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Diffstat (limited to 'sys/kern/device_if.m')
| -rw-r--r-- | sys/kern/device_if.m | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/sys/kern/device_if.m b/sys/kern/device_if.m new file mode 100644 index 0000000..eb720eb --- /dev/null +++ b/sys/kern/device_if.m @@ -0,0 +1,318 @@ +#- +# Copyright (c) 1998-2004 Doug Rabson +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions +# are met: +# 1. Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# 2. Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# +# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +# SUCH DAMAGE. +# +# $FreeBSD$ +# + +#include <sys/bus.h> + +/** + * @defgroup DEVICE device - KObj methods for all device drivers + * @brief A basic set of methods required for all device drivers. + * + * The device interface is used to match devices to drivers during + * autoconfiguration and provides methods to allow drivers to handle + * system-wide events such as suspend, resume or shutdown. + * @{ + */ +INTERFACE device; + +# +# Default implementations of some methods. +# +CODE { + static int null_shutdown(device_t dev) + { + return 0; + } + + static int null_suspend(device_t dev) + { + return 0; + } + + static int null_resume(device_t dev) + { + return 0; + } + + static int null_quiesce(device_t dev) + { + return EOPNOTSUPP; + } +}; + +/** + * @brief Probe to see if a device matches a driver. + * + * Users should not call this method directly. Normally, this + * is called via device_probe_and_attach() to select a driver + * calling the DEVICE_PROBE() of all candidate drivers and attach + * the winning driver (if any) to the device. + * + * This function is used to match devices to device drivers. + * Typically, the driver will examine the device to see if + * it is suitable for this driver. This might include checking + * the values of various device instance variables or reading + * hardware registers. + * + * In some cases, there may be more than one driver available + * which can be used for a device (for instance there might + * be a generic driver which works for a set of many types of + * device and a more specific driver which works for a subset + * of devices). Because of this, a driver should not assume + * that it will be the driver that attaches to the device even + * if it returns a success status from DEVICE_PROBE(). In particular, + * a driver must free any resources which it allocated during + * the probe before returning. The return value of DEVICE_PROBE() + * is used to elect which driver is used - the driver which returns + * the largest non-error value wins the election and attaches to + * the device. Common non-error values are described in the + * DEVICE_PROBE(9) manual page. + * + * If a driver matches the hardware, it should set the device + * description string using device_set_desc() or + * device_set_desc_copy(). This string is used to generate an + * informative message when DEVICE_ATTACH() is called. + * + * As a special case, if a driver returns zero, the driver election + * is cut short and that driver will attach to the device + * immediately. This should rarely be used. + * + * For example, a probe method for a PCI device driver might look + * like this: + * + * @code + * int + * foo_probe(device_t dev) + * { + * if (pci_get_vendor(dev) == FOOVENDOR && + * pci_get_device(dev) == FOODEVICE) { + * device_set_desc(dev, "Foo device"); + * return (BUS_PROBE_DEFAULT); + * } + * return (ENXIO); + * } + * @endcode + * + * To include this method in a device driver, use a line like this + * in the driver's method list: + * + * @code + * KOBJMETHOD(device_probe, foo_probe) + * @endcode + * + * @param dev the device to probe + * + * @retval 0 if this is the only possible driver for this + * device + * @retval negative if the driver can match this device - the + * least negative value is used to select the + * driver + * @retval ENXIO if the driver does not match the device + * @retval positive if some kind of error was detected during + * the probe, a regular unix error code should + * be returned to indicate the type of error + * @see DEVICE_ATTACH(), pci_get_vendor(), pci_get_device() + */ +METHOD int probe { + device_t dev; +}; + +/** + * @brief Allow a device driver to detect devices not otherwise enumerated. + * + * The DEVICE_IDENTIFY() method is used by some drivers (e.g. the ISA + * bus driver) to help populate the bus device with a useful set of + * child devices, normally by calling the BUS_ADD_CHILD() method of + * the parent device. For instance, the ISA bus driver uses several + * special drivers, including the isahint driver and the pnp driver to + * create child devices based on configuration hints and PnP bus + * probes respectively. + * + * Many bus drivers which support true plug-and-play do not need to + * use this method at all since child devices can be discovered + * automatically without help from child drivers. + * + * To include this method in a device driver, use a line like this + * in the driver's method list: + * + * @code + * KOBJMETHOD(device_identify, foo_identify) + * @endcode + * + * @param driver the driver whose identify method is being called + * @param parent the parent device to use when adding new children + */ +STATICMETHOD void identify { + driver_t *driver; + device_t parent; +}; + +/** + * @brief Attach a device to a device driver + * + * Normally only called via device_probe_and_attach(), this is called + * when a driver has succeeded in probing against a device. + * This method should initialise the hardware and allocate other + * system resources (e.g. devfs entries) as required. + * + * To include this method in a device driver, use a line like this + * in the driver's method list: + * + * @code + * KOBJMETHOD(device_attach, foo_attach) + * @endcode + * + * @param dev the device to probe + * + * @retval 0 success + * @retval non-zero if some kind of error was detected during + * the attach, a regular unix error code should + * be returned to indicate the type of error + * @see DEVICE_PROBE() + */ +METHOD int attach { + device_t dev; +}; + +/** + * @brief Detach a driver from a device. + * + * This can be called if the user is replacing the + * driver software or if a device is about to be physically removed + * from the system (e.g. for removable hardware such as USB or PCCARD). + * + * To include this method in a device driver, use a line like this + * in the driver's method list: + * + * @code + * KOBJMETHOD(device_detach, foo_detach) + * @endcode + * + * @param dev the device to detach + * + * @retval 0 success + * @retval non-zero the detach could not be performed, e.g. if the + * driver does not support detaching. + * + * @see DEVICE_ATTACH() + */ +METHOD int detach { + device_t dev; +}; + +/** + * @brief Called during system shutdown. + * + * This method allows drivers to detect when the system is being shut down. + * Some drivers need to use this to place their hardware in a consistent + * state before rebooting the computer. + * + * To include this method in a device driver, use a line like this + * in the driver's method list: + * + * @code + * KOBJMETHOD(device_shutdown, foo_shutdown) + * @endcode + */ +METHOD int shutdown { + device_t dev; +} DEFAULT null_shutdown; + +/** + * @brief This is called by the power-management subsystem when a + * suspend has been requested by the user or by some automatic + * mechanism. + * + * This gives drivers a chance to veto the suspend or save their + * configuration before power is removed. + * + * To include this method in a device driver, use a line like this in + * the driver's method list: + * + * @code + * KOBJMETHOD(device_suspend, foo_suspend) + * @endcode + * + * @param dev the device being suspended + * + * @retval 0 success + * @retval non-zero an error occurred while attempting to prepare the + * device for suspension + * + * @see DEVICE_RESUME() + */ +METHOD int suspend { + device_t dev; +} DEFAULT null_suspend; + +/** + * @brief This is called when the system resumes after a suspend. + * + * To include this method in a device driver, use a line like this + * in the driver's method list: + * + * @code + * KOBJMETHOD(device_resume, foo_resume) + * @endcode + * + * @param dev the device being resumed + * + * @retval 0 success + * @retval non-zero an error occurred while attempting to restore the + * device from suspension + * + * @see DEVICE_SUSPEND() + */ +METHOD int resume { + device_t dev; +} DEFAULT null_resume; + +/** + * @brief This is called when the driver is asked to quiesce itself. + * + * The driver should arrange for the orderly shutdown of this device. + * All further access to the device should be curtailed. Soon there + * will be a request to detach, but there won't necessarily be one. + * + * To include this method in a device driver, use a line like this + * in the driver's method list: + * + * @code + * KOBJMETHOD(device_quiesce, foo_quiesce) + * @endcode + * + * @param dev the device being quiesced + * + * @retval 0 success + * @retval non-zero an error occurred while attempting to quiesce the + * device + * + * @see DEVICE_DETACH() + */ +METHOD int quiesce { + device_t dev; +} DEFAULT null_quiesce; |
