[PATCH 3/3] ACPI EC: Add support for non-AML EC query handlers

[Alexey Starikovskiy <aystarik@gmail.com>]

Signed-off-by: Alexey Starikovskiy <aystarik@gmail.com>
---

 drivers/acpi/ec.c |  175 ++++++++++++++++++++++++++++++++++++++---------------
 1 files changed, 125 insertions(+), 50 deletions(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index ffb8361..10e8510 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -34,6 +34,7 @@
 #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>
@@ -43,6 +44,7 @@
 #define ACPI_EC_HID			"PNP0C09"
 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
 #define ACPI_EC_FILE_INFO		"info"
+
 #undef PREFIX
 #define PREFIX				"ACPI: EC: "
 
@@ -60,6 +62,7 @@ enum ec_command {
 	ACPI_EC_BURST_DISABLE = 0x83,
 	ACPI_EC_COMMAND_QUERY = 0x84,
 };
+
 /* EC events */
 enum ec_event {
 	ACPI_EC_EVENT_OBF_1 = 1,	/* Output buffer full */
@@ -93,6 +96,16 @@ static struct acpi_driver acpi_ec_driver = {
 
 /* 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;
@@ -103,6 +116,7 @@ static struct acpi_ec {
 	atomic_t query_pending;
 	atomic_t event_count;
 	wait_queue_head_t wait;
+	struct list_head list;
 } *boot_ec, *first_ec;
 
 /* --------------------------------------------------------------------------
@@ -393,21 +407,67 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 /* --------------------------------------------------------------------------
                                 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_tail(&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;
+	mutex_lock(&ec->lock);
+	list_for_each_entry(handler, &ec->list, node) {
+		if (query_bit == handler->query_bit) {
+			list_del(&handler->node);
+			kfree(handler);
+			break;
+		}
+	}
+	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;
-	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);
-
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", 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);
+	printk(KERN_ERR PREFIX "Handler for query 0x%x is not found!\n", value);
 }
 
 static u32 acpi_ec_gpe_handler(void *data)
@@ -426,8 +486,7 @@ static u32 acpi_ec_gpe_handler(void *data)
 	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);
+		    acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);
 	}
 
 	return status == AE_OK ?
@@ -574,9 +633,6 @@ static int acpi_ec_remove_fs(struct acpi_device *device)
 static acpi_status
 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 
-static acpi_status
-ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval);
-
 static struct acpi_ec *make_acpi_ec(void)
 {
 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
@@ -587,13 +643,52 @@ static struct acpi_ec *make_acpi_ec(void)
 	atomic_set(&ec->event_count, 1);
 	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 int ec_parse_device(struct acpi_ec *ec, acpi_handle handle)
+{
+	if (ACPI_FAILURE(acpi_walk_resources(handle, METHOD_NAME__CRS,
+				     ec_parse_io_ports, ec)))
+		return -EINVAL;
+
+	/* Get GPE bit assignment (EC events). */
+	/* TODO: Add support for _GPE returning a package */
+	if (ACPI_FAILURE(acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe)))
+		return -EINVAL;
+
+	/* Use the global lock for all EC transactions? */
+	acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
+
+	/* Find and register all query methods */
+	acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
+			    acpi_ec_register_query_methods, ec, NULL);
+
+	ec->handle = handle;
+
+	printk(KERN_INFO PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx",
+			  ec->gpe, ec->command_addr, ec->data_addr);
+
+	return 0;
+}
+
 static int acpi_ec_add(struct acpi_device *device)
 {
-	acpi_status status = AE_OK;
 	struct acpi_ec *ec = NULL;
 
 	if (!device)
@@ -606,8 +701,7 @@ static int acpi_ec_add(struct acpi_device *device)
 	if (!ec)
 		return -ENOMEM;
 
-	status = ec_parse_device(device->handle, 0, ec, NULL);
-	if (status != AE_CTRL_TERMINATE) {
+	if (ec_parse_device(ec, device->handle)) {
 		kfree(ec);
 		return -EINVAL;
 	}
@@ -618,6 +712,8 @@ static int acpi_ec_add(struct acpi_device *device)
 			/* We might have incorrect info for GL at boot time */
 			mutex_lock(&boot_ec->lock);
 			boot_ec->global_lock = ec->global_lock;
+			/* Copy handlers from new ec into boot ec */
+			list_splice(&ec->list, &boot_ec->list);
 			mutex_unlock(&boot_ec->lock);
 			kfree(ec);
 			ec = boot_ec;
@@ -628,18 +724,24 @@ static int acpi_ec_add(struct acpi_device *device)
 	acpi_driver_data(device) = ec;
 
 	acpi_ec_add_fs(device);
-
 	return 0;
 }
 
 static int acpi_ec_remove(struct acpi_device *device, int type)
 {
 	struct acpi_ec *ec;
+	struct acpi_ec_query_handler *handler;
 
 	if (!device)
 		return -EINVAL;
 
 	ec = acpi_driver_data(device);
+	mutex_lock(&ec->lock);
+	list_for_each_entry(handler, &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)
@@ -695,15 +797,13 @@ static int ec_install_handlers(struct acpi_ec *ec)
 		return -ENODEV;
 	}
 
-	/* EC is fully operational, allow queries */
-	atomic_set(&ec->query_pending, 0);
-
 	return 0;
 }
 
 static int acpi_ec_start(struct acpi_device *device)
 {
 	struct acpi_ec *ec;
+	int ret = 0;
 
 	if (!device)
 		return -EINVAL;
@@ -714,10 +814,13 @@ static int acpi_ec_start(struct acpi_device *device)
 		return -EINVAL;
 
 	/* Boot EC is already working */
-	if (ec == boot_ec)
-		return 0;
+	if (ec != boot_ec)
+		ret = ec_install_handlers(ec);
+
+	/* EC is fully operational, allow queries */
+	atomic_set(&ec->query_pending, 0);
 
-	return ec_install_handlers(ec);
+	return ret;
 }
 
 static int acpi_ec_stop(struct acpi_device *device, int type)
@@ -749,34 +852,6 @@ static int acpi_ec_stop(struct acpi_device *device, int type)
 	return 0;
 }
 
-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;
-
-	/* Use the global lock for all EC transactions? */
-	acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
-
-	ec->handle = handle;
-
-	printk(KERN_INFO PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx",
-			  ec->gpe, ec->command_addr, ec->data_addr);
-
-	return AE_CTRL_TERMINATE;
-}
-
 int __init acpi_ec_ecdt_probe(void)
 {
 	int ret;