292 lines
9.1 KiB
C
292 lines
9.1 KiB
C
/*
|
|
* (C) Copyright 2001
|
|
* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation; either version 2 of
|
|
* the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
#ifndef _SPI_GENERIC_H_
|
|
#define _SPI_GENERIC_H_
|
|
|
|
#include <commonlib/region.h>
|
|
#include <stdint.h>
|
|
#include <stddef.h>
|
|
|
|
/* Controller-specific definitions: */
|
|
|
|
struct spi_ctrlr;
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Representation of a SPI slave, i.e. what we're communicating with.
|
|
*
|
|
* bus: ID of the bus that the slave is attached to.
|
|
* cs: ID of the chip select connected to the slave.
|
|
* ctrlr: Pointer to SPI controller structure.
|
|
*/
|
|
struct spi_slave {
|
|
unsigned int bus;
|
|
unsigned int cs;
|
|
const struct spi_ctrlr *ctrlr;
|
|
};
|
|
|
|
/* Representation of SPI operation status. */
|
|
enum spi_op_status {
|
|
SPI_OP_NOT_EXECUTED = 0,
|
|
SPI_OP_SUCCESS = 1,
|
|
SPI_OP_FAILURE = 2,
|
|
};
|
|
|
|
/*
|
|
* Representation of a SPI operation.
|
|
*
|
|
* dout: Pointer to data to send.
|
|
* bytesout: Count of data in bytes to send.
|
|
* din: Pointer to store received data.
|
|
* bytesin: Count of data in bytes to receive.
|
|
*/
|
|
struct spi_op {
|
|
const void *dout;
|
|
size_t bytesout;
|
|
void *din;
|
|
size_t bytesin;
|
|
enum spi_op_status status;
|
|
};
|
|
|
|
enum spi_clock_phase {
|
|
SPI_CLOCK_PHASE_FIRST,
|
|
SPI_CLOCK_PHASE_SECOND
|
|
};
|
|
|
|
enum spi_wire_mode {
|
|
SPI_4_WIRE_MODE,
|
|
SPI_3_WIRE_MODE
|
|
};
|
|
|
|
enum spi_polarity {
|
|
SPI_POLARITY_LOW,
|
|
SPI_POLARITY_HIGH
|
|
};
|
|
|
|
struct spi_cfg {
|
|
/* CLK phase - 0: Phase first, 1: Phase second */
|
|
enum spi_clock_phase clk_phase;
|
|
/* CLK polarity - 0: Low, 1: High */
|
|
enum spi_polarity clk_polarity;
|
|
/* CS polarity - 0: Low, 1: High */
|
|
enum spi_polarity cs_polarity;
|
|
/* Wire mode - 0: 4-wire, 1: 3-wire */
|
|
enum spi_wire_mode wire_mode;
|
|
/* Data bit length. */
|
|
unsigned int data_bit_length;
|
|
};
|
|
|
|
/*
|
|
* If there is no limit on the maximum transfer size for the controller,
|
|
* max_xfer_size can be set to SPI_CTRLR_DEFAULT_MAX_XFER_SIZE which is equal to
|
|
* UINT32_MAX.
|
|
*/
|
|
#define SPI_CTRLR_DEFAULT_MAX_XFER_SIZE (UINT32_MAX)
|
|
|
|
struct spi_flash;
|
|
|
|
enum {
|
|
/* Deduct the command length from the spi_crop_chunk() calculation for
|
|
sizing a transaction. */
|
|
SPI_CNTRLR_DEDUCT_CMD_LEN = 1 << 0,
|
|
/* Remove the opcode size from the command length used in the
|
|
spi_crop_chunk() calculation. Controllers which have a dedicated
|
|
register for the command byte would set this flag which would
|
|
allow the use of the maximum transfer size. */
|
|
SPI_CNTRLR_DEDUCT_OPCODE_LEN = 1 << 1,
|
|
};
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Representation of a SPI controller. Note the xfer() and xfer_vector()
|
|
* callbacks are meant to process full duplex transactions. If the
|
|
* controller cannot handle these transactions then return an error when
|
|
* din and dout are both set. See spi_xfer() below for more details.
|
|
*
|
|
* claim_bus: Claim SPI bus and prepare for communication.
|
|
* release_bus: Release SPI bus.
|
|
* setup: Setup given SPI device bus.
|
|
* xfer: Perform one SPI transfer operation.
|
|
* xfer_vector: Vector of SPI transfer operations.
|
|
* max_xfer_size: Maximum transfer size supported by the controller
|
|
* (0 = invalid,
|
|
* SPI_CTRLR_DEFAULT_MAX_XFER_SIZE = unlimited)
|
|
* flags: See SPI_CNTRLR_* enums above.
|
|
*
|
|
* Following member is provided by specialized SPI controllers that are
|
|
* actually SPI flash controllers.
|
|
*
|
|
* flash_probe: Specialized probe function provided by SPI flash
|
|
* controllers.
|
|
* flash_protect: Protect a region of flash using the SPI flash controller.
|
|
*/
|
|
struct spi_ctrlr {
|
|
int (*claim_bus)(const struct spi_slave *slave);
|
|
void (*release_bus)(const struct spi_slave *slave);
|
|
int (*setup)(const struct spi_slave *slave);
|
|
int (*xfer)(const struct spi_slave *slave, const void *dout,
|
|
size_t bytesout, void *din, size_t bytesin);
|
|
int (*xfer_vector)(const struct spi_slave *slave,
|
|
struct spi_op vectors[], size_t count);
|
|
uint32_t max_xfer_size;
|
|
uint32_t flags;
|
|
int (*flash_probe)(const struct spi_slave *slave,
|
|
struct spi_flash *flash);
|
|
int (*flash_protect)(const struct spi_flash *flash,
|
|
const struct region *region);
|
|
};
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Structure defining mapping of SPI buses to controller.
|
|
*
|
|
* ctrlr: Pointer to controller structure managing the given SPI buses.
|
|
* bus_start: Start bus number managed by the controller.
|
|
* bus_end: End bus number manager by the controller.
|
|
*/
|
|
struct spi_ctrlr_buses {
|
|
const struct spi_ctrlr *ctrlr;
|
|
unsigned int bus_start;
|
|
unsigned int bus_end;
|
|
};
|
|
|
|
/* Mapping of SPI buses to controllers - should be defined by platform. */
|
|
extern const struct spi_ctrlr_buses spi_ctrlr_bus_map[];
|
|
extern const size_t spi_ctrlr_bus_map_count;
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Initialization, must be called once on start up.
|
|
*
|
|
*/
|
|
void spi_init(void);
|
|
|
|
/*
|
|
* Get configuration of SPI bus.
|
|
*
|
|
* slave: Pointer to slave structure.
|
|
* cfg: Pointer to SPI configuration that needs to be filled.
|
|
*
|
|
* Returns:
|
|
* 0 on success, -1 on error
|
|
*/
|
|
int spi_get_config(const struct spi_slave *slave, struct spi_cfg *cfg);
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Set up communications parameters for a SPI slave.
|
|
*
|
|
* This must be called once for each slave. Note that this function
|
|
* usually doesn't touch any actual hardware, it only initializes the
|
|
* contents of spi_slave so that the hardware can be easily
|
|
* initialized later.
|
|
*
|
|
* bus: Bus ID of the slave chip.
|
|
* cs: Chip select ID of the slave chip on the specified bus.
|
|
* slave: Pointer to slave structure that needs to be initialized.
|
|
*
|
|
* Returns:
|
|
* 0 on success, -1 on error
|
|
*/
|
|
int spi_setup_slave(unsigned int bus, unsigned int cs, struct spi_slave *slave);
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Claim the bus and prepare it for communication with a given slave.
|
|
*
|
|
* This must be called before doing any transfers with a SPI slave. It
|
|
* will enable and initialize any SPI hardware as necessary, and make
|
|
* sure that the SCK line is in the correct idle state. It is not
|
|
* allowed to claim the same bus for several slaves without releasing
|
|
* the bus in between.
|
|
*
|
|
* slave: The SPI slave
|
|
*
|
|
* Returns: 0 if the bus was claimed successfully, or a negative value
|
|
* if it wasn't.
|
|
*/
|
|
int spi_claim_bus(const struct spi_slave *slave);
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Release the SPI bus
|
|
*
|
|
* This must be called once for every call to spi_claim_bus() after
|
|
* all transfers have finished. It may disable any SPI hardware as
|
|
* appropriate.
|
|
*
|
|
* slave: The SPI slave
|
|
*/
|
|
void spi_release_bus(const struct spi_slave *slave);
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* SPI transfer
|
|
*
|
|
* spi_xfer() interface:
|
|
* slave: The SPI slave which will be sending/receiving the data.
|
|
* dout: Pointer to a string of bytes to send out.
|
|
* bytesout: How many bytes to write.
|
|
* din: Pointer to a string of bytes that will be filled in.
|
|
* bytesin: How many bytes to read.
|
|
*
|
|
* Note that din and dout are transferred simulataneously in a full duplex
|
|
* transaction. The number of clocks within one transaction is calculated
|
|
* as: MAX(bytesout*8, bytesin*8).
|
|
*
|
|
* Returns: 0 on success, not 0 on failure
|
|
*/
|
|
int spi_xfer(const struct spi_slave *slave, const void *dout, size_t bytesout,
|
|
void *din, size_t bytesin);
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Vector of SPI transfer operations
|
|
*
|
|
* spi_xfer_vector() interface:
|
|
* slave: The SPI slave which will be sending/receiving the data.
|
|
* vectors: Array of SPI op structures.
|
|
* count: Number of SPI op vectors.
|
|
*
|
|
* Returns: 0 on success, not 0 on failure
|
|
*/
|
|
int spi_xfer_vector(const struct spi_slave *slave,
|
|
struct spi_op vectors[], size_t count);
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Given command length and length of remaining data, return the maximum data
|
|
* that can be transferred in next spi_xfer.
|
|
*
|
|
* Returns: 0 on error, non-zero data size that can be xfered on success.
|
|
*/
|
|
unsigned int spi_crop_chunk(const struct spi_slave *slave, unsigned int cmd_len,
|
|
unsigned int buf_len);
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Write 8 bits, then read 8 bits.
|
|
* slave: The SPI slave we're communicating with
|
|
* byte: Byte to be written
|
|
*
|
|
* Returns: The value that was read, or a negative value on error.
|
|
*
|
|
* TODO: This function probably shouldn't be inlined.
|
|
*/
|
|
static inline int spi_w8r8(const struct spi_slave *slave, unsigned char byte)
|
|
{
|
|
unsigned char dout[2];
|
|
unsigned char din[2];
|
|
int ret;
|
|
|
|
dout[0] = byte;
|
|
dout[1] = 0;
|
|
|
|
ret = spi_xfer(slave, dout, 2, din, 2);
|
|
return ret < 0 ? ret : din[1];
|
|
}
|
|
|
|
#endif /* _SPI_GENERIC_H_ */
|