[U-Boot] [U-Boot, v2, 4/4] arm: am33xx: Add support for mulitiple PLL input frequencies

[Robert Nelson]

On Wed, Jun 7, 2017 at 11:47 PM, Lokesh Vutla <lokeshvutla at ti.com> wrote:
>
>
> On Thursday 08 June 2017 12:20 AM, Emmanuel Vadot wrote:
>> On Fri, 12 May 2017 13:20:50 -0400
>> Tom Rini <trini at konsulko.com> wrote:
>>
>>> On Fri, May 05, 2017 at 12:59:10PM +0530, Lokesh Vutla wrote:
>>>
>>>> am335x supports various sysclk frequencies which can be determined
>>>> using sysboot pins. PLLs should be configures based on this
>>>> sysclk frequency. Add PLL configurations for all supported
>>>> frequencies.
>>>>
>>>> Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
>>>> Reviewed-by: Tom Rini <trini at konsulko.com>
>>>
>>> Applied to u-boot/master, thanks!
>>>
>>> --
>>> Tom
>>
>>  Hello,
>>
>>  This appears to break beaglebone black support, reverting this commit
>> make u-boot works again.
>
> hmm..I see the problem. Here we are hard coding MPU freq to 1GHz even
> efuse say it is not supported(I am not sure why this is being done, may
> be Tom can give more details). Even in kernel I see that cpufreq is
> reading efuse to determine mpu frequency. Now that we have jitter
> optimized pll configurations, looks like unsupported freq is causing an
> issue. Can you see if the below patch helps?
>
> ------------8<------------------8<--------------------------
> From 519035c54cef3f9156303b70322c02f10ec69e00 Mon Sep 17 00:00:00 2001
> From: Lokesh Vutla <lokeshvutla at ti.com>
> Date: Thu, 8 Jun 2017 09:34:52 +0530
> Subject: [PATCH] board: am335x: Do not harcode mpu freq for beagleboneblack
>
> For all am335x boards the mpu frequency is determined by readin
> efuse. But for beagleboneblack it is hard coded to 1GHz
> irrespective of efuse settings. Due to which some boards
> fails to boot with not recommended frequency. Fix it to
> use efuse to determine mpu frequency.
>
> Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
> ---
>  board/ti/am335x/board.c | 10 ----------
>  1 file changed, 10 deletions(-)
>
> diff --git a/board/ti/am335x/board.c b/board/ti/am335x/board.c
> index 517965c0f0..4cf6617efb 100644
> --- a/board/ti/am335x/board.c
> +++ b/board/ti/am335x/board.c
> @@ -294,9 +294,6 @@ const struct dpll_params *get_dpll_mpu_params(void)
>         if (bone_not_connected_to_ac_power())
>                 freq = MPUPLL_M_600;
>
> -       if (board_is_bone_lt())
> -               freq = MPUPLL_M_1000;
> -
>         switch (freq) {
>         case MPUPLL_M_1000:
>                 return &dpll_mpu_opp[ind][5];
> @@ -336,13 +333,6 @@ static void scale_vcores_bone(int freq)
>         if (bone_not_connected_to_ac_power())
>                 freq = MPUPLL_M_600;
>
> -       /*
> -        * Override what we have detected since we know if we have
> -        * a Beaglebone Black it supports 1GHz.
> -        */
> -       if (board_is_bone_lt())
> -               freq = MPUPLL_M_1000;
> -
>         if (freq == MPUPLL_M_1000) {
>                 usb_cur_lim = TPS65217_USB_INPUT_CUR_LIMIT_1800MA;
>                 mpu_vdd = TPS65217_DCDC_VOLT_SEL_1325MV;
> --
> 2.11.0
>
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Tested-by: Robert Nelson <robertcnelson at gmail.com>

On my BBB A5A (2GB), PG 2.0 non-efused silicon..

***************************

U-Boot SPL 2017.07-rc1-00075-g156d64fa55-dirty (Jun 09 2017 - 12:31:11)
Trying to boot from MMC1

** Unable to use mmc 0:1 for loading the env **
Using default environment



U-Boot 2017.07-rc1-00075-g156d64fa55-dirty (Jun 09 2017 - 12:31:11 -0500)

CPU  : AM335X-GP rev 2.0
Model: TI AM335x BeagleBone Black
DRAM:  512 MiB
NAND:  0 MiB
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1

** Unable to use mmc 0:1 for loading the env **
Using default environment

ERROR: No USB device found

at drivers/usb/gadget/ether.c:2709/usb_ether_init()
<ethaddr> not set. Validating first E-fuse MAC
Net:   CACHE: Misaligned operation at range [9df32580, 9df32624]
eth0: ethernet at 4a100000
Hit any key to stop autoboot:  0
switch to partitions #0, OK
mmc0 is current device
SD/MMC found on device 0
** File not found boot.scr **
** Unrecognized filesystem type **
switch to partitions #0, OK
mmc0 is current device
Scanning mmc 0:1...
switch to partitions #0, OK

***************************

Regards,

-- 
Robert Nelson
https://rcn-ee.com/