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>
This commit is contained in:
Chin-Ting Kuo 2022-08-19 17:01:08 +08:00 committed by Tom Rini
parent d37b4f37ea
commit f7e1de4c6a
3 changed files with 357 additions and 0 deletions

View File

@ -40,6 +40,16 @@ config SPI_MEM
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

View File

@ -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 @@ int spi_mem_adjust_op_size(struct spi_slave *slave, 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->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)
{

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@ -134,6 +134,48 @@ struct spi_mem_op {
.dummy = __dummy, \
.data = __data, \
}
/**
* struct spi_mem_dirmap_info - Direct mapping information
* @op_tmpl: operation template that should be used by the direct mapping when
* the memory device is accessed
* @offset: absolute offset this direct mapping is pointing to
* @length: length in byte of this direct mapping
*
* This information is used by the controller specific implementation to know
* the portion of memory that is directly mapped and the spi_mem_op that should
* be used to access the device.
* A direct mapping is only valid for one direction (read or write) and this
* direction is directly encoded in the ->op_tmpl.data.dir field.
*/
struct spi_mem_dirmap_info {
struct spi_mem_op op_tmpl;
u64 offset;
u64 length;
};
/**
* struct spi_mem_dirmap_desc - Direct mapping descriptor
* @mem: the SPI memory device this direct mapping is attached to
* @info: information passed at direct mapping creation time
* @nodirmap: set to 1 if the SPI controller does not implement
* ->mem_ops->dirmap_create() or when this function returned an
* error. If @nodirmap is true, all spi_mem_dirmap_{read,write}()
* calls will use spi_mem_exec_op() to access the memory. This is a
* degraded mode that allows spi_mem drivers to use the same code
* no matter whether the controller supports direct mapping or not
* @priv: field pointing to controller specific data
*
* Common part of a direct mapping descriptor. This object is created by
* spi_mem_dirmap_create() and controller implementation of ->create_dirmap()
* can create/attach direct mapping resources to the descriptor in the ->priv
* field.
*/
struct spi_mem_dirmap_desc {
struct spi_slave *slave;
struct spi_mem_dirmap_info info;
unsigned int nodirmap;
void *priv;
};
#ifndef __UBOOT__
/**
@ -183,10 +225,32 @@ static inline void *spi_mem_get_drvdata(struct spi_mem *mem)
* limitations)
* @supports_op: check if an operation is supported by the controller
* @exec_op: execute a SPI memory operation
* @dirmap_create: create a direct mapping descriptor that can later be used to
* access the memory device. This method is optional
* @dirmap_destroy: destroy a memory descriptor previous created by
* ->dirmap_create()
* @dirmap_read: read data from the memory device using the direct mapping
* created by ->dirmap_create(). The function can return less
* data than requested (for example when the request is crossing
* the currently mapped area), and the caller of
* spi_mem_dirmap_read() is responsible for calling it again in
* this case.
* @dirmap_write: write data to the memory device using the direct mapping
* created by ->dirmap_create(). The function can return less
* data than requested (for example when the request is crossing
* the currently mapped area), and the caller of
* spi_mem_dirmap_write() is responsible for calling it again in
* this case.
*
* This interface should be implemented by SPI controllers providing an
* high-level interface to execute SPI memory operation, which is usually the
* case for QSPI controllers.
*
* Note on ->dirmap_{read,write}(): drivers should avoid accessing the direct
* mapping from the CPU because doing that can stall the CPU waiting for the
* SPI mem transaction to finish, and this will make real-time maintainers
* unhappy and might make your system less reactive. Instead, drivers should
* use DMA to access this direct mapping.
*/
struct spi_controller_mem_ops {
int (*adjust_op_size)(struct spi_slave *slave, struct spi_mem_op *op);
@ -194,6 +258,12 @@ struct spi_controller_mem_ops {
const struct spi_mem_op *op);
int (*exec_op)(struct spi_slave *slave,
const struct spi_mem_op *op);
int (*dirmap_create)(struct spi_mem_dirmap_desc *desc);
void (*dirmap_destroy)(struct spi_mem_dirmap_desc *desc);
ssize_t (*dirmap_read)(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, void *buf);
ssize_t (*dirmap_write)(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, const void *buf);
};
#ifndef __UBOOT__
@ -260,6 +330,15 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op);
bool spi_mem_default_supports_op(struct spi_slave *mem,
const struct spi_mem_op *op);
struct spi_mem_dirmap_desc *
spi_mem_dirmap_create(struct spi_slave *mem,
const struct spi_mem_dirmap_info *info);
void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc);
ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, void *buf);
ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, const void *buf);
#ifndef __UBOOT__
int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
struct module *owner);