高通I2C control及gpio模拟添加I2C设备

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高通810，要用camera专用的CCI I2C(GPIO19,GPIO20)接口连外设，查看CCI I2C的调用，非常复杂，涉及到camera的子设备什么，不想去研究用法。

GOIO模拟I2c:

内核已经自带i2c-gpio.c支持模拟GPIO，所要做的就是配置。

打开内核的i2c-gpio功能，在defconfig文件中打开CONFIG_I2C_GPIO=y;

配置I2C GPIO及外设

&soc {
75 i2c@0 {
76 compatible = "i2c-gpio";
77 gpios = <&msm_gpio 19 0 /* sda */
78 &msm_gpio 20 0 /* scl */
79 >;
80 i2c-gpio,sda-open-drain;
81 i2c-gpio,scl-open-drain;
82 i2c-gpio,delay-us = <5>;
83 #address-cells = <1>;
84 #size-cells = <0>;
85 ndt@50 {
86 compatible = "ndt,77020";
87 reg = <0x50>;
88 ndt_vdd-supply = <&pm8994_l29>;
89 ndt,vdd = "ndt_vdd";
90 ndt_vio-supply = <&pm8994_lvs1>;
91 ndt,vio = "ndt_vio";
92 ndt,reset_gpio = <&msm_gpio 104 0>;
93 qcom,slave-address = <0x50>;
94 };
95 };
96 };

附件测试程序，可以编译进内核，通过写ndt_write_i2c节点测量波形输出。

其它尝试

将CCI的I2C配成BLSP QUP方式使用，查看文档，GPIO19,GPIO20可以配成BLSP4 bit0、bit1，添加了I2C control

2679 i2c_4: i2c@f9926000 {
2680 compatible = "qcom,i2c-msm-v2";
2681 #address-cells = <1>;
2682 #size-cells = <0>;
2683 reg-names = "qup_phys_addr";
2684 reg = <0xf9926000 0x1000>;
2685 interrupt-names = "qup_irq";
2686 interrupts = <0 98 0>;
2687 qcom,clk-freq-out = <100000>;
2688 qcom,clk-freq-in = <19200000>;
2689 clock-names = "iface_clk", "core_clk";
2690 clocks = <&clock_gcc clk_gcc_blsp1_ahb_clk>,
2691 <&clock_gcc clk_gcc_blsp1_qup4_i2c_apps_clk>;
2692
2693 pinctrl-names = "i2c_active", "i2c_sleep";
2694 pinctrl-0 = <&i2c_4_active>;
2695 pinctrl-1 = <&i2c_4_sleep>;
2696 qcom,noise-rjct-scl = <0>;
2697 qcom,noise-rjct-sda = <0>;
2698 dmas = <&dma_blsp1 16 64 0x20000020 0x20>, //不确定，缺少芯片资料
2699 <&dma_blsp1 17 32 0x20000020 0x20>; //不确定，缺少芯片资料
2700 dma-names = "tx", "rx";
2701 qcom,master-id = <86>;
2702 status = "ok";
2703 };

I2C对应PIN脚指定

1648 pmx_i2c_4 {
1649 qcom,pins = <&gp 19>, <&gp 20>;
1650 qcom,num-grp-pins = <2>;
1651 qcom,pin-func = <3>;
1652 label = "pmx_i2c_4";
1653
1654 i2c_4_active: i2c_4_active {
1655 drive-strength = <2>;
1656 bias-disable;
1657 };
1658
1659 i2c_4_sleep: i2c_4_sleep {
1660 drive-strength = <2>;
1661 bias-disable;
1662 };
1663 };

I2c外设添加

&soc {
55 i2c@f9924000 {
56 status = "ok";
57 #address-cells = <1>;
58 #size-cells = <0>;
59 qcom,clk-freq-out = <100000>;
60 ndt@50 {
61 compatible = "ndt,77020";
62 reg = <0x50>;
63 ndt_vdd-supply = <&pm8994_l29>;
64 ndt,vdd = "ndt_vdd";
65 ndt_vio-supply = <&pm8994_lvs1>;
66 ndt,vio = "ndt_vio";
67 ndt,reset_gpio = <&msm_gpio 104 0>;
68 qcom,slave-address = <0x50>;
71 };
72 };
73 };

写了各测试模块，I2C外设正常添加成功，写节点测试I2C写操作，但每次都fail，提示gpio misconfigure.研究一周无果。

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