USB Host 2 (i.MX31)
Using USB Host 2
If USB Host 2 is used, make sure that only Host Port 2 is selected in the kernel configuration. I you also use the OTG port, select that as well. Anyway, you need to make sure that Host 1 and Host 2 are NOT selected simultaneously as this will cause problems when loading the EHCI module. To use a usb mass storage device, make sure that you also select the Mass storage module.
Simply load the ehci module to use the usb device:
* modprobe ehci-hcd
Plug in the usb stick and it should be detected as a SCSI removeable disk. Check the UsbOtgDriver article or the commands below on how to use the device.
mx31# modprobe ehci-hcd fsl-ehci fsl-ehci.0: Freescale On-Chip EHCI Host Controller fsl-ehci fsl-ehci.0: new USB bus registered, assigned bus number 1 fsl-ehci fsl-ehci.0: irq 36, io mem 0x43f88400 fsl-ehci fsl-ehci.0: USB 2.0 started, EHCI 1.00, driver 10 Dec 2004 usb usb1: configuration #1 chosen from 1 choice hub 1-0:1.0: USB hub found hub 1-0:1.0: 1 port detected fsl-ehci fsl-ehci.1: Freescale On-Chip EHCI Host Controller fsl-ehci fsl-ehci.1: new USB bus registered, assigned bus number 2 fsl-ehci fsl-ehci.1: irq 37, io mem 0x43f88000 fsl-ehci fsl-ehci.1: USB 2.0 started, EHCI 1.00, driver 10 Dec 2004 usb usb2: configuration #1 chosen from 1 choice hub 2-0:1.0: USB hub found hub 2-0:1.0: 1 port detected <-- Plug in USB stick mx31# usb 1-1: new full speed USB device using fsl-ehci and address 2 usb 1-1: configuration #1 chosen from 1 choice Initializing USB Mass Storage driver... scsi0 : SCSI emulation for USB Mass Storage devices usbcore: registered new interface driver usb-storage USB Mass Storage support registered. scsi 0:0:0:0: Direct-Access UrDisk USB FLASH DISK 1.00 PQ: 0 ANSI: 2 sd 0:0:0:0: [sda] 256000 512-byte hardware sectors (131 MB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Assuming drive cache: write through sd 0:0:0:0: [sda] 256000 512-byte hardware sectors (131 MB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Assuming drive cache: write through sda: sda1 sd 0:0:0:0: [sda] Attached SCSI removable disk mx31# mkdir /mnt/usbstick mx31# mount /dev/sda1 /mnt/usbstick mx31# ls /mnt/usbstick chipse~1.exe graphi~1.exe kassab~1.mdb musike~1.lnk ethern~1.exe heimman.csl macsta~1.txt musikv~1
Using USB Host 2 with devices requiring more than 150mA
USB Host 2 is able to deliver more than 150mA to a device. The USB specification describes 500mA as a maximum value. Since the driver for the ISP1504 is used on both, the Host 2 and the OTG port, but only the Host 2 port is able to source 500mA, a workaround was developed which enables 500mA on that port. the value bus_mA of the hub device and mA_per_port are set to 500mA if the port number is 1. Port #1 is the Host 2 Port on the iMX31.
The patch for this is pasted below, it was created using the command diff -urNb hub.c.orig hub.c and affects the file linux/drivers/usb/core/hub.c
--- hub.c.orig 2008-02-14 15:02:36.000000000 +0100
+++ hub.c 2008-02-14 15:34:09.000000000 +0100
@@ -767,6 +767,27 @@
hub->mA_per_port = hdev->bus_mA;
hub->limited_power = 1;
}
+
+ /* Now this is some workaround for the isp1504 driver on
+ * the BT Developer board. This driver is used twice and
+ * it's not possible to determine in the driver, if it
+ * has an external current source.
+ * Therefore we will decide based on the bus number which
+ * IC we are and will set the maximum current manually for
+ * bus #1 (Host 2 Port on the i.MX31).
+ *
+ * You need to be aware that this is ONLY inteded for use
+ * with the specified board/IC
+ */
+
+ if (hdev->bus->busnum == 1)
+ {
+ dev_dbg(hub_dev, "setting max power for this port to 500mA manually\n");
+ hdev->bus_mA = 500;
+ hub->mA_per_port = hdev->bus_mA;
+ hub->limited_power = 1;
+ }
+
} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
hub->descriptor->bHubContrCurrent);