/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2018 Exceet Electronics GmbH
* Copyright (C) 2018 Bootlin
*
* Author:
* Peter Pan <[email protected]>
* Boris Brezillon <[email protected]>
*/
#ifndef __LINUX_SPI_MEM_H
#define __LINUX_SPI_MEM_H
#include <linux/spi/spi.h>
#define SPI_MEM_OP_CMD(__opcode, __buswidth) \
{ \
.buswidth = __buswidth, \
.opcode = __opcode, \
.nbytes = 1, \
}
#define SPI_MEM_OP_ADDR(__nbytes, __val, __buswidth) \
{ \
.nbytes = __nbytes, \
.val = __val, \
.buswidth = __buswidth, \
}
#define SPI_MEM_OP_NO_ADDR { }
#define SPI_MEM_OP_DUMMY(__nbytes, __buswidth) \
{ \
.nbytes = __nbytes, \
.buswidth = __buswidth, \
}
#define SPI_MEM_OP_NO_DUMMY { }
#define SPI_MEM_OP_DATA_IN(__nbytes, __buf, __buswidth) \
{ \
.dir = SPI_MEM_DATA_IN, \
.nbytes = __nbytes, \
.buf.in = __buf, \
.buswidth = __buswidth, \
}
#define SPI_MEM_OP_DATA_OUT(__nbytes, __buf, __buswidth) \
{ \
.dir = SPI_MEM_DATA_OUT, \
.nbytes = __nbytes, \
.buf.out = __buf, \
.buswidth = __buswidth, \
}
#define SPI_MEM_OP_NO_DATA { }
/**
* enum spi_mem_data_dir - describes the direction of a SPI memory data
* transfer from the controller perspective
* @SPI_MEM_NO_DATA: no data transferred
* @SPI_MEM_DATA_IN: data coming from the SPI memory
* @SPI_MEM_DATA_OUT: data sent to the SPI memory
*/
enum spi_mem_data_dir {
SPI_MEM_NO_DATA,
SPI_MEM_DATA_IN,
SPI_MEM_DATA_OUT,
};
/**
* struct spi_mem_op - describes a SPI memory operation
* @cmd.nbytes: number of opcode bytes (only 1 or 2 are valid). The opcode is
* sent MSB-first.
* @cmd.buswidth: number of IO lines used to transmit the command
* @cmd.opcode: operation opcode
* @cmd.dtr: whether the command opcode should be sent in DTR mode or not
* @addr.nbytes: number of address bytes to send. Can be zero if the operation
* does not need to send an address
* @addr.buswidth: number of IO lines used to transmit the address cycles
* @addr.dtr: whether the address should be sent in DTR mode or not
* @addr.val: address value. This value is always sent MSB first on the bus.
* Note that only @addr.nbytes are taken into account in this
* address value, so users should make sure the value fits in the
* assigned number of bytes.
* @dummy.nbytes: number of dummy bytes to send after an opcode or address. Can
* be zero if the operation does not require dummy bytes
* @dummy.buswidth: number of IO lanes used to transmit the dummy bytes
* @dummy.dtr: whether the dummy bytes should be sent in DTR mode or not
* @data.buswidth: number of IO lanes used to send/receive the data
* @data.dtr: whether the data should be sent in DTR mode or not
* @data.ecc: whether error correction is required or not
* @data.dir: direction of the transfer
* @data.nbytes: number of data bytes to send/receive. Can be zero if the
* operation does not involve transferring data
* @data.buf.in: input buffer (must be DMA-able)
* @data.buf.out: output buffer (must be DMA-able)
*/
struct spi_mem_op {
struct {
u8 nbytes;
u8 buswidth;
u8 dtr : 1;
u8 __pad : 7;
u16 opcode;
} cmd;
struct {
u8 nbytes;
u8 buswidth;
u8 dtr : 1;
u8 __pad : 7;
u64 val;
} addr;
struct {
u8 nbytes;
u8 buswidth;
u8 dtr : 1;
u8 __pad : 7;
} dummy;
struct {
u8 buswidth;
u8 dtr : 1;
u8 ecc : 1;
u8 __pad : 6;
enum spi_mem_data_dir dir;
unsigned int nbytes;
union {
void *in;
const void *out;
} buf;
} data;
};
#define SPI_MEM_OP(__cmd, __addr, __dummy, __data) \
{ \
.cmd = __cmd, \
.addr = __addr, \
.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
*
* These information are 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_mem *mem;
struct spi_mem_dirmap_info info;
unsigned int nodirmap;
void *priv;
};
/**
* struct spi_mem - describes a SPI memory device
* @spi: the underlying SPI device
* @drvpriv: spi_mem_driver private data
* @name: name of the SPI memory device
*
* Extra information that describe the SPI memory device and may be needed by
* the controller to properly handle this device should be placed here.
*
* One example would be the device size since some controller expose their SPI
* mem devices through a io-mapped region.
*/
struct spi_mem {
struct spi_device *spi;
void *drvpriv;
const char *name;
};
/**
* struct spi_mem_set_drvdata() - attach driver private data to a SPI mem
* device
* @mem: memory device
* @data: data to attach to the memory device
*/
static inline void spi_mem_set_drvdata(struct spi_mem *mem, void *data)
{
mem->drvpriv = data;
}
/**
* struct spi_mem_get_drvdata() - get driver private data attached to a SPI mem
* device
* @mem: memory device
*
* Return: the data attached to the mem device.
*/
static inline void *spi_mem_get_drvdata(struct spi_mem *mem)
{
return mem->drvpriv;
}
/**
* struct spi_controller_mem_ops - SPI memory operations
* @adjust_op_size: shrink the data xfer of an operation to match controller's
* limitations (can be alignment or max RX/TX size
* limitations)
* @supports_op: check if an operation is supported by the controller
* @exec_op: execute a SPI memory operation
* not all driver provides supports_op(), so it can return -EOPNOTSUPP
* if the op is not supported by the driver/controller
* @get_name: get a custom name for the SPI mem device from the controller.
* This might be needed if the controller driver has been ported
* to use the SPI mem layer and a custom name is used to keep
* mtdparts compatible.
* Note that if the implementation of this function allocates memory
* dynamically, then it should do so with devm_xxx(), as we don't
* have a ->free_name() function.
* @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.
* @poll_status: poll memory device status until (status & mask) == match or
* when the timeout has expired. It fills the data buffer with
* the last status value.
*
* 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_mem *mem, struct spi_mem_op *op);
bool (*supports_op)(struct spi_mem *mem,
const struct spi_mem_op *op);
int (*exec_op)(struct spi_mem *mem,
const struct spi_mem_op *op);
const char *(*get_name)(struct spi_mem *mem);
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);
int (*poll_status)(struct spi_mem *mem,
const struct spi_mem_op *op,
u16 mask, u16 match,
unsigned long initial_delay_us,
unsigned long polling_rate_us,
unsigned long timeout_ms);
};
/**
* struct spi_controller_mem_caps - SPI memory controller capabilities
* @dtr: Supports DTR operations
* @ecc: Supports operations with error correction
*/
struct spi_controller_mem_caps {
bool dtr;
bool ecc;
};
#define spi_mem_controller_is_capable(ctlr, cap) \
((ctlr)->mem_caps && (ctlr)->mem_caps->cap)
/**
* struct spi_mem_driver - SPI memory driver
* @spidrv: inherit from a SPI driver
* @probe: probe a SPI memory. Usually where detection/initialization takes
* place
* @remove: remove a SPI memory
* @shutdown: take appropriate action when the system is shutdown
*
* This is just a thin wrapper around a spi_driver. The core takes care of
* allocating the spi_mem object and forwarding the probe/remove/shutdown
* request to the spi_mem_driver. The reason we use this wrapper is because
* we might have to stuff more information into the spi_mem struct to let
* SPI controllers know more about the SPI memory they interact with, and
* having this intermediate layer allows us to do that without adding more
* useless fields to the spi_device object.
*/
struct spi_mem_driver {
struct spi_driver spidrv;
int (*probe)(struct spi_mem *mem);
int (*remove)(struct spi_mem *mem);
void (*shutdown)(struct spi_mem *mem);
};
#if IS_ENABLED(CONFIG_SPI_MEM)
int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
const struct spi_mem_op *op,
struct sg_table *sg);
void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
const struct spi_mem_op *op,
struct sg_table *sg);
bool spi_mem_default_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op);
#else
static inline int
spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
const struct spi_mem_op *op,
struct sg_table *sg)
{
return -ENOTSUPP;
}
static inline void
spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
const struct spi_mem_op *op,
struct sg_table *sg)
{
}
static inline
bool spi_mem_default_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
return false;
}
#endif /* CONFIG_SPI_MEM */
int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op);
bool spi_mem_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op);
int spi_mem_exec_op(struct spi_mem *mem,
const struct spi_mem_op *op);
const char *spi_mem_get_name(struct spi_mem *mem);
struct spi_mem_dirmap_desc *
spi_mem_dirmap_create(struct spi_mem *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);
struct spi_mem_dirmap_desc *
devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
const struct spi_mem_dirmap_info *info);
void devm_spi_mem_dirmap_destroy(struct device *dev,
struct spi_mem_dirmap_desc *desc);
int spi_mem_poll_status(struct spi_mem *mem,
const struct spi_mem_op *op,
u16 mask, u16 match,
unsigned long initial_delay_us,
unsigned long polling_delay_us,
u16 timeout_ms);
int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
struct module *owner);
void spi_mem_driver_unregister(struct spi_mem_driver *drv);
#define spi_mem_driver_register(__drv) \
spi_mem_driver_register_with_owner(__drv, THIS_MODULE)
#define module_spi_mem_driver(__drv) \
module_driver(__drv, spi_mem_driver_register, \
spi_mem_driver_unregister)
#endif /* __LINUX_SPI_MEM_H */
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