Hi All, Gentle ping. Are we happy with this patch? Please let me know. As mentioned in [1], it has dependency on reset patch [1] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20211112184413.4391-2-biju.das.jz@xxxxxxxxxxxxxx/ Regards, Biju > Subject: Re: [PATCH v3 3/4] clocksource/drivers/renesas-ostm: Add RZ/G2L > OSTM support > > Hi Biju, Daniel, > > On Mon, Nov 29, 2021 at 11:06 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> > wrote: > > > Subject: Re: [PATCH v3 3/4] clocksource/drivers/renesas-ostm: Add > > > RZ/G2L OSTM support > > > > > > On 12/11/2021 19:44, Biju Das wrote: > > > > RZ/G2L SoC has Generic Timer Module(a.k.a OSTM) which needs to > > > > deassert the reset line before accessing any registers. > > > > > > > > This patch adds an entry point for RZ/G2L so that we can deassert > > > > the reset line in probe callback. > > > > > > What is the connection between adding the reset line control and the > > > platform driver at the end of the driver ? > > > > The original driver has no arm architecture timer, so it needs to be > > s/driver/SoC used with this driver/ > > > called very early in the boot and using of calls for handling the > clocks. > > Hence must be handled by TIMER_OF_DECLARE(). > > > Where as RZ/G2L has arm architecture timer and it needs to release the > > module Reset before accessing any registers. So it has to be built in > > and it needs cpg driver which happens at later stage compared to the > original case, for de-asserting the reset. > > > > Geert, please correct me if I am wrong. > > The reset driver is not available yet at TIMER_OF_DECLARE() time, so > of_reset_control_get_optional_exclusive() returns -EPROBE_DEFER on RZ/G2L. > Fortunately there is no need to have this timer available early on RZ/G2L, > as it uses the arm architecture timer as the main clock source. Still, to > be available at all, the platform driver is needed to support re-probing > after the reset driver has become available. > > > > > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx> > > > > Reviewed-by: Lad Prabhakar > > > > <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > > > --- > > > > v2->v3: > > > > * Added reset_control_put() on error path. > > > > * enabled suppress_bind_attrs in ostm_device_driver structure > > > > v1->v2: > > > > * Added reset handling inside ostm_init > > > > * Used same compatible for builtin driver aswell > > > > --- > > > > drivers/clocksource/renesas-ostm.c | 39 > > > > +++++++++++++++++++++++++++++- > > > > 1 file changed, 38 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/clocksource/renesas-ostm.c > > > > b/drivers/clocksource/renesas-ostm.c > > > > index 3d06ba66008c..21d1392637b8 100644 > > > > --- a/drivers/clocksource/renesas-ostm.c > > > > +++ b/drivers/clocksource/renesas-ostm.c > > > > @@ -9,6 +9,8 @@ > > > > #include <linux/clk.h> > > > > #include <linux/clockchips.h> > > > > #include <linux/interrupt.h> > > > > +#include <linux/platform_device.h> #include <linux/reset.h> > > > > #include <linux/sched_clock.h> > > > > #include <linux/slab.h> > > > > > > > > @@ -159,6 +161,7 @@ static int __init ostm_init_clkevt(struct > > > > timer_of > > > > *to) > > > > > > > > static int __init ostm_init(struct device_node *np) { > > > > + struct reset_control *rstc; > > > > struct timer_of *to; > > > > int ret; > > > > > > > > @@ -166,6 +169,14 @@ static int __init ostm_init(struct device_node > *np) > > > > if (!to) > > > > return -ENOMEM; > > > > > > > > + rstc = of_reset_control_get_optional_exclusive(np, NULL); > > > > + if (IS_ERR(rstc)) { > > > > + ret = PTR_ERR(rstc); > > > > + goto err_free; > > > > + } > > > > + > > > > + reset_control_deassert(rstc); > > > > + > > > > to->flags = TIMER_OF_BASE | TIMER_OF_CLOCK; > > > > if (system_clock) { > > > > /* > > > > @@ -178,7 +189,7 @@ static int __init ostm_init(struct device_node > > > > *np) > > > > > > > > ret = timer_of_init(np, to); > > > > if (ret) > > > > - goto err_free; > > > > + goto err_reset; > > > > > > > > /* > > > > * First probed device will be used as system clocksource. Any > > > > @@ > > > > -203,9 +214,35 @@ static int __init ostm_init(struct device_node > > > > *np) > > > > > > > > err_cleanup: > > > > timer_of_cleanup(to); > > > > +err_reset: > > > > + reset_control_assert(rstc); > > > > + reset_control_put(rstc); > > > > err_free: > > > > kfree(to); > > > > return ret; > > > > } > > > > > > > > TIMER_OF_DECLARE(ostm, "renesas,ostm", ostm_init); > > > > + > > > > +#ifdef CONFIG_ARCH_R9A07G044 > > > > +static int __init ostm_probe(struct platform_device *pdev) { > > > > + struct device *dev = &pdev->dev; > > > > + > > > > + return ostm_init(dev->of_node); } > > > > + > > > > +static const struct of_device_id ostm_of_table[] = { > > > > + { .compatible = "renesas,ostm", }, > > > > + { /* sentinel */ } > > > > +}; > > > > + > > > > +static struct platform_driver ostm_device_driver = { > > > > + .driver = { > > > > + .name = "renesas_ostm", > > > > + .of_match_table = of_match_ptr(ostm_of_table), > > > > + .suppress_bind_attrs = true, > > > > + }, > > > > +}; > > > > +builtin_platform_driver_probe(ostm_device_driver, ostm_probe); > > > > +#endif > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux- > m68k.org > > In personal conversations with technical people, I call myself a hacker. > But when I'm talking to journalists I just say "programmer" or something > like that. > -- Linus Torvalds
