diff options
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/connector.rst | 2 | ||||
| -rw-r--r-- | Documentation/driver-api/dma-buf.rst | 2 | ||||
| -rw-r--r-- | Documentation/driver-api/dmaengine/client.rst | 4 | ||||
| -rw-r--r-- | Documentation/driver-api/driver-model/devres.rst | 6 | ||||
| -rw-r--r-- | Documentation/driver-api/gpio/consumer.rst | 18 | ||||
| -rw-r--r-- | Documentation/driver-api/gpio/driver.rst | 67 | ||||
| -rw-r--r-- | Documentation/driver-api/mtd/nand_ecc.rst | 2 | ||||
| -rw-r--r-- | Documentation/driver-api/mtdnand.rst | 3 |
8 files changed, 66 insertions, 38 deletions
diff --git a/Documentation/driver-api/connector.rst b/Documentation/driver-api/connector.rst index 23d068191fb1..631b84a48aa5 100644 --- a/Documentation/driver-api/connector.rst +++ b/Documentation/driver-api/connector.rst @@ -25,7 +25,7 @@ handling, etc... The Connector driver allows any kernelspace agents to use netlink based networking for inter-process communication in a significantly easier way:: - int cn_add_callback(struct cb_id *id, char *name, void (*callback) (struct cn_msg *, struct netlink_skb_parms *)); + int cn_add_callback(const struct cb_id *id, char *name, void (*callback) (struct cn_msg *, struct netlink_skb_parms *)); void cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 __group, int gfp_mask); void cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group, int gfp_mask); diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst index d6b2a195dbed..a2133d69872c 100644 --- a/Documentation/driver-api/dma-buf.rst +++ b/Documentation/driver-api/dma-buf.rst @@ -190,7 +190,7 @@ DMA Fence uABI/Sync File Indefinite DMA Fences ~~~~~~~~~~~~~~~~~~~~~ -At various times &dma_fence with an indefinite time until dma_fence_wait() +At various times struct dma_fence with an indefinite time until dma_fence_wait() finishes have been proposed. Examples include: * Future fences, used in HWC1 to signal when a buffer isn't used by the display diff --git a/Documentation/driver-api/dmaengine/client.rst b/Documentation/driver-api/dmaengine/client.rst index 09a3f66dcd26..bfd057b21a00 100644 --- a/Documentation/driver-api/dmaengine/client.rst +++ b/Documentation/driver-api/dmaengine/client.rst @@ -120,7 +120,9 @@ The details of these operations are: .. code-block:: c - nr_sg = dma_map_sg(chan->device->dev, sgl, sg_len); + struct device *dma_dev = dmaengine_get_dma_device(chan); + + nr_sg = dma_map_sg(dma_dev, sgl, sg_len); if (nr_sg == 0) /* error */ diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst index bb676570acc3..cd8b6e657b94 100644 --- a/Documentation/driver-api/driver-model/devres.rst +++ b/Documentation/driver-api/driver-model/devres.rst @@ -411,6 +411,12 @@ RESET devm_reset_control_get() devm_reset_controller_register() +RTC + devm_rtc_device_register() + devm_rtc_allocate_device() + devm_rtc_register_device() + devm_rtc_nvmem_register() + SERDEV devm_serdev_device_open() diff --git a/Documentation/driver-api/gpio/consumer.rst b/Documentation/driver-api/gpio/consumer.rst index 423492d125b9..173e4c7b037d 100644 --- a/Documentation/driver-api/gpio/consumer.rst +++ b/Documentation/driver-api/gpio/consumer.rst @@ -440,18 +440,20 @@ For details refer to Documentation/firmware-guide/acpi/gpio-properties.rst Interacting With the Legacy GPIO Subsystem ========================================== -Many kernel subsystems still handle GPIOs using the legacy integer-based -interface. Although it is strongly encouraged to upgrade them to the safer -descriptor-based API, the following two functions allow you to convert a GPIO -descriptor into the GPIO integer namespace and vice-versa:: +Many kernel subsystems and drivers still handle GPIOs using the legacy +integer-based interface. It is strongly recommended to update these to the new +gpiod interface. For cases where both interfaces need to be used, the following +two functions allow to convert a GPIO descriptor into the GPIO integer namespace +and vice-versa:: int desc_to_gpio(const struct gpio_desc *desc) struct gpio_desc *gpio_to_desc(unsigned gpio) -The GPIO number returned by desc_to_gpio() can be safely used as long as the -GPIO descriptor has not been freed. All the same, a GPIO number passed to -gpio_to_desc() must have been properly acquired, and usage of the returned GPIO -descriptor is only possible after the GPIO number has been released. +The GPIO number returned by desc_to_gpio() can safely be used as a parameter of +the gpio\_*() functions for as long as the GPIO descriptor `desc` is not freed. +All the same, a GPIO number passed to gpio_to_desc() must first be properly +acquired using e.g. gpio_request_one(), and the returned GPIO descriptor is only +considered valid until that GPIO number is released using gpio_free(). Freeing a GPIO obtained by one API with the other API is forbidden and an unchecked error. diff --git a/Documentation/driver-api/gpio/driver.rst b/Documentation/driver-api/gpio/driver.rst index 072a7455044e..0fb57e298b41 100644 --- a/Documentation/driver-api/gpio/driver.rst +++ b/Documentation/driver-api/gpio/driver.rst @@ -416,7 +416,8 @@ The preferred way to set up the helpers is to fill in the 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 cascaded interrupt handler using gpio_irq_chip: +is a typical example of a chained cascaded interrupt handler using +the gpio_irq_chip: .. code-block:: c @@ -452,7 +453,46 @@ is a typical example of a cascaded interrupt handler using gpio_irq_chip: return devm_gpiochip_add_data(dev, &g->gc, g); -The helper support using hierarchical interrupt controllers as well. +The helper supports using threaded interrupts as well. Then you just request +the interrupt separately and go with it: + +.. code-block:: c + + /* Typical state container with dynamic irqchip */ + struct my_gpio { + struct gpio_chip gc; + struct irq_chip irq; + }; + + 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) + return ret; + + /* Get a pointer to the gpio_irq_chip */ + girq = &g->gc.irq; + girq->chip = &g->irq; + /* This will let us handle the parent IRQ in the driver */ + girq->parent_handler = NULL; + girq->num_parents = 0; + girq->parents = NULL; + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_bad_irq; + + return devm_gpiochip_add_data(dev, &g->gc, g); + +The helper supports using hierarchical interrupt controllers as well. In this case the typical set-up will look like this: .. code-block:: c @@ -493,32 +533,13 @@ the parent hardware irq from a child (i.e. this gpio chip) hardware irq. As always it is good to look at examples in the kernel tree for advice on how to find the required pieces. -The old way of adding irqchips to gpiochips after registration is also still -available but we try to move away from this: - -- DEPRECATED: gpiochip_irqchip_add(): adds a chained cascaded irqchip to a - gpiochip. It will pass the struct gpio_chip* for the chip to all IRQ - callbacks, so the callbacks need to embed the gpio_chip in its state - container and obtain a pointer to the container using container_of(). - (See Documentation/driver-api/driver-model/design-patterns.rst) - -- gpiochip_irqchip_add_nested(): adds a nested cascaded irqchip to a gpiochip, - as discussed above regarding different types of cascaded irqchips. The - cascaded irq has to be handled by a threaded interrupt handler. - Apart from that it works exactly like the chained irqchip. - -- gpiochip_set_nested_irqchip(): sets up a nested cascaded irq handler for a - gpio_chip from a parent IRQ. As the parent IRQ has usually been - explicitly requested by the driver, this does very little more than - mark all the child IRQs as having the other IRQ as parent. - If there is a need to exclude certain GPIO lines from the IRQ domain handled by these helpers, we can set .irq.need_valid_mask of the gpiochip before devm_gpiochip_add_data() or gpiochip_add_data() is called. This allocates an .irq.valid_mask with as many bits set as there are GPIO lines in the chip, each bit representing line 0..n-1. Drivers can exclude GPIO lines by clearing bits -from this mask. The mask must be filled in before gpiochip_irqchip_add() or -gpiochip_irqchip_add_nested() is called. +from this mask. The mask can be filled in the init_valid_mask() callback +that is part of the struct gpio_irq_chip. To use the helpers please keep the following in mind: diff --git a/Documentation/driver-api/mtd/nand_ecc.rst b/Documentation/driver-api/mtd/nand_ecc.rst index e8d3c53a5056..74347c14a70b 100644 --- a/Documentation/driver-api/mtd/nand_ecc.rst +++ b/Documentation/driver-api/mtd/nand_ecc.rst @@ -5,7 +5,7 @@ NAND Error-correction Code Introduction ============ -Having looked at the linux mtd/nand driver and more specific at nand_ecc.c +Having looked at the linux mtd/nand Hamming software ECC engine driver I felt there was room for optimisation. I bashed the code for a few hours performing tricks like table lookup removing superfluous code etc. After that the speed was increased by 35-40%. diff --git a/Documentation/driver-api/mtdnand.rst b/Documentation/driver-api/mtdnand.rst index 0bf8d6ec3f54..ce77e024c4f1 100644 --- a/Documentation/driver-api/mtdnand.rst +++ b/Documentation/driver-api/mtdnand.rst @@ -972,9 +972,6 @@ hints" for an explanation. .. kernel-doc:: drivers/mtd/nand/raw/nand_base.c :export: -.. kernel-doc:: drivers/mtd/nand/raw/nand_ecc.c - :export: - Internal Functions Provided =========================== |