diff options
Diffstat (limited to 'include/hw/qdev-core.h')
| -rw-r--r-- | include/hw/qdev-core.h | 267 |
1 files changed, 265 insertions, 2 deletions
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index fe78073c70..ea3f73a282 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -320,10 +320,86 @@ compat_props_add(GPtrArray *arr, /*** Board API. This should go away once we have a machine config file. ***/ +/** + * qdev_new: Create a device on the heap + * @name: device type to create (we assert() that this type exists) + * + * This only allocates the memory and initializes the device state + * structure, ready for the caller to set properties if they wish. + * The device still needs to be realized. + * The returned object has a reference count of 1. + */ DeviceState *qdev_new(const char *name); +/** + * qdev_try_new: Try to create a device on the heap + * @name: device type to create + * + * This is like qdev_new(), except it returns %NULL when type @name + * does not exist, rather than asserting. + */ DeviceState *qdev_try_new(const char *name); +/** + * qdev_realize: Realize @dev. + * @dev: device to realize + * @bus: bus to plug it into (may be NULL) + * @errp: pointer to error object + * + * "Realize" the device, i.e. perform the second phase of device + * initialization. + * @dev must not be plugged into a bus already. + * If @bus, plug @dev into @bus. This takes a reference to @dev. + * If @dev has no QOM parent, make one up, taking another reference. + * On success, return true. + * On failure, store an error through @errp and return false. + * + * If you created @dev using qdev_new(), you probably want to use + * qdev_realize_and_unref() instead. + */ bool qdev_realize(DeviceState *dev, BusState *bus, Error **errp); +/** + * qdev_realize_and_unref: Realize @dev and drop a reference + * @dev: device to realize + * @bus: bus to plug it into (may be NULL) + * @errp: pointer to error object + * + * Realize @dev and drop a reference. + * This is like qdev_realize(), except the caller must hold a + * (private) reference, which is dropped on return regardless of + * success or failure. Intended use:: + * + * dev = qdev_new(); + * [...] + * qdev_realize_and_unref(dev, bus, errp); + * + * Now @dev can go away without further ado. + * + * If you are embedding the device into some other QOM device and + * initialized it via some variant on object_initialize_child() then + * do not use this function, because that family of functions arrange + * for the only reference to the child device to be held by the parent + * via the child<> property, and so the reference-count-drop done here + * would be incorrect. For that use case you want qdev_realize(). + */ bool qdev_realize_and_unref(DeviceState *dev, BusState *bus, Error **errp); +/** + * qdev_unrealize: Unrealize a device + * @dev: device to unrealize + * + * This function will "unrealize" a device, which is the first phase + * of correctly destroying a device that has been realized. It will: + * + * - unrealize any child buses by calling qbus_unrealize() + * (this will recursively unrealize any devices on those buses) + * - call the the unrealize method of @dev + * + * The device can then be freed by causing its reference count to go + * to zero. + * + * Warning: most devices in QEMU do not expect to be unrealized. Only + * devices which are hot-unpluggable should be unrealized (as part of + * the unplugging process); all other devices are expected to last for + * the life of the simulation and should not be unrealized and freed. + */ void qdev_unrealize(DeviceState *dev); void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id, int required_for_version); @@ -348,13 +424,132 @@ void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev, void qdev_machine_creation_done(void); bool qdev_machine_modified(void); +/** + * qdev_get_gpio_in: Get one of a device's anonymous input GPIO lines + * @dev: Device whose GPIO we want + * @n: Number of the anonymous GPIO line (which must be in range) + * + * Returns the qemu_irq corresponding to an anonymous input GPIO line + * (which the device has set up with qdev_init_gpio_in()). The index + * @n of the GPIO line must be valid (i.e. be at least 0 and less than + * the total number of anonymous input GPIOs the device has); this + * function will assert() if passed an invalid index. + * + * This function is intended to be used by board code or SoC "container" + * device models to wire up the GPIO lines; usually the return value + * will be passed to qdev_connect_gpio_out() or a similar function to + * connect another device's output GPIO line to this input. + * + * For named input GPIO lines, use qdev_get_gpio_in_named(). + */ qemu_irq qdev_get_gpio_in(DeviceState *dev, int n); +/** + * qdev_get_gpio_in_named: Get one of a device's named input GPIO lines + * @dev: Device whose GPIO we want + * @name: Name of the input GPIO array + * @n: Number of the GPIO line in that array (which must be in range) + * + * Returns the qemu_irq corresponding to a named input GPIO line + * (which the device has set up with qdev_init_gpio_in_named()). + * The @name string must correspond to an input GPIO array which exists on + * the device, and the index @n of the GPIO line must be valid (i.e. + * be at least 0 and less than the total number of input GPIOs in that + * array); this function will assert() if passed an invalid name or index. + * + * For anonymous input GPIO lines, use qdev_get_gpio_in(). + */ qemu_irq qdev_get_gpio_in_named(DeviceState *dev, const char *name, int n); +/** + * qdev_connect_gpio_out: Connect one of a device's anonymous output GPIO lines + * @dev: Device whose GPIO to connect + * @n: Number of the anonymous output GPIO line (which must be in range) + * @pin: qemu_irq to connect the output line to + * + * This function connects an anonymous output GPIO line on a device + * up to an arbitrary qemu_irq, so that when the device asserts that + * output GPIO line, the qemu_irq's callback is invoked. + * The index @n of the GPIO line must be valid (i.e. be at least 0 and + * less than the total number of anonymous output GPIOs the device has + * created with qdev_init_gpio_out()); otherwise this function will assert(). + * + * Outbound GPIO lines can be connected to any qemu_irq, but the common + * case is connecting them to another device's inbound GPIO line, using + * the qemu_irq returned by qdev_get_gpio_in() or qdev_get_gpio_in_named(). + * + * It is not valid to try to connect one outbound GPIO to multiple + * qemu_irqs at once, or to connect multiple outbound GPIOs to the + * same qemu_irq. (Warning: there is no assertion or other guard to + * catch this error: the model will just not do the right thing.) + * Instead, for fan-out you can use the TYPE_IRQ_SPLIT device: connect + * a device's outbound GPIO to the splitter's input, and connect each + * of the splitter's outputs to a different device. For fan-in you + * can use the TYPE_OR_IRQ device, which is a model of a logical OR + * gate with multiple inputs and one output. + * + * For named output GPIO lines, use qdev_connect_gpio_out_named(). + */ void qdev_connect_gpio_out(DeviceState *dev, int n, qemu_irq pin); +/** + * qdev_connect_gpio_out: Connect one of a device's anonymous output GPIO lines + * @dev: Device whose GPIO to connect + * @name: Name of the output GPIO array + * @n: Number of the anonymous output GPIO line (which must be in range) + * @pin: qemu_irq to connect the output line to + * + * This function connects an anonymous output GPIO line on a device + * up to an arbitrary qemu_irq, so that when the device asserts that + * output GPIO line, the qemu_irq's callback is invoked. + * The @name string must correspond to an output GPIO array which exists on + * the device, and the index @n of the GPIO line must be valid (i.e. + * be at least 0 and less than the total number of input GPIOs in that + * array); this function will assert() if passed an invalid name or index. + * + * Outbound GPIO lines can be connected to any qemu_irq, but the common + * case is connecting them to another device's inbound GPIO line, using + * the qemu_irq returned by qdev_get_gpio_in() or qdev_get_gpio_in_named(). + * + * It is not valid to try to connect one outbound GPIO to multiple + * qemu_irqs at once, or to connect multiple outbound GPIOs to the + * same qemu_irq; see qdev_connect_gpio_out() for details. + * + * For named output GPIO lines, use qdev_connect_gpio_out_named(). + */ void qdev_connect_gpio_out_named(DeviceState *dev, const char *name, int n, qemu_irq pin); +/** + * qdev_get_gpio_out_connector: Get the qemu_irq connected to an output GPIO + * @dev: Device whose output GPIO we are interested in + * @name: Name of the output GPIO array + * @n: Number of the output GPIO line within that array + * + * Returns whatever qemu_irq is currently connected to the specified + * output GPIO line of @dev. This will be NULL if the output GPIO line + * has never been wired up to the anything. Note that the qemu_irq + * returned does not belong to @dev -- it will be the input GPIO or + * IRQ of whichever device the board code has connected up to @dev's + * output GPIO. + * + * You probably don't need to use this function -- it is used only + * by the platform-bus subsystem. + */ qemu_irq qdev_get_gpio_out_connector(DeviceState *dev, const char *name, int n); +/** + * qdev_intercept_gpio_out: Intercept an existing GPIO connection + * @dev: Device to intercept the outbound GPIO line from + * @icpt: New qemu_irq to connect instead + * @name: Name of the output GPIO array + * @n: Number of the GPIO line in the array + * + * This function is provided only for use by the qtest testing framework + * and is not suitable for use in non-testing parts of QEMU. + * + * This function breaks an existing connection of an outbound GPIO + * line from @dev, and replaces it with the new qemu_irq @icpt, as if + * ``qdev_connect_gpio_out_named(dev, icpt, name, n)`` had been called. + * The previously connected qemu_irq is returned, so it can be restored + * by a second call to qdev_intercept_gpio_out() if desired. + */ qemu_irq qdev_intercept_gpio_out(DeviceState *dev, qemu_irq icpt, const char *name, int n); @@ -362,10 +557,59 @@ BusState *qdev_get_child_bus(DeviceState *dev, const char *name); /*** Device API. ***/ -/* Register device properties. */ -/* GPIO inputs also double as IRQ sinks. */ +/** + * qdev_init_gpio_in: create an array of anonymous input GPIO lines + * @dev: Device to create input GPIOs for + * @handler: Function to call when GPIO line value is set + * @n: Number of GPIO lines to create + * + * Devices should use functions in the qdev_init_gpio_in* family in + * their instance_init or realize methods to create any input GPIO + * lines they need. There is no functional difference between + * anonymous and named GPIO lines. Stylistically, named GPIOs are + * preferable (easier to understand at callsites) unless a device + * has exactly one uniform kind of GPIO input whose purpose is obvious. + * Note that input GPIO lines can serve as 'sinks' for IRQ lines. + * + * See qdev_get_gpio_in() for how code that uses such a device can get + * hold of an input GPIO line to manipulate it. + */ void qdev_init_gpio_in(DeviceState *dev, qemu_irq_handler handler, int n); +/** + * qdev_init_gpio_out: create an array of anonymous output GPIO lines + * @dev: Device to create output GPIOs for + * @pins: Pointer to qemu_irq or qemu_irq array for the GPIO lines + * @n: Number of GPIO lines to create + * + * Devices should use functions in the qdev_init_gpio_out* family + * in their instance_init or realize methods to create any output + * GPIO lines they need. There is no functional difference between + * anonymous and named GPIO lines. Stylistically, named GPIOs are + * preferable (easier to understand at callsites) unless a device + * has exactly one uniform kind of GPIO output whose purpose is obvious. + * + * The @pins argument should be a pointer to either a "qemu_irq" + * (if @n == 1) or a "qemu_irq []" array (if @n > 1) in the device's + * state structure. The device implementation can then raise and + * lower the GPIO line by calling qemu_set_irq(). (If anything is + * connected to the other end of the GPIO this will cause the handler + * function for that input GPIO to be called.) + * + * See qdev_connect_gpio_out() for how code that uses such a device + * can connect to one of its output GPIO lines. + */ void qdev_init_gpio_out(DeviceState *dev, qemu_irq *pins, int n); +/** + * qdev_init_gpio_out: create an array of named output GPIO lines + * @dev: Device to create output GPIOs for + * @pins: Pointer to qemu_irq or qemu_irq array for the GPIO lines + * @name: Name to give this array of GPIO lines + * @n: Number of GPIO lines to create + * + * Like qdev_init_gpio_out(), but creates an array of GPIO output lines + * with a name. Code using the device can then connect these GPIO lines + * using qdev_connect_gpio_out_named(). + */ void qdev_init_gpio_out_named(DeviceState *dev, qemu_irq *pins, const char *name, int n); /** @@ -397,6 +641,25 @@ static inline void qdev_init_gpio_in_named(DeviceState *dev, qdev_init_gpio_in_named_with_opaque(dev, handler, dev, name, n); } +/** + * qdev_pass_gpios: create GPIO lines on container which pass through to device + * @dev: Device which has GPIO lines + * @container: Container device which needs to expose them + * @name: Name of GPIO array to pass through (NULL for the anonymous GPIO array) + * + * In QEMU, complicated devices like SoCs are often modelled with a + * "container" QOM device which itself contains other QOM devices and + * which wires them up appropriately. This function allows the container + * to create GPIO arrays on itself which simply pass through to a GPIO + * array of one of its internal devices. + * + * If @dev has both input and output GPIOs named @name then both will + * be passed through. It is not possible to pass a subset of the array + * with this function. + * + * To users of the container device, the GPIO array created on @container + * behaves exactly like any other. + */ void qdev_pass_gpios(DeviceState *dev, DeviceState *container, const char *name); |