[U-Boot] [PATCH v2] OMAP5: USB: hsusbtll_clkctrl has to be in hw_auto for USB to work

[Lubomir Popov]

Hello Sricharan,

On 08/04/13 09:05, Sricharan R wrote:
> On Thursday 04 April 2013 09:21 PM, Lubomir Popov wrote:
>> V2 fixes line wrap issue of the patch itself.
>>
>> This fix is needed (but not sufficient) for USB EHCI operation.
>>
>> Signed-off-by: Lubomir Popov <lpopov at mm-sol.com>
>>
>> ---
>>  arch/arm/cpu/armv7/omap5/hw_data.c |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/cpu/armv7/omap5/hw_data.c b/arch/arm/cpu/armv7/omap5/hw_data.c
>> index ced274e..e5e41fd 100644
>> --- a/arch/arm/cpu/armv7/omap5/hw_data.c
>> +++ b/arch/arm/cpu/armv7/omap5/hw_data.c
>> @@ -403,6 +403,7 @@ void enable_basic_uboot_clocks(void)
>>  	};
>>  
>>  	u32 const clk_modules_hw_auto_essential[] = {
>> +		(*prcm)->cm_l3init_hsusbtll_clkctrl,
>>  		0
>>  	};
>>  
>> @@ -411,7 +412,6 @@ void enable_basic_uboot_clocks(void)
>>  		(*prcm)->cm_l4per_i2c2_clkctrl,
>>  		(*prcm)->cm_l4per_i2c3_clkctrl,
>>  		(*prcm)->cm_l4per_i2c4_clkctrl,
>> -		(*prcm)->cm_l3init_hsusbtll_clkctrl,
>>  		(*prcm)->cm_l3init_hsusbhost_clkctrl,
>>  		(*prcm)->cm_l3init_fsusb_clkctrl,
>>  		0
> 
> No, how is this helping you. Are you using EHCI at SPL ?
> Those usb clocks are anyways getting enabled at u-boot.
> 
> Regards,
>  Sricharan
> 

Why SPL? This is in the enable_basic_uboot_clocks() function. The problem seems to be
_when_ are they enabled.

This fix (moving cm_l3init_hsusbtll_clkctrl from the clk_modules_explicit_en_essential[]
array to clk_modules_hw_auto_essential[]) is something confirmed empirically (apart from
the fact that it is so for the OMAP4, which gave me the hint why USB was not working).

The following dump is for the SOM5 EVB (http://patchwork.ozlabs.org/patch/232739/) with all
needed patches applied (this one, as well as http://patchwork.ozlabs.org/patch/232742/).
Functional clocks are enabled/disabled in the board file. The boot script just sets a MAC
address for the USB Ethernet controller to env.

U-Boot SPL 2013.04-rc1-00400-g7f594d9 (Apr 02 2013 - 14:55:24)
OMAP5430 ES1.0
OMAP SD/MMC: 0
reading u-boot.img
reading u-boot.img


U-Boot 2013.04-rc1-00400-g7f594d9 (Apr 02 2013 - 14:55:24)

CPU  : OMAP5430 ES1.0
Board: MM Solutions SOM5 EVB
I2C:   ready
DRAM:  2 GiB
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1
Using default environment

In:    serial
Out:   serial
Err:   serial
Net:   No ethernet found.
Hit any key to stop autoboot:  0 
mmc0 is current device
reading boot.scr
109 bytes read in 3 ms (35.2 KiB/s)
Running bootscript from mmc0 ...
## Executing script at 82000000
SOM5_EVB # 
SOM5_EVB # usb start
(Re)start USB...
USB0:   USB EHCI 1.00
scanning bus 0 for devices... 6 USB Device(s) found
       scanning usb for storage devices... 3 Storage Device(s) found
       scanning usb for ethernet devices... 1 Ethernet Device(s) found
SOM5_EVB # usb tree
USB device tree:
  1  Hub (480 Mb/s, 0mA)
  |  u-boot EHCI Host Controller 
  |
  +-2  Mass Storage (480 Mb/s, 200mA)
  |    FSC                  MEMORYBIRD USB2      C157040817120315AA  
  |  
  +-3  Hub (480 Mb/s, 2mA)
  | |
  | +-4  Mass Storage (480 Mb/s, 96mA)
  | |    Generic Ultra Fast Media Reader 000000264001
  | |  
  | +-5  Mass Storage (480 Mb/s, 100mA)
  |      Generic Mass Storage C88BB2CE
  |    
  +-6  Vendor specific (480 Mb/s, 500mA)
     
SOM5_EVB # 

Now, for the experiment, I just moved cm_l3init_hsusbtll_clkctrl back to
clk_modules_explicit_en_essential[] and built again. As you can see, the
result is a Data Abort exception:

U-Boot SPL 2013.04-rc2-00020-g6b29a25-dirty (Apr 08 2013 - 11:14:14)
OMAP5430 ES1.0
OMAP SD/MMC: 0
reading u-boot.img
reading u-boot.img


U-Boot 2013.04-rc2-00020-g6b29a25-dirty (Apr 08 2013 - 11:14:14)

CPU  : OMAP5430 ES1.0
Board: MM Solutions SOM5 EVB
I2C:   ready
DRAM:  2 GiB
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1
Using default environment

In:    serial
Out:   serial
Err:   serial
Net:   No ethernet found.
Hit any key to stop autoboot:  0 
mmc0 is current device
reading boot.scr
109 bytes read in 3 ms (35.2 KiB/s)
Running bootscript from mmc0 ...
## Executing script at 82000000
SOM5_EVB # 
SOM5_EVB # usb start
(Re)start USB...
USB0:   data abort

    MAYBE you should read doc/README.arm-unaligned-accesses

pc : [<fef8f32c>]          lr : [<fef738b4>]
sp : feef2d50  ip : 00000034     fp : feef2dc4
r10: 00000000  r9 : fefbc0c4     r8 : feef2f40
r7 : 00000680  r6 : fefbc0c0     r5 : 000027da  r4 : 4a062000
r3 : 00000000  r2 : 000027da     r1 : 000027da  r0 : 000027da
Flags: nZcv  IRQs off  FIQs off  Mode SVC_32
Resetting CPU ...

resetting ...

U-Boot SPL 2013.04-rc2-00020-g6b29a25-dirty (Apr 08 2013 - 11:14:14)
OMAP5430 ES1.0
OMAP SD/MMC: 0
reading u-boot.img
reading u-boot.img

...

Best regards,
Lubomir