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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Common SPI Interface: Controller-specific definitions
*
* Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
*
* Based on U-boot's spi.h:
*
* (C) Copyright 2001
* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
*/
#pragma once
#include <types.h>
/* SPI mode flags */
#define SPI_CPHA BIT(0) /* clock phase (1 = SPI_CLOCK_PHASE_SECOND) */
#define SPI_CPOL BIT(1) /* clock polarity (1 = SPI_POLARITY_HIGH) */
#define SPI_MODE_0 (0|0) /* (original MicroWire) */
#define SPI_MODE_1 (0|SPI_CPHA)
#define SPI_MODE_2 (SPI_CPOL|0)
#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
struct spi_transfer {
const void *tx_buf;
void *rx_buf;
size_t len;
};
static inline size_t spi_message_len(const struct spi_transfer *msg, int n) {
size_t total = 0;
for (int i = 0; i < n; i++) {
total += msg[i].len;
}
return total;
}
int spi_init(unsigned int cs, unsigned int max_hz, unsigned int mode);
int spi_claim_bus(void);
void spi_release_bus(void);
int spi_xfer(const struct spi_transfer *msg, int n);
size_t spi_max_xfer(void);
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