From: Jiang Liu <[email protected]> This patch implements a default mechanism to detect and manage ACPI system device hotplug slots based on standard ACPI interfaces. 1) Detech hotplug slot by checking existence of _EJ0 and _STA methods. 2) Power off a slot by excuting _EJ0 method.
It's the default hotplug slot enumerating mechanism, platform specifc drivers may provide advanced implementation to override the default implementation. Signed-off-by: Jiang Liu <[email protected]> Signed-off-by: Gaohuai Han <[email protected]> Signed-off-by: Jiang Liu <[email protected]> --- drivers/acpi/Kconfig | 10 +++ drivers/acpi/hotplug/Makefile | 1 + drivers/acpi/hotplug/slot_enum.c | 3 + drivers/acpi/hotplug/slot_enum_ej0.c | 113 ++++++++++++++++++++++++++++++++++ 4 files changed, 127 insertions(+) create mode 100644 drivers/acpi/hotplug/slot_enum_ej0.c diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 711e18e..c9f7918 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -344,6 +344,16 @@ config ACPI_HOTPLUG_ENUM To compile this driver as a module, choose M here: the module will be called acpihp_enum. +config ACPI_HOTPLUG_ENUM_EJ0 + bool "Detecting ACPI Hotplug Slot by Checking _EJ0 Method" + depends on ACPI_HOTPLUG_ENUM + default y + help + Enable detecting ACPI hotplug slots by checking ACPI _EJ0 method + under ACPI device objects. + + It's the default method to detect ACPI hotplug slots. + config ACPI_CONTAINER tristate "Container and Module Devices (EXPERIMENTAL)" depends on EXPERIMENTAL diff --git a/drivers/acpi/hotplug/Makefile b/drivers/acpi/hotplug/Makefile index 41c0da9..23dfa93 100644 --- a/drivers/acpi/hotplug/Makefile +++ b/drivers/acpi/hotplug/Makefile @@ -7,3 +7,4 @@ acpihp-y = core.o obj-$(CONFIG_ACPI_HOTPLUG_ENUM) += acpihp_enum.o acpihp_enum-y = slot_enum.o +acpihp_enum-y += slot_enum_ej0.o diff --git a/drivers/acpi/hotplug/slot_enum.c b/drivers/acpi/hotplug/slot_enum.c index 80396a3..a251ecf 100644 --- a/drivers/acpi/hotplug/slot_enum.c +++ b/drivers/acpi/hotplug/slot_enum.c @@ -40,11 +40,14 @@ struct acpihp_slot_id { static struct acpihp_slot_ops *slot_ops_curr; +extern struct acpihp_slot_ops acpihp_enum_ej0; + /* * Array of platform specific enumeration methods. * Entries in the array should be sorted by descending priority order. */ static struct acpihp_slot_ops *slot_ops_array[] = { + &acpihp_enum_ej0, NULL }; diff --git a/drivers/acpi/hotplug/slot_enum_ej0.c b/drivers/acpi/hotplug/slot_enum_ej0.c new file mode 100644 index 0000000..2788860 --- /dev/null +++ b/drivers/acpi/hotplug/slot_enum_ej0.c @@ -0,0 +1,113 @@ +/* + * Copyright (C) 2011 Huawei Tech. Co., Ltd. + * Copyright (C) 2011 Gaohuai Han <[email protected]> + * Copyright (C) 2011 Jiang Liu <[email protected]> + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * 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. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ + +#include <linux/acpi.h> +#include <acpi/acpi.h> +#include <acpi/acpi_hotplug.h> + +static acpi_status acpihp_enum_ej0_init(void) +{ + return AE_OK; +} + +static void acpihp_enum_ej0_fini(void) +{ +} + +static acpi_status acpihp_enum_ej0_check(acpi_handle handle) +{ + acpi_handle tmp; + + /* Assume a device object with _EJ0 and _STA has a hotplug slot. */ + if (ACPI_FAILURE(acpi_get_handle(handle, "_EJ0", &tmp))) + return AE_ERROR; + if (ACPI_FAILURE(acpi_get_handle(handle, METHOD_NAME__STA, &tmp))) + return AE_ERROR; + + return AE_OK; +} + +static acpi_status +acpihp_enum_ej0_get_capabilities(acpi_handle handle, u32 *capability) +{ + /* + * Assume device objects with _EJ0 are capable of: + * ONLINE, OFFLINE, POWEROFF, HOTPLUG + */ + *capability = ACPIHP_SLOT_CAP_ONLINE | ACPIHP_SLOT_CAP_OFFLINE | + ACPIHP_SLOT_CAP_POWEROFF | ACPIHP_SLOT_CAP_HOTPLUG; + + return AE_OK; +} + +static acpi_status acpihp_enum_ej0_poweron(acpi_handle handle) +{ + return AE_SUPPORT; +} + +static acpi_status acpihp_enum_ej0_poweroff(acpi_handle handle) +{ + acpi_status status; + unsigned long long sta; + union acpi_object arg; + struct acpi_object_list arg_list; + + if (!handle) + return AE_BAD_PARAMETER; + + arg_list.count = 1; + arg_list.pointer = &arg; + arg.type = ACPI_TYPE_INTEGER; + arg.integer.value = 1; + status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL); + if (ACPI_FAILURE(status)) { + ACPIHP_WARN("fails to power off object %p.\n", handle); + return status; + } + + status = acpi_evaluate_integer(handle, METHOD_NAME__STA, NULL, &sta); + if (ACPI_FAILURE(status)) { + ACPIHP_WARN("fails to evaluate _STA method of object %p\n", + handle); + return status; + } + + if (sta & (ACPI_STA_DEVICE_FUNCTIONING | ACPI_STA_DEVICE_ENABLED)) { + ACPIHP_WARN("object %p is still active after executing _EJ0.\n", + handle); + return AE_ERROR; + } + + return AE_OK; +} + +struct acpihp_slot_ops acpihp_enum_ej0 = { + .init = acpihp_enum_ej0_init, + .fini = acpihp_enum_ej0_fini, + .check = acpihp_enum_ej0_check, + .get_capabilities = acpihp_enum_ej0_get_capabilities, + .poweron = acpihp_enum_ej0_poweron, + .poweroff = acpihp_enum_ej0_poweroff, + .owner = THIS_MODULE, + .desc = "ACPI _EJ0 Based Hotplug Slot Enumerator" +}; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
