ec.c

linux 内核源代码

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 */