[PATCH v3 2/3] drivers: timer: add timer driver for ARMv7 based Tegra devices

[Svyatoslav Ryhel]

вт, 17 січ. 2023 р. о 22:30 Simon Glass <sjg at chromium.org> пише:
>
> Hi Svyatoslav,
>
> On Tue, 17 Jan 2023 at 09:53, Svyatoslav Ryhel <clamor95 at gmail.com> wrote:
> >
> > 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.
> >
> > Tested-by: Andreas Westman Dorcsak <hedmoo at yahoo.com> # ASUS TF600T T30
> > Tested-by: Jonas Schwöbel <jonasschwoebel at yahoo.de> # Surface RT T30
> > Tested-by: Robert Eckelmann <longnoserob at gmail.com> # ASUS TF101 T20
> > Tested-by: Svyatoslav Ryhel <clamor95 at gmail.com> # LG P895 T30
> > Co-developed-by: Jonas Schwöbel <jonasschwoebel at yahoo.de>
> > Signed-off-by: Jonas Schwöbel <jonasschwoebel at yahoo.de>
> > Signed-off-by: Svyatoslav Ryhel <clamor95 at gmail.com>
> > ---
> >  drivers/timer/Kconfig       |   8 +++
> >  drivers/timer/Makefile      |   1 +
> >  drivers/timer/tegra-timer.c | 124 ++++++++++++++++++++++++++++++++++++
> >  3 files changed, 133 insertions(+)
> >  create mode 100644 drivers/timer/tegra-timer.c
> >
> > diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig
> > index 6d6665005c..f32bd16227 100644
> > --- a/drivers/timer/Kconfig
> > +++ b/drivers/timer/Kconfig
> > @@ -252,6 +252,14 @@ config STM32_TIMER
> >           Select this to enable support for the timer found on
> >           STM32 devices.
> >
> > +config TEGRA_TIMER
> > +       bool "Tegra timer support"
> > +       depends on TIMER
> > +       select TIMER_EARLY
> > +       help
> > +         Select this to enable support for the timer found on
> > +         Tegra devices.
> > +
> >  config X86_TSC_TIMER
> >         bool "x86 Time-Stamp Counter (TSC) timer support"
> >         depends on TIMER && X86
> > diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile
> > index 6470fd5426..3c92113fc6 100644
> > --- a/drivers/timer/Makefile
> > +++ b/drivers/timer/Makefile
> > @@ -27,6 +27,7 @@ obj-$(CONFIG_SP804_TIMER)     += sp804_timer.o
> >  obj-$(CONFIG_$(SPL_)SIFIVE_CLINT) += sifive_clint_timer.o
> >  obj-$(CONFIG_ARM_GLOBAL_TIMER) += arm_global_timer.o
> >  obj-$(CONFIG_STM32_TIMER)      += stm32_timer.o
> > +obj-$(CONFIG_TEGRA_TIMER)      += tegra-timer.o
> >  obj-$(CONFIG_X86_TSC_TIMER)    += tsc_timer.o
> >  obj-$(CONFIG_MTK_TIMER)                += mtk_timer.o
> >  obj-$(CONFIG_MCHP_PIT64B_TIMER)        += mchp-pit64b-timer.o
> > diff --git a/drivers/timer/tegra-timer.c b/drivers/timer/tegra-timer.c
> > new file mode 100644
> > index 0000000000..cda460921f
> > --- /dev/null
> > +++ b/drivers/timer/tegra-timer.c
> > @@ -0,0 +1,124 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright (C) 2022 Svyatoslav Ryhel <clamor95 at gmail.com>
> > + */
> > +
> > +#include <common.h>
> > +#include <dm.h>
> > +#include <errno.h>
> > +#include <timer.h>
> > +
> > +#include <asm/io.h>
> > +#include <asm/arch/clock.h>
> > +#include <asm/arch/tegra.h>
> > +
> > +#define TEGRA_OSC_CLK_ENB_L_SET                (NV_PA_CLK_RST_BASE + 0x320)
> > +#define TEGRA_OSC_SET_CLK_ENB_TMR      BIT(5)
> > +
> > +#define TEGRA_TIMER_USEC_CNTR          (NV_PA_TMRUS_BASE + 0)
> > +#define TEGRA_TIMER_USEC_CFG           (NV_PA_TMRUS_BASE + 4)
> > +
> > +#define TEGRA_TIMER_RATE               1000000 /* 1 MHz */
> > +
> > +u64 notrace timer_early_get_count(void)
> > +{
> > +       /* At this stage raw timer is used */
> > +       return readl(TEGRA_TIMER_USEC_CNTR);
> > +}
> > +
> > +unsigned long notrace timer_early_get_rate(void)
> > +{
> > +       return TEGRA_TIMER_RATE;
> > +}
> > +
> > +#if CONFIG_IS_ENABLED(BOOTSTAGE)
>
> You shouldn't need the #ifdef as the code will just be dropped by the
> linker if not used.

Hello Simon! Thank you for your review!
Will do in V4

>
> > +ulong timer_get_boot_us(void)
> > +{
> > +       u64 ticks = 0;
> > +       int ret;
> > +
> > +       ret = dm_timer_init();
>
> You can't call this here since tracing and bootstage won't work (they
> need the timer before driver model starts) . You can check gd->timer
> and use the early one or the driver model one.

Timer is tricky because it has to be active one of the first.
I consider using here early version unconditionally would be the best option.
Will update in V4

Best regards, Svyatoslav R.

>
> > +       if (!ret)
> > +               timer_get_count(gd->timer, &ticks);
> > +       else
> > +               ticks = timer_early_get_count();
> > +
> > +       return ticks;
> > +}
> > +#endif
> > +
> > +static notrace u64 tegra_timer_get_count(struct udevice *dev)
> > +{
> > +       u32 val = timer_early_get_count();
> > +       return timer_conv_64(val);
> > +}
> > +
> [..]
>
> Regards,
> Simon