Logo Search packages:      
Sourcecode: linux version File versions  Download package

ec.c

/*
 *  ec.c - ACPI Embedded Controller Driver (v2.0)
 *
 *  Copyright (C) 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
 *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
 *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

/* Uncomment next line to get verbose print outs*/
/* #define DEBUG */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <asm/io.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include <acpi/actypes.h>

#define ACPI_EC_CLASS               "embedded_controller"
#define ACPI_EC_DEVICE_NAME         "Embedded Controller"
#define ACPI_EC_FILE_INFO           "info"

#undef PREFIX
#define PREFIX                      "ACPI: EC: "

/* EC status register */
#define ACPI_EC_FLAG_OBF      0x01  /* Output buffer full */
#define ACPI_EC_FLAG_IBF      0x02  /* Input buffer full */
#define ACPI_EC_FLAG_BURST    0x10  /* burst mode */
#define ACPI_EC_FLAG_SCI      0x20  /* EC-SCI occurred */

/* EC commands */
enum ec_command {
      ACPI_EC_COMMAND_READ = 0x80,
      ACPI_EC_COMMAND_WRITE = 0x81,
      ACPI_EC_BURST_ENABLE = 0x82,
      ACPI_EC_BURST_DISABLE = 0x83,
      ACPI_EC_COMMAND_QUERY = 0x84,
};

/* EC events */
enum ec_event {
      ACPI_EC_EVENT_OBF_1 = 1,      /* Output buffer full */
      ACPI_EC_EVENT_IBF_0,          /* Input buffer empty */
};

#define ACPI_EC_DELAY         500   /* Wait 500ms max. during EC ops */
#define ACPI_EC_UDELAY_GLK    1000  /* Wait 1ms max. to get global lock */

enum {
      EC_FLAGS_WAIT_GPE = 0,        /* Don't check status until GPE arrives */
      EC_FLAGS_QUERY_PENDING,       /* Query is pending */
      EC_FLAGS_GPE_MODE,            /* Expect GPE to be sent for status change */
      EC_FLAGS_NO_ADDRESS_GPE,      /* Expect GPE only for non-address event */
      EC_FLAGS_ADDRESS,       /* Address is being written */
      EC_FLAGS_NO_WDATA_GPE,        /* Don't expect WDATA GPE event */
      EC_FLAGS_WDATA,               /* Data is being written */
      EC_FLAGS_NO_OBF1_GPE,         /* Don't expect GPE before read */
};

static int acpi_ec_remove(struct acpi_device *device, int type);
static int acpi_ec_start(struct acpi_device *device);
static int acpi_ec_stop(struct acpi_device *device, int type);
static int acpi_ec_add(struct acpi_device *device);

static const struct acpi_device_id ec_device_ids[] = {
      {"PNP0C09", 0},
      {"", 0},
};

static struct acpi_driver acpi_ec_driver = {
      .name = "ec",
      .class = ACPI_EC_CLASS,
      .ids = ec_device_ids,
      .ops = {
            .add = acpi_ec_add,
            .remove = acpi_ec_remove,
            .start = acpi_ec_start,
            .stop = acpi_ec_stop,
            },
};

/* If we find an EC via the ECDT, we need to keep a ptr to its context */
/* External interfaces use first EC only, so remember */
typedef int (*acpi_ec_query_func) (void *data);

struct acpi_ec_query_handler {
      struct list_head node;
      acpi_ec_query_func func;
      acpi_handle handle;
      void *data;
      u8 query_bit;
};

static struct acpi_ec {
      acpi_handle handle;
      unsigned long gpe;
      unsigned long command_addr;
      unsigned long data_addr;
      unsigned long global_lock;
      unsigned long flags;
      struct mutex lock;
      wait_queue_head_t wait;
      struct list_head list;
      u8 handlers_installed;
} *boot_ec, *first_ec;

/* --------------------------------------------------------------------------
                             Transaction Management
   -------------------------------------------------------------------------- */

static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
{
      u8 x = inb(ec->command_addr);
      pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
      return x;
}

static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
{
      u8 x = inb(ec->data_addr);
      pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
      return inb(ec->data_addr);
}

static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
{
      pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
      outb(command, ec->command_addr);
}

static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
{
      pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
      outb(data, ec->data_addr);
}

static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
{
      if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
            return 0;
      if (event == ACPI_EC_EVENT_OBF_1) {
            if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
                  return 1;
      } else if (event == ACPI_EC_EVENT_IBF_0) {
            if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
                  return 1;
      }

      return 0;
}

static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
{
      int ret = 0;

      if (unlikely(event == ACPI_EC_EVENT_OBF_1 &&
                 test_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags)))
            force_poll = 1;
      if (unlikely(test_bit(EC_FLAGS_ADDRESS, &ec->flags) &&
                 test_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags)))
            force_poll = 1;
      if (unlikely(test_bit(EC_FLAGS_WDATA, &ec->flags) &&
                 test_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags)))
            force_poll = 1;
      if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
          likely(!force_poll)) {
            if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
                               msecs_to_jiffies(ACPI_EC_DELAY)))
                  goto end;
            clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
            if (acpi_ec_check_status(ec, event)) {
                  if (event == ACPI_EC_EVENT_OBF_1) {
                        /* miss OBF_1 GPE, don't expect it */
                        pr_info(PREFIX "missing OBF confirmation, "
                              "don't expect it any longer.\n");
                        set_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags);
                  } else if (test_bit(EC_FLAGS_ADDRESS, &ec->flags)) {
                        /* miss address GPE, don't expect it anymore */
                        pr_info(PREFIX "missing address confirmation, "
                              "don't expect it any longer.\n");
                        set_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags);
                  } else if (test_bit(EC_FLAGS_WDATA, &ec->flags)) {
                        /* miss write data GPE, don't expect it */
                        pr_info(PREFIX "missing write data confirmation, "
                              "don't expect it any longer.\n");
                        set_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags);
                  } else {
                        /* missing GPEs, switch back to poll mode */
                        if (printk_ratelimit())
                              pr_info(PREFIX "missing confirmations, "
                                    "switch off interrupt mode.\n");
                        clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
                  }
                  goto end;
            }
      } else {
            unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
            clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
            while (time_before(jiffies, delay)) {
                  if (acpi_ec_check_status(ec, event))
                        goto end;
            }
      }
      pr_err(PREFIX "acpi_ec_wait timeout,"
                         " status = %d, expect_event = %d\n",
                         acpi_ec_read_status(ec), event);
      ret = -ETIME;
      end:
      clear_bit(EC_FLAGS_ADDRESS, &ec->flags);
      return ret;
}

static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
                              const u8 * wdata, unsigned wdata_len,
                              u8 * rdata, unsigned rdata_len,
                              int force_poll)
{
      int result = 0;
      set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
      acpi_ec_write_cmd(ec, command);
      pr_debug(PREFIX "transaction start\n");
      for (; wdata_len > 0; --wdata_len) {
            result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
            if (result) {
                  pr_err(PREFIX
                         "write_cmd timeout, command = %d\n", command);
                  goto end;
            }
            /* mark the address byte written to EC */
            if (rdata_len + wdata_len > 1)
                  set_bit(EC_FLAGS_ADDRESS, &ec->flags);
            set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
            acpi_ec_write_data(ec, *(wdata++));
      }

      if (!rdata_len) {
            set_bit(EC_FLAGS_WDATA, &ec->flags);
            result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
            if (result) {
                  pr_err(PREFIX
                         "finish-write timeout, command = %d\n", command);
                  goto end;
            }
      } else if (command == ACPI_EC_COMMAND_QUERY)
            clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);

      for (; rdata_len > 0; --rdata_len) {
            result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
            if (result) {
                  pr_err(PREFIX "read timeout, command = %d\n", command);
                  goto end;
            }
            /* Don't expect GPE after last read */
            if (rdata_len > 1)
                  set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
            *(rdata++) = acpi_ec_read_data(ec);
      }
      end:
      pr_debug(PREFIX "transaction end\n");
      return result;
}

static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
                         const u8 * wdata, unsigned wdata_len,
                         u8 * rdata, unsigned rdata_len,
                         int force_poll)
{
      int status;
      u32 glk;

      if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
            return -EINVAL;

      if (rdata)
            memset(rdata, 0, rdata_len);

      mutex_lock(&ec->lock);
      if (ec->global_lock) {
            status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
            if (ACPI_FAILURE(status)) {
                  mutex_unlock(&ec->lock);
                  return -ENODEV;
            }
      }

      status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
      if (status) {
            pr_err(PREFIX "input buffer is not empty, "
                        "aborting transaction\n");
            goto end;
      }

      status = acpi_ec_transaction_unlocked(ec, command,
                                    wdata, wdata_len,
                                    rdata, rdata_len,
                                    force_poll);

      end:

      if (ec->global_lock)
            acpi_release_global_lock(glk);
      mutex_unlock(&ec->lock);

      return status;
}

/*
 * Note: samsung nv5000 doesn't work with ec burst mode.
 * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 */
int acpi_ec_burst_enable(struct acpi_ec *ec)
{
      u8 d;
      return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
}

int acpi_ec_burst_disable(struct acpi_ec *ec)
{
      return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
}

static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
{
      int result;
      u8 d;

      result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
                             &address, 1, &d, 1, 0);
      *data = d;
      return result;
}

static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
{
      u8 wdata[2] = { address, data };
      return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
                           wdata, 2, NULL, 0, 0);
}

/*
 * Externally callable EC access functions. For now, assume 1 EC only
 */
int ec_burst_enable(void)
{
      if (!first_ec)
            return -ENODEV;
      return acpi_ec_burst_enable(first_ec);
}

EXPORT_SYMBOL(ec_burst_enable);

int ec_burst_disable(void)
{
      if (!first_ec)
            return -ENODEV;
      return acpi_ec_burst_disable(first_ec);
}

EXPORT_SYMBOL(ec_burst_disable);

int ec_read(u8 addr, u8 * val)
{
      int err;
      u8 temp_data;

      if (!first_ec)
            return -ENODEV;

      err = acpi_ec_read(first_ec, addr, &temp_data);

      if (!err) {
            *val = temp_data;
            return 0;
      } else
            return err;
}

EXPORT_SYMBOL(ec_read);

int ec_write(u8 addr, u8 val)
{
      int err;

      if (!first_ec)
            return -ENODEV;

      err = acpi_ec_write(first_ec, addr, val);

      return err;
}

EXPORT_SYMBOL(ec_write);

int ec_transaction(u8 command,
               const u8 * wdata, unsigned wdata_len,
               u8 * rdata, unsigned rdata_len,
               int force_poll)
{
      if (!first_ec)
            return -ENODEV;

      return acpi_ec_transaction(first_ec, command, wdata,
                           wdata_len, rdata, rdata_len,
                           force_poll);
}

EXPORT_SYMBOL(ec_transaction);

static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
{
      int result;
      u8 d;

      if (!ec || !data)
            return -EINVAL;

      /*
       * Query the EC to find out which _Qxx method we need to evaluate.
       * Note that successful completion of the query causes the ACPI_EC_SCI
       * bit to be cleared (and thus clearing the interrupt source).
       */

      result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
      if (result)
            return result;

      if (!d)
            return -ENODATA;

      *data = d;
      return 0;
}

/* --------------------------------------------------------------------------
                                Event Management
   -------------------------------------------------------------------------- */
int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
                        acpi_handle handle, acpi_ec_query_func func,
                        void *data)
{
      struct acpi_ec_query_handler *handler =
          kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
      if (!handler)
            return -ENOMEM;

      handler->query_bit = query_bit;
      handler->handle = handle;
      handler->func = func;
      handler->data = data;
      mutex_lock(&ec->lock);
      list_add(&handler->node, &ec->list);
      mutex_unlock(&ec->lock);
      return 0;
}

EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);

void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
{
      struct acpi_ec_query_handler *handler, *tmp;
      mutex_lock(&ec->lock);
      list_for_each_entry_safe(handler, tmp, &ec->list, node) {
            if (query_bit == handler->query_bit) {
                  list_del(&handler->node);
                  kfree(handler);
            }
      }
      mutex_unlock(&ec->lock);
}

EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);

static void acpi_ec_gpe_query(void *ec_cxt)
{
      struct acpi_ec *ec = ec_cxt;
      u8 value = 0;
      struct acpi_ec_query_handler *handler, copy;

      if (!ec || acpi_ec_query(ec, &value))
            return;
      mutex_lock(&ec->lock);
      list_for_each_entry(handler, &ec->list, node) {
            if (value == handler->query_bit) {
                  /* have custom handler for this bit */
                  memcpy(&copy, handler, sizeof(copy));
                  mutex_unlock(&ec->lock);
                  if (copy.func) {
                        copy.func(copy.data);
                  } else if (copy.handle) {
                        acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
                  }
                  return;
            }
      }
      mutex_unlock(&ec->lock);
}

static u32 acpi_ec_gpe_handler(void *data)
{
      acpi_status status = AE_OK;
      struct acpi_ec *ec = data;

      pr_debug(PREFIX "~~~> interrupt\n");
      clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
      if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
            wake_up(&ec->wait);

      if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI) {
            if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
                  status = acpi_os_execute(OSL_EC_BURST_HANDLER,
                        acpi_ec_gpe_query, ec);
      } else if (unlikely(!test_bit(EC_FLAGS_GPE_MODE, &ec->flags))) {
            /* this is non-query, must be confirmation */
            if (printk_ratelimit())
                  pr_info(PREFIX "non-query interrupt received,"
                        " switching to interrupt mode\n");
            set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
      }

      return ACPI_SUCCESS(status) ?
          ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
}

/* --------------------------------------------------------------------------
                             Address Space Management
   -------------------------------------------------------------------------- */

static acpi_status
acpi_ec_space_setup(acpi_handle region_handle,
                u32 function, void *handler_context, void **return_context)
{
      /*
       * The EC object is in the handler context and is needed
       * when calling the acpi_ec_space_handler.
       */
      *return_context = (function != ACPI_REGION_DEACTIVATE) ?
          handler_context : NULL;

      return AE_OK;
}

static acpi_status
acpi_ec_space_handler(u32 function, acpi_physical_address address,
                  u32 bits, acpi_integer *value,
                  void *handler_context, void *region_context)
{
      struct acpi_ec *ec = handler_context;
      int result = 0, i = 0;
      u8 temp = 0;

      if ((address > 0xFF) || !value || !handler_context)
            return AE_BAD_PARAMETER;

      if (function != ACPI_READ && function != ACPI_WRITE)
            return AE_BAD_PARAMETER;

      if (bits != 8 && acpi_strict)
            return AE_BAD_PARAMETER;

      while (bits - i > 0) {
            if (function == ACPI_READ) {
                  result = acpi_ec_read(ec, address, &temp);
                  (*value) |= ((acpi_integer)temp) << i;
            } else {
                  temp = 0xff & ((*value) >> i);
                  result = acpi_ec_write(ec, address, temp);
            }
            i += 8;
            ++address;
      }

      switch (result) {
      case -EINVAL:
            return AE_BAD_PARAMETER;
            break;
      case -ENODEV:
            return AE_NOT_FOUND;
            break;
      case -ETIME:
            return AE_TIME;
            break;
      default:
            return AE_OK;
      }
}

/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

static struct proc_dir_entry *acpi_ec_dir;

static int acpi_ec_read_info(struct seq_file *seq, void *offset)
{
      struct acpi_ec *ec = seq->private;

      if (!ec)
            goto end;

      seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
      seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
               (unsigned)ec->command_addr, (unsigned)ec->data_addr);
      seq_printf(seq, "use global lock:\t%s\n",
               ec->global_lock ? "yes" : "no");
      end:
      return 0;
}

static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
{
      return single_open(file, acpi_ec_read_info, PDE(inode)->data);
}

static struct file_operations acpi_ec_info_ops = {
      .open = acpi_ec_info_open_fs,
      .read = seq_read,
      .llseek = seq_lseek,
      .release = single_release,
      .owner = THIS_MODULE,
};

static int acpi_ec_add_fs(struct acpi_device *device)
{
      struct proc_dir_entry *entry = NULL;

      if (!acpi_device_dir(device)) {
            acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
                                         acpi_ec_dir);
            if (!acpi_device_dir(device))
                  return -ENODEV;
      }

      entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
                          acpi_device_dir(device));
      if (!entry)
            return -ENODEV;
      else {
            entry->proc_fops = &acpi_ec_info_ops;
            entry->data = acpi_driver_data(device);
            entry->owner = THIS_MODULE;
      }

      return 0;
}

static int acpi_ec_remove_fs(struct acpi_device *device)
{

      if (acpi_device_dir(device)) {
            remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
            remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
            acpi_device_dir(device) = NULL;
      }

      return 0;
}

/* --------------------------------------------------------------------------
                               Driver Interface
   -------------------------------------------------------------------------- */
static acpi_status
ec_parse_io_ports(struct acpi_resource *resource, void *context);

static struct acpi_ec *make_acpi_ec(void)
{
      struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
      if (!ec)
            return NULL;
      ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
      mutex_init(&ec->lock);
      init_waitqueue_head(&ec->wait);
      INIT_LIST_HEAD(&ec->list);
      return ec;
}

static acpi_status
acpi_ec_register_query_methods(acpi_handle handle, u32 level,
                         void *context, void **return_value)
{
      struct acpi_namespace_node *node = handle;
      struct acpi_ec *ec = context;
      int value = 0;
      if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
            acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
      }
      return AE_OK;
}

static acpi_status
ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
{
      acpi_status status;

      struct acpi_ec *ec = context;
      status = acpi_walk_resources(handle, METHOD_NAME__CRS,
                             ec_parse_io_ports, ec);
      if (ACPI_FAILURE(status))
            return status;

      /* Get GPE bit assignment (EC events). */
      /* TODO: Add support for _GPE returning a package */
      status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
      if (ACPI_FAILURE(status))
            return status;
      /* Find and register all query methods */
      acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
                      acpi_ec_register_query_methods, ec, NULL);
      /* Use the global lock for all EC transactions? */
      acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
      ec->handle = handle;
      return AE_CTRL_TERMINATE;
}

static void ec_remove_handlers(struct acpi_ec *ec)
{
      if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
                        ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
            pr_err(PREFIX "failed to remove space handler\n");
      if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
                        &acpi_ec_gpe_handler)))
            pr_err(PREFIX "failed to remove gpe handler\n");
      ec->handlers_installed = 0;
}

static int acpi_ec_add(struct acpi_device *device)
{
      struct acpi_ec *ec = NULL;

      if (!device)
            return -EINVAL;
      strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
      strcpy(acpi_device_class(device), ACPI_EC_CLASS);

      /* Check for boot EC */
      if (boot_ec) {
            if (boot_ec->handle == device->handle) {
                  /* Pre-loaded EC from DSDT, just move pointer */
                  ec = boot_ec;
                  boot_ec = NULL;
                  goto end;
            } else if (boot_ec->handle == ACPI_ROOT_OBJECT) {
                  /* ECDT-based EC, time to shut it down */
                  ec_remove_handlers(boot_ec);
                  kfree(boot_ec);
                  first_ec = boot_ec = NULL;
            }
      }

      ec = make_acpi_ec();
      if (!ec)
            return -ENOMEM;

      if (ec_parse_device(device->handle, 0, ec, NULL) !=
          AE_CTRL_TERMINATE) {
            kfree(ec);
            return -EINVAL;
      }
      ec->handle = device->handle;
      end:
      if (!first_ec)
            first_ec = ec;
      acpi_driver_data(device) = ec;
      acpi_ec_add_fs(device);
      pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
                    ec->gpe, ec->command_addr, ec->data_addr);
      pr_info(PREFIX "driver started in %s mode\n",
            (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
      return 0;
}

static int acpi_ec_remove(struct acpi_device *device, int type)
{
      struct acpi_ec *ec;
      struct acpi_ec_query_handler *handler, *tmp;

      if (!device)
            return -EINVAL;

      ec = acpi_driver_data(device);
      mutex_lock(&ec->lock);
      list_for_each_entry_safe(handler, tmp, &ec->list, node) {
            list_del(&handler->node);
            kfree(handler);
      }
      mutex_unlock(&ec->lock);
      acpi_ec_remove_fs(device);
      acpi_driver_data(device) = NULL;
      if (ec == first_ec)
            first_ec = NULL;
      kfree(ec);
      return 0;
}

static acpi_status
ec_parse_io_ports(struct acpi_resource *resource, void *context)
{
      struct acpi_ec *ec = context;

      if (resource->type != ACPI_RESOURCE_TYPE_IO)
            return AE_OK;

      /*
       * The first address region returned is the data port, and
       * the second address region returned is the status/command
       * port.
       */
      if (ec->data_addr == 0)
            ec->data_addr = resource->data.io.minimum;
      else if (ec->command_addr == 0)
            ec->command_addr = resource->data.io.minimum;
      else
            return AE_CTRL_TERMINATE;

      return AE_OK;
}

static int ec_install_handlers(struct acpi_ec *ec)
{
      acpi_status status;
      if (ec->handlers_installed)
            return 0;
      status = acpi_install_gpe_handler(NULL, ec->gpe,
                                ACPI_GPE_EDGE_TRIGGERED,
                                &acpi_ec_gpe_handler, ec);
      if (ACPI_FAILURE(status))
            return -ENODEV;

      acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
      acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);

      status = acpi_install_address_space_handler(ec->handle,
                                        ACPI_ADR_SPACE_EC,
                                        &acpi_ec_space_handler,
                                        &acpi_ec_space_setup, ec);
      if (ACPI_FAILURE(status)) {
            acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
            return -ENODEV;
      }

      ec->handlers_installed = 1;
      return 0;
}

static int acpi_ec_start(struct acpi_device *device)
{
      struct acpi_ec *ec;
      int ret = 0;

      if (!device)
            return -EINVAL;

      ec = acpi_driver_data(device);

      if (!ec)
            return -EINVAL;

      ret = ec_install_handlers(ec);

      /* EC is fully operational, allow queries */
      clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
      return ret;
}

static int acpi_ec_stop(struct acpi_device *device, int type)
{
      struct acpi_ec *ec;
      if (!device)
            return -EINVAL;
      ec = acpi_driver_data(device);
      if (!ec)
            return -EINVAL;
      ec_remove_handlers(ec);

      return 0;
}

int __init acpi_boot_ec_enable(void)
{
      if (!boot_ec || boot_ec->handlers_installed)
            return 0;
      if (!ec_install_handlers(boot_ec)) {
            first_ec = boot_ec;
            return 0;
      }
      return -EFAULT;
}

int __init acpi_ec_ecdt_probe(void)
{
      int ret;
      acpi_status status;
      struct acpi_table_ecdt *ecdt_ptr;

      boot_ec = make_acpi_ec();
      if (!boot_ec)
            return -ENOMEM;
      /*
       * Generate a boot ec context
       */
      status = acpi_get_table(ACPI_SIG_ECDT, 1,
                        (struct acpi_table_header **)&ecdt_ptr);
      if (ACPI_SUCCESS(status)) {
            pr_info(PREFIX "EC description table is found, configuring boot EC\n");
            boot_ec->command_addr = ecdt_ptr->control.address;
            boot_ec->data_addr = ecdt_ptr->data.address;
            boot_ec->gpe = ecdt_ptr->gpe;
            boot_ec->handle = ACPI_ROOT_OBJECT;
      } else {
            /* This workaround is needed only on some broken machines,
             * which require early EC, but fail to provide ECDT */
            acpi_handle x;
            printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
            status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
                                    boot_ec, NULL);
            /* Check that acpi_get_devices actually find something */
            if (ACPI_FAILURE(status) || !boot_ec->handle)
                  goto error;
            /* We really need to limit this workaround, the only ASUS,
             * which needs it, has fake EC._INI method, so use it as flag.
             * Keep boot_ec struct as it will be needed soon.
             */
            if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
                  return -ENODEV;
      }

      ret = ec_install_handlers(boot_ec);
      if (!ret) {
            first_ec = boot_ec;
            return 0;
      }
      error:
      kfree(boot_ec);
      boot_ec = NULL;
      return -ENODEV;
}

static int __init acpi_ec_init(void)
{
      int result = 0;

      if (acpi_disabled)
            return 0;

      acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
      if (!acpi_ec_dir)
            return -ENODEV;

      /* Now register the driver for the EC */
      result = acpi_bus_register_driver(&acpi_ec_driver);
      if (result < 0) {
            remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
            return -ENODEV;
      }

      return result;
}

subsys_initcall(acpi_ec_init);

/* EC driver currently not unloadable */
#if 0
static void __exit acpi_ec_exit(void)
{

      acpi_bus_unregister_driver(&acpi_ec_driver);

      remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);

      return;
}
#endif      /* 0 */

Generated by  Doxygen 1.6.0   Back to index