// SPDX-License-Identifier: GPL-2.0+ /* * Copyright (C) 2018 Exceet Electronics GmbH * Copyright (C) 2018 Bootlin * * Author: Boris Brezillon <[email protected]> */ #include <linux/dmaengine.h> #include <linux/iopoll.h> #include <linux/pm_runtime.h> #include <linux/spi/spi.h> #include <linux/spi/spi-mem.h> #include <linux/sched/task_stack.h> #include "internals.h" #define SPI_MEM_MAX_BUSWIDTH … /** * spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a * memory operation * @ctlr: the SPI controller requesting this dma_map() * @op: the memory operation containing the buffer to map * @sgt: a pointer to a non-initialized sg_table that will be filled by this * function * * Some controllers might want to do DMA on the data buffer embedded in @op. * This helper prepares everything for you and provides a ready-to-use * sg_table. This function is not intended to be called from spi drivers. * Only SPI controller drivers should use it. * Note that the caller must ensure the memory region pointed by * op->data.buf.{in,out} is DMA-able before calling this function. * * Return: 0 in case of success, a negative error code otherwise. */ int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr, const struct spi_mem_op *op, struct sg_table *sgt) { … } EXPORT_SYMBOL_GPL(…); /** * spi_controller_dma_unmap_mem_op_data() - DMA-unmap the buffer attached to a * memory operation * @ctlr: the SPI controller requesting this dma_unmap() * @op: the memory operation containing the buffer to unmap * @sgt: a pointer to an sg_table previously initialized by * spi_controller_dma_map_mem_op_data() * * Some controllers might want to do DMA on the data buffer embedded in @op. * This helper prepares things so that the CPU can access the * op->data.buf.{in,out} buffer again. * * This function is not intended to be called from SPI drivers. Only SPI * controller drivers should use it. * * This function should be called after the DMA operation has finished and is * only valid if the previous spi_controller_dma_map_mem_op_data() call * returned 0. * * Return: 0 in case of success, a negative error code otherwise. */ void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr, const struct spi_mem_op *op, struct sg_table *sgt) { … } EXPORT_SYMBOL_GPL(…); static int spi_check_buswidth_req(struct spi_mem *mem, u8 buswidth, bool tx) { … } static bool spi_mem_check_buswidth(struct spi_mem *mem, const struct spi_mem_op *op) { … } bool spi_mem_default_supports_op(struct spi_mem *mem, const struct spi_mem_op *op) { … } EXPORT_SYMBOL_GPL(…); static bool spi_mem_buswidth_is_valid(u8 buswidth) { … } static int spi_mem_check_op(const struct spi_mem_op *op) { … } static bool spi_mem_internal_supports_op(struct spi_mem *mem, const struct spi_mem_op *op) { … } /** * spi_mem_supports_op() - Check if a memory device and the controller it is * connected to support a specific memory operation * @mem: the SPI memory * @op: the memory operation to check * * Some controllers are only supporting Single or Dual IOs, others might only * support specific opcodes, or it can even be that the controller and device * both support Quad IOs but the hardware prevents you from using it because * only 2 IO lines are connected. * * This function checks whether a specific operation is supported. * * Return: true if @op is supported, false otherwise. */ bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op) { … } EXPORT_SYMBOL_GPL(…); static int spi_mem_access_start(struct spi_mem *mem) { … } static void spi_mem_access_end(struct spi_mem *mem) { … } static void spi_mem_add_op_stats(struct spi_statistics __percpu *pcpu_stats, const struct spi_mem_op *op, int exec_op_ret) { … } /** * spi_mem_exec_op() - Execute a memory operation * @mem: the SPI memory * @op: the memory operation to execute * * Executes a memory operation. * * This function first checks that @op is supported and then tries to execute * it. * * Return: 0 in case of success, a negative error code otherwise. */ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) { … } EXPORT_SYMBOL_GPL(…); /** * spi_mem_get_name() - Return the SPI mem device name to be used by the * upper layer if necessary * @mem: the SPI memory * * This function allows SPI mem users to retrieve the SPI mem device name. * It is useful if the upper layer needs to expose a custom name for * compatibility reasons. * * Return: a string containing the name of the memory device to be used * by the SPI mem user */ const char *spi_mem_get_name(struct spi_mem *mem) { … } EXPORT_SYMBOL_GPL(…); /** * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to * match controller limitations * @mem: the SPI memory * @op: the operation to adjust * * Some controllers have FIFO limitations and must split a data transfer * operation into multiple ones, others require a specific alignment for * optimized accesses. This function allows SPI mem drivers to split a single * operation into multiple sub-operations when required. * * Return: a negative error code if the controller can't properly adjust @op, * 0 otherwise. Note that @op->data.nbytes will be updated if @op * can't be handled in a single step. */ int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) { … } EXPORT_SYMBOL_GPL(…); static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc, u64 offs, size_t len, void *buf) { … } static ssize_t spi_mem_no_dirmap_write(struct spi_mem_dirmap_desc *desc, u64 offs, size_t len, const void *buf) { … } /** * spi_mem_dirmap_create() - Create a direct mapping descriptor * @mem: SPI mem device this direct mapping should be created for * @info: direct mapping information * * This function is creating a direct mapping descriptor which can then be used * to access the memory using spi_mem_dirmap_read() or spi_mem_dirmap_write(). * If the SPI controller driver does not support direct mapping, this function * falls back to an implementation using spi_mem_exec_op(), so that the caller * doesn't have to bother implementing a fallback on his own. * * Return: a valid pointer in case of success, and ERR_PTR() otherwise. */ struct spi_mem_dirmap_desc * spi_mem_dirmap_create(struct spi_mem *mem, const struct spi_mem_dirmap_info *info) { … } EXPORT_SYMBOL_GPL(…); /** * spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor * @desc: the direct mapping descriptor to destroy * * This function destroys a direct mapping descriptor previously created by * spi_mem_dirmap_create(). */ void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc) { … } EXPORT_SYMBOL_GPL(…); static void devm_spi_mem_dirmap_release(struct device *dev, void *res) { … } /** * devm_spi_mem_dirmap_create() - Create a direct mapping descriptor and attach * it to a device * @dev: device the dirmap desc will be attached to * @mem: SPI mem device this direct mapping should be created for * @info: direct mapping information * * devm_ variant of the spi_mem_dirmap_create() function. See * spi_mem_dirmap_create() for more details. * * Return: a valid pointer in case of success, and ERR_PTR() otherwise. */ struct spi_mem_dirmap_desc * devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem, const struct spi_mem_dirmap_info *info) { … } EXPORT_SYMBOL_GPL(…); static int devm_spi_mem_dirmap_match(struct device *dev, void *res, void *data) { … } /** * devm_spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor attached * to a device * @dev: device the dirmap desc is attached to * @desc: the direct mapping descriptor to destroy * * devm_ variant of the spi_mem_dirmap_destroy() function. See * spi_mem_dirmap_destroy() for more details. */ void devm_spi_mem_dirmap_destroy(struct device *dev, struct spi_mem_dirmap_desc *desc) { … } EXPORT_SYMBOL_GPL(…); /** * spi_mem_dirmap_read() - Read data through a direct mapping * @desc: direct mapping descriptor * @offs: offset to start reading from. Note that this is not an absolute * offset, but the offset within the direct mapping which already has * its own offset * @len: length in bytes * @buf: destination buffer. This buffer must be DMA-able * * This function reads data from a memory device using a direct mapping * previously instantiated with spi_mem_dirmap_create(). * * Return: the amount of data read from the memory device or a negative error * code. Note that the returned size might be smaller than @len, and the caller * is responsible for calling spi_mem_dirmap_read() again when that happens. */ ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc, u64 offs, size_t len, void *buf) { … } EXPORT_SYMBOL_GPL(…); /** * spi_mem_dirmap_write() - Write data through a direct mapping * @desc: direct mapping descriptor * @offs: offset to start writing from. Note that this is not an absolute * offset, but the offset within the direct mapping which already has * its own offset * @len: length in bytes * @buf: source buffer. This buffer must be DMA-able * * This function writes data to a memory device using a direct mapping * previously instantiated with spi_mem_dirmap_create(). * * Return: the amount of data written to the memory device or a negative error * code. Note that the returned size might be smaller than @len, and the caller * is responsible for calling spi_mem_dirmap_write() again when that happens. */ ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc, u64 offs, size_t len, const void *buf) { … } EXPORT_SYMBOL_GPL(…); static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv) { … } static int spi_mem_read_status(struct spi_mem *mem, const struct spi_mem_op *op, u16 *status) { … } /** * spi_mem_poll_status() - Poll memory device status * @mem: SPI memory device * @op: the memory operation to execute * @mask: status bitmask to ckeck * @match: (status & mask) expected value * @initial_delay_us: delay in us before starting to poll * @polling_delay_us: time to sleep between reads in us * @timeout_ms: timeout in milliseconds * * This function polls a status register and returns when * (status & mask) == match or when the timeout has expired. * * Return: 0 in case of success, -ETIMEDOUT in case of error, * -EOPNOTSUPP if not supported. */ int spi_mem_poll_status(struct spi_mem *mem, const struct spi_mem_op *op, u16 mask, u16 match, unsigned long initial_delay_us, unsigned long polling_delay_us, u16 timeout_ms) { … } EXPORT_SYMBOL_GPL(…); static int spi_mem_probe(struct spi_device *spi) { … } static void spi_mem_remove(struct spi_device *spi) { … } static void spi_mem_shutdown(struct spi_device *spi) { … } /** * spi_mem_driver_register_with_owner() - Register a SPI memory driver * @memdrv: the SPI memory driver to register * @owner: the owner of this driver * * Registers a SPI memory driver. * * Return: 0 in case of success, a negative error core otherwise. */ int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv, struct module *owner) { … } EXPORT_SYMBOL_GPL(…); /** * spi_mem_driver_unregister() - Unregister a SPI memory driver * @memdrv: the SPI memory driver to unregister * * Unregisters a SPI memory driver. */ void spi_mem_driver_unregister(struct spi_mem_driver *memdrv) { … } EXPORT_SYMBOL_GPL(…);
Codebase Browser
linux