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