linux_dsm_epyc7002/include/linux/spi/spi-mem.h
Boris Brezillon c36ff266dc
spi: Extend the core to ease integration of SPI memory controllers
Some controllers are exposing high-level interfaces to access various
kind of SPI memories. Unfortunately they do not fit in the current
spi_controller model and usually have drivers placed in
drivers/mtd/spi-nor which are only supporting SPI NORs and not SPI
memories in general.

This is an attempt at defining a SPI memory interface which works for
all kinds of SPI memories (NORs, NANDs, SRAMs).

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Frieder Schrempf <frieder.schrempf@exceet.de>
Tested-by: Frieder Schrempf <frieder.schrempf@exceet.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-05-11 11:32:43 +09:00

250 lines
6.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2018 Exceet Electronics GmbH
* Copyright (C) 2018 Bootlin
*
* Author: Boris Brezillon <boris.brezillon@bootlin.com>
*/
#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, \
}
#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_DATA_IN: data coming from the SPI memory
* @SPI_MEM_DATA_OUT: data sent the SPI memory
*/
enum spi_mem_data_dir {
SPI_MEM_DATA_IN,
SPI_MEM_DATA_OUT,
};
/**
* struct spi_mem_op - describes a SPI memory operation
* @cmd.buswidth: number of IO lines used to transmit the command
* @cmd.opcode: operation opcode
* @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.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
* @data.buswidth: number of IO lanes used to send/receive the data
* @data.dir: direction of the transfer
* @data.buf.in: input buffer
* @data.buf.out: output buffer
*/
struct spi_mem_op {
struct {
u8 buswidth;
u8 opcode;
} cmd;
struct {
u8 nbytes;
u8 buswidth;
u64 val;
} addr;
struct {
u8 nbytes;
u8 buswidth;
} dummy;
struct {
u8 buswidth;
enum spi_mem_data_dir dir;
unsigned int nbytes;
/* buf.{in,out} must be DMA-able. */
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 - describes a SPI memory device
* @spi: the underlying SPI device
* @drvpriv: spi_mem_drviver private data
*
* 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;
};
/**
* 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 of max RX/TX size
* limitations)
* @supports_op: check if an operation is supported by the controller
* @exec_op: execute a SPI memory operation
*
* 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.
*/
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);
};
/**
* 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);
#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)
{
}
#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);
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 */