/*
+ * Common SPI Interface: Controller-specific definitions
+ *
* (C) Copyright 2001
* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
*
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
+ * SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _SPI_H_
#define _SPI_H_
-/* Controller-specific definitions: */
-
/* SPI mode flags */
#define SPI_CPHA 0x01 /* clock phase */
#define SPI_CPOL 0x02 /* clock polarity */
#define SPI_PREAMBLE 0x80 /* Skip preamble bytes */
/* SPI transfer flags */
-#define SPI_XFER_BEGIN 0x01 /* Assert CS before transfer */
-#define SPI_XFER_END 0x02 /* Deassert CS after transfer */
+#define SPI_XFER_BEGIN 0x01 /* Assert CS before transfer */
+#define SPI_XFER_END 0x02 /* Deassert CS after transfer */
+#define SPI_XFER_MMAP 0x08 /* Memory Mapped start */
+#define SPI_XFER_MMAP_END 0x10 /* Memory Mapped End */
/* Header byte that marks the start of the message */
#define SPI_PREAMBLE_END_BYTE 0xec
-/*-----------------------------------------------------------------------
- * Representation of a SPI slave, i.e. what we're communicating with.
+/**
+ * struct spi_slave - Representation of a SPI slave
*
* 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.
- * max_write_size: If non-zero, the maximum number of bytes which can
- * be written at once, excluding command bytes.
+ * @bus: ID of the bus that the slave is attached to.
+ * @cs: ID of the chip select connected to the slave.
+ * @max_write_size: If non-zero, the maximum number of bytes which can
+ * be written at once, excluding command bytes.
+ * @memory_map: Address of read-only SPI flash access.
*/
struct spi_slave {
- unsigned int bus;
- unsigned int cs;
+ unsigned int bus;
+ unsigned int cs;
unsigned int max_write_size;
+ void *memory_map;
};
-/*-----------------------------------------------------------------------
+/**
* Initialization, must be called once on start up.
*
* TODO: I don't think we really need this.
* Allocate and zero all fields in the spi slave, and set the bus/chip
* select. Use the helper macro spi_alloc_slave() to call this.
*
- * @offset: Offset of struct spi_slave within slave structure
- * @size: Size of slave structure
- * @bus: Bus ID of the slave chip.
- * @cs: Chip select ID of the slave chip on the specified bus.
+ * @offset: Offset of struct spi_slave within slave structure.
+ * @size: Size of slave structure.
+ * @bus: Bus ID of the slave chip.
+ * @cs: Chip select ID of the slave chip on the specified bus.
*/
void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
unsigned int cs);
* Allocate and zero all fields in the spi slave, and set the bus/chip
* select.
*
- * @_struct: Name of structure to allocate (e.g. struct tegra_spi). This
- * structure must contain a member 'struct spi_slave *slave'.
- * @bus: Bus ID of the slave chip.
- * @cs: Chip select ID of the slave chip on the specified bus.
+ * @_struct: Name of structure to allocate (e.g. struct tegra_spi).
+ * This structure must contain a member 'struct spi_slave *slave'.
+ * @bus: Bus ID of the slave chip.
+ * @cs: Chip select ID of the slave chip on the specified bus.
*/
#define spi_alloc_slave(_struct, bus, cs) \
spi_do_alloc_slave(offsetof(_struct, slave), \
* Allocate and zero all fields in the spi slave, and set the bus/chip
* select.
*
- * @bus: Bus ID of the slave chip.
- * @cs: Chip select ID of the slave chip on the specified bus.
+ * @bus: Bus ID of the slave chip.
+ * @cs: Chip select ID of the slave chip on the specified bus.
*/
#define spi_alloc_slave_base(bus, cs) \
spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
-/*-----------------------------------------------------------------------
+/**
* Set up communications parameters for a SPI slave.
*
* This must be called once for each slave. Note that this function
* 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.
- * max_hz: Maximum SCK rate in Hz.
- * mode: Clock polarity, clock phase and other parameters.
+ * @bus: Bus ID of the slave chip.
+ * @cs: Chip select ID of the slave chip on the specified bus.
+ * @max_hz: Maximum SCK rate in Hz.
+ * @mode: Clock polarity, clock phase and other parameters.
*
* 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,
unsigned int max_hz, unsigned int mode);
-/*-----------------------------------------------------------------------
+/**
* Free any memory associated with a SPI slave.
*
- * slave: The SPI slave
+ * @slave: The SPI slave
*/
void spi_free_slave(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
* allowed to claim the same bus for several slaves without releasing
* the bus in between.
*
- * slave: The SPI slave
+ * @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
+ * @slave: The SPI slave
*/
void spi_release_bus(struct spi_slave *slave);
-/*-----------------------------------------------------------------------
+/**
* SPI transfer
*
* This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
* temporary variables, this is OK).
*
* spi_xfer() interface:
- * slave: The SPI slave which will be sending/receiving the data.
- * bitlen: How many bits to write and read.
- * dout: Pointer to a string of bits to send out. The bits are
+ * @slave: The SPI slave which will be sending/receiving the data.
+ * @bitlen: How many bits to write and read.
+ * @dout: Pointer to a string of bits to send out. The bits are
* held in a byte array and are sent MSB first.
- * din: Pointer to a string of bits that will be filled in.
- * flags: A bitwise combination of SPI_XFER_* flags.
+ * @din: Pointer to a string of bits that will be filled in.
+ * @flags: A bitwise combination of SPI_XFER_* flags.
*
- * Returns: 0 on success, not 0 on failure
+ * Returns: 0 on success, not 0 on failure
*/
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags);
-/*-----------------------------------------------------------------------
+/**
* Determine if a SPI chipselect is valid.
* This function is provided by the board if the low-level SPI driver
* needs it to determine if a given chipselect is actually valid.
*/
int spi_cs_is_valid(unsigned int bus, unsigned int cs);
-/*-----------------------------------------------------------------------
+/**
* Activate a SPI chipselect.
* This function is provided by the board code when using a driver
* that can't control its chipselects automatically (e.g.
*/
void spi_cs_activate(struct spi_slave *slave);
-/*-----------------------------------------------------------------------
+/**
* Deactivate a SPI chipselect.
* This function is provided by the board code when using a driver
* that can't control its chipselects automatically (e.g.
*/
void spi_cs_deactivate(struct spi_slave *slave);
-/*-----------------------------------------------------------------------
+/**
* Set transfer speed.
* This sets a new speed to be applied for next spi_xfer().
- * slave: The SPI slave
- * hz: The transfer speed
+ * @slave: The SPI slave
+ * @hz: The transfer speed
*/
void spi_set_speed(struct spi_slave *slave, uint hz);
-/*-----------------------------------------------------------------------
+/**
* Write 8 bits, then read 8 bits.
- * slave: The SPI slave we're communicating with
- * byte: Byte to be written
+ * @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.
*
return ret < 0 ? ret : din[1];
}
+/**
+ * Set up a SPI slave for a particular device tree node
+ *
+ * This calls spi_setup_slave() with the correct bus number. Call
+ * spi_free_slave() to free it later.
+ *
+ * @param blob: Device tree blob
+ * @param node: SPI peripheral node to use
+ * @param cs: Chip select to use
+ * @param max_hz: Maximum SCK rate in Hz (0 for default)
+ * @param mode: Clock polarity, clock phase and other parameters
+ * @return pointer to new spi_slave structure
+ */
+struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
+ unsigned int cs, unsigned int max_hz, unsigned int mode);
+
#endif /* _SPI_H_ */