ACPI: EC: Detect irq storm
[safe/jmp/linux-2.6] / drivers / acpi / ec.c
index 8ef74e7..f0e8216 100644 (file)
@@ -1,6 +1,8 @@
 /*
- *  acpi_ec.c - ACPI Embedded Controller Driver ($Revision: 38 $)
+ *  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>
@@ -24,6 +26,9 @@
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 
+/* Uncomment next line to get verbose print outs*/
+/* #define DEBUG */
+
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.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 _COMPONENT             ACPI_EC_COMPONENT
-ACPI_MODULE_NAME("acpi_ec")
-#define ACPI_EC_COMPONENT              0x00100000
 #define ACPI_EC_CLASS                  "embedded_controller"
-#define ACPI_EC_HID                    "PNP0C09"
-#define ACPI_EC_DRIVER_NAME            "ACPI Embedded Controller Driver"
 #define ACPI_EC_DEVICE_NAME            "Embedded Controller"
 #define ACPI_EC_FILE_INFO              "info"
 
@@ -56,60 +57,58 @@ ACPI_MODULE_NAME("acpi_ec")
 #define ACPI_EC_FLAG_SCI       0x20    /* EC-SCI occurred */
 
 /* EC commands */
-#define ACPI_EC_COMMAND_READ   0x80
-#define ACPI_EC_COMMAND_WRITE  0x81
-#define ACPI_EC_BURST_ENABLE   0x82
-#define ACPI_EC_BURST_DISABLE  0x83
-#define ACPI_EC_COMMAND_QUERY  0x84
+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 {
+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 */
+#define ACPI_EC_UDELAY         100     /* Wait 100us before polling EC again */
 
 enum {
-       EC_INTR = 1,    /* Output buffer full */
-       EC_POLL,        /* Input buffer empty */
+       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_GPE,                /* Don't use GPE mode */
+       EC_FLAGS_RESCHEDULE_POLL        /* Re-schedule poll */
 };
 
-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);
+/* 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);
 
-static struct acpi_driver acpi_ec_driver = {
-       .name = ACPI_EC_DRIVER_NAME,
-       .class = ACPI_EC_CLASS,
-       .ids = ACPI_EC_HID,
-       .ops = {
-               .add = acpi_ec_add,
-               .remove = acpi_ec_remove,
-               .start = acpi_ec_start,
-               .stop = acpi_ec_stop,
-               },
+struct acpi_ec_query_handler {
+       struct list_head node;
+       acpi_ec_query_func func;
+       acpi_handle handle;
+       void *data;
+       u8 query_bit;
 };
 
-/* If we find an EC via the ECDT, we need to keep a ptr to its context */
-struct acpi_ec {
+static struct acpi_ec {
        acpi_handle handle;
-       unsigned long uid;
        unsigned long gpe;
        unsigned long command_addr;
        unsigned long data_addr;
        unsigned long global_lock;
+       unsigned long flags;
        struct mutex lock;
-       atomic_t query_pending;
-       atomic_t leaving_burst; /* 0 : No, 1 : Yes, 2: abort */
        wait_queue_head_t wait;
-} *ec_ecdt;
-
-/* External interfaces use first EC only, so remember */
-static struct acpi_device *first_ec;
-static int acpi_ec_mode = EC_INTR;
+       struct list_head list;
+       struct delayed_work work;
+       atomic_t irq_count;
+       u8 handlers_installed;
+} *boot_ec, *first_ec;
 
 /* --------------------------------------------------------------------------
                              Transaction Management
@@ -117,165 +116,143 @@ static int acpi_ec_mode = EC_INTR;
 
 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 {
-       return inb(ec->command_addr);
+       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 int acpi_ec_check_status(struct acpi_ec *ec, u8 event)
+static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 {
-       u8 status = acpi_ec_read_status(ec);
-       switch (event) {
-       case ACPI_EC_EVENT_OBF_1:
-               if (status & ACPI_EC_FLAG_OBF)
+       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;
-               break;
-       case ACPI_EC_EVENT_IBF_0:
-               if (!(status & ACPI_EC_FLAG_IBF))
+       } else if (event == ACPI_EC_EVENT_IBF_0) {
+               if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
                        return 1;
-               break;
-       default:
-               break;
        }
 
        return 0;
 }
 
-static int acpi_ec_wait(struct acpi_ec *ec, u8 event)
+static void ec_schedule_ec_poll(struct acpi_ec *ec)
 {
-       if (acpi_ec_mode == EC_POLL) {
-               unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
-               while (time_before(jiffies, delay)) {
-                       if (acpi_ec_check_status(ec, event))
-                               return 0;
-               }
-       } else {
-               if (wait_event_timeout(ec->wait,
-                                      acpi_ec_check_status(ec, event),
-                                      msecs_to_jiffies(ACPI_EC_DELAY)) ||
-                   acpi_ec_check_status(ec, event)) {
-                       return 0;
-               } else {
-                       printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
-                              " status = %d, expect_event = %d\n",
-                            acpi_ec_read_status(ec), event);
-               }
-       }
-
-       return -ETIME;
+       if (test_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags))
+               schedule_delayed_work(&ec->work,
+                                     msecs_to_jiffies(ACPI_EC_DELAY));
 }
 
-#ifdef ACPI_FUTURE_USAGE
-/*
- * Note: samsung nv5000 doesn't work with ec burst mode.
- * http://bugzilla.kernel.org/show_bug.cgi?id=4980
- */
-int acpi_ec_enter_burst_mode(struct acpi_ec *ec)
+static void ec_switch_to_poll_mode(struct acpi_ec *ec)
 {
-       u8 tmp = 0;
-       u8 status = 0;
-
-
-       status = acpi_ec_read_status(ec);
-       if (status != -EINVAL && !(status & ACPI_EC_FLAG_BURST)) {
-               status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
-               if (status)
-                       goto end;
-               acpi_ec_write_cmd(ec, ACPI_EC_BURST_ENABLE);
-               status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
-               tmp = acpi_ec_read_data(ec);
-               if (tmp != 0x90) {      /* Burst ACK byte */
-                       return -EINVAL;
-               }
-       }
-
-       atomic_set(&ec->leaving_burst, 0);
-       return 0;
-  end:
-       ACPI_EXCEPTION((AE_INFO, status, "EC wait, burst mode"));
-       return -1;
+       set_bit(EC_FLAGS_NO_GPE, &ec->flags);
+       clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+       acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
+       set_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 }
 
-int acpi_ec_leave_burst_mode(struct acpi_ec *ec)
+static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 {
-       u8 status = 0;
-
-
-       status = acpi_ec_read_status(ec);
-       if (status != -EINVAL && (status & ACPI_EC_FLAG_BURST)){
-               status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
-               if(status)
-                       goto end;
-               acpi_ec_write_cmd(ec, ACPI_EC_BURST_DISABLE);
-               acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
+       atomic_set(&ec->irq_count, 0);
+       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)))
+                       return 0;
+               clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+               if (acpi_ec_check_status(ec, event)) {
+                       /* missing GPEs, switch back to poll mode */
+                       if (printk_ratelimit())
+                               pr_info(PREFIX "missing confirmations, "
+                                               "switch off interrupt mode.\n");
+                       ec_switch_to_poll_mode(ec);
+                       ec_schedule_ec_poll(ec);
+                       return 0;
+               }
+       } 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))
+                               return 0;
+                       udelay(ACPI_EC_UDELAY);
+               }
        }
-       atomic_set(&ec->leaving_burst, 1);
-       return 0;
-  end:
-       ACPI_EXCEPTION((AE_INFO, status, "EC leave burst mode"));
-       return -1;
+       pr_err(PREFIX "acpi_ec_wait timeout, status = 0x%2.2x, event = %s\n",
+               acpi_ec_read_status(ec),
+               (event == ACPI_EC_EVENT_OBF_1) ? "\"b0=1\"" : "\"b1=0\"");
+       return -ETIME;
 }
-#endif /* ACPI_FUTURE_USAGE */
 
 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
-                                       const u8 *wdata, unsigned wdata_len,
-                                       u8 *rdata, unsigned rdata_len)
+                                       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);
+       pr_debug(PREFIX "transaction start\n");
        acpi_ec_write_cmd(ec, command);
-
-       for (; wdata_len > 0; wdata_len --) {
-               result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
+       for (; wdata_len > 0; --wdata_len) {
+               result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
                if (result) {
-                       printk(KERN_ERR PREFIX "write_cmd timeout, command = %d\n",
-                            command);
+                       pr_err(PREFIX
+                              "write_cmd timeout, command = %d\n", command);
                        goto end;
                }
+               set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
                acpi_ec_write_data(ec, *(wdata++));
        }
 
        if (!rdata_len) {
-               result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
+               result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
                if (result) {
-                       printk(KERN_ERR PREFIX "finish-write timeout, command = %d\n",
-                            command);
+                       pr_err(PREFIX
+                              "finish-write timeout, command = %d\n", command);
                        goto end;
                }
-       } else if (command == ACPI_EC_COMMAND_QUERY) {
-               atomic_set(&ec->query_pending, 0);
-       }
+       } 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);
+       for (; rdata_len > 0; --rdata_len) {
+               result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
                if (result) {
-                       printk(KERN_ERR PREFIX "read timeout, command = %d\n",
-                            command);
+                       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)
+                              const u8 * wdata, unsigned wdata_len,
+                              u8 * rdata, unsigned rdata_len,
+                              int force_poll)
 {
        int status;
        u32 glk;
@@ -283,71 +260,102 @@ static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
        if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
                return -EINVAL;
 
-        if (rdata)
-                memset(rdata, 0, rdata_len);
+       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))
+               if (ACPI_FAILURE(status)) {
+                       mutex_unlock(&ec->lock);
                        return -ENODEV;
+               }
        }
-       mutex_lock(&ec->lock);
 
-       /* Make sure GPE is enabled before doing transaction */
-       acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
-
-       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
+       status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
        if (status) {
-               printk(KERN_DEBUG PREFIX "read EC, IB not empty\n");
+               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);
+       status = acpi_ec_transaction_unlocked(ec, command,
+                                             wdata, wdata_len,
+                                             rdata, rdata_len,
+                                             force_poll);
 
-end:
-       mutex_unlock(&ec->lock);
+      end:
 
        if (ec->global_lock)
                acpi_release_global_lock(glk);
+       mutex_unlock(&ec->lock);
 
        return status;
 }
 
-static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
+/*
+ * 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);
+                                    &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);
+       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_read(u8 addr, u8 *val)
+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)
 {
-       struct acpi_ec *ec;
        int err;
        u8 temp_data;
 
        if (!first_ec)
                return -ENODEV;
 
-       ec = acpi_driver_data(first_ec);
-
-       err = acpi_ec_read(ec, addr, &temp_data);
+       err = acpi_ec_read(first_ec, addr, &temp_data);
 
        if (!err) {
                *val = temp_data;
@@ -360,104 +368,166 @@ EXPORT_SYMBOL(ec_read);
 
 int ec_write(u8 addr, u8 val)
 {
-       struct acpi_ec *ec;
        int err;
 
        if (!first_ec)
                return -ENODEV;
 
-       ec = acpi_driver_data(first_ec);
-
-       err = acpi_ec_write(ec, addr, val);
+       err = acpi_ec_write(first_ec, addr, val);
 
        return err;
 }
 
 EXPORT_SYMBOL(ec_write);
 
-extern int ec_transaction(u8 command,
-                          const u8 *wdata, unsigned wdata_len,
-                          u8 *rdata, unsigned rdata_len)
+int ec_transaction(u8 command,
+                  const u8 * wdata, unsigned wdata_len,
+                  u8 * rdata, unsigned rdata_len,
+                  int force_poll)
 {
-       struct acpi_ec *ec;
-
        if (!first_ec)
                return -ENODEV;
 
-       ec = acpi_driver_data(first_ec);
-
-       return acpi_ec_transaction(ec, command, wdata,
-                                  wdata_len, rdata, rdata_len);
+       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)
+static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 {
        int result;
-        u8 d;
+       u8 d;
 
-        if (!ec || !data)
-                return -EINVAL;
+       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).
-         */
+       /*
+        * 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);
-        if (result)
-                return result;
+       result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
+       if (result)
+               return result;
 
-        if (!d)
-                return -ENODATA;
+       if (!d)
+               return -ENODATA;
 
-        *data = d;
-        return 0;
+       *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 = (struct acpi_ec *)ec_cxt;
+       struct acpi_ec *ec = ec_cxt;
        u8 value = 0;
-       char object_name[8];
+       struct acpi_ec_query_handler *handler, copy;
 
        if (!ec || acpi_ec_query(ec, &value))
                return;
-
-       snprintf(object_name, 8, "_Q%2.2X", value);
-
-       printk(KERN_INFO PREFIX "evaluating %s\n", object_name);
-
-       acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
+       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;
-       u8 value;
-       struct acpi_ec *ec = (struct acpi_ec *)data;
-
-
-       if (acpi_ec_mode == EC_INTR) {
-               wake_up(&ec->wait);
+       struct acpi_ec *ec = data;
+       u8 state = acpi_ec_read_status(ec);
+
+       pr_debug(PREFIX "~~~> interrupt\n");
+       atomic_inc(&ec->irq_count);
+       if (atomic_read(&ec->irq_count) > 5) {
+               pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");
+               ec_switch_to_poll_mode(ec);
+               goto end;
        }
+       clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+       if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
+               wake_up(&ec->wait);
 
-       value = acpi_ec_read_status(ec);
-       if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
-               atomic_set(&ec->query_pending, 1);
-               status = acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);
+       if (state & 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 (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
+                  !test_bit(EC_FLAGS_NO_GPE, &ec->flags) &&
+                  in_interrupt()) {
+               /* 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);
+               clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
        }
-
-       return status == AE_OK ?
+end:
+       ec_schedule_ec_poll(ec);
+       return ACPI_SUCCESS(status) ?
            ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 }
 
+static void do_ec_poll(struct work_struct *work)
+{
+       struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);
+       atomic_set(&ec->irq_count, 0);
+       (void)acpi_ec_gpe_handler(ec);
+}
+
 /* --------------------------------------------------------------------------
                              Address Space Management
    -------------------------------------------------------------------------- */
@@ -477,60 +547,46 @@ acpi_ec_space_setup(acpi_handle region_handle,
 }
 
 static acpi_status
-acpi_ec_space_handler(u32 function,
-                     acpi_physical_address address,
-                     u32 bit_width,
-                     acpi_integer * value,
+acpi_ec_space_handler(u32 function, acpi_physical_address address,
+                     u32 bits, acpi_integer *value,
                      void *handler_context, void *region_context)
 {
-       int result = 0;
-       struct acpi_ec *ec = NULL;
-       u64 temp = *value;
-       acpi_integer f_v = 0;
-       int i = 0;
-
+       struct acpi_ec *ec = handler_context;
+       int result = 0, i;
+       u8 temp = 0;
 
        if ((address > 0xFF) || !value || !handler_context)
                return AE_BAD_PARAMETER;
 
-       if (bit_width != 8 && acpi_strict) {
+       if (function != ACPI_READ && function != ACPI_WRITE)
                return AE_BAD_PARAMETER;
-       }
 
-       ec = (struct acpi_ec *)handler_context;
+       if (bits != 8 && acpi_strict)
+               return AE_BAD_PARAMETER;
 
-      next_byte:
-       switch (function) {
-       case ACPI_READ:
-               temp = 0;
-               result = acpi_ec_read(ec, (u8) address, (u8 *) &temp);
-               break;
-       case ACPI_WRITE:
-               result = acpi_ec_write(ec, (u8) address, (u8) temp);
-               break;
-       default:
-               result = -EINVAL;
-               goto out;
-               break;
-       }
+       acpi_ec_burst_enable(ec);
 
-       bit_width -= 8;
-       if (bit_width) {
-               if (function == ACPI_READ)
-                       f_v |= temp << 8 * i;
-               if (function == ACPI_WRITE)
-                       temp >>= 8;
-               i++;
-               address++;
-               goto next_byte;
+       if (function == ACPI_READ) {
+               result = acpi_ec_read(ec, address, &temp);
+               *value = temp;
+       } else {
+               temp = 0xff & (*value);
+               result = acpi_ec_write(ec, address, temp);
        }
 
-       if (function == ACPI_READ) {
-               f_v |= temp << 8 * i;
-               *value = f_v;
+       for (i = 8; unlikely(bits - i > 0); i += 8) {
+               ++address;
+               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);
+               }
        }
 
-      out:
+       acpi_ec_burst_disable(ec);
+
        switch (result) {
        case -EINVAL:
                return AE_BAD_PARAMETER;
@@ -554,21 +610,16 @@ static struct proc_dir_entry *acpi_ec_dir;
 
 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 {
-       struct acpi_ec *ec = (struct acpi_ec *)seq->private;
-
+       struct acpi_ec *ec = seq->private;
 
        if (!ec)
                goto end;
 
-       seq_printf(seq, "gpe:                 0x%02x\n",
-                  (u32) ec->gpe);
-       seq_printf(seq, "ports:                   0x%02x, 0x%02x\n",
-                  (u32) ec->command_addr,
-                  (u32) ec->data_addr);
-       seq_printf(seq, "use global lock:         %s\n",
+       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");
-       acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
-
       end:
        return 0;
 }
@@ -590,7 +641,6 @@ 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);
@@ -626,159 +676,182 @@ static int acpi_ec_remove_fs(struct acpi_device *device)
 /* --------------------------------------------------------------------------
                                Driver Interface
    -------------------------------------------------------------------------- */
+static acpi_status
+ec_parse_io_ports(struct acpi_resource *resource, void *context);
 
-static int acpi_ec_add(struct acpi_device *device)
+static struct acpi_ec *make_acpi_ec(void)
 {
-       int result = 0;
-       acpi_status status = AE_OK;
-       struct acpi_ec *ec = NULL;
-
-
-       if (!device)
-               return -EINVAL;
-
-       ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
+       struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
        if (!ec)
-               return -ENOMEM;
-       memset(ec, 0, sizeof(struct acpi_ec));
-
-       ec->handle = device->handle;
-       ec->uid = -1;
+               return NULL;
+       ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
        mutex_init(&ec->lock);
-       atomic_set(&ec->query_pending, 0);
-       if (acpi_ec_mode == EC_INTR) {
-               atomic_set(&ec->leaving_burst, 1);
-               init_waitqueue_head(&ec->wait);
-       }
-       strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
-       strcpy(acpi_device_class(device), ACPI_EC_CLASS);
-       acpi_driver_data(device) = ec;
-
-       /* Use the global lock for all EC transactions? */
-       acpi_evaluate_integer(ec->handle, "_GLK", NULL,
-                             &ec->global_lock);
+       init_waitqueue_head(&ec->wait);
+       INIT_LIST_HEAD(&ec->list);
+       INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
+       atomic_set(&ec->irq_count, 0);
+       return ec;
+}
 
-       /* XXX we don't test uids, because on some boxes ecdt uid = 0, see:
-          http://bugzilla.kernel.org/show_bug.cgi?id=6111 */
-       if (ec_ecdt) {
-               acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
-                                                 ACPI_ADR_SPACE_EC,
-                                                 &acpi_ec_space_handler);
+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;
+}
 
-               acpi_remove_gpe_handler(NULL, ec_ecdt->gpe,
-                                       &acpi_ec_gpe_handler);
+static acpi_status
+ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
+{
+       acpi_status status;
 
-               kfree(ec_ecdt);
-       }
+       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(ec->handle, "_GPE", NULL,
-                                 &ec->gpe);
-       if (ACPI_FAILURE(status)) {
-               ACPI_EXCEPTION((AE_INFO, status, "Obtaining GPE bit assignment"));
-               result = -ENODEV;
-               goto end;
-       }
+       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;
+}
 
-       result = acpi_ec_add_fs(device);
-       if (result)
-               goto end;
+static void ec_poll_stop(struct acpi_ec *ec)
+{
+       clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
+       cancel_delayed_work(&ec->work);
+}
 
-       ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s [%s] (gpe %d) interrupt mode.",
-              acpi_device_name(device), acpi_device_bid(device),
-              (u32) ec->gpe));
+static void ec_remove_handlers(struct acpi_ec *ec)
+{
+       ec_poll_stop(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;
+}
 
-       if (!first_ec)
-               first_ec = device;
+static int acpi_ec_add(struct acpi_device *device)
+{
+       struct acpi_ec *ec = NULL;
 
-  end:
-       if (result)
-               kfree(ec);
+       if (!device)
+               return -EINVAL;
+       strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
+       strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 
-       return result;
+       /* 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 = NULL;
-
+       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
-acpi_ec_io_ports(struct acpi_resource *resource, void *context)
+ec_parse_io_ports(struct acpi_resource *resource, void *context)
 {
-       struct acpi_ec *ec = (struct acpi_ec *)context;
+       struct acpi_ec *ec = context;
 
-       if (resource->type != ACPI_RESOURCE_TYPE_IO) {
+       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) {
+       if (ec->data_addr == 0)
                ec->data_addr = resource->data.io.minimum;
-       } else if (ec->command_addr == 0) {
+       else if (ec->command_addr == 0)
                ec->command_addr = resource->data.io.minimum;
-       } else {
+       else
                return AE_CTRL_TERMINATE;
-       }
 
        return AE_OK;
 }
 
-static int acpi_ec_start(struct acpi_device *device)
+static int ec_install_handlers(struct acpi_ec *ec)
 {
-       acpi_status status = AE_OK;
-       struct acpi_ec *ec = NULL;
-
-
-       if (!device)
-               return -EINVAL;
-
-       ec = acpi_driver_data(device);
-
-       if (!ec)
-               return -EINVAL;
-
-       /*
-        * Get I/O port addresses. Convert to GAS format.
-        */
-       status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
-                                    acpi_ec_io_ports, ec);
-       if (ACPI_FAILURE(status) || ec->command_addr == 0) {
-               ACPI_EXCEPTION((AE_INFO, status,
-                               "Error getting I/O port addresses"));
-               return -ENODEV;
-       }
-
-       ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02lx, ports=0x%2lx,0x%2lx",
-                         ec->gpe, ec->command_addr, ec->data_addr));
-
-       /*
-        * Install GPE handler
-        */
+       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)) {
+       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);
 
@@ -787,210 +860,150 @@ static int acpi_ec_start(struct acpi_device *device)
                                                    &acpi_ec_space_handler,
                                                    &acpi_ec_space_setup, ec);
        if (ACPI_FAILURE(status)) {
-               acpi_remove_gpe_handler(NULL, ec->gpe,
-                                       &acpi_ec_gpe_handler);
+               acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
                return -ENODEV;
        }
 
-       return AE_OK;
+       ec->handlers_installed = 1;
+       return 0;
 }
 
-static int acpi_ec_stop(struct acpi_device *device, int type)
+static int acpi_ec_start(struct acpi_device *device)
 {
-       acpi_status status = AE_OK;
-       struct acpi_ec *ec = NULL;
-
+       struct acpi_ec *ec;
+       int ret = 0;
 
        if (!device)
                return -EINVAL;
 
        ec = acpi_driver_data(device);
 
-       status = acpi_remove_address_space_handler(ec->handle,
-                                                  ACPI_ADR_SPACE_EC,
-                                                  &acpi_ec_space_handler);
-       if (ACPI_FAILURE(status))
-               return -ENODEV;
+       if (!ec)
+               return -EINVAL;
 
-       status =
-           acpi_remove_gpe_handler(NULL, ec->gpe,
-                                   &acpi_ec_gpe_handler);
-       if (ACPI_FAILURE(status))
-               return -ENODEV;
+       ret = ec_install_handlers(ec);
 
-       return 0;
+       /* EC is fully operational, allow queries */
+       clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
+       ec_schedule_ec_poll(ec);
+       return ret;
 }
 
-static acpi_status __init
-acpi_fake_ecdt_callback(acpi_handle handle,
-                       u32 Level, void *context, void **retval)
+static int acpi_ec_stop(struct acpi_device *device, int type)
 {
-       acpi_status status;
-
-       mutex_init(&ec_ecdt->lock);
-       if (acpi_ec_mode == EC_INTR) {
-               init_waitqueue_head(&ec_ecdt->wait);
-       }
-       status = acpi_walk_resources(handle, METHOD_NAME__CRS,
-                                    acpi_ec_io_ports, ec_ecdt);
-       if (ACPI_FAILURE(status))
-               return status;
-
-       ec_ecdt->uid = -1;
-       acpi_evaluate_integer(handle, "_UID", NULL, &ec_ecdt->uid);
-
-       status =
-           acpi_evaluate_integer(handle, "_GPE", NULL,
-                                 &ec_ecdt->gpe);
-       if (ACPI_FAILURE(status))
-               return status;
-       ec_ecdt->global_lock = TRUE;
-       ec_ecdt->handle = handle;
-
-       ACPI_DEBUG_PRINT((ACPI_DB_INFO, "GPE=0x%02lx, ports=0x%2lx, 0x%2lx",
-              ec_ecdt->gpe, ec_ecdt->command_addr, ec_ecdt->data_addr));
+       struct acpi_ec *ec;
+       if (!device)
+               return -EINVAL;
+       ec = acpi_driver_data(device);
+       if (!ec)
+               return -EINVAL;
+       ec_remove_handlers(ec);
 
-       return AE_CTRL_TERMINATE;
+       return 0;
 }
 
-/*
- * Some BIOS (such as some from Gateway laptops) access EC region very early
- * such as in BAT0._INI or EC._INI before an EC device is found and
- * do not provide an ECDT. According to ACPI spec, ECDT isn't mandatorily
- * required, but if EC regison is accessed early, it is required.
- * The routine tries to workaround the BIOS bug by pre-scan EC device
- * It assumes that _CRS, _HID, _GPE, _UID methods of EC don't touch any
- * op region (since _REG isn't invoked yet). The assumption is true for
- * all systems found.
- */
-static int __init acpi_ec_fake_ecdt(void)
+int __init acpi_boot_ec_enable(void)
 {
-       acpi_status status;
-       int ret = 0;
-
-       ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Try to make an fake ECDT"));
-
-       ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
-       if (!ec_ecdt) {
-               ret = -ENOMEM;
-               goto error;
-       }
-       memset(ec_ecdt, 0, sizeof(struct acpi_ec));
-
-       status = acpi_get_devices(ACPI_EC_HID,
-                                 acpi_fake_ecdt_callback, NULL, NULL);
-       if (ACPI_FAILURE(status)) {
-               kfree(ec_ecdt);
-               ec_ecdt = NULL;
-               ret = -ENODEV;
-               ACPI_EXCEPTION((AE_INFO, status, "Can't make an fake ECDT"));
-               goto error;
+       if (!boot_ec || boot_ec->handlers_installed)
+               return 0;
+       if (!ec_install_handlers(boot_ec)) {
+               first_ec = boot_ec;
+               return 0;
        }
-       return 0;
-  error:
-       return ret;
+       return -EFAULT;
 }
 
-static int __init acpi_ec_get_real_ecdt(void)
+static const struct acpi_device_id ec_device_ids[] = {
+       {"PNP0C09", 0},
+       {"", 0},
+};
+
+int __init acpi_ec_ecdt_probe(void)
 {
+       int ret;
        acpi_status status;
        struct acpi_table_ecdt *ecdt_ptr;
 
-       status = acpi_get_firmware_table("ECDT", 1, ACPI_LOGICAL_ADDRESSING,
-                                        (struct acpi_table_header **)
-                                        &ecdt_ptr);
-       if (ACPI_FAILURE(status))
-               return -ENODEV;
-
-       ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found ECDT"));
-
+       boot_ec = make_acpi_ec();
+       if (!boot_ec)
+               return -ENOMEM;
        /*
-        * Generate a temporary ec context to use until the namespace is scanned
+        * Generate a boot ec context
         */
-       ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
-       if (!ec_ecdt)
-               return -ENOMEM;
-       memset(ec_ecdt, 0, sizeof(struct acpi_ec));
-
-       mutex_init(&ec_ecdt->lock);
-       if (acpi_ec_mode == EC_INTR) {
-               init_waitqueue_head(&ec_ecdt->wait);
-       }
-       ec_ecdt->command_addr = ecdt_ptr->ec_control.address;
-       ec_ecdt->data_addr = ecdt_ptr->ec_data.address;
-       ec_ecdt->gpe = ecdt_ptr->gpe_bit;
-       /* use the GL just to be safe */
-       ec_ecdt->global_lock = TRUE;
-       ec_ecdt->uid = ecdt_ptr->uid;
-
-       status =
-           acpi_get_handle(NULL, ecdt_ptr->ec_id, &ec_ecdt->handle);
-       if (ACPI_FAILURE(status)) {
-               goto error;
+       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;
        }
 
-       return 0;
-  error:
-       ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
-       kfree(ec_ecdt);
-       ec_ecdt = NULL;
-
+       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 __initdata acpi_fake_ecdt_enabled;
-int __init acpi_ec_ecdt_probe(void)
+static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
 {
-       acpi_status status;
-       int ret;
-
-       ret = acpi_ec_get_real_ecdt();
-       /* Try to make a fake ECDT */
-       if (ret && acpi_fake_ecdt_enabled) {
-               ret = acpi_ec_fake_ecdt();
-       }
-
-       if (ret)
-               return 0;
-
-       /*
-        * Install GPE handler
-        */
-       status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe,
-                                         ACPI_GPE_EDGE_TRIGGERED,
-                                         &acpi_ec_gpe_handler, ec_ecdt);
-       if (ACPI_FAILURE(status)) {
-               goto error;
-       }
-       acpi_set_gpe_type(NULL, ec_ecdt->gpe, ACPI_GPE_TYPE_RUNTIME);
-       acpi_enable_gpe(NULL, ec_ecdt->gpe, ACPI_NOT_ISR);
-
-       status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
-                                                   ACPI_ADR_SPACE_EC,
-                                                   &acpi_ec_space_handler,
-                                                   &acpi_ec_space_setup,
-                                                   ec_ecdt);
-       if (ACPI_FAILURE(status)) {
-               acpi_remove_gpe_handler(NULL, ec_ecdt->gpe,
-                                       &acpi_ec_gpe_handler);
-               goto error;
-       }
-
+       struct acpi_ec *ec = acpi_driver_data(device);
+       /* Stop using GPE */
+       set_bit(EC_FLAGS_NO_GPE, &ec->flags);
+       clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+       acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
        return 0;
+}
 
-      error:
-       ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
-       kfree(ec_ecdt);
-       ec_ecdt = NULL;
-
-       return -ENODEV;
+static int acpi_ec_resume(struct acpi_device *device)
+{
+       struct acpi_ec *ec = acpi_driver_data(device);
+       /* Enable use of GPE back */
+       clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
+       acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
+       return 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,
+               .suspend = acpi_ec_suspend,
+               .resume = acpi_ec_resume,
+               },
+};
+
 static int __init acpi_ec_init(void)
 {
        int result = 0;
 
-
        if (acpi_disabled)
                return 0;
 
@@ -1021,31 +1034,4 @@ static void __exit acpi_ec_exit(void)
 
        return;
 }
-#endif                         /* 0 */
-
-static int __init acpi_fake_ecdt_setup(char *str)
-{
-       acpi_fake_ecdt_enabled = 1;
-       return 1;
-}
-
-__setup("acpi_fake_ecdt", acpi_fake_ecdt_setup);
-static int __init acpi_ec_set_intr_mode(char *str)
-{
-       int intr;
-
-       if (!get_option(&str, &intr))
-               return 0;
-
-       if (intr) {
-               acpi_ec_mode = EC_INTR;
-       } else {
-               acpi_ec_mode = EC_POLL;
-       }
-       acpi_ec_driver.ops.add = acpi_ec_add;
-       ACPI_DEBUG_PRINT((ACPI_DB_INFO, "EC %s mode.\n", intr ? "interrupt" : "polling"));
-
-       return 1;
-}
-
-__setup("ec_intr=", acpi_ec_set_intr_mode);
+#endif /* 0 */