when doing a write transaction (writing
        * address and then data values.)
        */
       atomic_add_int(&sc->ec_gencount, 1);
       wakeup(&sc->ec_gencount);
   
       /*
        * If the EC_SCI bit of the status register is set, queue a query handler.
        * It will run the query and _Qxx method later, under the lock.
        */
       EcStatus = EC_GET_CSR(sc);
       if ((EcStatus & EC_EVENT_SCI) && !sc->ec_sci_pend) {
           CTR0(KTR_ACPI, "ec gpe queueing query handler");
           Status = AcpiOsExecute(OSL_GPE_HANDLER, EcGpeQueryHandler, Context);
           if (ACPI_SUCCESS(Status))
               sc->ec_sci_pend = TRUE;
           else
               printf("EcGpeHandler: queuing GPE query handler failed\n");
       }
       return (0);
   }
   
   static ACPI_STATUS
   EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function, void *Context,
                void **RegionContext)
   {
   
       ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
   
       /*
        * If deactivating a region, always set the output to NULL.  Otherwise,
        * just pass the context through.
        */
       if (Function == ACPI_REGION_DEACTIVATE)
           *RegionContext = NULL;
       else
           *RegionContext = Context;
   
       return_ACPI_STATUS (AE_OK);
   }
   
   static ACPI_STATUS
   EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 width,
                  UINT64 *Value, void *Context, void *RegionContext)
   {
       struct acpi_ec_softc        *sc = (struct acpi_ec_softc *)Context;
       ACPI_STATUS                 Status;
       UINT8                       EcAddr, EcData;
       int                         i;
   
       ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, (UINT32)Address);
   
       if (width % 8 != 0 || Value == NULL || Context == NULL)
           return_ACPI_STATUS (AE_BAD_PARAMETER);
       if (Address + (width / 8) - 1 > 0xFF)
           return_ACPI_STATUS (AE_BAD_ADDRESS);
   
       if (Function == ACPI_READ)
           *Value = 0;
       EcAddr = Address;
       Status = AE_ERROR;
   
       /*
        * If booting, check if we need to run the query handler.  If so, we
        * we call it directly here since our thread taskq is not active yet.
        */
       if (cold || rebooting || sc->ec_suspending) {
           if ((EC_GET_CSR(sc) & EC_EVENT_SCI)) {
               CTR0(KTR_ACPI, "ec running gpe handler directly");
               EcGpeQueryHandler(sc);
           }
       }
   
       /* Serialize with EcGpeQueryHandler() at transaction granularity. */
       Status = EcLock(sc);
       if (ACPI_FAILURE(Status))
           return_ACPI_STATUS (Status);
   
       /* Perform the transaction(s), based on width. */
       for (i = 0; i < width; i += 8, EcAddr++) {
           switch (Function) {
           case ACPI_READ:
               Status = EcRead(sc, EcAddr, &EcData);
               if (ACPI_SUCCESS(Status))
                   *Value |= ((UINT64)EcData) << i;
               break;
           case ACPI_WRITE:
               EcData = (UINT8)((*Value) >> i);
               Status = EcWrite(sc, EcAddr, &EcData);
               break;
           default:
               device_printf(sc->ec_dev, "invalid EcSpaceHandler function %d\n",
                             Function);
               Status = AE_BAD_PARAMETER;
               break;
           }
           if (ACPI_FAILURE(Status))
               break;
       }
   
       EcUnlock(sc);
       return_ACPI_STATUS (Status);
   }
   
   static ACPI_STATUS
   EcCheckStatus(struct acpi_ec_softc *sc, const char *msg, EC_EVENT event)
   {
       ACPI_STATUS status;
       EC_STATUS ec_status;
   
       status = AE_NO_HARDWARE_RESPONSE;
       ec_status = EC_GET_CSR(sc);
       if (sc->ec_burstactive && !(ec_status & EC_FLAG_BURST_MODE)) {
           CTR1(KTR_ACPI, "ec burst disabled in waitevent (%s)", msg);
           sc->ec_burstactive = FALSE;
       }
       if (EVENT_READY(event, ec_status)) {
           CTR2(KTR_ACPI, "ec %s wait ready, status %#x", msg, ec_status);
           status = AE_OK;
       }
       return (status);
   }
   
   static ACPI_STATUS
   EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event, u_int gen_count)
   {
       ACPI_STATUS Status;
       int         count, i, slp_ival;
   
       ACPI_SERIAL_ASSERT(ec);
       Status = AE_NO_HARDWARE_RESPONSE;
       int need_poll = cold || rebooting || ec_polled_mode || sc->ec_suspending;
       /*
        * The main CPU should be much faster than the EC.  So the status should
        * be "not ready" when we start waiting.  But if the main CPU is really
        * slow, it's possible we see the current "ready" response.  Since that
        * can't be distinguished from the previous response in polled mode,
        * this is a potential issue.  We really should have interrupts enabled
        * during boot so there is no ambiguity in polled mode.
        *
        * If this occurs, we add an additional delay before actually entering
        * the status checking loop, hopefully to allow the EC to go to work
        * and produce a non-stale status.
        */
       if (need_poll) {
           static int      once;
   
           if (EcCheckStatus(sc, "pre-check", Event) == AE_OK) {
               if (!once) {
                   device_printf(sc->ec_dev,
                       "warning: EC done before starting event wait\n");
                   once = 1;
               }
               AcpiOsStall(10);
           }
       }
   
       /* Wait for event by polling or GPE (interrupt). */
       if (need_poll) {
           count = (ec_timeout * 1000) / EC_POLL_DELAY;
           if (count == 0)
               count = 1;
           for (i = 0; i < count; i++) {
               Status = EcCheckStatus(sc, "poll", Event);
               if (Status == AE_OK)
                   break;
               AcpiOsStall(EC_POLL_DELAY);
           }
       } else {
           slp_ival = hz / 1000;
           if (slp_ival != 0) {
               count = ec_timeout;
           } else {
               /* hz has less than 1 ms resolution so scale timeout. */
               slp_ival = 1;
               count = ec_timeout / (1000 / hz);
           }
   
           /*
            * Wait for the GPE to signal the status changed, checking the
            * status register each time we get one.  It's possible to get a
            * GPE for an event we're not interested in here (i.e., SCI for
            * EC query).
            */
           for (i = 0; i < count; i++) {
               if (gen_count != sc->ec_gencount) {
                   /*
                    * Record new generation count.  It's possible the GPE was
                    * just to notify us that a query is needed and we need to
                    * wait for a second GPE to signal the completion of the
                    * event we are actually waiting for.
                    */
                   gen_count = sc->ec_gencount;
                   Status = EcCheckStatus(sc, "sleep", Event);
                   if (Status == AE_OK)
                       break;
               }
               tsleep(&sc->ec_gencount, PZERO, "ecgpe", slp_ival);
           }
   
           /*
            * We finished waiting for the GPE and it never arrived.  Try to
            * read the register once and trust whatever value we got.  This is
            * the best we can do at this point.  Then, force polled mode on
            * since this system doesn't appear to generate GPEs.
            */
           if (Status != AE_OK) {
               Status = EcCheckStatus(sc, "sleep_end", Event);
               device_printf(sc->ec_dev,
                   "wait timed out (%sresponse), forcing polled mode\n",
                   Status == AE_OK ? "" : "no ");
               ec_polled_mode = TRUE;
           }
       }
       if (Status != AE_OK)
               CTR0(KTR_ACPI, "error: ec wait timed out");
       return (Status);
   }
   
   static ACPI_STATUS
   EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd)
   {
       ACPI_STATUS status;
       EC_EVENT    event;
       EC_STATUS   ec_status;
       u_int       gen_count;
   
       ACPI_SERIAL_ASSERT(ec);
   
       /* Don't use burst mode if user disabled it. */
       if (!ec_burst_mode && cmd == EC_COMMAND_BURST_ENABLE)
           return (AE_ERROR);
   
       /* Decide what to wait for based on command type. */
       switch (cmd) {
       case EC_COMMAND_READ:
       case EC_COMMAND_WRITE:
       case EC_COMMAND_BURST_DISABLE:
           event = EC_EVENT_INPUT_BUFFER_EMPTY;
           break;
       case EC_COMMAND_QUERY:
       case EC_COMMAND_BURST_ENABLE:
           event = EC_EVENT_OUTPUT_BUFFER_FULL;
           break;
       default:
           device_printf(sc->ec_dev, "EcCommand: invalid command %#x\n", cmd);
           return (AE_BAD_PARAMETER);
       }
   
       /* Run the command and wait for the chosen event. */
       CTR1(KTR_ACPI, "ec running command %#x", cmd);
       gen_count = sc->ec_gencount;
       EC_SET_CSR(sc, cmd);
       status = EcWaitEvent(sc, event, gen_count);
       if (ACPI_SUCCESS(status)) {
           /* If we succeeded, burst flag should now be present. */
           if (cmd == EC_COMMAND_BURST_ENABLE) {
               ec_status = EC_GET_CSR(sc);
               if ((ec_status & EC_FLAG_BURST_MODE) == 0)
                   status = AE_ERROR;
           }
       } else
           device_printf(sc->ec_dev, "EcCommand: no response to %#x\n", cmd);
       return (status);
   }
   
   static ACPI_STATUS
   EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
   {
       ACPI_STATUS status;
       UINT8 data;
       u_int gen_count;
   
       ACPI_SERIAL_ASSERT(ec);
       CTR1(KTR_ACPI, "ec read from %#x", Address);
   
       /* If we can't start burst mode, continue anyway. */
       status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
       if (status == AE_OK) {
           data = EC_GET_DATA(sc);
           if (data == EC_BURST_ACK) {
               CTR0(KTR_ACPI, "ec burst enabled");
               sc->ec_burstactive = TRUE;
           }
       }
   
       status = EcCommand(sc, EC_COMMAND_READ);
       if (ACPI_FAILURE(status))
           return (status);
   
       gen_count = sc->ec_gencount;
       EC_SET_DATA(sc, Address);
       status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL, gen_count);
       if (ACPI_FAILURE(status)) {
           device_printf(sc->ec_dev, "EcRead: failed waiting to get data\n");
           return (status);
       }
       *Data = EC_GET_DATA(sc);
   
       if (sc->ec_burstactive) {
           sc->ec_burstactive = FALSE;
           status = EcCommand(sc, EC_COMMAND_BURST_DISABLE);
           if (ACPI_FAILURE(status))
               return (status);
           CTR0(KTR_ACPI, "ec disabled burst ok");
       }
   
       return (AE_OK);
   }
   
   static ACPI_STATUS
   EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
   {
       ACPI_STATUS status;
       UINT8 data;
       u_int gen_count;
   
       ACPI_SERIAL_ASSERT(ec);
       CTR2(KTR_ACPI, "ec write to %#x, data %#x", Address, *Data);
   
       /* If we can't start burst mode, continue anyway. */
       status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
      if (status == AE_OK) {
          data = EC_GET_DATA(sc);
          if (data == EC_BURST_ACK) {
              CTR0(KTR_ACPI, "ec burst enabled");
              sc->ec_burstactive = TRUE;
          }
      }
  
      status = EcCommand(sc, EC_COMMAND_WRITE);
      if (ACPI_FAILURE(status))
          return (status);
  
      gen_count = sc->ec_gencount;
      EC_SET_DATA(sc, Address);
      status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
      if (ACPI_FAILURE(status)) {
          device_printf(sc->ec_dev, "EcRead: failed waiting for sent address\n");
          return (status);
      }
  
      gen_count = sc->ec_gencount;
      EC_SET_DATA(sc, *Data);
      status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
      if (ACPI_FAILURE(status)) {
          device_printf(sc->ec_dev, "EcWrite: failed waiting for sent data\n");
          return (status);
      }
  
      if (sc->ec_burstactive) {
          sc->ec_burstactive = FALSE;
          status = EcCommand(sc, EC_COMMAND_BURST_DISABLE);
          if (ACPI_FAILURE(status))
              return (status);
          CTR0(KTR_ACPI, "ec disabled burst ok");
      }
  
      return (AE_OK);
  }

Cache object: e332dc190e896b4737bb6dee5b37e5bc