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AM3352: USB register access

Part Number: AM3352
Other Parts Discussed in Thread: TX12

Tool/software: Linux

Hi,

I am developing on am3352, with sdk3.0.0.4.

I use the default device tree am33xx.dtsi, in which usb has address defined as following. In user space,  how can I access the usb0/usb1 register and read/write to usb0/usb1 endpoints? 

Please provide with some example codes.  Thank you very much.

aliases {
i2c0 = &i2c0;
i2c1 = &i2c1;
i2c2 = &i2c2;
serial0 = &uart0;
serial1 = &uart1;
serial2 = &uart2;
serial3 = &uart3;
serial4 = &uart4;
serial5 = &uart5;
d_can0 = &dcan0;
d_can1 = &dcan1;
usb0 = &usb0;
usb1 = &usb1;
phy0 = &usb0_phy;
phy1 = &usb1_phy;
ethernet0 = &cpsw_emac0;
ethernet1 = &cpsw_emac1;
};

:

:

usb: usb@47400000 {
compatible = "ti,am33xx-usb";
reg = <0x47400000 0x1000>;
ranges;
#address-cells = <1>;
#size-cells = <1>;
ti,hwmods = "usb_otg_hs";
status = "disabled";

usb_ctrl_mod: control@44e10620 {
compatible = "ti,am335x-usb-ctrl-module";
reg = <0x44e10620 0x10
0x44e10648 0x4>;
reg-names = "phy_ctrl", "wakeup";
status = "disabled";
};

usb0_phy: usb-phy@47401300 {
compatible = "ti,am335x-usb-phy";
reg = <0x47401300 0x100>;
reg-names = "phy";
status = "disabled";
ti,ctrl_mod = <&usb_ctrl_mod>;
};

usb0: usb@47401000 {
compatible = "ti,musb-am33xx";
status = "disabled";
reg = <0x47401400 0x400
0x47401000 0x200>;
reg-names = "mc", "control";

interrupts = <18>;
interrupt-names = "mc";
dr_mode = "otg";
mentor,multipoint = <1>;
mentor,num-eps = <16>;
mentor,ram-bits = <12>;
mentor,power = <500>;
phys = <&usb0_phy>;

dmas = <&cppi41dma 0 0 &cppi41dma 1 0
&cppi41dma 2 0 &cppi41dma 3 0
&cppi41dma 4 0 &cppi41dma 5 0
&cppi41dma 6 0 &cppi41dma 7 0
&cppi41dma 8 0 &cppi41dma 9 0
&cppi41dma 10 0 &cppi41dma 11 0
&cppi41dma 12 0 &cppi41dma 13 0
&cppi41dma 14 0 &cppi41dma 0 1
&cppi41dma 1 1 &cppi41dma 2 1
&cppi41dma 3 1 &cppi41dma 4 1
&cppi41dma 5 1 &cppi41dma 6 1
&cppi41dma 7 1 &cppi41dma 8 1
&cppi41dma 9 1 &cppi41dma 10 1
&cppi41dma 11 1 &cppi41dma 12 1
&cppi41dma 13 1 &cppi41dma 14 1>;
dma-names =
"rx1", "rx2", "rx3", "rx4", "rx5", "rx6", "rx7",
"rx8", "rx9", "rx10", "rx11", "rx12", "rx13",
"rx14", "rx15",
"tx1", "tx2", "tx3", "tx4", "tx5", "tx6", "tx7",
"tx8", "tx9", "tx10", "tx11", "tx12", "tx13",
"tx14", "tx15";
};

usb1_phy: usb-phy@47401b00 {
compatible = "ti,am335x-usb-phy";
reg = <0x47401b00 0x100>;
reg-names = "phy";
status = "disabled";
ti,ctrl_mod = <&usb_ctrl_mod>;
};

usb1: usb@47401800 {
compatible = "ti,musb-am33xx";
status = "disabled";
reg = <0x47401c00 0x400
0x47401800 0x200>;
reg-names = "mc", "control";
interrupts = <19>;
interrupt-names = "mc";
dr_mode = "otg";
mentor,multipoint = <1>;
mentor,num-eps = <16>;
mentor,ram-bits = <12>;
mentor,power = <500>;
phys = <&usb1_phy>;

dmas = <&cppi41dma 15 0 &cppi41dma 16 0
&cppi41dma 17 0 &cppi41dma 18 0
&cppi41dma 19 0 &cppi41dma 20 0
&cppi41dma 21 0 &cppi41dma 22 0
&cppi41dma 23 0 &cppi41dma 24 0
&cppi41dma 25 0 &cppi41dma 26 0
&cppi41dma 27 0 &cppi41dma 28 0
&cppi41dma 29 0 &cppi41dma 15 1
&cppi41dma 16 1 &cppi41dma 17 1
&cppi41dma 18 1 &cppi41dma 19 1
&cppi41dma 20 1 &cppi41dma 21 1
&cppi41dma 22 1 &cppi41dma 23 1
&cppi41dma 24 1 &cppi41dma 25 1
&cppi41dma 26 1 &cppi41dma 27 1
&cppi41dma 28 1 &cppi41dma 29 1>;
dma-names =
"rx1", "rx2", "rx3", "rx4", "rx5", "rx6", "rx7",
"rx8", "rx9", "rx10", "rx11", "rx12", "rx13",
"rx14", "rx15",
"tx1", "tx2", "tx3", "tx4", "tx5", "tx6", "tx7",
"tx8", "tx9", "tx10", "tx11", "tx12", "tx13",
"tx14", "tx15";
};

  • Hi,

    We're looking into this.

    Best Regards,
    Yordan
  • Hi,
    Since there is no suggestion on my question, I want to ask whether the following is a correct way to access usb register.

    Device tree defines the usb0 address = 0x47401000, hence I defined the a variable in my file.
    volatile uint32_t * USB0_addr = (uint32_t*) 0x47401000,

    When I need to write or read from a usb0 register, e.g. USB0RXMODE (1074h), I do the following
    read: st=USB0_addr[0x74]
    write: USB0_addr[0x74]=st

    Is the above correct?

    Still I am not sure how to write to or read from a usb Endpoint.
  • An Endpoint is not a register.

    Please use a library like libusb.

  • I am writing my own driver module without using libusb. I use USB0 as peripheral, and emulate it as multiple devices, e.g keyboard, mouse and mass storage. My device applications can open the usb driver module and write to specific endpoints through I/O control functions defined in the driver module.
    In order to do this, I need to at least know the address of data port of an endpoint where I can write/read data . The TRM doesn't provide enough details on how to use USB.
  • It is not a valid design to implement a driver to directly access the usb controller endpoints In Linux.
    If you try to write a kernel driver, you should use the usb core API, as other USB class drivers do;
    Or if you try to write a user space driver, libusb is highly recommended.

    I am closing this thread.