I2C Block Read Problem?

[George Ioakimedes]

I'm working on my new Baseboard design which has a Microchip 4-port USB Hub chip on it. This chip uses only a SMBus Write and Read command. I upgraded the kernel to 3.4.90 since 3.4.75 was still using 200kHz as the I2C default speed.

I'm using Python to issue commands and looking at a write_i2c_block_data command on the scope I have confirmed that the command structure is sent properly. I need to also decode on the scope the read but it appears that the read is missing the 1st byte. 

If I issue a

sudo i2cdump -y 1 0x2c s

Error: Adapter does not have SMBus block read capability

but if I issue a 

cubie@Cubian:~$ sudo i2cdump -y 1 0x2c i

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef

00: 20 24 04 14 25 b3 0b 9b 00 01 00 00 00 01 32 01     $??%???.?...?2?

10: 32 32 04 09 13 15 0a 49 00 4f 00 00 00 54 00 45    22?????I.O...T.E

20: 20 43 00 48 00 4e 00 4f 00 4c 00 4f 00 47 00 49     C.H.N.O.L.O.G.I

30: 00 45 00 53 00 00 00 4c 00 4c 00 43 00 00 00 00    .E.S...L.L.C....

40: 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00     ...............

50: 00 00 00 00 00 42 00 69 00 67 00 00 00 42 00 72    .....B.i.g...B.r

60: 20 6f 00 74 00 68 00 65 00 72 00 00 00 42 00 61     o.t.h.e.r...B.a

70: 00 73 00 65 00 62 00 6f 00 61 00 72 00 64 00 00    .s.e.b.o.a.r.d..

80: 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00     ...............

90: 00 00 00 32 00 30 00 31 00 34 00 30 00 38 00 30    ...2.0.1.4.0.8.0

a0: 20 30 00 30 00 31 00 00 00 00 00 00 00 00 00 00     0.0.1..........

b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

c0: 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00     ...............

d0: 00 e1 00 00 00 00 00 00 00 00 00 00 00 00 00 00    .?..............

e0: 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00     ...............

f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

Notice how every other "0" byte is a 0x20?

If I run this code:

import smbus

bus = smbus.SMBus(1)

reg00 = [0x20, 0x24, 0x04, 0x14, 0x25, 0xB3, 0x0B, 0x9B, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x32, 0x01, 0x32]

bus.write_i2c_block_data(0x2c, 0x00, reg00)

You get the above dump. From my understanding the 1st byte is supposed to be the number of bytes being sent. That code does appear correctly on the scope when I'm writing data

I've made some progress and it appears that the hub does get enumerated:

cubie@Cubian:~$ lsusb

Bus 001 Device 003: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

But if I try to get some additional information about the hub, lsusb complains that it couldn't open the hub so I'm not sure if it really enumerated properly

cubie@Cubian:~$ lsusb -v -s 001:003

Bus 001 Device 003: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub

Couldn't open device, some information will be missing

Device Descriptor:

  bLength                18

  bDescriptorType         1

  bcdUSB               2.00

  bDeviceClass            9 Hub

  bDeviceSubClass         0 Unused

  bDeviceProtocol         2 TT per port

  bMaxPacketSize0        64

  idVendor           0x0424 Standard Microsystems Corp.

  idProduct          0x2514 USB 2.0 Hub

  bcdDevice            b.b3

  iManufacturer           1

  iProduct                2

  iSerial                 3

  bNumConfigurations      1

  Configuration Descriptor:

    bLength                 9

    bDescriptorType         2

    wTotalLength           41

    bNumInterfaces          1

    bConfigurationValue     1

    iConfiguration          0

    bmAttributes         0xe0

      Self Powered

      Remote Wakeup

    MaxPower                2mA

    Interface Descriptor:

      bLength                 9

      bDescriptorType         4

      bInterfaceNumber        0

      bAlternateSetting       0

      bNumEndpoints           1

      bInterfaceClass         9 Hub

      bInterfaceSubClass      0 Unused

      bInterfaceProtocol      1 Single TT

      iInterface              0

      Endpoint Descriptor:

        bLength                 7

        bDescriptorType         5

        bEndpointAddress     0x81  EP 1 IN

        bmAttributes            3

          Transfer Type            Interrupt

          Synch Type               None

          Usage Type               Data

        wMaxPacketSize     0x0001  1x 1 bytes

        bInterval              12

    Interface Descriptor:

      bLength                 9

      bDescriptorType         4

      bInterfaceNumber        0

      bAlternateSetting       1

      bNumEndpoints           1

      bInterfaceClass         9 Hub

      bInterfaceSubClass      0 Unused

      bInterfaceProtocol      2 TT per port

      iInterface              0

      Endpoint Descriptor:

        bLength                 7

        bDescriptorType         5

        bEndpointAddress     0x81  EP 1 IN

        bmAttributes            3

          Transfer Type            Interrupt

          Synch Type               None

          Usage Type               Data

        wMaxPacketSize     0x0001  1x 1 bytes

        bInterval              12

If I plug a keyboard into the hub it does not show up so I know that something is still not right. Since the idVendor and idProduct come through correctly I am going to assume that at least part of the registers did get written correctly even though reading them says they did not.

If anyone has any helpful advice or knowledge of this I would greatly appreciate some feedback!

Thanks,

George

[jons...@gmail.com]

Do you know about the GL850G? It is about $0.30. The chip is
automatic, no need for SMBUS.

http://www.kean.com.au/oshw/WR703N/GL850G%20USB%20Hub%201.07.pdf

http://www.aliexpress.com/item/new-hope-GL850G-GL850-SSOP28-100pcs-lots/1860488763.html

> --
> You received this message because you are subscribed to the Google Groups
> "linux-sunxi" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to linux-sunxi...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.



--
Jon Smirl
jons...@gmail.com

[George Ioakimedes]

No, I didn't look at that part but the board is already designed with the USB2514B and I'm working on the prototypes. If the GL850G is really that cost I might have to look into it later though.

[jons...@gmail.com]

On Mon, Aug 18, 2014 at 4:29 PM, George Ioakimedes <georg...@gmail.com> wrote:
> No, I didn't look at that part but the board is already designed with the
> USB2514B and I'm working on the prototypes. If the GL850G is really that
> cost I might have to look into it later though.

I have an A20 board on my desk that uses it. It has three USB jacks,
wifi, POTS telephone, SD, HDMI, camera, Ethernet, IR, etc. Does that
board work for you? I can put you in touch with the vendor.

[George Ioakimedes]

For now I need to get my board design up and running but getting help from Microchip is not working out so far

[jons...@gmail.com]

I see you are making an expansion board the the Cubieboard. Does it
have a UART to USB chip on it? PL2303 is $0.30
http://www.aliexpress.com/item/Free-Shipping-PL-2303HX-PL2303HX-usb-to-serial-control-chip/1911511366.html

What other chips are you using?

[jons...@gmail.com]

Cheap camera modules here:
http://cmoscamera.1688.com/

--
Jon Smirl
jons...@gmail.com

[jons...@gmail.com]

OV5640 module for under $10 in small quantity.
http://detail.1688.com/offer/1128568755.html
They don't speak English, you will need help buying from them.

This looks like the same one, easier to buy on Aliexpress but $21.
http://www.aliexpress.com/item/Strong-Sale-5-0megapixel-golden-finger-MP4-camera-module-mini-dvr-module-vw-reverse-camera/747713861.html

--
Jon Smirl
jons...@gmail.com

[George Ioakimedes]

Yes, it has the FTDI FT230XQ-T part on it

[George Ioakimedes]

I do have an OV5640 module and went with a standard header so people could play more easily. 

[jons...@gmail.com]

My experience on Aliexpress is that 19 out of 20 vendors are honest.
One of out 20 the product will not be what you ordered. There is a
free, automatic escrow service as part of every Aliexpress order. You
should immediately inspect the chips that are sent to you. If they
don't work use the escrow service to get a refund.

But... you will have to mail the parts back to China to get a refund.
So for me, if the order is under $50 I just throw it in the trash.
Report the problem vendor to Aliexpress, and move onto another one.

If you do open an escrow dispute you will almost always win and get a
refund. It is not a level playing field, the customer wins even if
they are wrong. Aliexpress understands that customers are more
important to them.

One thing I don't know - is the vendor dishonest, or has someone else
in the supply chain duped the vendor? There is no way to know. I
suspect the vendors are being duped up the supply chain. If a vendor
gets four or five negative reports Aliexpress will ban them.

Don't, don't, don't buy a $1,000 worth of chips and not inspect them
before the escrow period expires. Most of the Aliexpress horror
stories result from failing to do this inspection and then you are
stuck with the bad product. I have no pity for these people - you had
a free escrow and failed to use it on the terms given. I wouldn't use
Aliexpress to order large amounts of chips, instead I would deal
directly with a chip supplier who will be cheaper.

--
Jon Smirl
jons...@gmail.com