From 8e02d188698851436f76038ea998b726193d1b10 Mon Sep 17 00:00:00 2001 From: David Lechner Date: Fri, 7 Feb 2025 14:08:58 -0600 Subject: spi: add basic support for SPI offloading 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 Reviewed-by: Nuno Sa Signed-off-by: David Lechner Link: https://patch.msgid.link/20250207-dlech-mainline-spi-engine-offload-2-v8-1-e48a489be48c@baylibre.com Signed-off-by: Mark Brown --- 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 ++++++++++++++ 4 files changed, 101 insertions(+) create mode 100644 include/linux/spi/offload/consumer.h create mode 100644 include/linux/spi/offload/provider.h create mode 100644 include/linux/spi/offload/types.h (limited to 'include/linux') diff --git a/include/linux/spi/offload/consumer.h b/include/linux/spi/offload/consumer.h new file mode 100644 index 000000000000..05543dbedf30 --- /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 +#include +#include + +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 000000000000..278c4edfcdb7 --- /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 +#include + +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 000000000000..a74f8d84541b --- /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 + +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 8497f4747e24..98bdc8c16c20 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; }; -- cgit v1.2.3 From d7231be4b4657e5f922a4c6dc11e8dffc71fee87 Mon Sep 17 00:00:00 2001 From: David Lechner Date: Fri, 7 Feb 2025 14:08:59 -0600 Subject: spi: offload: add support for hardware triggers Extend SPI offloading to support hardware triggers. This allows an arbitrary hardware trigger to be used to start a SPI transfer that was previously set up with spi_optimize_message(). A new struct spi_offload_trigger is introduced that can be used to configure any type of trigger. It has a type discriminator and a union to allow it to be extended in the future. Two trigger types are defined to start with. One is a trigger that indicates that the SPI peripheral is ready to read or write data. The other is a periodic trigger to repeat a SPI message at a fixed rate. There is also a spi_offload_hw_trigger_validate() function that works similar to clk_round_rate(). It basically asks the question of if we enabled the hardware trigger what would the actual parameters be. This can be used to test if the requested trigger type is actually supported by the hardware and for periodic triggers, it can be used to find the actual rate that the hardware is capable of. Reviewed-by: Jonathan Cameron Reviewed-by: Nuno Sa Signed-off-by: David Lechner Link: https://patch.msgid.link/20250207-dlech-mainline-spi-engine-offload-2-v8-2-e48a489be48c@baylibre.com Signed-off-by: Mark Brown --- drivers/spi/spi-offload.c | 281 +++++++++++++++++++++++++++++++++++ include/linux/spi/offload/consumer.h | 12 ++ include/linux/spi/offload/provider.h | 28 ++++ include/linux/spi/offload/types.h | 37 +++++ 4 files changed, 358 insertions(+) (limited to 'include/linux') diff --git a/drivers/spi/spi-offload.c b/drivers/spi/spi-offload.c index 3a40ef30debf..43582e50e279 100644 --- a/drivers/spi/spi-offload.c +++ b/drivers/spi/spi-offload.c @@ -19,7 +19,11 @@ #include #include #include +#include +#include #include +#include +#include #include #include #include @@ -31,6 +35,23 @@ struct spi_controller_and_offload { struct spi_offload *offload; }; +struct spi_offload_trigger { + struct list_head list; + struct kref ref; + struct fwnode_handle *fwnode; + /* synchronizes calling ops and driver registration */ + struct mutex lock; + /* + * If the provider goes away while the consumer still has a reference, + * ops and priv will be set to NULL and all calls will fail with -ENODEV. + */ + const struct spi_offload_trigger_ops *ops; + void *priv; +}; + +static LIST_HEAD(spi_offload_triggers); +static DEFINE_MUTEX(spi_offload_triggers_lock); + /** * devm_spi_offload_alloc() - Allocate offload instance * @dev: Device for devm purposes and assigned to &struct spi_offload.provider_dev @@ -112,3 +133,263 @@ struct spi_offload *devm_spi_offload_get(struct device *dev, return resource->offload; } EXPORT_SYMBOL_GPL(devm_spi_offload_get); + +static void spi_offload_trigger_free(struct kref *ref) +{ + struct spi_offload_trigger *trigger = + container_of(ref, struct spi_offload_trigger, ref); + + mutex_destroy(&trigger->lock); + fwnode_handle_put(trigger->fwnode); + kfree(trigger); +} + +static void spi_offload_trigger_put(void *data) +{ + struct spi_offload_trigger *trigger = data; + + scoped_guard(mutex, &trigger->lock) + if (trigger->ops && trigger->ops->release) + trigger->ops->release(trigger); + + kref_put(&trigger->ref, spi_offload_trigger_free); +} + +static struct spi_offload_trigger +*spi_offload_trigger_get(enum spi_offload_trigger_type type, + struct fwnode_reference_args *args) +{ + struct spi_offload_trigger *trigger; + bool match = false; + int ret; + + guard(mutex)(&spi_offload_triggers_lock); + + list_for_each_entry(trigger, &spi_offload_triggers, list) { + if (trigger->fwnode != args->fwnode) + continue; + + match = trigger->ops->match(trigger, type, args->args, args->nargs); + if (match) + break; + } + + if (!match) + return ERR_PTR(-EPROBE_DEFER); + + guard(mutex)(&trigger->lock); + + if (!trigger->ops) + return ERR_PTR(-ENODEV); + + if (trigger->ops->request) { + ret = trigger->ops->request(trigger, type, args->args, args->nargs); + if (ret) + return ERR_PTR(ret); + } + + kref_get(&trigger->ref); + + return trigger; +} + +/** + * devm_spi_offload_trigger_get() - Get an offload trigger instance + * @dev: Device for devm purposes. + * @offload: Offload instance connected to a trigger. + * @type: Trigger type to get. + * + * Return: Offload trigger instance or error on failure. + */ +struct spi_offload_trigger +*devm_spi_offload_trigger_get(struct device *dev, + struct spi_offload *offload, + enum spi_offload_trigger_type type) +{ + struct spi_offload_trigger *trigger; + struct fwnode_reference_args args; + int ret; + + ret = fwnode_property_get_reference_args(dev_fwnode(offload->provider_dev), + "trigger-sources", + "#trigger-source-cells", 0, 0, + &args); + if (ret) + return ERR_PTR(ret); + + trigger = spi_offload_trigger_get(type, &args); + fwnode_handle_put(args.fwnode); + if (IS_ERR(trigger)) + return trigger; + + ret = devm_add_action_or_reset(dev, spi_offload_trigger_put, trigger); + if (ret) + return ERR_PTR(ret); + + return trigger; +} +EXPORT_SYMBOL_GPL(devm_spi_offload_trigger_get); + +/** + * spi_offload_trigger_validate - Validate the requested trigger + * @trigger: Offload trigger instance + * @config: Trigger config to validate + * + * On success, @config may be modifed to reflect what the hardware can do. + * For example, the frequency of a periodic trigger may be adjusted to the + * nearest supported value. + * + * Callers will likely need to do additional validation of the modified trigger + * parameters. + * + * Return: 0 on success, negative error code on failure. + */ +int spi_offload_trigger_validate(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config) +{ + guard(mutex)(&trigger->lock); + + if (!trigger->ops) + return -ENODEV; + + if (!trigger->ops->validate) + return -EOPNOTSUPP; + + return trigger->ops->validate(trigger, config); +} +EXPORT_SYMBOL_GPL(spi_offload_trigger_validate); + +/** + * spi_offload_trigger_enable - enables trigger for offload + * @offload: Offload instance + * @trigger: Offload trigger instance + * @config: Trigger config to validate + * + * There must be a prepared offload instance with the specified ID (i.e. + * spi_optimize_message() was called with the same offload assigned to the + * message). This will also reserve the bus for exclusive use by the offload + * instance until the trigger is disabled. Any other attempts to send a + * transfer or lock the bus will fail with -EBUSY during this time. + * + * Calls must be balanced with spi_offload_trigger_disable(). + * + * Context: can sleep + * Return: 0 on success, else a negative error code. + */ +int spi_offload_trigger_enable(struct spi_offload *offload, + struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config) +{ + int ret; + + guard(mutex)(&trigger->lock); + + if (!trigger->ops) + return -ENODEV; + + if (offload->ops && offload->ops->trigger_enable) { + ret = offload->ops->trigger_enable(offload); + if (ret) + return ret; + } + + if (trigger->ops->enable) { + ret = trigger->ops->enable(trigger, config); + if (ret) { + if (offload->ops->trigger_disable) + offload->ops->trigger_disable(offload); + return ret; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(spi_offload_trigger_enable); + +/** + * spi_offload_trigger_disable - disables hardware trigger for offload + * @offload: Offload instance + * @trigger: Offload trigger instance + * + * Disables the hardware trigger for the offload instance with the specified ID + * and releases the bus for use by other clients. + * + * Context: can sleep + */ +void spi_offload_trigger_disable(struct spi_offload *offload, + struct spi_offload_trigger *trigger) +{ + if (offload->ops && offload->ops->trigger_disable) + offload->ops->trigger_disable(offload); + + guard(mutex)(&trigger->lock); + + if (!trigger->ops) + return; + + if (trigger->ops->disable) + trigger->ops->disable(trigger); +} +EXPORT_SYMBOL_GPL(spi_offload_trigger_disable); + +/* Triggers providers */ + +static void spi_offload_trigger_unregister(void *data) +{ + struct spi_offload_trigger *trigger = data; + + scoped_guard(mutex, &spi_offload_triggers_lock) + list_del(&trigger->list); + + scoped_guard(mutex, &trigger->lock) { + trigger->priv = NULL; + trigger->ops = NULL; + } + + kref_put(&trigger->ref, spi_offload_trigger_free); +} + +/** + * devm_spi_offload_trigger_register() - Allocate and register an offload trigger + * @dev: Device for devm purposes. + * @info: Provider-specific trigger info. + * + * Return: 0 on success, else a negative error code. + */ +int devm_spi_offload_trigger_register(struct device *dev, + struct spi_offload_trigger_info *info) +{ + struct spi_offload_trigger *trigger; + + if (!info->fwnode || !info->ops) + return -EINVAL; + + trigger = kzalloc(sizeof(*trigger), GFP_KERNEL); + if (!trigger) + return -ENOMEM; + + kref_init(&trigger->ref); + mutex_init(&trigger->lock); + trigger->fwnode = fwnode_handle_get(info->fwnode); + trigger->ops = info->ops; + trigger->priv = info->priv; + + scoped_guard(mutex, &spi_offload_triggers_lock) + list_add_tail(&trigger->list, &spi_offload_triggers); + + return devm_add_action_or_reset(dev, spi_offload_trigger_unregister, trigger); +} +EXPORT_SYMBOL_GPL(devm_spi_offload_trigger_register); + +/** + * spi_offload_trigger_get_priv() - Get the private data for the trigger + * + * @trigger: Offload trigger instance. + * + * Return: Private data for the trigger. + */ +void *spi_offload_trigger_get_priv(struct spi_offload_trigger *trigger) +{ + return trigger->priv; +} +EXPORT_SYMBOL_GPL(spi_offload_trigger_get_priv); diff --git a/include/linux/spi/offload/consumer.h b/include/linux/spi/offload/consumer.h index 05543dbedf30..5a0ec5303d60 100644 --- a/include/linux/spi/offload/consumer.h +++ b/include/linux/spi/offload/consumer.h @@ -19,4 +19,16 @@ struct spi_device; struct spi_offload *devm_spi_offload_get(struct device *dev, struct spi_device *spi, const struct spi_offload_config *config); +struct spi_offload_trigger +*devm_spi_offload_trigger_get(struct device *dev, + struct spi_offload *offload, + enum spi_offload_trigger_type type); +int spi_offload_trigger_validate(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config); +int spi_offload_trigger_enable(struct spi_offload *offload, + struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config); +void spi_offload_trigger_disable(struct spi_offload *offload, + struct spi_offload_trigger *trigger); + #endif /* __LINUX_SPI_OFFLOAD_CONSUMER_H */ diff --git a/include/linux/spi/offload/provider.h b/include/linux/spi/offload/provider.h index 278c4edfcdb7..76c7cf651092 100644 --- a/include/linux/spi/offload/provider.h +++ b/include/linux/spi/offload/provider.h @@ -8,12 +8,40 @@ #define __LINUX_SPI_OFFLOAD_PROVIDER_H #include +#include #include MODULE_IMPORT_NS("SPI_OFFLOAD"); struct device; +struct spi_offload_trigger; struct spi_offload *devm_spi_offload_alloc(struct device *dev, size_t priv_size); +struct spi_offload_trigger_ops { + bool (*match)(struct spi_offload_trigger *trigger, + enum spi_offload_trigger_type type, u64 *args, u32 nargs); + int (*request)(struct spi_offload_trigger *trigger, + enum spi_offload_trigger_type type, u64 *args, u32 nargs); + void (*release)(struct spi_offload_trigger *trigger); + int (*validate)(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config); + int (*enable)(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config); + void (*disable)(struct spi_offload_trigger *trigger); +}; + +struct spi_offload_trigger_info { + /** @fwnode: Provider fwnode, used to match to consumer. */ + struct fwnode_handle *fwnode; + /** @ops: Provider-specific callbacks. */ + const struct spi_offload_trigger_ops *ops; + /** Provider-specific state to be used in callbacks. */ + void *priv; +}; + +int devm_spi_offload_trigger_register(struct device *dev, + struct spi_offload_trigger_info *info); +void *spi_offload_trigger_get_priv(struct spi_offload_trigger *trigger); + #endif /* __LINUX_SPI_OFFLOAD_PROVIDER_H */ diff --git a/include/linux/spi/offload/types.h b/include/linux/spi/offload/types.h index a74f8d84541b..7476f2073b02 100644 --- a/include/linux/spi/offload/types.h +++ b/include/linux/spi/offload/types.h @@ -38,6 +38,43 @@ struct spi_offload { struct device *provider_dev; /** @priv: provider driver private data */ void *priv; + /** @ops: callbacks for offload support */ + const struct spi_offload_ops *ops; +}; + +enum spi_offload_trigger_type { + /* Indication from SPI peripheral that data is read to read. */ + SPI_OFFLOAD_TRIGGER_DATA_READY, + /* Trigger comes from a periodic source such as a clock. */ + SPI_OFFLOAD_TRIGGER_PERIODIC, +}; + +struct spi_offload_trigger_periodic { + u64 frequency_hz; +}; + +struct spi_offload_trigger_config { + /** @type: type discriminator for union */ + enum spi_offload_trigger_type type; + union { + struct spi_offload_trigger_periodic periodic; + }; +}; + +/** + * struct spi_offload_ops - callbacks implemented by offload providers + */ +struct spi_offload_ops { + /** + * @trigger_enable: Optional callback to enable the trigger for the + * given offload instance. + */ + int (*trigger_enable)(struct spi_offload *offload); + /** + * @trigger_disable: Optional callback to disable the trigger for the + * given offload instance. + */ + void (*trigger_disable)(struct spi_offload *offload); }; #endif /* __LINUX_SPI_OFFLOAD_TYPES_H */ -- cgit v1.2.3 From 700a281905f2a4ccf6f3b2d3cd6985e034b4b021 Mon Sep 17 00:00:00 2001 From: David Lechner Date: Fri, 7 Feb 2025 14:09:02 -0600 Subject: spi: add offload TX/RX streaming APIs Most configuration of SPI offloads is handled opaquely using the offload pointer that is passed to the various offload functions. However, there are some offload features that need to be controlled on a per transfer basis. This patch adds a flag field to struct spi_transfer to allow specifying such features. The first feature to be added is the ability to stream data to/from a hardware sink/source rather than using a tx or rx buffer. Additional flags can be added in the future as needed. A flags field is also added to the offload struct for providers to indicate which flags are supported. This allows for generic checking of offload capabilities during __spi_validate() so that each offload provider doesn't have to implement their own validation. As a first users of this streaming capability, getter functions are added to get a DMA channel that is directly connected to the offload. Peripheral drivers will use this to get a DMA channel and configure it to suit their needs. Reviewed-by: Jonathan Cameron Reviewed-by: Nuno Sa Signed-off-by: David Lechner Link: https://patch.msgid.link/20250207-dlech-mainline-spi-engine-offload-2-v8-5-e48a489be48c@baylibre.com Signed-off-by: Mark Brown --- drivers/spi/spi-offload.c | 70 ++++++++++++++++++++++++++++++++++++ drivers/spi/spi.c | 10 ++++++ include/linux/spi/offload/consumer.h | 5 +++ include/linux/spi/offload/types.h | 19 ++++++++++ include/linux/spi/spi.h | 3 ++ 5 files changed, 107 insertions(+) (limited to 'include/linux') diff --git a/drivers/spi/spi-offload.c b/drivers/spi/spi-offload.c index 43582e50e279..df5e963d5ee2 100644 --- a/drivers/spi/spi-offload.c +++ b/drivers/spi/spi-offload.c @@ -18,6 +18,7 @@ #include #include +#include #include #include #include @@ -332,6 +333,75 @@ void spi_offload_trigger_disable(struct spi_offload *offload, } EXPORT_SYMBOL_GPL(spi_offload_trigger_disable); +static void spi_offload_release_dma_chan(void *chan) +{ + dma_release_channel(chan); +} + +/** + * devm_spi_offload_tx_stream_request_dma_chan - Get the DMA channel info for the TX stream + * @dev: Device for devm purposes. + * @offload: Offload instance + * + * This is the DMA channel that will provide data to transfers that use the + * %SPI_OFFLOAD_XFER_TX_STREAM offload flag. + * + * Return: Pointer to DMA channel info, or negative error code + */ +struct dma_chan +*devm_spi_offload_tx_stream_request_dma_chan(struct device *dev, + struct spi_offload *offload) +{ + struct dma_chan *chan; + int ret; + + if (!offload->ops || !offload->ops->tx_stream_request_dma_chan) + return ERR_PTR(-EOPNOTSUPP); + + chan = offload->ops->tx_stream_request_dma_chan(offload); + if (IS_ERR(chan)) + return chan; + + ret = devm_add_action_or_reset(dev, spi_offload_release_dma_chan, chan); + if (ret) + return ERR_PTR(ret); + + return chan; +} +EXPORT_SYMBOL_GPL(devm_spi_offload_tx_stream_request_dma_chan); + +/** + * devm_spi_offload_rx_stream_request_dma_chan - Get the DMA channel info for the RX stream + * @dev: Device for devm purposes. + * @offload: Offload instance + * + * This is the DMA channel that will receive data from transfers that use the + * %SPI_OFFLOAD_XFER_RX_STREAM offload flag. + * + * Return: Pointer to DMA channel info, or negative error code + */ +struct dma_chan +*devm_spi_offload_rx_stream_request_dma_chan(struct device *dev, + struct spi_offload *offload) +{ + struct dma_chan *chan; + int ret; + + if (!offload->ops || !offload->ops->rx_stream_request_dma_chan) + return ERR_PTR(-EOPNOTSUPP); + + chan = offload->ops->rx_stream_request_dma_chan(offload); + if (IS_ERR(chan)) + return chan; + + ret = devm_add_action_or_reset(dev, spi_offload_release_dma_chan, chan); + if (ret) + return ERR_PTR(ret); + + return chan; +} +EXPORT_SYMBOL_GPL(devm_spi_offload_rx_stream_request_dma_chan); + /* Triggers providers */ static void spi_offload_trigger_unregister(void *data) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index a7a4647717d4..10c365e9100a 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -4158,6 +4159,15 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) if (_spi_xfer_word_delay_update(xfer, spi)) return -EINVAL; + + /* Make sure controller supports required offload features. */ + if (xfer->offload_flags) { + if (!message->offload) + return -EINVAL; + + if (xfer->offload_flags & ~message->offload->xfer_flags) + return -EINVAL; + } } message->status = -EINPROGRESS; diff --git a/include/linux/spi/offload/consumer.h b/include/linux/spi/offload/consumer.h index 5a0ec5303d60..cd7d5daa21e6 100644 --- a/include/linux/spi/offload/consumer.h +++ b/include/linux/spi/offload/consumer.h @@ -31,4 +31,9 @@ int spi_offload_trigger_enable(struct spi_offload *offload, void spi_offload_trigger_disable(struct spi_offload *offload, struct spi_offload_trigger *trigger); +struct dma_chan *devm_spi_offload_tx_stream_request_dma_chan(struct device *dev, + struct spi_offload *offload); +struct dma_chan *devm_spi_offload_rx_stream_request_dma_chan(struct device *dev, + struct spi_offload *offload); + #endif /* __LINUX_SPI_OFFLOAD_CONSUMER_H */ diff --git a/include/linux/spi/offload/types.h b/include/linux/spi/offload/types.h index 7476f2073b02..86d0e8cb9495 100644 --- a/include/linux/spi/offload/types.h +++ b/include/linux/spi/offload/types.h @@ -11,6 +11,11 @@ struct device; +/* This is write xfer but TX uses external data stream rather than tx_buf. */ +#define SPI_OFFLOAD_XFER_TX_STREAM BIT(0) +/* This is read xfer but RX uses external data stream rather than rx_buf. */ +#define SPI_OFFLOAD_XFER_RX_STREAM BIT(1) + /* 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. */ @@ -40,6 +45,8 @@ struct spi_offload { void *priv; /** @ops: callbacks for offload support */ const struct spi_offload_ops *ops; + /** @xfer_flags: %SPI_OFFLOAD_XFER_* flags supported by provider */ + u32 xfer_flags; }; enum spi_offload_trigger_type { @@ -75,6 +82,18 @@ struct spi_offload_ops { * given offload instance. */ void (*trigger_disable)(struct spi_offload *offload); + /** + * @tx_stream_request_dma_chan: Optional callback for controllers that + * have an offload where the TX data stream is connected directly to a + * DMA channel. + */ + struct dma_chan *(*tx_stream_request_dma_chan)(struct spi_offload *offload); + /** + * @rx_stream_request_dma_chan: Optional callback for controllers that + * have an offload where the RX data stream is connected directly to a + * DMA channel. + */ + struct dma_chan *(*rx_stream_request_dma_chan)(struct spi_offload *offload); }; #endif /* __LINUX_SPI_OFFLOAD_TYPES_H */ diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 98bdc8c16c20..4c087009cf97 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -1093,6 +1093,9 @@ struct spi_transfer { u32 effective_speed_hz; + /* Use %SPI_OFFLOAD_XFER_* from spi-offload.h */ + unsigned int offload_flags; + unsigned int ptp_sts_word_pre; unsigned int ptp_sts_word_post; -- cgit v1.2.3