From 0ebb261a0b2d090de618a383d2378d4a00834958 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Tue, 6 Nov 2018 17:05:31 +0100 Subject: spi: spi-mem: Add SPI_MEM_NO_DATA to the spi_mem_data_dir enum When defining spi_mem_op templates we don't necessarily know the size that will be passed when the template is actually used, and basing the supports_op() check on op->data.nbytes to know whether there will be data transferred for a specific operation is this not possible. Add SPI_MEM_NO_DATA to the spi_mem_data_dir enum so that we can base our checks on op->data.dir instead of op->data.nbytes. Signed-off-by: Boris Brezillon Reviewed-by: Miquel Raynal Signed-off-by: Mark Brown --- drivers/spi/spi-mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/spi/spi-mem.c') diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index 62a7b80801d2..967f581bca4f 100644 --- a/drivers/spi/spi-mem.c +++ b/drivers/spi/spi-mem.c @@ -142,7 +142,7 @@ static bool spi_mem_default_supports_op(struct spi_mem *mem, spi_check_buswidth_req(mem, op->dummy.buswidth, true)) return false; - if (op->data.nbytes && + if (op->data.dir != SPI_MEM_NO_DATA && spi_check_buswidth_req(mem, op->data.buswidth, op->data.dir == SPI_MEM_DATA_OUT)) return false; -- cgit v1.2.3 From f86c24f4795303e4024bc113196de32782f6ccb5 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Tue, 6 Nov 2018 17:05:32 +0100 Subject: spi: spi-mem: Split spi_mem_exec_op() code The logic surrounding the ->exec_op() call applies to direct mapping accessors. Move this code to separate functions to avoid duplicating code. Signed-off-by: Boris Brezillon Reviewed-by: Miquel Raynal Signed-off-by: Mark Brown --- drivers/spi/spi-mem.c | 63 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 42 insertions(+), 21 deletions(-) (limited to 'drivers/spi/spi-mem.c') diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index 967f581bca4f..7916e655afc8 100644 --- a/drivers/spi/spi-mem.c +++ b/drivers/spi/spi-mem.c @@ -213,6 +213,44 @@ bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op) } EXPORT_SYMBOL_GPL(spi_mem_supports_op); +static int spi_mem_access_start(struct spi_mem *mem) +{ + struct spi_controller *ctlr = mem->spi->controller; + + /* + * Flush the message queue before executing our SPI memory + * operation to prevent preemption of regular SPI transfers. + */ + spi_flush_queue(ctlr); + + if (ctlr->auto_runtime_pm) { + int ret; + + ret = pm_runtime_get_sync(ctlr->dev.parent); + if (ret < 0) { + dev_err(&ctlr->dev, "Failed to power device: %d\n", + ret); + return ret; + } + } + + mutex_lock(&ctlr->bus_lock_mutex); + mutex_lock(&ctlr->io_mutex); + + return 0; +} + +static void spi_mem_access_end(struct spi_mem *mem) +{ + struct spi_controller *ctlr = mem->spi->controller; + + mutex_unlock(&ctlr->io_mutex); + mutex_unlock(&ctlr->bus_lock_mutex); + + if (ctlr->auto_runtime_pm) + pm_runtime_put(ctlr->dev.parent); +} + /** * spi_mem_exec_op() - Execute a memory operation * @mem: the SPI memory @@ -242,30 +280,13 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) return -ENOTSUPP; if (ctlr->mem_ops) { - /* - * Flush the message queue before executing our SPI memory - * operation to prevent preemption of regular SPI transfers. - */ - spi_flush_queue(ctlr); - - if (ctlr->auto_runtime_pm) { - ret = pm_runtime_get_sync(ctlr->dev.parent); - if (ret < 0) { - dev_err(&ctlr->dev, - "Failed to power device: %d\n", - ret); - return ret; - } - } + ret = spi_mem_access_start(mem); + if (ret) + return ret; - mutex_lock(&ctlr->bus_lock_mutex); - mutex_lock(&ctlr->io_mutex); ret = ctlr->mem_ops->exec_op(mem, op); - mutex_unlock(&ctlr->io_mutex); - mutex_unlock(&ctlr->bus_lock_mutex); - if (ctlr->auto_runtime_pm) - pm_runtime_put(ctlr->dev.parent); + spi_mem_access_end(mem); /* * Some controllers only optimize specific paths (typically the -- cgit v1.2.3 From aa167f3fed0c37e0e4c707d4331d827661f46644 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Tue, 6 Nov 2018 17:05:33 +0100 Subject: spi: spi-mem: Add a new API to support direct mapping Most modern SPI controllers can directly map a SPI memory (or a portion of the SPI memory) in the CPU address space. Most of the time this brings significant performance improvements as it automates the whole process of sending SPI memory operations every time a new region is accessed. This new API allows SPI memory drivers to create direct mappings and then use them to access the memory instead of using spi_mem_exec_op(). Signed-off-by: Boris Brezillon Reviewed-by: Miquel Raynal Signed-off-by: Mark Brown --- drivers/spi/spi-mem.c | 204 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 204 insertions(+) (limited to 'drivers/spi/spi-mem.c') diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index 7916e655afc8..b12a7974b665 100644 --- a/drivers/spi/spi-mem.c +++ b/drivers/spi/spi-mem.c @@ -432,6 +432,210 @@ int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) } EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size); +static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc, + u64 offs, size_t len, void *buf) +{ + struct spi_mem_op op = desc->info.op_tmpl; + int ret; + + op.addr.val = desc->info.offset + offs; + op.data.buf.in = buf; + op.data.nbytes = len; + ret = spi_mem_adjust_op_size(desc->mem, &op); + if (ret) + return ret; + + ret = spi_mem_exec_op(desc->mem, &op); + if (ret) + return ret; + + return op.data.nbytes; +} + +static ssize_t spi_mem_no_dirmap_write(struct spi_mem_dirmap_desc *desc, + u64 offs, size_t len, const void *buf) +{ + struct spi_mem_op op = desc->info.op_tmpl; + int ret; + + op.addr.val = desc->info.offset + offs; + op.data.buf.out = buf; + op.data.nbytes = len; + ret = spi_mem_adjust_op_size(desc->mem, &op); + if (ret) + return ret; + + ret = spi_mem_exec_op(desc->mem, &op); + if (ret) + return ret; + + return op.data.nbytes; +} + +/** + * 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 + * fallback 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) +{ + struct spi_controller *ctlr = mem->spi->controller; + struct spi_mem_dirmap_desc *desc; + int ret = -ENOTSUPP; + + /* Make sure the number of address cycles is between 1 and 8 bytes. */ + if (!info->op_tmpl.addr.nbytes || info->op_tmpl.addr.nbytes > 8) + return ERR_PTR(-EINVAL); + + /* data.dir should either be SPI_MEM_DATA_IN or SPI_MEM_DATA_OUT. */ + if (info->op_tmpl.data.dir == SPI_MEM_NO_DATA) + return ERR_PTR(-EINVAL); + + desc = kzalloc(sizeof(*desc), GFP_KERNEL); + if (!desc) + return ERR_PTR(-ENOMEM); + + desc->mem = mem; + desc->info = *info; + if (ctlr->mem_ops && ctlr->mem_ops->dirmap_create) + ret = ctlr->mem_ops->dirmap_create(desc); + + if (ret) { + desc->nodirmap = true; + if (!spi_mem_supports_op(desc->mem, &desc->info.op_tmpl)) + ret = -ENOTSUPP; + else + ret = 0; + } + + if (ret) { + kfree(desc); + return ERR_PTR(ret); + } + + return desc; +} +EXPORT_SYMBOL_GPL(spi_mem_dirmap_create); + +/** + * spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor + * @desc: the direct mapping descriptor to destroy + * @info: direct mapping information + * + * 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) +{ + struct spi_controller *ctlr = desc->mem->spi->controller; + + if (!desc->nodirmap && ctlr->mem_ops && ctlr->mem_ops->dirmap_destroy) + ctlr->mem_ops->dirmap_destroy(desc); +} +EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy); + +/** + * spi_mem_dirmap_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) +{ + struct spi_controller *ctlr = desc->mem->spi->controller; + ssize_t ret; + + if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN) + return -EINVAL; + + if (!len) + return 0; + + if (desc->nodirmap) { + ret = spi_mem_no_dirmap_read(desc, offs, len, buf); + } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_read) { + ret = spi_mem_access_start(desc->mem); + if (ret) + return ret; + + ret = ctlr->mem_ops->dirmap_read(desc, offs, len, buf); + + spi_mem_access_end(desc->mem); + } else { + ret = -ENOTSUPP; + } + + return ret; +} +EXPORT_SYMBOL_GPL(spi_mem_dirmap_read); + +/** + * spi_mem_dirmap_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) +{ + struct spi_controller *ctlr = desc->mem->spi->controller; + ssize_t ret; + + if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_OUT) + return -EINVAL; + + if (!len) + return 0; + + if (desc->nodirmap) { + ret = spi_mem_no_dirmap_write(desc, offs, len, buf); + } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_write) { + ret = spi_mem_access_start(desc->mem); + if (ret) + return ret; + + ret = ctlr->mem_ops->dirmap_write(desc, offs, len, buf); + + spi_mem_access_end(desc->mem); + } else { + ret = -ENOTSUPP; + } + + return ret; +} +EXPORT_SYMBOL_GPL(spi_mem_dirmap_write); + static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv) { return container_of(drv, struct spi_mem_driver, spidrv.driver); -- cgit v1.2.3