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AM335X SPI如何使用GPIO控制CS?

user1490342
Prodigy 200 points
Other Parts Discussed in Thread: ADS1220, AM3352

TI工程师您好!

      我目前遇到的问题是,如何将3352 SPI1的CS配置为GPIO CS功能,然后通过软件控制CS?

      Linux版本:3.2

      ADS1220片选为AM3352 SPI1的SPI1_CS0管脚.

      问题描述:

AM3352的SPI1上接了一个ADS1220,将CS设置成SPI1硬CS(即SPI1_CS0功能)读写ADS1220成功,由于想使用ADS1220的DOUT/RDY管脚中断功能,故ADS1220的CS在AD转换期间须保持低电平时ADS1220才会有转换完成中断输出.

看了内核的代码,spi_board_info中有个controller_data成员,应该是用omap2_mcspi_cs结构体初始化,但是查看源码,实在不知道如何初始化omap2_mcspi_cs结构体?网络搜索也没有此类应用.

  • 0
    Prodigy 200 points
    #define ADS1220_IRQ_GPIO GPIO_TO_PIN(3, 15)
    #define ADS1220_CS_GPIO GPIO_TO_PIN(3, 17)

    static struct omap2_mcspi_cs ads1220_spi1_csinfo = {
    .base = ioremap(AM33XX_GPIO3_BASE, SZ_64), //GPIO3_17,SZ_??
    .phys = 17? or 1<<17? or??, //?
    .word_len = 8, //SPI one transfer bits size?
    .node = ? //??
    .chconf0 = 0, //??
    };

    static struct spi_board_info am335x_spi1_slave_info[] = {
    {
    .modalias = "ads1220",
    .irq = OMAP_GPIO_IRQ(ADS1220_IRQ_GPIO),
    .max_speed_hz = 5000000, //min 150ns=6.666MHz
    .bus_num = 2, //start at 1
    .mode = SPI_MODE_1,
    .chip_select = 0,
    .platform_data = &ads1220_data,
    .controller_data = &ads1220_spi1_csinfo,
    },
    };