spi-mem: Add dirmap API from Linux
This adds the dirmap API originally introduced in
Linux commit aa167f3fed0c
("spi: spi-mem: Add a new API to support direct mapping").
This also includes several follow-up patches and fixes.
Changes from Linux include:
* Added Kconfig option
* Changed struct device to struct udevice
* Changed struct spi_mem to struct spi_slave
This patch is obtained from the following patch
https://patchwork.ozlabs.org/project/uboot/patch/20210205043924.149504-3-seanga2@gmail.com/
The corresponding Linux kernel SHA1 is aa167f3fed0c.
Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Acked-by: Pratyush Yadav <p.yadav@ti.com>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 8ca9274..ac91d82 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -40,6 +40,16 @@
This extension is meant to simplify interaction with SPI memories
by providing an high-level interface to send memory-like commands.
+config SPI_DIRMAP
+ bool "SPI direct mapping"
+ depends on SPI_MEM
+ help
+ Enable the SPI direct mapping API. 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.
+
if DM_SPI
config ALTERA_SPI
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 9c1ede1..8e8995f 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -21,6 +21,8 @@
#include <spi.h>
#include <spi-mem.h>
#include <dm/device_compat.h>
+#include <dm/devres.h>
+#include <linux/bug.h>
#endif
#ifndef __UBOOT__
@@ -491,6 +493,272 @@
}
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->slave, &op);
+ if (ret)
+ return ret;
+
+ ret = spi_mem_exec_op(desc->slave, &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->slave, &op);
+ if (ret)
+ return ret;
+
+ ret = spi_mem_exec_op(desc->slave, &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
+ * 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_slave *slave,
+ const struct spi_mem_dirmap_info *info)
+{
+ struct udevice *bus = slave->dev->parent;
+ struct dm_spi_ops *ops = spi_get_ops(bus);
+ struct spi_mem_dirmap_desc *desc;
+ int ret = -EOPNOTSUPP;
+
+ /* 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->slave = slave;
+ desc->info = *info;
+ if (ops->mem_ops && ops->mem_ops->dirmap_create)
+ ret = ops->mem_ops->dirmap_create(desc);
+
+ if (ret) {
+ desc->nodirmap = true;
+ if (!spi_mem_supports_op(desc->slave, &desc->info.op_tmpl))
+ ret = -EOPNOTSUPP;
+ 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 udevice *bus = desc->slave->dev->parent;
+ struct dm_spi_ops *ops = spi_get_ops(bus);
+
+ if (!desc->nodirmap && ops->mem_ops && ops->mem_ops->dirmap_destroy)
+ ops->mem_ops->dirmap_destroy(desc);
+
+ kfree(desc);
+}
+EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy);
+
+#ifndef __UBOOT__
+static void devm_spi_mem_dirmap_release(struct udevice *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 udevice *dev, struct spi_slave *slave,
+ 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(slave, 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 udevice *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 udevice *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);
+#endif /* __UBOOT__ */
+
+/**
+ * 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 udevice *bus = desc->slave->dev->parent;
+ struct dm_spi_ops *ops = spi_get_ops(bus);
+ 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 (ops->mem_ops && ops->mem_ops->dirmap_read)
+ ret = ops->mem_ops->dirmap_read(desc, offs, len, buf);
+ else
+ ret = -EOPNOTSUPP;
+
+ 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 udevice *bus = desc->slave->dev->parent;
+ struct dm_spi_ops *ops = spi_get_ops(bus);
+ 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 (ops->mem_ops && ops->mem_ops->dirmap_write)
+ ret = ops->mem_ops->dirmap_write(desc, offs, len, buf);
+ else
+ ret = -EOPNOTSUPP;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(spi_mem_dirmap_write);
+
#ifndef __UBOOT__
static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
{