LS1021A USB Serial support for MCP2200

[ramkrishnan]

We have a LS1021A board based on the TWR board. Our board has a MCP2200 USB to Serial Coverted connected to USB1_D lines. I was trying to figure out how to get the linux kernel to create a tty device to communicate to an external serial port from the arm. 

I tried enabling the ftdi_sio drivers using the CONFIG_USB_SERIAL_FTDI_SIO as well as enabling CONFIG_USB_SERIAL, and setting them to y so that they built in. 

I also tried adding the following to the dtb. But no luck there either. 

usb@8600000 {
compatible = "fsl-usb2-dr-v2.5", "fsl-usb2-dr";
reg = <0x0 0x8600000 0x0 0x1000>;
interrupts = <0x0 0xab 0x4>;
dr_mode = "host";
phy_type = "serial";
};

Any help would be appreciated. 

Thank you,

Ram Krishnan

[ramkrishnan · Accepted solution]

Finally works now. Two changes were needed.

RCW[SDHC] needs to be set to 1 (or anything but 3) because the PWR FAULT and DRV BUS has to be ignored since this chip has its own power.

RCW[USB3_CLK_FSEL] has to be set to 57 to enable clocks for USB3.

Thanks,

Ram

[ramkrishnan]

In the schematic should the USB1_VBUS be connected for the application above ? It appears to be connected on the TWR eval board. But that use case is different from this one. 

Thank you,

Ram Krishnan

[ramkrishnan]

I added CONFIG_USB_ACM and still no luck. It is not recognizing the device. We checked the power to the chip as well as RST lines and they all seem to be good. I also removed the CONFIG_USB_SERIAL_FTDI_SIO definition and still nothing. Should I do anything different in the dts files ? 

In the uboot I do the following to detect the usb device

=> usb start
starting USB...
USB0: Register 200017f NbrPorts 2
Starting the controller
USB XHCI 1.00
scanning bus 0 for devices... 1 USB Device(s) found
scanning usb for storage devices... 0 Storage Device(s) found
=> usb info
1: Hub, USB Revision 3.0
- U-Boot XHCI Host Controller
- Class: Hub
- PacketSize: 512 Configurations: 1
- Vendor: 0x0000 Product 0x0000 Version 1.0
Configuration: 1
- Interfaces: 1 Self Powered 0mA
Interface: 0
- Alternate Setting 0, Endpoints: 1
- Class Hub
- Endpoint 1 In Interrupt MaxPacket 8 Interval 255ms

It does not look like it detects the usb device. Is there anything to be enabled in uboot to detect the MCP2200 ? Please let me know if you need any more information. 

Thank you,

Ram Krishnan

[yipingwang]

Please verify whether there is information with the following command.

dmesg | grep ttyACM

[ramkrishnan]

We found one issue in which the RCW[SDHC] should be set to anything non-usb1 since this device will have its own power. So we set that to 1 to make it all GPIO4 and now we see activity when we probe the D_M and D_P lines but the ttyACM0 is still not coming up. 

On the uboot if we do start usb we get the following message

USB device not accepting new address (error=80000000)

I have enabled debug on common/usb.c

=> usb start
starting USB...
USB0: Register 200017f NbrPorts 2
Starting the controller
USB XHCI 1.00
scanning bus 0 for devices...
set address 1
usb_control_msg: request: 0x5, requesttype: 0x0, value 0x1 index 0x0 length 0x0
usb_control_msg: request: 0x6, requesttype: 0x80, value 0x100 index 0x0 length 0x12
usb_control_msg: request: 0x6, requesttype: 0x80, value 0x200 index 0x0 length 0x9
usb_control_msg: request: 0x6, requesttype: 0x80, value 0x200 index 0x0 length 0x1F
get_conf_no 0 Result 25, wLength 31
if 0, ep 0
##EP epmaxpacketin[1] = 8
set configuration 1
usb_control_msg: request: 0x9, requesttype: 0x0, value 0x1 index 0x0 length 0x0
new device strings: Mfr=1, Product=2, SerialNumber=0
usb_control_msg: request: 0x6, requesttype: 0x80, value 0x300 index 0x0 length 0xFF
USB device number 1 default language ID 0x409
usb_control_msg: request: 0x6, requesttype: 0x80, value 0x301 index 0x409 length 0xFF
usb_control_msg: request: 0x6, requesttype: 0x80, value 0x302 index 0x409 length 0xFF
Manufacturer U-Boot
Product XHCI Host Controller
SerialNumber
usb_control_msg: request: 0x6, requesttype: 0xA0, value 0x2A00 index 0x0 length 0x4
usb_control_msg: request: 0x6, requesttype: 0xA0, value 0x2A00 index 0x0 length 0xC
usb_control_msg: request: 0x0, requesttype: 0xA0, value 0x0 index 0x0 length 0x4
usb_control_msg: request: 0x3, requesttype: 0x23, value 0x8 index 0x1 length 0x0
usb_control_msg: request: 0x3, requesttype: 0x23, value 0x8 index 0x2 length 0x0
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x1 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x1 length 0x4
usb_control_msg: request: 0x1, requesttype: 0x23, value 0x10 index 0x1 length 0x0
usb_control_msg: request: 0x3, requesttype: 0x23, value 0x4 index 0x1 length 0x0
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x1 length 0x4
usb_control_msg: request: 0x1, requesttype: 0x23, value 0x14 index 0x1 length 0x0
set address 2
usb_control_msg: request: 0x5, requesttype: 0x0, value 0x2 index 0x0 length 0x0
Device not responding to set address.

USB device not accepting new address (error=80000000)
usb_control_msg: request: 0x1, requesttype: 0x23, value 0x1 index 0x1 length 0x0
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
usb_control_msg: request: 0x0, requesttype: 0xA3, value 0x0 index 0x2 length 0x4
1 USB Device(s) found

scanning usb for storage devices... 0 Storage Device(s) found

[ramkrishnan]

Output pasted below. There is no device ttyACM and I also grepped for usb and I see the cdc_acm driver registered. Does the schematic as far as the connection to LS1021A look correct ? Is there a way to detect the usb device from the uboot ? 

Thanks,

Ram Krishann

root@WBADS:~# dmesg | grep ttyACM
root@WBADS:~# dmesg | grep -i usb
[ 0.034406] usbcore: registered new interface driver usbfs
[ 0.034448] usbcore: registered new interface driver hub
[ 0.034494] usbcore: registered new device driver usb
[ 1.326517] pegasus: v0.9.3 (2013/04/25), Pegasus/Pegasus II USB Ethernet driver
[ 1.333934] usbcore: registered new interface driver pegasus
[ 1.339599] usbcore: registered new interface driver asix
[ 1.344987] usbcore: registered new interface driver ax88179_178a
[ 1.351090] usbcore: registered new interface driver cdc_ether
[ 1.356918] usbcore: registered new interface driver smsc75xx
[ 1.362670] usbcore: registered new interface driver smsc95xx
[ 1.368414] usbcore: registered new interface driver net1080
[ 1.374060] usbcore: registered new interface driver cdc_subset
[ 1.379974] usbcore: registered new interface driver zaurus
[ 1.385553] usbcore: registered new interface driver cdc_ncm
[ 1.392055] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 1.433646] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[ 1.462809] usbcore: registered new interface driver cdc_acm
[ 1.468444] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
[ 1.476438] usbcore: registered new interface driver usb-storage
[ 1.482502] usbcore: registered new interface driver usbserial
[ 1.673722] usbcore: registered new interface driver usbhid
[ 1.679310] usbhid: USB HID core driver

[ramkrishnan]

One more datapoint.

We replaced Y1 i.e the oscillator with a different oscillator with 12M clock and scoped it and it was all good. But nothing in that scenario either. 

Is there something I might be missing in the software. If I do a usb start and usb info on the uboot I see only the HUB and no device. 

If I do the same thing on the TWR board I see 3 devices. 1 HUB and 2 more Port HUBS. 

If you could see any issues please let us know. We are a wit's end as to wether the device is not setup correctly in hardware or if the software is not detecting it. 

Thanks,

Ram

[yipingwang]

In order to be able to use the MCP2200 with Linux, the kernel must have support for USB CDC class drivers. The cdc_acm driver is used for MCP2200 CDC interface.
Please refer to http://ww1.microchip.com/downloads/en/DeviceDoc/mcp2200_linux_driver_readme.txt

Please enable CONFIG_USB_ACM in Linux Kernel configuration file.

[ramkrishnan]

Attached are the schematics for that chip