diff options
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/dma-buf.rst | 6 | ||||
| -rw-r--r-- | Documentation/driver-api/driver-model/devres.rst | 2 | ||||
| -rw-r--r-- | Documentation/driver-api/gpio/driver.rst | 181 | ||||
| -rw-r--r-- | Documentation/driver-api/libata.rst | 11 | ||||
| -rw-r--r-- | Documentation/driver-api/media/cec-core.rst | 13 | ||||
| -rw-r--r-- | Documentation/driver-api/media/mc-core.rst | 13 | ||||
| -rw-r--r-- | Documentation/driver-api/media/v4l2-subdev.rst | 69 | ||||
| -rw-r--r-- | Documentation/driver-api/thermal/intel_dptf.rst | 2 | ||||
| -rw-r--r-- | Documentation/driver-api/vfio-mediated-device.rst | 27 |
9 files changed, 252 insertions, 72 deletions
diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst index 55006678394a..36a76cbe9095 100644 --- a/Documentation/driver-api/dma-buf.rst +++ b/Documentation/driver-api/dma-buf.rst @@ -185,6 +185,12 @@ DMA Fence Chain .. kernel-doc:: include/linux/dma-fence-chain.h :internal: +DMA Fence unwrap +~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/linux/dma-fence-unwrap.h + :internal: + DMA Fence uABI/Sync File ~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst index 5018403fe82f..2d39967bafcc 100644 --- a/Documentation/driver-api/driver-model/devres.rst +++ b/Documentation/driver-api/driver-model/devres.rst @@ -249,7 +249,7 @@ CLOCK devm_clk_bulk_get() devm_clk_bulk_get_all() devm_clk_bulk_get_optional() - devm_get_clk_from_childl() + devm_get_clk_from_child() devm_clk_hw_register() devm_of_clk_add_hw_provider() devm_clk_hw_register_clkdev() diff --git a/Documentation/driver-api/gpio/driver.rst b/Documentation/driver-api/gpio/driver.rst index bbc53920d4dd..70ff43ac4fcc 100644 --- a/Documentation/driver-api/gpio/driver.rst +++ b/Documentation/driver-api/gpio/driver.rst @@ -417,30 +417,68 @@ struct gpio_irq_chip inside struct gpio_chip before adding the gpio_chip. If you do this, the additional irq_chip will be set up by gpiolib at the same time as setting up the rest of the GPIO functionality. The following is a typical example of a chained cascaded interrupt handler using -the gpio_irq_chip: +the gpio_irq_chip. Note how the mask/unmask (or disable/enable) functions +call into the core gpiolib code: .. code-block:: c - /* Typical state container with dynamic irqchip */ + /* Typical state container */ struct my_gpio { struct gpio_chip gc; - struct irq_chip irq; + }; + + static void my_gpio_mask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + + /* + * Perform any necessary action to mask the interrupt, + * and then call into the core code to synchronise the + * state. + */ + + gpiochip_disable_irq(gc, hwirq); + } + + static void my_gpio_unmask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + + gpiochip_enable_irq(gc, hwirq); + + /* + * Perform any necessary action to unmask the interrupt, + * after having called into the core code to synchronise + * the state. + */ + } + + /* + * Statically populate the irqchip. Note that it is made const + * (further indicated by the IRQCHIP_IMMUTABLE flag), and that + * the GPIOCHIP_IRQ_RESOURCE_HELPER macro adds some extra + * callbacks to the structure. + */ + static const struct irq_chip my_gpio_irq_chip = { + .name = "my_gpio_irq", + .irq_ack = my_gpio_ack_irq, + .irq_mask = my_gpio_mask_irq, + .irq_unmask = my_gpio_unmask_irq, + .irq_set_type = my_gpio_set_irq_type, + .flags = IRQCHIP_IMMUTABLE, + /* Provide the gpio resource callbacks */ + GPIOCHIP_IRQ_RESOURCE_HELPERS, }; int irq; /* from platform etc */ struct my_gpio *g; struct gpio_irq_chip *girq; - /* Set up the irqchip dynamically */ - g->irq.name = "my_gpio_irq"; - g->irq.irq_ack = my_gpio_ack_irq; - g->irq.irq_mask = my_gpio_mask_irq; - g->irq.irq_unmask = my_gpio_unmask_irq; - g->irq.irq_set_type = my_gpio_set_irq_type; - /* Get a pointer to the gpio_irq_chip */ girq = &g->gc.irq; - girq->chip = &g->irq; + gpio_irq_chip_set_chip(girq, &my_gpio_irq_chip); girq->parent_handler = ftgpio_gpio_irq_handler; girq->num_parents = 1; girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents), @@ -458,23 +496,60 @@ the interrupt separately and go with it: .. code-block:: c - /* Typical state container with dynamic irqchip */ + /* Typical state container */ struct my_gpio { struct gpio_chip gc; - struct irq_chip irq; + }; + + static void my_gpio_mask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + + /* + * Perform any necessary action to mask the interrupt, + * and then call into the core code to synchronise the + * state. + */ + + gpiochip_disable_irq(gc, hwirq); + } + + static void my_gpio_unmask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + + gpiochip_enable_irq(gc, hwirq); + + /* + * Perform any necessary action to unmask the interrupt, + * after having called into the core code to synchronise + * the state. + */ + } + + /* + * Statically populate the irqchip. Note that it is made const + * (further indicated by the IRQCHIP_IMMUTABLE flag), and that + * the GPIOCHIP_IRQ_RESOURCE_HELPER macro adds some extra + * callbacks to the structure. + */ + static const struct irq_chip my_gpio_irq_chip = { + .name = "my_gpio_irq", + .irq_ack = my_gpio_ack_irq, + .irq_mask = my_gpio_mask_irq, + .irq_unmask = my_gpio_unmask_irq, + .irq_set_type = my_gpio_set_irq_type, + .flags = IRQCHIP_IMMUTABLE, + /* Provide the gpio resource callbacks */ + GPIOCHIP_IRQ_RESOURCE_HELPERS, }; int irq; /* from platform etc */ struct my_gpio *g; struct gpio_irq_chip *girq; - /* Set up the irqchip dynamically */ - g->irq.name = "my_gpio_irq"; - g->irq.irq_ack = my_gpio_ack_irq; - g->irq.irq_mask = my_gpio_mask_irq; - g->irq.irq_unmask = my_gpio_unmask_irq; - g->irq.irq_set_type = my_gpio_set_irq_type; - ret = devm_request_threaded_irq(dev, irq, NULL, irq_thread_fn, IRQF_ONESHOT, "my-chip", g); if (ret < 0) @@ -482,7 +557,7 @@ the interrupt separately and go with it: /* Get a pointer to the gpio_irq_chip */ girq = &g->gc.irq; - girq->chip = &g->irq; + gpio_irq_chip_set_chip(girq, &my_gpio_irq_chip); /* This will let us handle the parent IRQ in the driver */ girq->parent_handler = NULL; girq->num_parents = 0; @@ -500,24 +575,63 @@ In this case the typical set-up will look like this: /* Typical state container with dynamic irqchip */ struct my_gpio { struct gpio_chip gc; - struct irq_chip irq; struct fwnode_handle *fwnode; }; - int irq; /* from platform etc */ + static void my_gpio_mask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + + /* + * Perform any necessary action to mask the interrupt, + * and then call into the core code to synchronise the + * state. + */ + + gpiochip_disable_irq(gc, hwirq); + irq_mask_mask_parent(d); + } + + static void my_gpio_unmask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + + gpiochip_enable_irq(gc, hwirq); + + /* + * Perform any necessary action to unmask the interrupt, + * after having called into the core code to synchronise + * the state. + */ + + irq_mask_unmask_parent(d); + } + + /* + * Statically populate the irqchip. Note that it is made const + * (further indicated by the IRQCHIP_IMMUTABLE flag), and that + * the GPIOCHIP_IRQ_RESOURCE_HELPER macro adds some extra + * callbacks to the structure. + */ + static const struct irq_chip my_gpio_irq_chip = { + .name = "my_gpio_irq", + .irq_ack = my_gpio_ack_irq, + .irq_mask = my_gpio_mask_irq, + .irq_unmask = my_gpio_unmask_irq, + .irq_set_type = my_gpio_set_irq_type, + .flags = IRQCHIP_IMMUTABLE, + /* Provide the gpio resource callbacks */ + GPIOCHIP_IRQ_RESOURCE_HELPERS, + }; + struct my_gpio *g; struct gpio_irq_chip *girq; - /* Set up the irqchip dynamically */ - g->irq.name = "my_gpio_irq"; - g->irq.irq_ack = my_gpio_ack_irq; - g->irq.irq_mask = my_gpio_mask_irq; - g->irq.irq_unmask = my_gpio_unmask_irq; - g->irq.irq_set_type = my_gpio_set_irq_type; - /* Get a pointer to the gpio_irq_chip */ girq = &g->gc.irq; - girq->chip = &g->irq; + gpio_irq_chip_set_chip(girq, &my_gpio_irq_chip); girq->default_type = IRQ_TYPE_NONE; girq->handler = handle_bad_irq; girq->fwnode = g->fwnode; @@ -605,8 +719,9 @@ When implementing an irqchip inside a GPIO driver, these two functions should typically be called in the .irq_disable() and .irq_enable() callbacks from the irqchip. -When using the gpiolib irqchip helpers, these callbacks are automatically -assigned. +When IRQCHIP_IMMUTABLE is not advertised by the irqchip, these callbacks +are automatically assigned. This behaviour is deprecated and on its way +to be removed from the kernel. Real-Time compliance for GPIO IRQ chips diff --git a/Documentation/driver-api/libata.rst b/Documentation/driver-api/libata.rst index d477e296bda5..311af516a3fd 100644 --- a/Documentation/driver-api/libata.rst +++ b/Documentation/driver-api/libata.rst @@ -424,12 +424,6 @@ How commands are issued ----------------------- Internal commands - First, qc is allocated and initialized using :c:func:`ata_qc_new_init`. - Although :c:func:`ata_qc_new_init` doesn't implement any wait or retry - mechanism when qc is not available, internal commands are currently - issued only during initialization and error recovery, so no other - command is active and allocation is guaranteed to succeed. - Once allocated qc's taskfile is initialized for the command to be executed. qc currently has two mechanisms to notify completion. One is via ``qc->complete_fn()`` callback and the other is completion @@ -447,11 +441,6 @@ SCSI commands translated. No qc is involved in processing a simulated scmd. The result is computed right away and the scmd is completed. - For a translated scmd, :c:func:`ata_qc_new_init` is invoked to allocate a - qc and the scmd is translated into the qc. SCSI midlayer's - completion notification function pointer is stored into - ``qc->scsidone``. - ``qc->complete_fn()`` callback is used for completion notification. ATA commands use :c:func:`ata_scsi_qc_complete` while ATAPI commands use :c:func:`atapi_qc_complete`. Both functions end up calling ``qc->scsidone`` diff --git a/Documentation/driver-api/media/cec-core.rst b/Documentation/driver-api/media/cec-core.rst index c6194ee81c41..ae0d20798edc 100644 --- a/Documentation/driver-api/media/cec-core.rst +++ b/Documentation/driver-api/media/cec-core.rst @@ -109,6 +109,7 @@ your driver: int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable); int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); + void (*adap_configured)(struct cec_adapter *adap, bool configured); int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, u32 signal_free_time, struct cec_msg *msg); void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); @@ -117,7 +118,7 @@ your driver: /* Error injection callbacks */ ... - /* High-level callbacks */ + /* High-level callback */ ... }; @@ -178,6 +179,16 @@ can receive directed messages to that address. Note that adap_log_addr must return 0 if logical_addr is CEC_LOG_ADDR_INVALID. +Called when the adapter is fully configured or unconfigured:: + + void (*adap_configured)(struct cec_adapter *adap, bool configured); + +If configured == true, then the adapter is fully configured, i.e. all logical +addresses have been successfully claimed. If configured == false, then the +adapter is unconfigured. If the driver has to take specific actions after +(un)configuration, then that can be done through this optional callback. + + To transmit a new message:: int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, diff --git a/Documentation/driver-api/media/mc-core.rst b/Documentation/driver-api/media/mc-core.rst index 57b5bbba944e..02481a2513b9 100644 --- a/Documentation/driver-api/media/mc-core.rst +++ b/Documentation/driver-api/media/mc-core.rst @@ -42,9 +42,16 @@ Allocation of the structure is handled by the media device driver, usually by embedding the :c:type:`media_device` instance in a larger driver-specific structure. -Drivers register media device instances by calling -:c:func:`__media_device_register()` via the macro ``media_device_register()`` -and unregistered by calling :c:func:`media_device_unregister()`. +Drivers initialise media device instances by calling +:c:func:`media_device_init()`. After initialising a media device instance, it is +registered by calling :c:func:`__media_device_register()` via the macro +``media_device_register()`` and unregistered by calling +:c:func:`media_device_unregister()`. An initialised media device must be +eventually cleaned up by calling :c:func:`media_device_cleanup()`. + +Note that it is not allowed to unregister a media device instance that was not +previously registered, or clean up a media device instance that was not +previously initialised. Entities ^^^^^^^^ diff --git a/Documentation/driver-api/media/v4l2-subdev.rst b/Documentation/driver-api/media/v4l2-subdev.rst index 08ea2673b19e..cf3b52bdbfb9 100644 --- a/Documentation/driver-api/media/v4l2-subdev.rst +++ b/Documentation/driver-api/media/v4l2-subdev.rst @@ -518,6 +518,75 @@ The :c:func:`v4l2_i2c_new_subdev` function will call :c:type:`i2c_board_info` structure using the ``client_type`` and the ``addr`` to fill it. +Centrally managed subdev active state +------------------------------------- + +Traditionally V4L2 subdev drivers maintained internal state for the active +device configuration. This is often implemented as e.g. an array of struct +v4l2_mbus_framefmt, one entry for each pad, and similarly for crop and compose +rectangles. + +In addition to the active configuration, each subdev file handle has an array of +struct v4l2_subdev_pad_config, managed by the V4L2 core, which contains the try +configuration. + +To simplify the subdev drivers the V4L2 subdev API now optionally supports a +centrally managed active configuration represented by +:c:type:`v4l2_subdev_state`. One instance of state, which contains the active +device configuration, is stored in the sub-device itself as part of +the :c:type:`v4l2_subdev` structure, while the core associates a try state to +each open file handle, to store the try configuration related to that file +handle. + +Sub-device drivers can opt-in and use state to manage their active configuration +by initializing the subdevice state with a call to v4l2_subdev_init_finalize() +before registering the sub-device. They must also call v4l2_subdev_cleanup() +to release all the allocated resources before unregistering the sub-device. +The core automatically allocates and initializes a state for each open file +handle to store the try configurations and frees it when closing the file +handle. + +V4L2 sub-device operations that use both the :ref:`ACTIVE and TRY formats +<v4l2-subdev-format-whence>` receive the correct state to operate on through +the 'state' parameter. The state must be locked and unlocked by the +caller by calling :c:func:`v4l2_subdev_lock_state()` and +:c:func:`v4l2_subdev_unlock_state()`. The caller can do so by calling the subdev +operation through the :c:func:`v4l2_subdev_call_state_active()` macro. + +Operations that do not receive a state parameter implicitly operate on the +subdevice active state, which drivers can exclusively access by +calling :c:func:`v4l2_subdev_lock_and_get_active_state()`. The sub-device active +state must equally be released by calling :c:func:`v4l2_subdev_unlock_state()`. + +Drivers must never manually access the state stored in the :c:type:`v4l2_subdev` +or in the file handle without going through the designated helpers. + +While the V4L2 core passes the correct try or active state to the subdevice +operations, many existing device drivers pass a NULL state when calling +operations with :c:func:`v4l2_subdev_call()`. This legacy construct causes +issues with subdevice drivers that let the V4L2 core manage the active state, +as they expect to receive the appropriate state as a parameter. To help the +conversion of subdevice drivers to a managed active state without having to +convert all callers at the same time, an additional wrapper layer has been +added to v4l2_subdev_call(), which handles the NULL case by geting and locking +the callee's active state with :c:func:`v4l2_subdev_lock_and_get_active_state()`, +and unlocking the state after the call. + +The whole subdev state is in reality split into three parts: the +v4l2_subdev_state, subdev controls and subdev driver's internal state. In the +future these parts should be combined into a single state. For the time being +we need a way to handle the locking for these parts. This can be accomplished +by sharing a lock. The v4l2_ctrl_handler already supports this via its 'lock' +pointer and the same model is used with states. The driver can do the following +before calling v4l2_subdev_init_finalize(): + +.. code-block:: c + + sd->ctrl_handler->lock = &priv->mutex; + sd->state_lock = &priv->mutex; + +This shares the driver's private mutex between the controls and the states. + V4L2 sub-device functions and data structures --------------------------------------------- diff --git a/Documentation/driver-api/thermal/intel_dptf.rst b/Documentation/driver-api/thermal/intel_dptf.rst index 96668dca753a..372bdb4d04c6 100644 --- a/Documentation/driver-api/thermal/intel_dptf.rst +++ b/Documentation/driver-api/thermal/intel_dptf.rst @@ -4,7 +4,7 @@ Intel(R) Dynamic Platform and Thermal Framework Sysfs Interface =============================================================== -:Copyright: |copy| 2022 Intel Corporation +:Copyright: © 2022 Intel Corporation :Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst index 9f26079cacae..784bbeb22adc 100644 --- a/Documentation/driver-api/vfio-mediated-device.rst +++ b/Documentation/driver-api/vfio-mediated-device.rst @@ -105,6 +105,7 @@ structure to represent a mediated device's driver:: struct mdev_driver { int (*probe) (struct mdev_device *dev); void (*remove) (struct mdev_device *dev); + struct attribute_group **supported_type_groups; struct device_driver driver; }; @@ -119,33 +120,15 @@ to register and unregister itself with the core driver: extern void mdev_unregister_driver(struct mdev_driver *drv); -The mediated bus driver is responsible for adding mediated devices to the VFIO -group when devices are bound to the driver and removing mediated devices from -the VFIO when devices are unbound from the driver. - - -Physical Device Driver Interface --------------------------------- - -The physical device driver interface provides the mdev_parent_ops[3] structure -to define the APIs to manage work in the mediated core driver that is related -to the physical device. - -The structures in the mdev_parent_ops structure are as follows: - -* dev_attr_groups: attributes of the parent device -* mdev_attr_groups: attributes of the mediated device -* supported_config: attributes to define supported configurations -* device_driver: device driver to bind for mediated device instances - -The mdev_parent_ops also still has various functions pointers. Theses exist -for historical reasons only and shall not be used for new drivers. +The mediated bus driver's probe function should create a vfio_device on top of +the mdev_device and connect it to an appropriate implementation of +vfio_device_ops. When a driver wants to add the GUID creation sysfs to an existing device it has probe'd to then it should call:: extern int mdev_register_device(struct device *dev, - const struct mdev_parent_ops *ops); + struct mdev_driver *mdev_driver); This will provide the 'mdev_supported_types/XX/create' files which can then be used to trigger the creation of a mdev_device. The created mdev_device will be |