coreboot-kgpe-d16/src/include/spi-generic.h

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/*
* (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 <stdint.h>
/* Controller-specific definitions: */
/* SPI opcodes */
#define SPI_OPCODE_WREN 0x06
#define SPI_OPCODE_FAST_READ 0x0b
#define SPI_READ_FLAG 0x01
#define SPI_WRITE_FLAG 0x02
/*-----------------------------------------------------------------------
* Representation of a SPI slave, i.e. what we're communicating with.
*
* Drivers are expected to extend this with controller-specific data.
*
* bus: ID of the bus that the slave is attached to.
* cs: ID of the chip select connected to the slave.
* rw: Read or Write flag
spi: support controllers with limited transfer size capabilities Some SPI controllers (like Imgtec Pistachio), have a hard limit on SPI read and write transactions. Limiting transfer size in the wrapper allows to provide the API user with unlimited transfer size transactions. The tranfer size limitation is added to the spi_slave structure, which is set up by the controller driver. The value of zero in this field means 'unlimited transfer size'. It will work with existion drivers, as they all either keep structures in the bss segment, or initialize them to all zeros. This patch addresses the problem for reads only, as coreboot is not expected to require to write long chunks into SPI devices. BRANCH=none BUG=chrome-os-partner:32441, chrome-os-partner:31438 TEST=set transfer size limit to artificially low value (4K) and observed proper operation on both Pistachio and ipq8086: both Storm and Urara booted through romstage and ramstage. Change-Id: Ibb96aa499c3eec458c94bf1193fbbbf5f54e1477 Signed-off-by: Stefan Reinauer <reinauer@chromium.org> Original-Commit-Id: 4f064fdca5b6c214e7a7f2751dc24e33cac2ea45 Original-Change-Id: I9df24f302edc872bed991ea450c0af33a1c0ff7b Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/232239 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Original-Reviewed-by: David Hendricks <dhendrix@chromium.org> Reviewed-on: http://review.coreboot.org/9571 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2014-11-30 00:06:26 +01:00
* max_transfer_size: maximum amount of bytes which can be sent in a single
* read or write transaction, usually this is a controller
* property, kept in the slave structure for convenience. Zero in
* this field means 'unlimited'.
*/
struct spi_slave {
unsigned int bus;
unsigned int cs;
unsigned int rw;
spi: support controllers with limited transfer size capabilities Some SPI controllers (like Imgtec Pistachio), have a hard limit on SPI read and write transactions. Limiting transfer size in the wrapper allows to provide the API user with unlimited transfer size transactions. The tranfer size limitation is added to the spi_slave structure, which is set up by the controller driver. The value of zero in this field means 'unlimited transfer size'. It will work with existion drivers, as they all either keep structures in the bss segment, or initialize them to all zeros. This patch addresses the problem for reads only, as coreboot is not expected to require to write long chunks into SPI devices. BRANCH=none BUG=chrome-os-partner:32441, chrome-os-partner:31438 TEST=set transfer size limit to artificially low value (4K) and observed proper operation on both Pistachio and ipq8086: both Storm and Urara booted through romstage and ramstage. Change-Id: Ibb96aa499c3eec458c94bf1193fbbbf5f54e1477 Signed-off-by: Stefan Reinauer <reinauer@chromium.org> Original-Commit-Id: 4f064fdca5b6c214e7a7f2751dc24e33cac2ea45 Original-Change-Id: I9df24f302edc872bed991ea450c0af33a1c0ff7b Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/232239 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Original-Reviewed-by: David Hendricks <dhendrix@chromium.org> Reviewed-on: http://review.coreboot.org/9571 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2014-11-30 00:06:26 +01:00
unsigned int max_transfer_size;
int force_programmer_specific;
struct spi_flash * (*programmer_specific_probe) (struct spi_slave *spi);
};
/*-----------------------------------------------------------------------
* Initialization, must be called once on start up.
*
*/
void spi_init(void);
/*-----------------------------------------------------------------------
* 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.
*
* Returns: A spi_slave reference that can be used in subsequent SPI
* calls, or NULL if one or more of the parameters are not supported.
*/
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs);
/*-----------------------------------------------------------------------
* 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(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(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.
*
* Returns: 0 on success, not 0 on failure
*/
int spi_xfer(struct spi_slave *slave, const void *dout, unsigned int bytesout,
void *din, unsigned int bytesin);
unsigned int spi_crop_chunk(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(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_ */