| Message ID | 20241211-dlech-mainline-spi-engine-offload-2-v6-1-88ee574d5d03@baylibre.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | spi: axi-spi-engine: add offload support | expand |
On Wed, 2024-12-11 at 14:54 -0600, David Lechner wrote: > Add the basic infrastructure to support SPI offload providers and > consumers. > > SPI offloading is a feature that allows the SPI controller to perform > transfers without any CPU intervention. This is useful, e.g. for > high-speed data acquisition. > > SPI controllers with offload support need to implement the get_offload > and put_offload callbacks and can use the devm_spi_offload_alloc() to > allocate offload instances. > > SPI peripheral drivers will call devm_spi_offload_get() to get a > reference to the matching offload instance. This offload instance can > then be attached to a SPI message to request offloading that message. > > It is expected that SPI controllers with offload support will check for > the offload instance in the SPI message in the ctlr->optimize_message() > callback and handle it accordingly. > > CONFIG_SPI_OFFLOAD is intended to be a select-only option. Both > consumer and provider drivers should `select SPI_OFFLOAD` in their > Kconfig to ensure that the SPI core is built with offload support. > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: David Lechner <dlechner@baylibre.com> > --- LGTM, Reviewed-by: Nuno Sa <nuno.sa@analog.com> > > v6 changes: > * Drop use of PTR_ERR_OR_ZERO(). > * Split header into types.h/provider.h/consumer.h. > * Remove unused spi_controller_offload_ops forward declaration. > > v5 changes: > * Don't include linux/property.h (moved to later patch). > * Only allocate single offload instance instead of array. > * Allocate *priv separately to avoid alignment issues. > * Add put_offload() callback instead of assuming devm semantics. > * Drop struct spi_offload::spi. It was only being used as a flag. > * Don't get/put struct spi_offload::provider_dev. > * Add MAINTAINERS entry for me as reviewer for anything related to > SPI offload. > > v4 changes: > * SPI offload functions moved to a separate file instead of spi.c > (spi.c is already too long). > * struct spi_offload and devm_spi_offload_get() are back, similar to > but improved over v1. This avoids having to pass the function ID > string to every function call and re-lookup the offload instance. > * offload message prepare/unprepare functions are removed. Instead the > existing optimize/unoptimize functions should be used. Setting > spi_message::offload pointer is used as a flag to differentiate > between an offloaded message and a regular message. > > v3 changes: > * Minor changes to doc comments. > * Changed to use phandle array for spi-offloads. > * Changed id to string to make use of spi-offload-names. > > v2 changes: > * This is a rework of "spi: add core support for controllers with offload > capabilities" from v1. > * The spi_offload_get() function that Nuno didn't like is gone. Instead, > there is now a mapping callback that uses the new generic devicetree > binding to request resources automatically when a SPI device is probed. > * The spi_offload_enable/disable() functions for dealing with hardware > triggers are deferred to a separate patch. > * This leaves adding spi_offload_prepare/unprepare() which have been > reworked to be a bit more robust. > --- > MAINTAINERS | 6 ++ > drivers/spi/Kconfig | 3 + > drivers/spi/Makefile | 1 + > drivers/spi/spi-offload.c | 114 > +++++++++++++++++++++++++++++++++++ > include/linux/spi/offload/consumer.h | 22 +++++++ > include/linux/spi/offload/provider.h | 19 ++++++ > include/linux/spi/offload/types.h | 43 +++++++++++++ > include/linux/spi/spi.h | 17 ++++++ > 8 files changed, 225 insertions(+) > > diff --git a/MAINTAINERS b/MAINTAINERS > index > bf2dcd4e0261785add520b5eac747ceac523e112..9284a257607a740ab7f6fd960c2bcdc34ead > 7586 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -22129,6 +22129,12 @@ > F: Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml > F: drivers/mtd/spi-nor/ > F: include/linux/mtd/spi-nor.h > > +SPI OFFLOAD > +R: David Lechner <dlechner@baylibre.com> > +F: drivers/spi/spi-offload.c > +F: include/linux/spi/spi-offload.h > +K: spi_offload > + > SPI SUBSYSTEM > M: Mark Brown <broonie@kernel.org> > L: linux-spi@vger.kernel.org > diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig > index > ea8a310329274bb2701e265cd152a56fb4e0f3a7..02064a4e292815ec0213e2e446b4f90ed885 > 5a52 100644 > --- a/drivers/spi/Kconfig > +++ b/drivers/spi/Kconfig > @@ -55,6 +55,9 @@ config SPI_MEM > This extension is meant to simplify interaction with SPI memories > by providing a high-level interface to send memory-like commands. > > +config SPI_OFFLOAD > + bool > + > comment "SPI Master Controller Drivers" > > config SPI_AIROHA_SNFI > diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile > index > 9db7554c1864bf9b37dcf59c16eb76f5af03a7e8..bb5fc20df21332232533c2e70c0cc230f6bc > f27f 100644 > --- a/drivers/spi/Makefile > +++ b/drivers/spi/Makefile > @@ -10,6 +10,7 @@ ccflags-$(CONFIG_SPI_DEBUG) := -DDEBUG > obj-$(CONFIG_SPI_MASTER) += spi.o > obj-$(CONFIG_SPI_MEM) += spi-mem.o > obj-$(CONFIG_SPI_MUX) += spi-mux.o > +obj-$(CONFIG_SPI_OFFLOAD) += spi-offload.o > obj-$(CONFIG_SPI_SPIDEV) += spidev.o > obj-$(CONFIG_SPI_LOOPBACK_TEST) += spi-loopback-test.o > > diff --git a/drivers/spi/spi-offload.c b/drivers/spi/spi-offload.c > new file mode 100644 > index > 0000000000000000000000000000000000000000..3a40ef30debf09c6fd7b2c14526f3e5976e2 > b21f > --- /dev/null > +++ b/drivers/spi/spi-offload.c > @@ -0,0 +1,114 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (C) 2024 Analog Devices Inc. > + * Copyright (C) 2024 BayLibre, SAS > + */ > + > +/* > + * SPI Offloading support. > + * > + * Some SPI controllers support offloading of SPI transfers. Essentially, > this > + * is the ability for a SPI controller to perform SPI transfers with minimal > + * or even no CPU intervention, e.g. via a specialized SPI controller with a > + * hardware trigger or via a conventional SPI controller using a non-Linux > MCU > + * processor core to offload the work. > + */ > + > +#define DEFAULT_SYMBOL_NAMESPACE "SPI_OFFLOAD" > + > +#include <linux/cleanup.h> > +#include <linux/device.h> > +#include <linux/export.h> > +#include <linux/mutex.h> > +#include <linux/spi/offload/consumer.h> > +#include <linux/spi/offload/provider.h> > +#include <linux/spi/offload/types.h> > +#include <linux/spi/spi.h> > +#include <linux/types.h> > + > +struct spi_controller_and_offload { > + struct spi_controller *controller; > + struct spi_offload *offload; > +}; > + > +/** > + * devm_spi_offload_alloc() - Allocate offload instance > + * @dev: Device for devm purposes and assigned to &struct > spi_offload.provider_dev > + * @priv_size: Size of private data to allocate > + * > + * Offload providers should use this to allocate offload instances. > + * > + * Return: Pointer to new offload instance or error on failure. > + */ > +struct spi_offload *devm_spi_offload_alloc(struct device *dev, > + size_t priv_size) > +{ > + struct spi_offload *offload; > + void *priv; > + > + offload = devm_kzalloc(dev, sizeof(*offload), GFP_KERNEL); > + if (!offload) > + return ERR_PTR(-ENOMEM); > + > + priv = devm_kzalloc(dev, priv_size, GFP_KERNEL); > + if (!priv) > + return ERR_PTR(-ENOMEM); > + > + offload->provider_dev = dev; > + offload->priv = priv; > + > + return offload; > +} > +EXPORT_SYMBOL_GPL(devm_spi_offload_alloc); > + > +static void spi_offload_put(void *data) > +{ > + struct spi_controller_and_offload *resource = data; > + > + resource->controller->put_offload(resource->offload); > + kfree(resource); > +} > + > +/** > + * devm_spi_offload_get() - Get an offload instance > + * @dev: Device for devm purposes > + * @spi: SPI device to use for the transfers > + * @config: Offload configuration > + * > + * Peripheral drivers call this function to get an offload instance that > meets > + * the requirements specified in @config. If no suitable offload instance is > + * available, -ENODEV is returned. > + * > + * Return: Offload instance or error on failure. > + */ > +struct spi_offload *devm_spi_offload_get(struct device *dev, > + struct spi_device *spi, > + const struct spi_offload_config > *config) > +{ > + struct spi_controller_and_offload *resource; > + int ret; > + > + if (!spi || !config) > + return ERR_PTR(-EINVAL); > + > + if (!spi->controller->get_offload) > + return ERR_PTR(-ENODEV); > + > + resource = kzalloc(sizeof(*resource), GFP_KERNEL); > + if (!resource) > + return ERR_PTR(-ENOMEM); > + > + resource->controller = spi->controller; > + resource->offload = spi->controller->get_offload(spi, config); > + if (IS_ERR(resource->offload)) { > + kfree(resource); > + return resource->offload; > + } > + > + ret = devm_add_action_or_reset(dev, spi_offload_put, resource); > + if (ret) > + return ERR_PTR(ret); > + > + return resource->offload; > +} > +EXPORT_SYMBOL_GPL(devm_spi_offload_get); > diff --git a/include/linux/spi/offload/consumer.h > b/include/linux/spi/offload/consumer.h > new file mode 100644 > index > 0000000000000000000000000000000000000000..05543dbedf3086fb4befcd149cff3c8c70a8 > 8825 > --- /dev/null > +++ b/include/linux/spi/offload/consumer.h > @@ -0,0 +1,22 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Copyright (C) 2024 Analog Devices Inc. > + * Copyright (C) 2024 BayLibre, SAS > + */ > + > +#ifndef __LINUX_SPI_OFFLOAD_CONSUMER_H > +#define __LINUX_SPI_OFFLOAD_CONSUMER_H > + > +#include <linux/module.h> > +#include <linux/spi/offload/types.h> > +#include <linux/types.h> > + > +MODULE_IMPORT_NS("SPI_OFFLOAD"); > + > +struct device; > +struct spi_device; > + > +struct spi_offload *devm_spi_offload_get(struct device *dev, struct > spi_device *spi, > + const struct spi_offload_config > *config); > + > +#endif /* __LINUX_SPI_OFFLOAD_CONSUMER_H */ > diff --git a/include/linux/spi/offload/provider.h > b/include/linux/spi/offload/provider.h > new file mode 100644 > index > 0000000000000000000000000000000000000000..278c4edfcdb7b1f43870ca99d2ba252bf282 > 0576 > --- /dev/null > +++ b/include/linux/spi/offload/provider.h > @@ -0,0 +1,19 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Copyright (C) 2024 Analog Devices Inc. > + * Copyright (C) 2024 BayLibre, SAS > + */ > + > +#ifndef __LINUX_SPI_OFFLOAD_PROVIDER_H > +#define __LINUX_SPI_OFFLOAD_PROVIDER_H > + > +#include <linux/module.h> > +#include <linux/types.h> > + > +MODULE_IMPORT_NS("SPI_OFFLOAD"); > + > +struct device; > + > +struct spi_offload *devm_spi_offload_alloc(struct device *dev, size_t > priv_size); > + > +#endif /* __LINUX_SPI_OFFLOAD_PROVIDER_H */ > diff --git a/include/linux/spi/offload/types.h > b/include/linux/spi/offload/types.h > new file mode 100644 > index > 0000000000000000000000000000000000000000..a74f8d84541b10062353e81a638f05628b69 > 6394 > --- /dev/null > +++ b/include/linux/spi/offload/types.h > @@ -0,0 +1,43 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Copyright (C) 2024 Analog Devices Inc. > + * Copyright (C) 2024 BayLibre, SAS > + */ > + > +#ifndef __LINUX_SPI_OFFLOAD_TYPES_H > +#define __LINUX_SPI_OFFLOAD_TYPES_H > + > +#include <linux/types.h> > + > +struct device; > + > +/* Offload can be triggered by external hardware event. */ > +#define SPI_OFFLOAD_CAP_TRIGGER BIT(0) > +/* Offload can record and then play back TX data when triggered. */ > +#define SPI_OFFLOAD_CAP_TX_STATIC_DATA BIT(1) > +/* Offload can get TX data from an external stream source. */ > +#define SPI_OFFLOAD_CAP_TX_STREAM_DMA BIT(2) > +/* Offload can send RX data to an external stream sink. */ > +#define SPI_OFFLOAD_CAP_RX_STREAM_DMA BIT(3) > + > +/** > + * struct spi_offload_config - offload configuration > + * > + * This is used to request an offload with specific configuration. > + */ > +struct spi_offload_config { > + /** @capability_flags: required capabilities. See %SPI_OFFLOAD_CAP_* > */ > + u32 capability_flags; > +}; > + > +/** > + * struct spi_offload - offload instance > + */ > +struct spi_offload { > + /** @provider_dev: for get/put reference counting */ > + struct device *provider_dev; > + /** @priv: provider driver private data */ > + void *priv; > +}; > + > +#endif /* __LINUX_SPI_OFFLOAD_TYPES_H */ > diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h > index > 8497f4747e24d4ecd85b74f49609ac1c82c73535..98bdc8c16c20521c0a94e5f72f5e71c4f6d7 > d11e 100644 > --- a/include/linux/spi/spi.h > +++ b/include/linux/spi/spi.h > @@ -31,6 +31,8 @@ struct spi_transfer; > struct spi_controller_mem_ops; > struct spi_controller_mem_caps; > struct spi_message; > +struct spi_offload; > +struct spi_offload_config; > > /* > * INTERFACES between SPI master-side drivers and SPI slave protocol > handlers, > @@ -496,6 +498,10 @@ extern struct spi_device *spi_new_ancillary_device(struct > spi_device *spi, u8 ch > * @mem_ops: optimized/dedicated operations for interactions with SPI memory. > * This field is optional and should only be implemented if the > * controller has native support for memory like operations. > + * @get_offload: callback for controllers with offload support to get > matching > + * offload instance. Implementations should return -ENODEV if no match > is > + * found. > + * @put_offload: release the offload instance acquired by @get_offload. > * @mem_caps: controller capabilities for the handling of memory operations. > * @unprepare_message: undo any work done by prepare_message(). > * @target_abort: abort the ongoing transfer request on an SPI target > controller > @@ -740,6 +746,10 @@ struct spi_controller { > const struct spi_controller_mem_ops *mem_ops; > const struct spi_controller_mem_caps *mem_caps; > > + struct spi_offload *(*get_offload)(struct spi_device *spi, > + const struct spi_offload_config > *config); > + void (*put_offload)(struct spi_offload *offload); > + > /* GPIO chip select */ > struct gpio_desc **cs_gpiods; > bool use_gpio_descriptors; > @@ -1108,6 +1118,7 @@ struct spi_transfer { > * @state: for use by whichever driver currently owns the message > * @opt_state: for use by whichever driver currently owns the message > * @resources: for resource management when the SPI message is processed > + * @offload: (optional) offload instance used by this message > * > * A @spi_message is used to execute an atomic sequence of data transfers, > * each represented by a struct spi_transfer. The sequence is "atomic" > @@ -1168,6 +1179,12 @@ struct spi_message { > */ > void *opt_state; > > + /* > + * Optional offload instance used by this message. This must be set > + * by the peripheral driver before calling spi_optimize_message(). > + */ > + struct spi_offload *offload; > + > /* List of spi_res resources when the SPI message is processed */ > struct list_head resources; > }; >
diff --git a/MAINTAINERS b/MAINTAINERS index bf2dcd4e0261785add520b5eac747ceac523e112..9284a257607a740ab7f6fd960c2bcdc34ead7586 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -22129,6 +22129,12 @@ F: Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml F: drivers/mtd/spi-nor/ F: include/linux/mtd/spi-nor.h +SPI OFFLOAD +R: David Lechner <dlechner@baylibre.com> +F: drivers/spi/spi-offload.c +F: include/linux/spi/spi-offload.h +K: spi_offload + SPI SUBSYSTEM M: Mark Brown <broonie@kernel.org> L: linux-spi@vger.kernel.org diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index ea8a310329274bb2701e265cd152a56fb4e0f3a7..02064a4e292815ec0213e2e446b4f90ed8855a52 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -55,6 +55,9 @@ config SPI_MEM This extension is meant to simplify interaction with SPI memories by providing a high-level interface to send memory-like commands. +config SPI_OFFLOAD + bool + comment "SPI Master Controller Drivers" config SPI_AIROHA_SNFI diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 9db7554c1864bf9b37dcf59c16eb76f5af03a7e8..bb5fc20df21332232533c2e70c0cc230f6bcf27f 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -10,6 +10,7 @@ ccflags-$(CONFIG_SPI_DEBUG) := -DDEBUG obj-$(CONFIG_SPI_MASTER) += spi.o obj-$(CONFIG_SPI_MEM) += spi-mem.o obj-$(CONFIG_SPI_MUX) += spi-mux.o +obj-$(CONFIG_SPI_OFFLOAD) += spi-offload.o obj-$(CONFIG_SPI_SPIDEV) += spidev.o obj-$(CONFIG_SPI_LOOPBACK_TEST) += spi-loopback-test.o diff --git a/drivers/spi/spi-offload.c b/drivers/spi/spi-offload.c new file mode 100644 index 0000000000000000000000000000000000000000..3a40ef30debf09c6fd7b2c14526f3e5976e2b21f --- /dev/null +++ b/drivers/spi/spi-offload.c @@ -0,0 +1,114 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 Analog Devices Inc. + * Copyright (C) 2024 BayLibre, SAS + */ + +/* + * SPI Offloading support. + * + * Some SPI controllers support offloading of SPI transfers. Essentially, this + * is the ability for a SPI controller to perform SPI transfers with minimal + * or even no CPU intervention, e.g. via a specialized SPI controller with a + * hardware trigger or via a conventional SPI controller using a non-Linux MCU + * processor core to offload the work. + */ + +#define DEFAULT_SYMBOL_NAMESPACE "SPI_OFFLOAD" + +#include <linux/cleanup.h> +#include <linux/device.h> +#include <linux/export.h> +#include <linux/mutex.h> +#include <linux/spi/offload/consumer.h> +#include <linux/spi/offload/provider.h> +#include <linux/spi/offload/types.h> +#include <linux/spi/spi.h> +#include <linux/types.h> + +struct spi_controller_and_offload { + struct spi_controller *controller; + struct spi_offload *offload; +}; + +/** + * devm_spi_offload_alloc() - Allocate offload instance + * @dev: Device for devm purposes and assigned to &struct spi_offload.provider_dev + * @priv_size: Size of private data to allocate + * + * Offload providers should use this to allocate offload instances. + * + * Return: Pointer to new offload instance or error on failure. + */ +struct spi_offload *devm_spi_offload_alloc(struct device *dev, + size_t priv_size) +{ + struct spi_offload *offload; + void *priv; + + offload = devm_kzalloc(dev, sizeof(*offload), GFP_KERNEL); + if (!offload) + return ERR_PTR(-ENOMEM); + + priv = devm_kzalloc(dev, priv_size, GFP_KERNEL); + if (!priv) + return ERR_PTR(-ENOMEM); + + offload->provider_dev = dev; + offload->priv = priv; + + return offload; +} +EXPORT_SYMBOL_GPL(devm_spi_offload_alloc); + +static void spi_offload_put(void *data) +{ + struct spi_controller_and_offload *resource = data; + + resource->controller->put_offload(resource->offload); + kfree(resource); +} + +/** + * devm_spi_offload_get() - Get an offload instance + * @dev: Device for devm purposes + * @spi: SPI device to use for the transfers + * @config: Offload configuration + * + * Peripheral drivers call this function to get an offload instance that meets + * the requirements specified in @config. If no suitable offload instance is + * available, -ENODEV is returned. + * + * Return: Offload instance or error on failure. + */ +struct spi_offload *devm_spi_offload_get(struct device *dev, + struct spi_device *spi, + const struct spi_offload_config *config) +{ + struct spi_controller_and_offload *resource; + int ret; + + if (!spi || !config) + return ERR_PTR(-EINVAL); + + if (!spi->controller->get_offload) + return ERR_PTR(-ENODEV); + + resource = kzalloc(sizeof(*resource), GFP_KERNEL); + if (!resource) + return ERR_PTR(-ENOMEM); + + resource->controller = spi->controller; + resource->offload = spi->controller->get_offload(spi, config); + if (IS_ERR(resource->offload)) { + kfree(resource); + return resource->offload; + } + + ret = devm_add_action_or_reset(dev, spi_offload_put, resource); + if (ret) + return ERR_PTR(ret); + + return resource->offload; +} +EXPORT_SYMBOL_GPL(devm_spi_offload_get); diff --git a/include/linux/spi/offload/consumer.h b/include/linux/spi/offload/consumer.h new file mode 100644 index 0000000000000000000000000000000000000000..05543dbedf3086fb4befcd149cff3c8c70a88825 --- /dev/null +++ b/include/linux/spi/offload/consumer.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2024 Analog Devices Inc. + * Copyright (C) 2024 BayLibre, SAS + */ + +#ifndef __LINUX_SPI_OFFLOAD_CONSUMER_H +#define __LINUX_SPI_OFFLOAD_CONSUMER_H + +#include <linux/module.h> +#include <linux/spi/offload/types.h> +#include <linux/types.h> + +MODULE_IMPORT_NS("SPI_OFFLOAD"); + +struct device; +struct spi_device; + +struct spi_offload *devm_spi_offload_get(struct device *dev, struct spi_device *spi, + const struct spi_offload_config *config); + +#endif /* __LINUX_SPI_OFFLOAD_CONSUMER_H */ diff --git a/include/linux/spi/offload/provider.h b/include/linux/spi/offload/provider.h new file mode 100644 index 0000000000000000000000000000000000000000..278c4edfcdb7b1f43870ca99d2ba252bf2820576 --- /dev/null +++ b/include/linux/spi/offload/provider.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2024 Analog Devices Inc. + * Copyright (C) 2024 BayLibre, SAS + */ + +#ifndef __LINUX_SPI_OFFLOAD_PROVIDER_H +#define __LINUX_SPI_OFFLOAD_PROVIDER_H + +#include <linux/module.h> +#include <linux/types.h> + +MODULE_IMPORT_NS("SPI_OFFLOAD"); + +struct device; + +struct spi_offload *devm_spi_offload_alloc(struct device *dev, size_t priv_size); + +#endif /* __LINUX_SPI_OFFLOAD_PROVIDER_H */ diff --git a/include/linux/spi/offload/types.h b/include/linux/spi/offload/types.h new file mode 100644 index 0000000000000000000000000000000000000000..a74f8d84541b10062353e81a638f05628b696394 --- /dev/null +++ b/include/linux/spi/offload/types.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2024 Analog Devices Inc. + * Copyright (C) 2024 BayLibre, SAS + */ + +#ifndef __LINUX_SPI_OFFLOAD_TYPES_H +#define __LINUX_SPI_OFFLOAD_TYPES_H + +#include <linux/types.h> + +struct device; + +/* Offload can be triggered by external hardware event. */ +#define SPI_OFFLOAD_CAP_TRIGGER BIT(0) +/* Offload can record and then play back TX data when triggered. */ +#define SPI_OFFLOAD_CAP_TX_STATIC_DATA BIT(1) +/* Offload can get TX data from an external stream source. */ +#define SPI_OFFLOAD_CAP_TX_STREAM_DMA BIT(2) +/* Offload can send RX data to an external stream sink. */ +#define SPI_OFFLOAD_CAP_RX_STREAM_DMA BIT(3) + +/** + * struct spi_offload_config - offload configuration + * + * This is used to request an offload with specific configuration. + */ +struct spi_offload_config { + /** @capability_flags: required capabilities. See %SPI_OFFLOAD_CAP_* */ + u32 capability_flags; +}; + +/** + * struct spi_offload - offload instance + */ +struct spi_offload { + /** @provider_dev: for get/put reference counting */ + struct device *provider_dev; + /** @priv: provider driver private data */ + void *priv; +}; + +#endif /* __LINUX_SPI_OFFLOAD_TYPES_H */ diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 8497f4747e24d4ecd85b74f49609ac1c82c73535..98bdc8c16c20521c0a94e5f72f5e71c4f6d7d11e 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -31,6 +31,8 @@ struct spi_transfer; struct spi_controller_mem_ops; struct spi_controller_mem_caps; struct spi_message; +struct spi_offload; +struct spi_offload_config; /* * INTERFACES between SPI master-side drivers and SPI slave protocol handlers, @@ -496,6 +498,10 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch * @mem_ops: optimized/dedicated operations for interactions with SPI memory. * This field is optional and should only be implemented if the * controller has native support for memory like operations. + * @get_offload: callback for controllers with offload support to get matching + * offload instance. Implementations should return -ENODEV if no match is + * found. + * @put_offload: release the offload instance acquired by @get_offload. * @mem_caps: controller capabilities for the handling of memory operations. * @unprepare_message: undo any work done by prepare_message(). * @target_abort: abort the ongoing transfer request on an SPI target controller @@ -740,6 +746,10 @@ struct spi_controller { const struct spi_controller_mem_ops *mem_ops; const struct spi_controller_mem_caps *mem_caps; + struct spi_offload *(*get_offload)(struct spi_device *spi, + const struct spi_offload_config *config); + void (*put_offload)(struct spi_offload *offload); + /* GPIO chip select */ struct gpio_desc **cs_gpiods; bool use_gpio_descriptors; @@ -1108,6 +1118,7 @@ struct spi_transfer { * @state: for use by whichever driver currently owns the message * @opt_state: for use by whichever driver currently owns the message * @resources: for resource management when the SPI message is processed + * @offload: (optional) offload instance used by this message * * A @spi_message is used to execute an atomic sequence of data transfers, * each represented by a struct spi_transfer. The sequence is "atomic" @@ -1168,6 +1179,12 @@ struct spi_message { */ void *opt_state; + /* + * Optional offload instance used by this message. This must be set + * by the peripheral driver before calling spi_optimize_message(). + */ + struct spi_offload *offload; + /* List of spi_res resources when the SPI message is processed */ struct list_head resources; };