Stefano, Jeroen,
On Wed, 10 Jul 2013 18:04:04 +0200 Jeroen Hofstee jeroen@myspectrum.nl wrote:
Hello Stefano / Tapani,
On 07/10/2013 04:27 PM, Stefano Babic wrote:
On 09/07/2013 21:46, Jeroen Hofstee wrote:
I cannot find any document mentioning gpio_25 though. Any reason for this usage?
That is right. There is no written documentation by Technexion about this pin. I have added in CC Tapani, maybe he can tell us something more. The GPIO is used internally on the TAM3517 SOM, and we have no schematics about it. We have to guess about its usage.
Yes, and some clarification of the pin 35 would be appreciated as well, since it is marked as ball X, I guess it is controlled by hardware and the hub cannot be reset from software, but that is just guessing...
The reason to have it is that the sources for the kernel provided by Technexion (an ancient 2.6.32 Version) set this pin to reset the EHCI. As I said, there is no further documentation and rather we can only make some supposition. The usage in U-Boot then reflects the usage made by Technexion.
Fyi my linux copy (3.7) with this gpio set as the phy_reset is also unable to properly reset it and times out. The usb is working though, also without a proper reset..
p.s. I found by sheer accidence that the usb is behaving completely normal (after the patch) on rev B1. It is broken on rev B without the patch and working buggy with it. On rev B1 + patch the USB to SATA converter is discovered as well, which I have never seen before.
I can confirm issues with version B of the TAM3517-SOM. I am testing a B1 SOM with a B twister. I do not know the details about changelog between B and B1 version of the SOM, but I got both USB and Ethernet problems with TAM3517-B. The same image runs without the same problems on a B1.
ok, good to know.
There is also this pending patch by Michael:
http://patchwork.ozlabs.org/patch/250290/
It is applied to u-boot-ti, not yet to mainline.
on top of usb master this patch leads to: USB0: ULPI: ulpi_reset: failed writing reset bit ULPI: ulpi_reset: failed writing reset bit
It does always find the stick though and never the SATA converter.
without the gpio_25 reset, the second error goes away and the SATA is back.
@@ -92,9 +92,6 @@ int board_init(void) enable_gpmc_cs_config(gpmc_XR16L2751, &gpmc_cfg->cs[3], XR16L2751_UART2_BASE, GPMC_SIZE_16M);
- gpio_request(CONFIG_OMAP_EHCI_PHY1_RESET_GPIO, "USB_PHY1_RESET");
- gpio_direction_output(CONFIG_OMAP_EHCI_PHY1_RESET_GPIO, 1);
See my concerns above. Do not reset the hub in the kernel ?
I don't get the last part, but feedback from Technexion is needed first to remove all the guess, maybe etc. If it has a valid function, not setting it's value might not be such a good idea...
GPIO_25 is indeed USB PHY reset. (Pull low to reset).
regards,
//Tapani