Re: [PATCH v2 1/4] ARM: davinci: fix cpufreq registration on da850-evm

From: Adam Ford
Date: Tue Mar 26 2019 - 10:00:36 EST


On Fri, Mar 22, 2019 at 8:31 AM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
>
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
>
> The system_rev variable is never set on davinci and is always 0, so
> we're using the default max operating point of 300MHz. The cvdd supply
> comes from the tps6507 pmic and the voltage can go all the way to 1.3V
> so the maximum supported rate should be 456MHz.

My understanding is that only certain revisions of the silicon can go
to 456MHz. The L138's Datasheet lists both a 456 and 375 version. I
cannot find a way to read a register to determine which version of the
silicon is available. Maybe Sekhar can confirm.

adam
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> ---
> arch/arm/mach-davinci/board-da850-evm.c | 12 +-----------
> 1 file changed, 1 insertion(+), 11 deletions(-)
>
> diff --git a/arch/arm/mach-davinci/board-da850-evm.c b/arch/arm/mach-davinci/board-da850-evm.c
> index 1fdc9283a8c5..58b2a485b527 100644
> --- a/arch/arm/mach-davinci/board-da850-evm.c
> +++ b/arch/arm/mach-davinci/board-da850-evm.c
> @@ -1155,17 +1155,7 @@ static struct edma_rsv_info *da850_edma_rsv[2] = {
> #ifdef CONFIG_CPU_FREQ
> static __init int da850_evm_init_cpufreq(void)
> {
> - switch (system_rev & 0xF) {
> - case 3:
> - da850_max_speed = 456000;
> - break;
> - case 2:
> - da850_max_speed = 408000;
> - break;
> - case 1:
> - da850_max_speed = 372000;
> - break;
> - }
> + da850_max_speed = 456000;
>
> return da850_register_cpufreq("pll0_sysclk3");
> }
> --
> 2.20.1
>
>
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