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 --- 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(+) create mode 100644 drivers/spi/spi-offload.c 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 diff --git a/MAINTAINERS b/MAINTAINERS index 896a307fa065..0f230ff5be25 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -22295,6 +22295,12 @@ 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 +F: drivers/spi/spi-offload.c +F: include/linux/spi/spi-offload.h +K: spi_offload + SPI SUBSYSTEM M: Mark Brown L: linux-spi@vger.kernel.org diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index ea8a31032927..02064a4e2928 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 9db7554c1864..bb5fc20df213 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 000000000000..3a40ef30debf --- /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 +#include +#include +#include +#include +#include +#include +#include +#include + +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 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(+) 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 83f37ba7b76ab17e029ab4127ec64ccccce64c00 Mon Sep 17 00:00:00 2001 From: David Lechner Date: Fri, 7 Feb 2025 14:09:00 -0600 Subject: dt-bindings: trigger-source: add generic PWM trigger source Add a new binding for using a PWM signal as a trigger source. The idea here is similar to e.g. "pwm-clock" to allow a trigger source consumer to use a PWM provider as a trigger source. Reviewed-by: Jonathan Cameron Reviewed-by: Rob Herring (Arm) Signed-off-by: David Lechner Link: https://patch.msgid.link/20250207-dlech-mainline-spi-engine-offload-2-v8-3-e48a489be48c@baylibre.com Signed-off-by: Mark Brown --- .../bindings/trigger-source/pwm-trigger.yaml | 37 ++++++++++++++++++++++ MAINTAINERS | 5 +++ 2 files changed, 42 insertions(+) create mode 100644 Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml diff --git a/Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml b/Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml new file mode 100644 index 000000000000..1eac20031dc3 --- /dev/null +++ b/Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml @@ -0,0 +1,37 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/trigger-source/pwm-trigger.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Generic trigger source using PWM + +description: Remaps a PWM channel as a trigger source. + +maintainers: + - David Lechner + +properties: + compatible: + const: pwm-trigger + + '#trigger-source-cells': + const: 0 + + pwms: + maxItems: 1 + +required: + - compatible + - '#trigger-source-cells' + - pwms + +additionalProperties: false + +examples: + - | + trigger { + compatible = "pwm-trigger"; + #trigger-source-cells = <0>; + pwms = <&pwm 0 1000000 0>; + }; diff --git a/MAINTAINERS b/MAINTAINERS index 0f230ff5be25..b5cc91d10bc0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -24056,6 +24056,11 @@ W: https://github.com/srcres258/linux-doc T: git git://github.com/srcres258/linux-doc.git doc-zh-tw F: Documentation/translations/zh_TW/ +TRIGGER SOURCE - PWM +M: David Lechner +S: Maintained +F: Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml + TRUSTED SECURITY MODULE (TSM) ATTESTATION REPORTS M: Dan Williams L: linux-coco@lists.linux.dev -- cgit v1.2.3 From ebb398ae1e052c4245b7bcea679fe073111db2ce Mon Sep 17 00:00:00 2001 From: David Lechner Date: Fri, 7 Feb 2025 14:09:01 -0600 Subject: spi: offload-trigger: add PWM trigger driver Add a new driver for a generic PWM trigger for SPI offloads. 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-v8-4-e48a489be48c@baylibre.com Signed-off-by: Mark Brown --- MAINTAINERS | 1 + drivers/spi/Kconfig | 12 +++ drivers/spi/Makefile | 3 + drivers/spi/spi-offload-trigger-pwm.c | 162 ++++++++++++++++++++++++++++++++++ 4 files changed, 178 insertions(+) create mode 100644 drivers/spi/spi-offload-trigger-pwm.c diff --git a/MAINTAINERS b/MAINTAINERS index b5cc91d10bc0..9fae4aa36beb 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -22297,6 +22297,7 @@ F: include/linux/mtd/spi-nor.h SPI OFFLOAD R: David Lechner +F: drivers/spi/spi-offload-trigger-pwm.c F: drivers/spi/spi-offload.c F: include/linux/spi/spi-offload.h K: spi_offload diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 02064a4e2928..2cfc14be8697 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -1320,4 +1320,16 @@ endif # SPI_SLAVE config SPI_DYNAMIC def_bool ACPI || OF_DYNAMIC || SPI_SLAVE +if SPI_OFFLOAD + +comment "SPI Offload triggers" + +config SPI_OFFLOAD_TRIGGER_PWM + tristate "SPI offload trigger using PWM" + depends on PWM + help + Generic SPI offload trigger implemented using PWM output. + +endif # SPI_OFFLOAD + endif # SPI diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index bb5fc20df213..0068d170bc99 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -164,3 +164,6 @@ obj-$(CONFIG_SPI_AMD) += spi-amd.o # SPI slave protocol handlers obj-$(CONFIG_SPI_SLAVE_TIME) += spi-slave-time.o obj-$(CONFIG_SPI_SLAVE_SYSTEM_CONTROL) += spi-slave-system-control.o + +# SPI offload triggers +obj-$(CONFIG_SPI_OFFLOAD_TRIGGER_PWM) += spi-offload-trigger-pwm.o diff --git a/drivers/spi/spi-offload-trigger-pwm.c b/drivers/spi/spi-offload-trigger-pwm.c new file mode 100644 index 000000000000..b26d4437c589 --- /dev/null +++ b/drivers/spi/spi-offload-trigger-pwm.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 Analog Devices Inc. + * Copyright (C) 2024 BayLibre, SAS + * + * Generic PWM trigger for SPI offload. + */ + +#include +#include +#include +#include +#include + +struct spi_offload_trigger_pwm_state { + struct device *dev; + struct pwm_device *pwm; +}; + +static bool spi_offload_trigger_pwm_match(struct spi_offload_trigger *trigger, + enum spi_offload_trigger_type type, + u64 *args, u32 nargs) +{ + if (nargs) + return false; + + return type == SPI_OFFLOAD_TRIGGER_PERIODIC; +} + +static int spi_offload_trigger_pwm_validate(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config) +{ + struct spi_offload_trigger_pwm_state *st = spi_offload_trigger_get_priv(trigger); + struct spi_offload_trigger_periodic *periodic = &config->periodic; + struct pwm_waveform wf = { }; + int ret; + + if (config->type != SPI_OFFLOAD_TRIGGER_PERIODIC) + return -EINVAL; + + if (!periodic->frequency_hz) + return -EINVAL; + + wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic->frequency_hz); + /* REVISIT: 50% duty-cycle for now - may add config parameter later */ + wf.duty_length_ns = wf.period_length_ns / 2; + + ret = pwm_round_waveform_might_sleep(st->pwm, &wf); + if (ret < 0) + return ret; + + periodic->frequency_hz = DIV_ROUND_UP_ULL(NSEC_PER_SEC, wf.period_length_ns); + + return 0; +} + +static int spi_offload_trigger_pwm_enable(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config) +{ + struct spi_offload_trigger_pwm_state *st = spi_offload_trigger_get_priv(trigger); + struct spi_offload_trigger_periodic *periodic = &config->periodic; + struct pwm_waveform wf = { }; + + if (config->type != SPI_OFFLOAD_TRIGGER_PERIODIC) + return -EINVAL; + + if (!periodic->frequency_hz) + return -EINVAL; + + wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic->frequency_hz); + /* REVISIT: 50% duty-cycle for now - may add config parameter later */ + wf.duty_length_ns = wf.period_length_ns / 2; + + return pwm_set_waveform_might_sleep(st->pwm, &wf, false); +} + +static void spi_offload_trigger_pwm_disable(struct spi_offload_trigger *trigger) +{ + struct spi_offload_trigger_pwm_state *st = spi_offload_trigger_get_priv(trigger); + struct pwm_waveform wf; + int ret; + + ret = pwm_get_waveform_might_sleep(st->pwm, &wf); + if (ret < 0) { + dev_err(st->dev, "failed to get waveform: %d\n", ret); + return; + } + + wf.duty_length_ns = 0; + + ret = pwm_set_waveform_might_sleep(st->pwm, &wf, false); + if (ret < 0) + dev_err(st->dev, "failed to disable PWM: %d\n", ret); +} + +static const struct spi_offload_trigger_ops spi_offload_trigger_pwm_ops = { + .match = spi_offload_trigger_pwm_match, + .validate = spi_offload_trigger_pwm_validate, + .enable = spi_offload_trigger_pwm_enable, + .disable = spi_offload_trigger_pwm_disable, +}; + +static void spi_offload_trigger_pwm_release(void *data) +{ + pwm_disable(data); +} + +static int spi_offload_trigger_pwm_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct spi_offload_trigger_info info = { + .fwnode = dev_fwnode(dev), + .ops = &spi_offload_trigger_pwm_ops, + }; + struct spi_offload_trigger_pwm_state *st; + struct pwm_state state; + int ret; + + st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); + if (!st) + return -ENOMEM; + + info.priv = st; + st->dev = dev; + + st->pwm = devm_pwm_get(dev, NULL); + if (IS_ERR(st->pwm)) + return dev_err_probe(dev, PTR_ERR(st->pwm), "failed to get PWM\n"); + + /* init with duty_cycle = 0, output enabled to ensure trigger off */ + pwm_init_state(st->pwm, &state); + state.enabled = true; + + ret = pwm_apply_might_sleep(st->pwm, &state); + if (ret < 0) + return dev_err_probe(dev, ret, "failed to apply PWM state\n"); + + ret = devm_add_action_or_reset(dev, spi_offload_trigger_pwm_release, st->pwm); + if (ret) + return ret; + + return devm_spi_offload_trigger_register(dev, &info); +} + +static const struct of_device_id spi_offload_trigger_pwm_of_match_table[] = { + { .compatible = "pwm-trigger" }, + { } +}; +MODULE_DEVICE_TABLE(of, spi_offload_trigger_pwm_of_match_table); + +static struct platform_driver spi_offload_trigger_pwm_driver = { + .driver = { + .name = "pwm-trigger", + .of_match_table = spi_offload_trigger_pwm_of_match_table, + }, + .probe = spi_offload_trigger_pwm_probe, +}; +module_platform_driver(spi_offload_trigger_pwm_driver); + +MODULE_AUTHOR("David Lechner "); +MODULE_DESCRIPTION("Generic PWM trigger"); +MODULE_LICENSE("GPL"); -- 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(+) 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 From e1101373df5cd7672d988bb4e9cdd5eb97003165 Mon Sep 17 00:00:00 2001 From: David Lechner Date: Fri, 7 Feb 2025 14:09:03 -0600 Subject: spi: dt-bindings: axi-spi-engine: add SPI offload properties The AXI SPI Engine has support for hardware offloading capabilities. This includes a connection to a DMA controller for streaming RX or TX data and a trigger input for starting execution of the SPI message programmed in the offload. It is designed to support up to 32 offload instances. Reviewed-by: Jonathan Cameron Reviewed-by: Rob Herring (Arm) Signed-off-by: David Lechner Link: https://patch.msgid.link/20250207-dlech-mainline-spi-engine-offload-2-v8-6-e48a489be48c@baylibre.com Signed-off-by: Mark Brown --- .../bindings/spi/adi,axi-spi-engine.yaml | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml b/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml index d48faa42d025..4b3828eda6cb 100644 --- a/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml +++ b/Documentation/devicetree/bindings/spi/adi,axi-spi-engine.yaml @@ -41,6 +41,26 @@ properties: - const: s_axi_aclk - const: spi_clk + trigger-sources: + description: + An array of trigger source phandles for offload instances. The index in + the array corresponds to the offload instance number. + minItems: 1 + maxItems: 32 + + dmas: + description: + DMA channels connected to the input or output stream interface of an + offload instance. + minItems: 1 + maxItems: 32 + + dma-names: + items: + pattern: "^offload(?:[12]?[0-9]|3[01])-[tr]x$" + minItems: 1 + maxItems: 32 + required: - compatible - reg @@ -59,6 +79,10 @@ examples: clocks = <&clkc 15>, <&clkc 15>; clock-names = "s_axi_aclk", "spi_clk"; + trigger-sources = <&trigger_clock>; + dmas = <&dma 0>; + dma-names = "offload0-rx"; + #address-cells = <1>; #size-cells = <0>; -- cgit v1.2.3 From 5a19e1985d014fab9892348f6175a19143cec810 Mon Sep 17 00:00:00 2001 From: David Lechner Date: Fri, 7 Feb 2025 14:09:04 -0600 Subject: spi: axi-spi-engine: implement offload support Implement SPI offload support for the AXI SPI Engine. Currently, the hardware only supports triggering offload transfers with a hardware trigger so attempting to use an offload message in the regular SPI message queue will fail. Also, only allows streaming rx data to an external sink, so attempts to use a rx_buf in the offload message will fail. 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-v8-7-e48a489be48c@baylibre.com Signed-off-by: Mark Brown --- drivers/spi/Kconfig | 1 + drivers/spi/spi-axi-spi-engine.c | 315 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 309 insertions(+), 7 deletions(-) diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 2cfc14be8697..f496ab127ef0 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -179,6 +179,7 @@ config SPI_AU1550 config SPI_AXI_SPI_ENGINE tristate "Analog Devices AXI SPI Engine controller" depends on HAS_IOMEM + select SPI_OFFLOAD help This enables support for the Analog Devices AXI SPI Engine SPI controller. It is part of the SPI Engine framework that is used in some Analog Devices diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c index 7c252126b33e..da9840957778 100644 --- a/drivers/spi/spi-axi-spi-engine.c +++ b/drivers/spi/spi-axi-spi-engine.c @@ -2,11 +2,15 @@ /* * SPI-Engine SPI controller driver * Copyright 2015 Analog Devices Inc. + * Copyright 2024 BayLibre, SAS * Author: Lars-Peter Clausen */ +#include +#include #include #include +#include #include #include #include @@ -14,9 +18,11 @@ #include #include #include +#include #include #include +#define SPI_ENGINE_REG_OFFLOAD_MEM_ADDR_WIDTH 0x10 #define SPI_ENGINE_REG_RESET 0x40 #define SPI_ENGINE_REG_INT_ENABLE 0x80 @@ -24,6 +30,7 @@ #define SPI_ENGINE_REG_INT_SOURCE 0x88 #define SPI_ENGINE_REG_SYNC_ID 0xc0 +#define SPI_ENGINE_REG_OFFLOAD_SYNC_ID 0xc4 #define SPI_ENGINE_REG_CMD_FIFO_ROOM 0xd0 #define SPI_ENGINE_REG_SDO_FIFO_ROOM 0xd4 @@ -34,10 +41,24 @@ #define SPI_ENGINE_REG_SDI_DATA_FIFO 0xe8 #define SPI_ENGINE_REG_SDI_DATA_FIFO_PEEK 0xec +#define SPI_ENGINE_MAX_NUM_OFFLOADS 32 + +#define SPI_ENGINE_REG_OFFLOAD_CTRL(x) (0x100 + SPI_ENGINE_MAX_NUM_OFFLOADS * (x)) +#define SPI_ENGINE_REG_OFFLOAD_STATUS(x) (0x104 + SPI_ENGINE_MAX_NUM_OFFLOADS * (x)) +#define SPI_ENGINE_REG_OFFLOAD_RESET(x) (0x108 + SPI_ENGINE_MAX_NUM_OFFLOADS * (x)) +#define SPI_ENGINE_REG_OFFLOAD_CMD_FIFO(x) (0x110 + SPI_ENGINE_MAX_NUM_OFFLOADS * (x)) +#define SPI_ENGINE_REG_OFFLOAD_SDO_FIFO(x) (0x114 + SPI_ENGINE_MAX_NUM_OFFLOADS * (x)) + +#define SPI_ENGINE_SPI_OFFLOAD_MEM_WIDTH_SDO GENMASK(15, 8) +#define SPI_ENGINE_SPI_OFFLOAD_MEM_WIDTH_CMD GENMASK(7, 0) + #define SPI_ENGINE_INT_CMD_ALMOST_EMPTY BIT(0) #define SPI_ENGINE_INT_SDO_ALMOST_EMPTY BIT(1) #define SPI_ENGINE_INT_SDI_ALMOST_FULL BIT(2) #define SPI_ENGINE_INT_SYNC BIT(3) +#define SPI_ENGINE_INT_OFFLOAD_SYNC BIT(4) + +#define SPI_ENGINE_OFFLOAD_CTRL_ENABLE BIT(0) #define SPI_ENGINE_CONFIG_CPHA BIT(0) #define SPI_ENGINE_CONFIG_CPOL BIT(1) @@ -79,6 +100,10 @@ #define SPI_ENGINE_CMD_CS_INV(flags) \ SPI_ENGINE_CMD(SPI_ENGINE_INST_CS_INV, 0, (flags)) +/* default sizes - can be changed when SPI Engine firmware is compiled */ +#define SPI_ENGINE_OFFLOAD_CMD_FIFO_SIZE 16 +#define SPI_ENGINE_OFFLOAD_SDO_FIFO_SIZE 16 + struct spi_engine_program { unsigned int length; uint16_t instructions[] __counted_by(length); @@ -106,6 +131,17 @@ struct spi_engine_message_state { uint8_t *rx_buf; }; +enum { + SPI_ENGINE_OFFLOAD_FLAG_ASSIGNED, + SPI_ENGINE_OFFLOAD_FLAG_PREPARED, +}; + +struct spi_engine_offload { + struct spi_engine *spi_engine; + unsigned long flags; + unsigned int offload_num; +}; + struct spi_engine { struct clk *clk; struct clk *ref_clk; @@ -118,6 +154,11 @@ struct spi_engine { unsigned int int_enable; /* shadows hardware CS inversion flag state */ u8 cs_inv; + + unsigned int offload_ctrl_mem_size; + unsigned int offload_sdo_mem_size; + struct spi_offload *offload; + u32 offload_caps; }; static void spi_engine_program_add_cmd(struct spi_engine_program *p, @@ -163,9 +204,9 @@ static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry, unsigned int n = min(len, 256U); unsigned int flags = 0; - if (xfer->tx_buf) + if (xfer->tx_buf || (xfer->offload_flags & SPI_OFFLOAD_XFER_TX_STREAM)) flags |= SPI_ENGINE_TRANSFER_WRITE; - if (xfer->rx_buf) + if (xfer->rx_buf || (xfer->offload_flags & SPI_OFFLOAD_XFER_RX_STREAM)) flags |= SPI_ENGINE_TRANSFER_READ; spi_engine_program_add_cmd(p, dry, @@ -217,16 +258,24 @@ static void spi_engine_gen_cs(struct spi_engine_program *p, bool dry, * * NB: This is separate from spi_engine_compile_message() because the latter * is called twice and would otherwise result in double-evaluation. + * + * Returns 0 on success, -EINVAL on failure. */ -static void spi_engine_precompile_message(struct spi_message *msg) +static int spi_engine_precompile_message(struct spi_message *msg) { unsigned int clk_div, max_hz = msg->spi->controller->max_speed_hz; struct spi_transfer *xfer; list_for_each_entry(xfer, &msg->transfers, transfer_list) { + /* If we have an offload transfer, we can't rx to buffer */ + if (msg->offload && xfer->rx_buf) + return -EINVAL; + clk_div = DIV_ROUND_UP(max_hz, xfer->speed_hz); xfer->effective_speed_hz = max_hz / min(clk_div, 256U); } + + return 0; } static void spi_engine_compile_message(struct spi_message *msg, bool dry, @@ -521,11 +570,105 @@ static irqreturn_t spi_engine_irq(int irq, void *devid) return IRQ_HANDLED; } +static int spi_engine_offload_prepare(struct spi_message *msg) +{ + struct spi_controller *host = msg->spi->controller; + struct spi_engine *spi_engine = spi_controller_get_devdata(host); + struct spi_engine_program *p = msg->opt_state; + struct spi_engine_offload *priv = msg->offload->priv; + struct spi_transfer *xfer; + void __iomem *cmd_addr; + void __iomem *sdo_addr; + size_t tx_word_count = 0; + unsigned int i; + + if (p->length > spi_engine->offload_ctrl_mem_size) + return -EINVAL; + + /* count total number of tx words in message */ + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + /* no support for reading to rx_buf */ + if (xfer->rx_buf) + return -EINVAL; + + if (!xfer->tx_buf) + continue; + + if (xfer->bits_per_word <= 8) + tx_word_count += xfer->len; + else if (xfer->bits_per_word <= 16) + tx_word_count += xfer->len / 2; + else + tx_word_count += xfer->len / 4; + } + + if (tx_word_count && !(spi_engine->offload_caps & SPI_OFFLOAD_CAP_TX_STATIC_DATA)) + return -EINVAL; + + if (tx_word_count > spi_engine->offload_sdo_mem_size) + return -EINVAL; + + /* + * This protects against calling spi_optimize_message() with an offload + * that has already been prepared with a different message. + */ + if (test_and_set_bit_lock(SPI_ENGINE_OFFLOAD_FLAG_PREPARED, &priv->flags)) + return -EBUSY; + + cmd_addr = spi_engine->base + + SPI_ENGINE_REG_OFFLOAD_CMD_FIFO(priv->offload_num); + sdo_addr = spi_engine->base + + SPI_ENGINE_REG_OFFLOAD_SDO_FIFO(priv->offload_num); + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + if (!xfer->tx_buf) + continue; + + if (xfer->bits_per_word <= 8) { + const u8 *buf = xfer->tx_buf; + + for (i = 0; i < xfer->len; i++) + writel_relaxed(buf[i], sdo_addr); + } else if (xfer->bits_per_word <= 16) { + const u16 *buf = xfer->tx_buf; + + for (i = 0; i < xfer->len / 2; i++) + writel_relaxed(buf[i], sdo_addr); + } else { + const u32 *buf = xfer->tx_buf; + + for (i = 0; i < xfer->len / 4; i++) + writel_relaxed(buf[i], sdo_addr); + } + } + + for (i = 0; i < p->length; i++) + writel_relaxed(p->instructions[i], cmd_addr); + + return 0; +} + +static void spi_engine_offload_unprepare(struct spi_offload *offload) +{ + struct spi_engine_offload *priv = offload->priv; + struct spi_engine *spi_engine = priv->spi_engine; + + writel_relaxed(1, spi_engine->base + + SPI_ENGINE_REG_OFFLOAD_RESET(priv->offload_num)); + writel_relaxed(0, spi_engine->base + + SPI_ENGINE_REG_OFFLOAD_RESET(priv->offload_num)); + + clear_bit_unlock(SPI_ENGINE_OFFLOAD_FLAG_PREPARED, &priv->flags); +} + static int spi_engine_optimize_message(struct spi_message *msg) { struct spi_engine_program p_dry, *p; + int ret; - spi_engine_precompile_message(msg); + ret = spi_engine_precompile_message(msg); + if (ret) + return ret; p_dry.length = 0; spi_engine_compile_message(msg, true, &p_dry); @@ -537,20 +680,61 @@ static int spi_engine_optimize_message(struct spi_message *msg) spi_engine_compile_message(msg, false, p); spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC( - AXI_SPI_ENGINE_CUR_MSG_SYNC_ID)); + msg->offload ? 0 : AXI_SPI_ENGINE_CUR_MSG_SYNC_ID)); msg->opt_state = p; + if (msg->offload) { + ret = spi_engine_offload_prepare(msg); + if (ret) { + msg->opt_state = NULL; + kfree(p); + return ret; + } + } + return 0; } static int spi_engine_unoptimize_message(struct spi_message *msg) { + if (msg->offload) + spi_engine_offload_unprepare(msg->offload); + kfree(msg->opt_state); return 0; } +static struct spi_offload +*spi_engine_get_offload(struct spi_device *spi, + const struct spi_offload_config *config) +{ + struct spi_controller *host = spi->controller; + struct spi_engine *spi_engine = spi_controller_get_devdata(host); + struct spi_engine_offload *priv; + + if (!spi_engine->offload) + return ERR_PTR(-ENODEV); + + if (config->capability_flags & ~spi_engine->offload_caps) + return ERR_PTR(-EINVAL); + + priv = spi_engine->offload->priv; + + if (test_and_set_bit_lock(SPI_ENGINE_OFFLOAD_FLAG_ASSIGNED, &priv->flags)) + return ERR_PTR(-EBUSY); + + return spi_engine->offload; +} + +static void spi_engine_put_offload(struct spi_offload *offload) +{ + struct spi_engine_offload *priv = offload->priv; + + clear_bit_unlock(SPI_ENGINE_OFFLOAD_FLAG_ASSIGNED, &priv->flags); +} + static int spi_engine_setup(struct spi_device *device) { struct spi_controller *host = device->controller; @@ -583,6 +767,12 @@ static int spi_engine_transfer_one_message(struct spi_controller *host, unsigned int int_enable = 0; unsigned long flags; + if (msg->offload) { + dev_err(&host->dev, "Single transfer offload not supported\n"); + msg->status = -EOPNOTSUPP; + goto out; + } + /* reinitialize message state for this transfer */ memset(st, 0, sizeof(*st)); st->cmd_buf = p->instructions; @@ -632,11 +822,68 @@ static int spi_engine_transfer_one_message(struct spi_controller *host, trace_spi_transfer_stop(msg, xfer); } +out: spi_finalize_current_message(host); return msg->status; } +static int spi_engine_trigger_enable(struct spi_offload *offload) +{ + struct spi_engine_offload *priv = offload->priv; + struct spi_engine *spi_engine = priv->spi_engine; + unsigned int reg; + + reg = readl_relaxed(spi_engine->base + + SPI_ENGINE_REG_OFFLOAD_CTRL(priv->offload_num)); + reg |= SPI_ENGINE_OFFLOAD_CTRL_ENABLE; + writel_relaxed(reg, spi_engine->base + + SPI_ENGINE_REG_OFFLOAD_CTRL(priv->offload_num)); + return 0; +} + +static void spi_engine_trigger_disable(struct spi_offload *offload) +{ + struct spi_engine_offload *priv = offload->priv; + struct spi_engine *spi_engine = priv->spi_engine; + unsigned int reg; + + reg = readl_relaxed(spi_engine->base + + SPI_ENGINE_REG_OFFLOAD_CTRL(priv->offload_num)); + reg &= ~SPI_ENGINE_OFFLOAD_CTRL_ENABLE; + writel_relaxed(reg, spi_engine->base + + SPI_ENGINE_REG_OFFLOAD_CTRL(priv->offload_num)); +} + +static struct dma_chan +*spi_engine_tx_stream_request_dma_chan(struct spi_offload *offload) +{ + struct spi_engine_offload *priv = offload->priv; + char name[16]; + + snprintf(name, sizeof(name), "offload%u-tx", priv->offload_num); + + return dma_request_chan(offload->provider_dev, name); +} + +static struct dma_chan +*spi_engine_rx_stream_request_dma_chan(struct spi_offload *offload) +{ + struct spi_engine_offload *priv = offload->priv; + char name[16]; + + snprintf(name, sizeof(name), "offload%u-rx", priv->offload_num); + + return dma_request_chan(offload->provider_dev, name); +} + +static const struct spi_offload_ops spi_engine_offload_ops = { + .trigger_enable = spi_engine_trigger_enable, + .trigger_disable = spi_engine_trigger_disable, + .tx_stream_request_dma_chan = spi_engine_tx_stream_request_dma_chan, + .rx_stream_request_dma_chan = spi_engine_rx_stream_request_dma_chan, +}; + static void spi_engine_release_hw(void *p) { struct spi_engine *spi_engine = p; @@ -651,8 +898,7 @@ static int spi_engine_probe(struct platform_device *pdev) struct spi_engine *spi_engine; struct spi_controller *host; unsigned int version; - int irq; - int ret; + int irq, ret; irq = platform_get_irq(pdev, 0); if (irq < 0) @@ -667,6 +913,46 @@ static int spi_engine_probe(struct platform_device *pdev) spin_lock_init(&spi_engine->lock); init_completion(&spi_engine->msg_complete); + /* + * REVISIT: for now, all SPI Engines only have one offload. In the + * future, this should be read from a memory mapped register to + * determine the number of offloads enabled at HDL compile time. For + * now, we can tell if an offload is present if there is a trigger + * source wired up to it. + */ + if (device_property_present(&pdev->dev, "trigger-sources")) { + struct spi_engine_offload *priv; + + spi_engine->offload = + devm_spi_offload_alloc(&pdev->dev, + sizeof(struct spi_engine_offload)); + if (IS_ERR(spi_engine->offload)) + return PTR_ERR(spi_engine->offload); + + priv = spi_engine->offload->priv; + priv->spi_engine = spi_engine; + priv->offload_num = 0; + + spi_engine->offload->ops = &spi_engine_offload_ops; + spi_engine->offload_caps = SPI_OFFLOAD_CAP_TRIGGER; + + if (device_property_match_string(&pdev->dev, "dma-names", "offload0-rx") >= 0) { + spi_engine->offload_caps |= SPI_OFFLOAD_CAP_RX_STREAM_DMA; + spi_engine->offload->xfer_flags |= SPI_OFFLOAD_XFER_RX_STREAM; + } + + if (device_property_match_string(&pdev->dev, "dma-names", "offload0-tx") >= 0) { + spi_engine->offload_caps |= SPI_OFFLOAD_CAP_TX_STREAM_DMA; + spi_engine->offload->xfer_flags |= SPI_OFFLOAD_XFER_TX_STREAM; + } else { + /* + * HDL compile option to enable TX DMA stream also disables + * the SDO memory, so can't do both at the same time. + */ + spi_engine->offload_caps |= SPI_OFFLOAD_CAP_TX_STATIC_DATA; + } + } + spi_engine->clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk"); if (IS_ERR(spi_engine->clk)) return PTR_ERR(spi_engine->clk); @@ -688,6 +974,19 @@ static int spi_engine_probe(struct platform_device *pdev) return -ENODEV; } + if (ADI_AXI_PCORE_VER_MINOR(version) >= 1) { + unsigned int sizes = readl(spi_engine->base + + SPI_ENGINE_REG_OFFLOAD_MEM_ADDR_WIDTH); + + spi_engine->offload_ctrl_mem_size = 1 << + FIELD_GET(SPI_ENGINE_SPI_OFFLOAD_MEM_WIDTH_CMD, sizes); + spi_engine->offload_sdo_mem_size = 1 << + FIELD_GET(SPI_ENGINE_SPI_OFFLOAD_MEM_WIDTH_SDO, sizes); + } else { + spi_engine->offload_ctrl_mem_size = SPI_ENGINE_OFFLOAD_CMD_FIFO_SIZE; + spi_engine->offload_sdo_mem_size = SPI_ENGINE_OFFLOAD_SDO_FIFO_SIZE; + } + writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET); writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING); writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE); @@ -709,6 +1008,8 @@ static int spi_engine_probe(struct platform_device *pdev) host->transfer_one_message = spi_engine_transfer_one_message; host->optimize_message = spi_engine_optimize_message; host->unoptimize_message = spi_engine_unoptimize_message; + host->get_offload = spi_engine_get_offload; + host->put_offload = spi_engine_put_offload; host->num_chipselect = 8; /* Some features depend of the IP core version. */ -- cgit v1.2.3