omapl138 SPI读数据一直为0xff，读8位数据，CLK输出64个脉冲

在omapl138 arm侧驱动SPI1，通过linux spi_write和spi_write_then_read接口进行读写，spi底层寄存器操作调用官方提供的spi-davinci.c文件，读数据一直为0xff；通过抓取读写时序，发现写8位地址，CLK发出64个脉冲，请问这是什么原因？在哪里可以配置的吗？

时序图见链接：note.youdao.com/noteshare

部分配置代码如下

static struct spi_board_info da850_spi_board_info[] = {
{
.modalias = "sc16is762",
.mode = SPI_MODE_0,
.max_speed_hz = 2000000,
.bus_num = 1,
.chip_select = 1,
//.irq = SC16_IRQ_TEP,
},
};

static struct davinci_spi_platform_data da850_spi1_pdata = {
.version = SPI_VERSION_2,
.num_chipselect = 2,
.wdelay = 0x4,
.odd_parity = 0,
.parity_enable = 0,
.wait_enable = 0,
.timer_disable = 0,
.clk_internal = 1,
.cs_hold = 1,
.intr_level = 0,
.poll_mode = 1,
.use_dma = 0,
.c2tdelay = 8,
.t2cdelay = 8,
};