From patchwork Wed Dec 11 20:54:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Lechner X-Patchwork-Id: 849669 Received: from mail-oo1-f41.google.com (mail-oo1-f41.google.com [209.85.161.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DA2E92288D2 for ; Wed, 11 Dec 2024 20:54:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.41 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733950500; cv=none; b=q41Y+U5YcBhw3MWRaTuT/BK/PALP7ZmyZBi0adZ8Y4iE4xlTaY+Lgm1cxNOtHhke6AMEcO1CNtU9suzeV08+i4LMsVGrLb2pWKxtsLP6UVr5Bu17G5kuhc0tGy+CegIIaubgvPfR9HE5qLYHznLeLAGuiwBcTjMnJEwxlkeMvFU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733950500; c=relaxed/simple; bh=RGggUajwKcxwMBqnwmDZ76Eu+OfENqU99nf0uDpoQRo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=oHFqwNkTc5sYB1gJzu9/u7F5xzAU99hAsw5yggo85BuBCV7mY7TYZ0VgRVzlpWr7kRBF0SZGsh6okMEDXLfnn7vlghnsn3/6Gng1XbgGrdS09EsORuCb9qzEj39Q7Hxpu+a5fvhwa4x9izz2i6iNWVOdtBY6iicp/Ya3u7w185k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com; spf=pass smtp.mailfrom=baylibre.com; dkim=pass (2048-bit key) header.d=baylibre-com.20230601.gappssmtp.com header.i=@baylibre-com.20230601.gappssmtp.com header.b=t4W4CT+W; arc=none smtp.client-ip=209.85.161.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=baylibre.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20230601.gappssmtp.com header.i=@baylibre-com.20230601.gappssmtp.com header.b="t4W4CT+W" Received: by mail-oo1-f41.google.com with SMTP id 006d021491bc7-5f2e370bb3aso200124eaf.0 for ; Wed, 11 Dec 2024 12:54:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20230601.gappssmtp.com; s=20230601; t=1733950497; x=1734555297; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=4ffc3LxMkAvRH+svHl43EnhBnXUPIwZq2nOCjPB5PSI=; b=t4W4CT+WaFUICIFPy9VoOBAfzBVgHz8ww/CDhMDHqjy1ZVxq8ukEjYeweTgPl5ioyg lgexYO2GBpzXrzhNPZ34NGBDEuTOMFzk5eQu+bpHdurTIlBYlYTO8zM+OH7TJZbRmS4N 5cHBa/YvQoDYJkV8BUOrmrTLHJoLNxtlXpiUQ+Sq4sDnwWYcIF2GGK/2QHhuB0oy7baS vvd624yUoRzu3prnU75f1saGZoC7NvtSh5I0iXbPZ9gQFNxpQ0kdcg0hXNPPI/JFHX10 F7cC6Edets41PNObY2p4y3CMMzk9SwfDowf6+Vq7nHwPmAfRdd/Bg3pJGMe9lNedrTRd 5DOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733950497; x=1734555297; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=4ffc3LxMkAvRH+svHl43EnhBnXUPIwZq2nOCjPB5PSI=; b=bYdm7m/eHCZ6Wa5hmqAWnVJ5rWKWq01EzzCQulIFE14j/Y+plr9LJqNyOGDVRUw8n7 DLZUC449ACDTb5t6DnhCMVsd7TusRnBbGwCq4zSdKP16Yi/YHpv1/G/m38MYgG8xKlI0 EC+qPFr2IC7Cgj2Xjk2oZjIbIR8KFaF39bEW5zYZlfmm75tABsWQ/PLu5zqxGqgtKHfq PeULakqKxTuGy8L0YUq9V2mVIVWoht+59hIOtQsGNycHsoKoAP+vJTOSMGq1hdp0KSLA o52fFt19+4BWsOt50K4SEkErorZn6abM1wvoG0GIA8cfZN+rrPkkROK3NNovV7CuDGeh YTxQ== X-Forwarded-Encrypted: i=1; AJvYcCVzVQYrDRcGWJrlldRV+T3xGOWyU+Vvy+HyG7jFeSosllIYpbCVAJMo1cvzPdDqS1FOVanQYTxKGSQ=@vger.kernel.org X-Gm-Message-State: AOJu0YwjOhTeh1xpM14XZcUETy/nGyhyxJcpOh6Y4GoRwmTFjUjEx1fd uUghieXoJ1z577jftOJJWGnlAbbQT5oCraObCunWD3kad8Sp6WccpFsAxLyTI0k= X-Gm-Gg: ASbGncuGCkbbtVtaGQBHD4D2hZcsI+hsc7mIqZUHLn/vbK1/n1zDknwNom/R7GNprn/ OB8e12rFpyn0vGT8SdZ4D0ihre9+rPLQEeHFl3P6VxKIDO7zYKdEGIq7hjbQnNJOy+Qf7Vt/rFF SVp1AEaWKUwVfuk2b1Nm7K9iwgFNyHhDqzjZXgPSujG1jxj7ROVKdYGKNxrW25PvQjxq7obIgHD VSyk0z2QEGkjG4153uBy4OWTET91OzLyTFIUzA9DDkznfCopBeWm/+A6raF51lzGL9teF0Iv3dB fQLwoCxing== X-Google-Smtp-Source: AGHT+IG7inO0xnuwDZeUqSYTrfiBKUGM+ravvukMEKOFTzNGsJgAfy6fOUDwdyEAKDaxSFKj91kwLA== X-Received: by 2002:a05:6820:1989:b0:5f1:e3d1:b994 with SMTP id 006d021491bc7-5f2ef873a5emr610173eaf.0.1733950496838; Wed, 11 Dec 2024 12:54:56 -0800 (PST) Received: from [127.0.1.1] (ip98-183-112-25.ok.ok.cox.net. [98.183.112.25]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-71def651fb2sm1888288a34.27.2024.12.11.12.54.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Dec 2024 12:54:55 -0800 (PST) From: David Lechner Date: Wed, 11 Dec 2024 14:54:38 -0600 Subject: [PATCH v6 01/17] spi: add basic support for SPI offloading Precedence: bulk X-Mailing-List: linux-spi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241211-dlech-mainline-spi-engine-offload-2-v6-1-88ee574d5d03@baylibre.com> References: <20241211-dlech-mainline-spi-engine-offload-2-v6-0-88ee574d5d03@baylibre.com> In-Reply-To: <20241211-dlech-mainline-spi-engine-offload-2-v6-0-88ee574d5d03@baylibre.com> To: Mark Brown , Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley , =?utf-8?q?Nuno_S=C3=A1?= Cc: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Michael Hennerich , Lars-Peter Clausen , David Jander , Martin Sperl , linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, linux-pwm@vger.kernel.org, Jonathan Cameron , David Lechner X-Mailer: b4 0.14.2 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 Signed-off-by: David Lechner --- 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..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 +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 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 +#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 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 +#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 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 +#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 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 + +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; };