This adds the dirmap API originally introduced in Linux commit aa167f3 ("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-sea...
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 --- v2: Remove "#if CONFIG_SPI_DIRMAP" compile wrapper. v3: Fix a grammatical error in spi-mem.h.
drivers/spi/Kconfig | 10 ++ drivers/spi/spi-mem.c | 268 ++++++++++++++++++++++++++++++++++++++++++ include/spi-mem.h | 79 +++++++++++++ 3 files changed, 357 insertions(+)
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index a616294910..297253714a 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -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 diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index 9c1ede1b61..8e8995fc53 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 @@ 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) { diff --git a/include/spi-mem.h b/include/spi-mem.h index 32ffdc2e0f..b07cf2ed83 100644 --- a/include/spi-mem.h +++ b/include/spi-mem.h @@ -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);