[PATCH v6 0/3] Timer support for ARM Tegra

[Svyatoslav Ryhel]

чт, 26 січ. 2023 р. о 12:35 Thierry Reding <thierry.reding at gmail.com> пише:
>
> On Wed, Jan 25, 2023 at 05:41:08PM +0100, Thierry Reding wrote:
> > On Tue, Jan 24, 2023 at 08:57:48AM +0200, Svyatoslav Ryhel wrote:
> > > - ARM: tegra: remap clock_osc_freq for all Tegra family
> > > Enum clock_osc_freq was designed to use only with T20.
> > > This patch remaps it to use additional frequencies, added in
> > > T30+ SoC while maintaining backwards compatibility with T20.
> > >
> > > - drivers: timer: add timer driver for ARMv7 based Tegra devices
> > > Add timer support for T20/T30/T114 and T124 based devices.
> > > Driver is based on DM, has device tree support and can be
> > > used on SPL and early boot stage.
> > >
> > > - ARM: tegra: include timer as default option
> > > Enable TIMER as default option for all Tegra devices and
> > > enable TEGRA_TIMER for TEGRA_ARMV7_COMMON. Additionally
> > > enable SPL_TIMER if build as SPL part and drop deprecated
> > > configs from common header.
> > >
> > > P. S. I have no arm64 Tegra and according to comment in
> > > tegra-common.h
> > > Use the Tegra US timer on ARMv7, but the architected timer on ARMv8.
> > >
> > > Svyatoslav Ryhel (3):
> > >   ARM: tegra: remap clock_osc_freq for all Tegra family
> > >   drivers: timer: add timer driver for ARMv7 based Tegra devices
> > >   ARM: tegra: include timer as default option
> >
> > This causes a regression on Tegra210 (Jetson TX1). I'm trying to
> > investigate, but it's complicated by the fact that I'm not getting out
> > any debug prints, so I suspect the issue is happening quite early.
>
> Alright, I managed to make this work on Tegra210 using the following
> patch on top of this series:
>

Hello! Thanks for testing this on T210 SoC.

> --- >8 ---
> diff --git a/arch/arm/dts/tegra210.dtsi b/arch/arm/dts/tegra210.dtsi
> index a521a43d6cfd..ccb5a927da89 100644
> --- a/arch/arm/dts/tegra210.dtsi
> +++ b/arch/arm/dts/tegra210.dtsi
> @@ -318,7 +318,7 @@
>         };
>
>         timer at 60005000 {
> -               compatible = "nvidia,tegra210-timer", "nvidia,tegra20-timer";
> +               compatible = "nvidia,tegra210-timer", "nvidia,tegra30-timer", "nvidia,tegra20-timer";

This compatibe should not be needed since the driver will have t210
compatible included.

>                 reg = <0x0 0x60005000 0x0 0x400>;
>                 interrupts = <GIC_SPI 0 IRQ_TYPE_LEVEL_HIGH>,
>                              <GIC_SPI 1 IRQ_TYPE_LEVEL_HIGH>,
> diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
> index cc3f00e50128..b50eec5b8c9b 100644
> --- a/arch/arm/mach-tegra/Kconfig
> +++ b/arch/arm/mach-tegra/Kconfig
> @@ -136,6 +136,7 @@ config TEGRA210
>         select TEGRA_PINCTRL
>         select TEGRA_PMC
>         select TEGRA_PMC_SECURE
> +       select TEGRA_TIMER
>
>  config TEGRA186
>         bool "Tegra186 family"
> diff --git a/drivers/timer/tegra-timer.c b/drivers/timer/tegra-timer.c
> index d2d163cf3fef..235532ba8926 100644
> --- a/drivers/timer/tegra-timer.c
> +++ b/drivers/timer/tegra-timer.c
> @@ -58,17 +58,26 @@ static notrace u64 tegra_timer_get_count(struct udevice *dev)
>  static int tegra_timer_probe(struct udevice *dev)
>  {
>         struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
> +       enum clock_osc_freq freq;
>         u32 usec_config, value;
>
>         /* Timer rate has to be set unconditionally */
>         uc_priv->clock_rate = TEGRA_TIMER_RATE;
>
> +       /*
> +        * The microsecond timer runs off of clk_m on Tegra210, and clk_m
> +        * runs at half the OSC, so fake this up.
> +        */
> +       freq = clock_get_osc_freq();
> +       if (freq == CLOCK_OSC_FREQ_38_4)
> +               freq = CLOCK_OSC_FREQ_19_2;
> +

May you confirm that ALL known T210 devices use 19.2MHz as calibration
clock for timer?
If yes I can set this change in simpler as a separate commit or
including into existing patches.

>         /*
>          * Configure microsecond timers to have 1MHz clock
>          * Config register is 0xqqww, where qq is "dividend", ww is "divisor"
>          * Uses n+1 scheme
>          */
> -       switch (clock_get_osc_freq()) {
> +       switch (freq) {
>         case CLOCK_OSC_FREQ_13_0:
>                 usec_config = 0x000c; /* (12+1)/(0+1) */
>                 break;
> @@ -113,6 +122,7 @@ static const struct udevice_id tegra_timer_ids[] = {
>         { .compatible = "nvidia,tegra30-timer" },
>         { .compatible = "nvidia,tegra114-timer" },
>         { .compatible = "nvidia,tegra124-timer" },
> +       { .compatible = "nvidia,tegra210-timer" },
>         { }
>  };
> --- >8 ---
>
> I've also tested this on Tegra186, though no additional changes were
> needed since Tegra186 doesn't use the Tegra timer.
>
> With the above folded in, the series is:
>
> Tested-by: Thierry Reding <treding at nvidia.com>