ti-processor-sdk-linux-am335x-evm-02.00.00.00下的SPI

你说的GPEVM指的是什么？

请参考：

http://processors.wiki.ti.com/index.php/Linux_Core_SPI_User%27s_Guide

感谢回复，我是新加了一个

static struct spi_board_info spi_board_info_array[] = {
    {
    .modalias = "spidev",
    .max_speed_hz = 10000000,
    .bus_num = 1,
    .mode    = SPI_MODE_0,
    },
};

然后调用spi_register_board_info

现在是可以在/dev/下生成/dev/spidev1.0设备，我也用Documentation/spi/spidev_test.c程序进行测试，但是接收到的数据全部为0,并且通过示波器去抓取SCLK管脚未发现时钟。

打印如下（我在内核中加了一些打印）：

./spidev_test -D /dev/spidev1.0 
spi mode: 0x0[  606.942403] spidev_message 230

bits per word: 8
max speed: 500000 Hz (500 KHz)
[  606.946578] omap2_mcspi_transfer_one_message 1222 1 fa1a0100 481a0100
[  606.957600] --omap2_mcspi_work 1158 0 32
RX | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  | ................................

驱动最终是进入omap2_mcspi_txrx_pio函数。操作寄存器的基地址是0x481a0100，是SPI1的地址

是否需要配置SPI1对应的GPIO管脚复用功能，如果需要，那是在ti-processor-sdk-linux-am335x-evm-02.00.00.00中的哪里进行修改？

我在设备树里添加了管脚配置

		pinctrl-single,pins = <
		    0x190 ( PIN_OUTPUT | MUX_MODE3 ) /* (A13) mcasp0_aclkx.spi1_sclk */
		    0x194 ( PIN_INPUT | MUX_MODE3 ) /* (B13) mcasp0_fsx.spi1_d0 */
		    0x198 ( PIN_OUTPUT | MUX_MODE3 ) /* (D12) mcasp0_axr0.spi1_d1 */
		    0x19c ( PIN_OUTPUT | MUX_MODE3 ) /* (C12) mcasp0_ahclkr.spi1_cs0 */
		>;

现在SPI1_SCK、SPI1_CS0、SPI1_D1、都有数据。

我将SPI1_D1和SPI1_D0短路，然后用spidev_test测试读出来的数据与发送的数据不一样，读出来的数据全为0,就算我将SPI1_D0接到高电平，读出来的数据依然为0。

我哪个地方配置错误？

写数据时内核打印信息如下

[   15.721310] 0x481a0114 = 0x00000001
[   15.724826] 0x481a0124 = 0x00000000
[   15.728324] 0x481a0128 = 0x00000001
[   15.731839] 0x481a012c = 0x201103fc
[   15.735337] 0x481a0130 = 0x00000002
[   15.738834] 0x481a0134 = 0x00000501
[   15.750035] write-8 ff
[   15.752428] read-8 00
[   15.754705] write-8 ff
[   15.757086] read-8 00
[   15.759363] write-8 ff
[   15.761747] read-8 00
[   15.764024] write-8 ff
[   15.766405] read-8 00
[   15.768682] write-8 ff
[   15.771063] read-8 00
[   15.773378] write-8 ff
[   15.775760] read-8 00
[   15.778037] write-8 40
[   15.780418] read-8 00
[   15.782709] write-8 00
[   15.785091] read-8 00
[   15.787367] write-8 00
[   15.789748] read-8 00
[   15.792077] write-8 00
[   15.794460] read-8 00
[   15.796830] write-8 00
[   15.799214] read-8 00
[   15.801491] write-8 95
[   15.803894] read-8 00
[   15.806173] write-8 ff
[   15.808553] read-8 00
[   15.810830] write-8 ff
[   15.813223] read-8 00
[   15.815501] write-8 ff
[   15.817882] read-8 00
[   15.820159] write-8 ff
[   15.822551] read-8 00
[   15.824828] write-8 ff
[   15.827209] read-8 00
[   15.829486] write-8 ff
[   15.831877] read-8 00
[   15.834155] write-8 ff
[   15.836536] read-8 00
[   15.838812] write-8 ff
[   15.841193] read-8 00
[   15.843483] write-8 ff
[   15.845864] read-8 00
[   15.848141] write-8 ff
[   15.850522] read-8 00
[   15.852809] write-8 ff
[   15.855191] read-8 00
[   15.857468] write-8 ff
[   15.859848] read-8 00
[   15.862136] write-8 ff
[   15.864517] read-8 00
[   15.866794] write-8 ff
[   15.869174] read-8 00
[   15.871450] write-8 ff
[   15.873842] read-8 00
[   15.876119] write-8 ff
[   15.878500] read-8 00
[   15.880776] write-8 ff
[   15.883168] read-8 00
[   15.885446] write-8 ff
[   15.887827] read-8 00
[   15.890103] write-8 f0
[   15.892495] read-8 00
[   15.894773] write-8 0d
[   15.897153] read-8 00

写入数据是没有问题，读出来的数据都是为0,SPI寄存器的值我也打印出来了

我看3.12的dts文件里面，SPI的pin设置成了：

spi0_pins: pinmux_spi0_pins {
pinctrl-single,pins = <
0x150 (PIN_INPUT_PULLUP | MUX_MODE0) /* spi0_clk.spi0_clk */
0x154 (PIN_INPUT_PULLUP | MUX_MODE0) /* spi0_d0.spi0_d0 */
0x158 (PIN_INPUT_PULLUP | MUX_MODE0) /* spi0_d1.spi0_d1 */
0x15c (PIN_INPUT_PULLUP | MUX_MODE0) /* spi0_cs0.spi0_cs0 */
>;
};

你改成这个试一下

SDK 2.00.01.07 折腾了下，

搞好了:

1：先配置好TI的默认配置

2：make ARCH=arm CROSS_COMPLIE=arm-linux-gnueabihf- menuconfig

依次选择
Device Drivers --->
SPI support --->
<*>McSPI driver for OMAP
<*>User mode SPI device driver support

然后编译新的内核，

设备树 加入:

&spi1 {
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&spi1_pins_s0>;
spidev@1 {
spi-max-frequency = <24000000>;
reg = <0>;
compatible = "rohm,dh2228fv";
};
};

spi1_pins_s0 是引脚的定义，compatible = "rohm,dh2228fv"; 为啥这么奇怪的名字，我也不晓得，反正写错了就没有spidev1.0

然后系统里就有/dev/spidev1.0了