ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/drivers/spi/spi-mem.c b/marvell/linux/drivers/spi/spi-mem.c
new file mode 100644
index 0000000..4e7ebc4
--- /dev/null
+++ b/marvell/linux/drivers/spi/spi-mem.c
@@ -0,0 +1,811 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Exceet Electronics GmbH
+ * Copyright (C) 2018 Bootlin
+ *
+ * Author: Boris Brezillon <boris.brezillon@bootlin.com>
+ */
+#include <linux/dmaengine.h>
+#include <linux/pm_runtime.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
+
+#include "internals.h"
+
+#define SPI_MEM_MAX_BUSWIDTH 8
+
+/**
+ * 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)
+{
+ struct device *dmadev;
+
+ if (!op->data.nbytes)
+ return -EINVAL;
+
+ if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
+ dmadev = ctlr->dma_tx->device->dev;
+ else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
+ dmadev = ctlr->dma_rx->device->dev;
+ else
+ dmadev = ctlr->dev.parent;
+
+ if (!dmadev)
+ return -EINVAL;
+
+ return spi_map_buf(ctlr, dmadev, sgt, op->data.buf.in, op->data.nbytes,
+ op->data.dir == SPI_MEM_DATA_IN ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
+}
+EXPORT_SYMBOL_GPL(spi_controller_dma_map_mem_op_data);
+
+/**
+ * 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)
+{
+ struct device *dmadev;
+
+ if (!op->data.nbytes)
+ return;
+
+ if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
+ dmadev = ctlr->dma_tx->device->dev;
+ else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
+ dmadev = ctlr->dma_rx->device->dev;
+ else
+ dmadev = ctlr->dev.parent;
+
+ spi_unmap_buf(ctlr, dmadev, sgt,
+ op->data.dir == SPI_MEM_DATA_IN ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
+}
+EXPORT_SYMBOL_GPL(spi_controller_dma_unmap_mem_op_data);
+
+static int spi_check_buswidth_req(struct spi_mem *mem, u8 buswidth, bool tx)
+{
+ u32 mode = mem->spi->mode;
+
+ switch (buswidth) {
+ case 1:
+ return 0;
+
+ case 2:
+ if ((tx &&
+ (mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL))) ||
+ (!tx &&
+ (mode & (SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))))
+ return 0;
+
+ break;
+
+ case 4:
+ if ((tx && (mode & (SPI_TX_QUAD | SPI_TX_OCTAL))) ||
+ (!tx && (mode & (SPI_RX_QUAD | SPI_RX_OCTAL))))
+ return 0;
+
+ break;
+
+ case 8:
+ if ((tx && (mode & SPI_TX_OCTAL)) ||
+ (!tx && (mode & SPI_RX_OCTAL)))
+ return 0;
+
+ break;
+
+ default:
+ break;
+ }
+
+ return -ENOTSUPP;
+}
+
+bool spi_mem_default_supports_op(struct spi_mem *mem,
+ const struct spi_mem_op *op)
+{
+ if (spi_check_buswidth_req(mem, op->cmd.buswidth, true))
+ return false;
+
+ if (op->addr.nbytes &&
+ spi_check_buswidth_req(mem, op->addr.buswidth, true))
+ return false;
+
+ if (op->dummy.nbytes &&
+ spi_check_buswidth_req(mem, op->dummy.buswidth, true))
+ return false;
+
+ 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;
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
+
+static bool spi_mem_buswidth_is_valid(u8 buswidth)
+{
+ if (hweight8(buswidth) > 1 || buswidth > SPI_MEM_MAX_BUSWIDTH)
+ return false;
+
+ return true;
+}
+
+static int spi_mem_check_op(const struct spi_mem_op *op)
+{
+ if (!op->cmd.buswidth)
+ return -EINVAL;
+
+ if ((op->addr.nbytes && !op->addr.buswidth) ||
+ (op->dummy.nbytes && !op->dummy.buswidth) ||
+ (op->data.nbytes && !op->data.buswidth))
+ return -EINVAL;
+
+ if (!spi_mem_buswidth_is_valid(op->cmd.buswidth) ||
+ !spi_mem_buswidth_is_valid(op->addr.buswidth) ||
+ !spi_mem_buswidth_is_valid(op->dummy.buswidth) ||
+ !spi_mem_buswidth_is_valid(op->data.buswidth))
+ return -EINVAL;
+
+ return 0;
+}
+
+static bool spi_mem_internal_supports_op(struct spi_mem *mem,
+ const struct spi_mem_op *op)
+{
+ struct spi_controller *ctlr = mem->spi->controller;
+
+ if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
+ return ctlr->mem_ops->supports_op(mem, op);
+
+ return spi_mem_default_supports_op(mem, 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)
+{
+ if (spi_mem_check_op(op))
+ return false;
+
+ return spi_mem_internal_supports_op(mem, 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) {
+ pm_runtime_put_noidle(ctlr->dev.parent);
+ 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
+ * @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)
+{
+ unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0;
+ struct spi_controller *ctlr = mem->spi->controller;
+ struct spi_transfer xfers[4] = { };
+ struct spi_message msg;
+ u8 *tmpbuf;
+ int ret;
+
+ ret = spi_mem_check_op(op);
+ if (ret)
+ return ret;
+
+ if (!spi_mem_internal_supports_op(mem, op))
+ return -ENOTSUPP;
+
+ if (ctlr->mem_ops) {
+ ret = spi_mem_access_start(mem);
+ if (ret)
+ return ret;
+
+ ret = ctlr->mem_ops->exec_op(mem, op);
+
+ spi_mem_access_end(mem);
+
+ /*
+ * Some controllers only optimize specific paths (typically the
+ * read path) and expect the core to use the regular SPI
+ * interface in other cases.
+ */
+ if (!ret || ret != -ENOTSUPP)
+ return ret;
+ }
+
+ tmpbufsize = sizeof(op->cmd.opcode) + op->addr.nbytes +
+ op->dummy.nbytes;
+
+ /*
+ * Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
+ * we're guaranteed that this buffer is DMA-able, as required by the
+ * SPI layer.
+ */
+ tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
+ if (!tmpbuf)
+ return -ENOMEM;
+
+ spi_message_init(&msg);
+
+ tmpbuf[0] = op->cmd.opcode;
+ xfers[xferpos].tx_buf = tmpbuf;
+ xfers[xferpos].len = sizeof(op->cmd.opcode);
+ xfers[xferpos].tx_nbits = op->cmd.buswidth;
+ spi_message_add_tail(&xfers[xferpos], &msg);
+ xferpos++;
+ totalxferlen++;
+
+ if (op->addr.nbytes) {
+ int i;
+
+ for (i = 0; i < op->addr.nbytes; i++)
+ tmpbuf[i + 1] = op->addr.val >>
+ (8 * (op->addr.nbytes - i - 1));
+
+ xfers[xferpos].tx_buf = tmpbuf + 1;
+ xfers[xferpos].len = op->addr.nbytes;
+ xfers[xferpos].tx_nbits = op->addr.buswidth;
+ spi_message_add_tail(&xfers[xferpos], &msg);
+ xferpos++;
+ totalxferlen += op->addr.nbytes;
+ }
+
+ if (op->dummy.nbytes) {
+ memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes);
+ xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
+ xfers[xferpos].len = op->dummy.nbytes;
+ xfers[xferpos].tx_nbits = op->dummy.buswidth;
+ spi_message_add_tail(&xfers[xferpos], &msg);
+ xferpos++;
+ totalxferlen += op->dummy.nbytes;
+ }
+
+ if (op->data.nbytes) {
+ if (op->data.dir == SPI_MEM_DATA_IN) {
+ xfers[xferpos].rx_buf = op->data.buf.in;
+ xfers[xferpos].rx_nbits = op->data.buswidth;
+ } else {
+ xfers[xferpos].tx_buf = op->data.buf.out;
+ xfers[xferpos].tx_nbits = op->data.buswidth;
+ }
+
+ xfers[xferpos].len = op->data.nbytes;
+ spi_message_add_tail(&xfers[xferpos], &msg);
+ xferpos++;
+ totalxferlen += op->data.nbytes;
+ }
+
+ ret = spi_sync(mem->spi, &msg);
+
+ kfree(tmpbuf);
+
+ if (ret)
+ return ret;
+
+ if (msg.actual_length != totalxferlen)
+ return -EIO;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(spi_mem_exec_op);
+
+/**
+ * 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)
+{
+ return mem->name;
+}
+EXPORT_SYMBOL_GPL(spi_mem_get_name);
+
+/**
+ * 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)
+{
+ struct spi_controller *ctlr = mem->spi->controller;
+ size_t len;
+
+ len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
+
+ if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
+ return ctlr->mem_ops->adjust_op_size(mem, op);
+
+ if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
+ if (len > spi_max_transfer_size(mem->spi))
+ return -EINVAL;
+
+ op->data.nbytes = min3((size_t)op->data.nbytes,
+ spi_max_transfer_size(mem->spi),
+ spi_max_message_size(mem->spi) -
+ len);
+ if (!op->data.nbytes)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
+
+int spi_mem_adjust_timing(struct spi_mem *mem, struct spi_mem_timing *timing)
+{
+ struct spi_controller *ctlr = mem->spi->controller;
+
+ if (ctlr->mem_ops && ctlr->mem_ops->adjust_timing)
+ return ctlr->mem_ops->adjust_timing(mem, timing);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(spi_mem_adjust_timing);
+
+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
+ *
+ * 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);
+
+ kfree(desc);
+}
+EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy);
+
+static void devm_spi_mem_dirmap_release(struct device *dev, void *res)
+{
+ struct spi_mem_dirmap_desc *desc = *(struct spi_mem_dirmap_desc **)res;
+
+ spi_mem_dirmap_destroy(desc);
+}
+
+/**
+ * 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)
+{
+ struct spi_mem_dirmap_desc **ptr, *desc;
+
+ ptr = devres_alloc(devm_spi_mem_dirmap_release, sizeof(*ptr),
+ GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ desc = spi_mem_dirmap_create(mem, info);
+ if (IS_ERR(desc)) {
+ devres_free(ptr);
+ } else {
+ *ptr = desc;
+ devres_add(dev, ptr);
+ }
+
+ return desc;
+}
+EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_create);
+
+static int devm_spi_mem_dirmap_match(struct device *dev, void *res, void *data)
+{
+ struct spi_mem_dirmap_desc **ptr = res;
+
+ if (WARN_ON(!ptr || !*ptr))
+ return 0;
+
+ return *ptr == 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)
+{
+ devres_release(dev, devm_spi_mem_dirmap_release,
+ devm_spi_mem_dirmap_match, desc);
+}
+EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_destroy);
+
+/**
+ * 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)
+{
+ 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_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);
+}
+
+static int spi_mem_probe(struct spi_device *spi)
+{
+ struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
+ struct spi_controller *ctlr = spi->controller;
+ struct spi_mem *mem;
+
+ mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
+ if (!mem)
+ return -ENOMEM;
+
+ mem->spi = spi;
+
+ if (ctlr->mem_ops && ctlr->mem_ops->get_name)
+ mem->name = ctlr->mem_ops->get_name(mem);
+ else
+ mem->name = dev_name(&spi->dev);
+
+ if (IS_ERR_OR_NULL(mem->name))
+ return PTR_ERR(mem->name);
+
+ spi_set_drvdata(spi, mem);
+
+ return memdrv->probe(mem);
+}
+
+static int spi_mem_remove(struct spi_device *spi)
+{
+ struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
+ struct spi_mem *mem = spi_get_drvdata(spi);
+
+ if (memdrv->remove)
+ return memdrv->remove(mem);
+
+ return 0;
+}
+
+static void spi_mem_shutdown(struct spi_device *spi)
+{
+ struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
+ struct spi_mem *mem = spi_get_drvdata(spi);
+
+ if (memdrv->shutdown)
+ memdrv->shutdown(mem);
+}
+
+/**
+ * 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)
+{
+ memdrv->spidrv.probe = spi_mem_probe;
+ memdrv->spidrv.remove = spi_mem_remove;
+ memdrv->spidrv.shutdown = spi_mem_shutdown;
+
+ return __spi_register_driver(owner, &memdrv->spidrv);
+}
+EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner);
+
+/**
+ * spi_mem_driver_unregister_with_owner() - 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)
+{
+ spi_unregister_driver(&memdrv->spidrv);
+}
+EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);