drv_spi.c

/*
 * File      : drv_spi.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
 *
 *  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.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2017-11-02     勤为本       first version
 */

#include <rtthread.h>
#include <drivers/spi.h>
#include "drv_spi.h"


//#define DEBUG

#ifdef DEBUG
#define DEBUG_PRINTF(...)           rt_kprintf(__VA_ARGS__)
#else
#define DEBUG_PRINTF(...)
#endif


static rt_err_t configure(struct rt_spi_device *device, struct rt_spi_configuration *configuration);
static rt_uint32_t xfer(struct rt_spi_device *device, struct rt_spi_message *message);


static struct rt_spi_ops ls1c_spi_ops = 
{
    .configure  = configure,
    .xfer       = xfer
};


static rt_err_t configure(struct rt_spi_device *device, 
                          struct rt_spi_configuration *configuration)
{
    struct rt_spi_bus *spi_bus = NULL;
    struct ls1c_spi *ls1c_spi = NULL;
    unsigned char SPIx = 0;
    void *spi_base = NULL;
    unsigned char cpol = 0;
    unsigned char cpha = 0;
    unsigned char val = 0;

    RT_ASSERT(NULL != device);
    RT_ASSERT(NULL != configuration);

    spi_bus = device->bus;
    ls1c_spi = (struct ls1c_spi *)spi_bus->parent.user_data;
    SPIx = ls1c_spi->SPIx;
    spi_base = ls1c_spi_get_base(SPIx);

    {
        // 使能SPI控制器，master模式，关闭中断
        reg_write_8(0x53, spi_base + LS1C_SPI_SPCR_OFFSET);

        // 清空状态寄存器
        reg_write_8(0xc0, spi_base + LS1C_SPI_SPSR_OFFSET);

        // 1字节产生中断，采样(读)与发送(写)时机同时
        reg_write_8(0x03, spi_base + LS1C_SPI_SPER_OFFSET);

        // 关闭SPI flash
        val = reg_read_8(spi_base + LS1C_SPI_SFC_PARAM_OFFSET);
        val &= 0xfe;
        reg_write_8(val, spi_base + LS1C_SPI_SFC_PARAM_OFFSET);

        // spi flash时序控制寄存器
        reg_write_8(0x05, spi_base + LS1C_SPI_SFC_TIMING_OFFSET);
    }
    
    // baudrate
    ls1c_spi_set_clock(spi_base, configuration->max_hz);

    // 设置通信模式(时钟极性和相位)
    if (configuration->mode & RT_SPI_CPOL)      // cpol
    {
        cpol = SPI_CPOL_1;
    }
    else
    {
        cpol = SPI_CPOL_0;
    }
    if (configuration->mode & RT_SPI_CPHA)      // cpha
    {
        cpha = SPI_CPHA_1;
    }
    else
    {
        cpha = SPI_CPHA_0;
    }
    ls1c_spi_set_mode(spi_base, cpol, cpha);

    DEBUG_PRINTF("ls1c spi%d configuration\n", SPIx);

    return RT_EOK;
}


static rt_uint32_t xfer(struct rt_spi_device *device, 
                        struct rt_spi_message *message)
{
    struct rt_spi_bus *spi_bus = NULL;
    struct ls1c_spi *ls1c_spi = NULL;
    void *spi_base = NULL;
    unsigned char SPIx = 0;
    struct ls1c_spi_cs *ls1c_spi_cs = NULL;
    unsigned char cs = 0;
    rt_uint32_t size = 0;
    const rt_uint8_t *send_ptr = NULL;
    rt_uint8_t *recv_ptr = NULL;
    rt_uint8_t data = 0;

    RT_ASSERT(NULL != device);
    RT_ASSERT(NULL != message);

    spi_bus = device->bus;
    ls1c_spi = spi_bus->parent.user_data;
    SPIx = ls1c_spi->SPIx;
    spi_base = ls1c_spi_get_base(SPIx);
    ls1c_spi_cs = device->parent.user_data;
    cs = ls1c_spi_cs->cs;
    size = message->length;

    DEBUG_PRINTF("[%s] SPIx=%d, cs=%d\n", __FUNCTION__, SPIx, cs);

    // take cs
    if (message->cs_take)
    {
        ls1c_spi_set_cs(spi_base, cs, 0);
    }

    // 收发数据
    send_ptr = message->send_buf;
    recv_ptr = message->recv_buf;
    while (size--)
    {
        data = 0xFF;
        if (NULL != send_ptr)
        {
            data = *send_ptr++;
        }

        if (NULL != recv_ptr)
        {
            *recv_ptr++ = ls1c_spi_txrx_byte(spi_base, data);
        }
        else
        {
            ls1c_spi_txrx_byte(spi_base, data);
        }
    }

    // release cs
    if (message->cs_release)
    {
        ls1c_spi_set_cs(spi_base, cs, 1);
    }

    return message->length;
}


#ifdef RT_USING_SPI0
struct ls1c_spi ls1c_spi0 = 
{
    .SPIx = LS1C_SPI_0,
};

static struct rt_spi_bus spi0_bus;
#endif


#ifdef RT_USING_SPI1
struct ls1c_spi ls1c_spi1 = 
{
    .SPIx = LS1C_SPI_1,
};

static struct rt_spi_bus spi1_bus;
#endif


/*
 * 初始化并注册龙芯1c的spi总线
 * @SPI SPI总线，比如LS1C_SPI_0， LS1C_SPI_1
 * @spi_bus_name 总线名字
 * @ret 
 */
rt_err_t ls1c_spi_bus_register(rt_uint8_t SPI, const char *spi_bus_name)
{
    struct rt_spi_bus *spi_bus = NULL;

#ifdef RT_USING_SPI0
    if (LS1C_SPI_0 == SPI)
    {
        spi_bus = &spi0_bus;
        spi_bus->parent.user_data = &ls1c_spi0;
    }
#endif

#ifdef RT_USING_SPI1
    if (LS1C_SPI_1 == SPI)
    {
        spi_bus = &spi1_bus;
        spi_bus->parent.user_data = &ls1c_spi1;
    }
#endif

    return rt_spi_bus_register(spi_bus, spi_bus_name, &ls1c_spi_ops);
}