lws-spi.h

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/*
 * Generic I2C ops
 *
 * Copyright (C) 2019 - 2020 Andy Green <andy@warmcat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * This is like an abstract class for spi, a real implementation provides
 * functions for the ops that use the underlying OS arrangements.
 *
 * It uses descriptor / queuing semantics but eg the GPIO BB implementantion is
 * synchronous.
 */
 
#if !defined(__LWS_SPI_H__)
#define __LWS_SPI_H__
 
#include <stdint.h>
#include <stddef.h>
 
typedef int (*lws_spi_cb_t)(void *opaque);
 
enum {
        LWSSPIMODE_CPOL                                 = (1 << 0),
        LWSSPIMODE_CPHA                                 = (1 << 1),
 
        LWS_SPI_BUSMODE_CLK_IDLE_LOW_SAMP_RISING        = 0,
        LWS_SPI_BUSMODE_CLK_IDLE_HIGH_SAMP_RISING       = LWSSPIMODE_CPOL,
        LWS_SPI_BUSMODE_CLK_IDLE_LOW_SAMP_FALLING       = LWSSPIMODE_CPHA,
        LWS_SPI_BUSMODE_CLK_IDLE_HIGH_SAMP_FALLING      = LWSSPIMODE_CPHA |
                                                          LWSSPIMODE_CPOL,
 
        LWS_SPI_TXN_HALF_DUPLEX_DISCRETE        = 0,
 
        LWS_SPI_FLAG_DATA_CONTINUE                      = (1 << 0),
        LWS_SPI_FLAG_DC_CMD_IS_HIGH                     = (1 << 1),
        LWS_SPI_FLAG_DMA_BOUNCE_NOT_NEEDED              = (1 << 2),
};
 
typedef struct lws_spi_desc {
        const uint8_t           *src;
        const uint8_t           *data;
        uint8_t                 *dest;
        void                    *opaque;
        lws_spi_cb_t            completion_cb;
        uint16_t                count_cmd;
        uint16_t                count_write;
        uint16_t                count_read;
        uint8_t                 txn_type;
        uint8_t                 channel;
 
        uint8_t                 flags;
} lws_spi_desc_t;
 
typedef struct lws_spi_ops {
        int  (*init)(const struct lws_spi_ops *ctx);
        int  (*queue)(const struct lws_spi_ops *ctx, const lws_spi_desc_t *desc);
        void * (*alloc_dma)(const struct lws_spi_ops *ctx, size_t size);
        void (*free_dma)(const struct lws_spi_ops *ctx, void **p);
        int (*in_flight)(const struct lws_spi_ops *ctx);
        uint32_t        spi_clk_hz;
        uint8_t         bus_mode;
} lws_spi_ops_t;
 
LWS_VISIBLE LWS_EXTERN int
lws_spi_table_issue(const lws_spi_ops_t *spi_ops, uint32_t flags, const uint8_t *p, size_t len);
 
LWS_VISIBLE LWS_EXTERN int
lws_spi_readback(const lws_spi_ops_t *spi_ops, uint32_t flags,
                 const uint8_t *p, size_t len, uint8_t *rb, size_t rb_len);
 
#endif