SPI1上加两个74x595可以吗？

青晗发表于 2020-3-9 22:32:01

在spi1上加两个595，同spi4 一样的，怎么更改设备树呀？
spi4 {
compatible = "spi-gpio";
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_spi4>;
pinctrl-assert-gpios = <&gpio5 8 GPIO_ACTIVE_LOW>;
status = "okay";
gpio-sck = <&gpio5 11 0>;
gpio-mosi = <&gpio5 10 0>;
cs-gpios = <&gpio5 7 0>;
num-chipselects = <1>;
#address-cells = <1>;
#size-cells = <0>;

gpio_spi: gpio_spi@0 {
compatible = "fairchild,74hc595";
gpio-controller;
#gpio-cells = <2>;
reg = <0>;
registers-number = <1>;
registers-default = /bits/ 8 <0xa7>;
spi-max-frequency = <100000>;
};
};

zhichao 发表于 2020-3-10 08:59:01

本帖最后由 zhichao 于 2020-3-10 09:00 编辑

先参考应用笔记添加spi1，再参考spi4添加74hc595

青晗发表于 2020-3-10 09:33:51

registers-default = /bits/ 16 <0x00a7>;
因为我是两片，这个地方是不是要改成16？
我用 cat /sys/kernel/debug/gpio，怎么是空的，查不到gpio

zhichao 发表于 2020-3-10 09:50:08

路径应该是/sys/class/gpio/吧，ls /sys/class/gpio/查看

青晗发表于 2020-3-10 22:23:17

root@freescale ~$ mount -t debugfs none /sys/kernel/debug
root@freescale ~$cat /sys/kernel/debug/gpio
GPIOs 0-31, platform/209c000.gpio, 209c000.gpio:
gpio-9 (led2             ) out lo
gpio-19(2190000.usdhc cd ) inhi

GPIOs 32-63, platform/20a0000.gpio, 20a0000.gpio:

GPIOs 64-95, platform/20a4000.gpio, 20a4000.gpio:
gpio-66(usb_otg1_vbus    ) out lo

GPIOs 96-127, platform/20a8000.gpio, 20a8000.gpio:

GPIOs 128-159, platform/20ac000.gpio, 20ac000.gpio:
gpio-128 (GTP RST PORT    ) inhi
gpio-129 (GTP INT IRQ       ) inhi
gpio-131 (?                ) out lo
gpio-133 (heartbeat       ) out lo
gpio-135 (spi32766.0       ) out lo
gpio-136 (?                ) out lo
gpio-137 (led1             ) out lo
gpio-138 (spi4.15          ) out lo
gpio-139 (spi4.15          ) out lo

GPIOs 248-255, spi/spi32766.0, 74hc595, can sleep:
挂载后能看到GPIO的信息了，可我的SPI1下接的595没有看到，我的设备树是这样改的

spi4 {
compatible = "spi-gpio";
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_spi4>;
pinctrl-assert-gpios = <&gpio5 8 GPIO_ACTIVE_LOW>; //NOE
status = "okay";
gpio-sck = <&gpio5 11 0>; //SHCP
gpio-mosi = <&gpio5 10 0>; //SDI
cs-gpios = <&gpio5 7 0>; //STCP
num-chipselects = <1>;
#address-cells = <1>;
#size-cells = <0>;

gpio_spi: gpio_spi@0 {
compatible = "fairchild,74hc595";
gpio-controller;
#gpio-cells = <2>;
reg = <0>;
registers-number = <1>;
registers-default = /bits/ 8 <0xa7>;
spi-max-frequency = <100000>;
};
};
/*新增GPIO SPI1*/
spi1 {
compatible = "spi-gpio";
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_spi1>;
//pinctrl-assert-gpios = <&gpio5 8 GPIO_ACTIVE_LOW>; OE固定接低
status = "okay";
gpio-sck = <&gpio4 25 0>;
gpio-mosi = <&gpio4 27 0>;
cs-gpios = <&gpio4 26 0>;
num-chipselects = <1>;
#address-cells = <1>;
#size-cells = <0>;

gpio_spi1: gpio_spi1@0 {
compatible = "fairchild,74hc595";
gpio-controller;
#gpio-cells = <2>;
reg = <0>;
registers-number = <1>;
registers-default = /bits/ 16 <0x00a7>;
spi-max-frequency = <100000>;
};
};

   /*新增GPIO SPi1*/
   pinctrl_spi1: spi1grp {
fsl,pins = <
MX6UL_PAD_CSI_DATA06__GPIO4_IO27 0x70a1
MX6UL_PAD_CSI_DATA05__GPIO4_IO26 0x70a1
MX6UL_PAD_CSI_DATA04__GPIO4_IO25 0x70a1
MX6UL_PAD_CSI_DATA07__GPIO4_IO28 0x70a1
>;
};

zhichao 发表于 2020-3-11 08:41:29

参考应用笔记去掉SN74HC595芯片，以其中的修改为参考添加芯片

青晗发表于 2020-3-11 21:53:28

:@:@:@怎么又成去掉了，我是想在SPI1上再加两块595,不是去掉SPI4上的595

zhichao 发表于 2020-3-12 09:05:16

只是参考改动了哪些位置，另外，您看看您使用的引脚是否在其他地方复用，595芯片是否接好

青晗发表于 2020-3-12 09:47:56

能看一下5#我发的配置吗？

青晗发表于 2020-3-12 09:49:23

问题总没有回答在点上，答非所问的感觉:funk:

zhichao 发表于 2020-3-12 17:39:50

您可参考已有程序自行调试，可以用示波器测量各引脚状态，判断哪里有问题

青晗发表于 2020-3-14 14:57:27

服务确实垃圾，早知道用米尔了

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SPI1上加两个74x595可以吗？