From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH RESEND V4 1/5] clocksource: timer-of: Support getting clock frequency from DT Date: Tue, 2 Jul 2019 10:06:44 +0200 Message-ID: References: <20190702075513.17451-1-Anson.Huang@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190702075513.17451-1-Anson.Huang@nxp.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Anson.Huang@nxp.com, tglx@linutronix.de, robh+dt@kernel.org, mark.rutland@arm.com, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, leonard.crestez@nxp.com, viresh.kumar@linaro.org, daniel.baluta@nxp.com, ping.bai@nxp.com, l.stach@pengutronix.de, abel.vesa@nxp.com, andrew.smirnov@gmail.com, ccaione@baylibre.com, angus@akkea.ca, agx@sigxcpu.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Linux-imx@nxp.com List-Id: devicetree@vger.kernel.org Hi Anson, why did you resend the series? On 02/07/2019 09:55, Anson.Huang@nxp.com wrote: > From: Anson Huang > > More and more platforms use platform driver model for clock driver, > so the clock driver is NOT ready during timer initialization phase, > it will cause timer initialization failed. > > To support those platforms with upper scenario, introducing a new > flag TIMER_OF_CLOCK_FREQUENCY which is mutually exclusive with > TIMER_OF_CLOCK flag to support getting timer clock frequency from > DT's timer node, the property name should be "clock-frequency", > then of_clk operations can be skipped. > > User needs to select either TIMER_OF_CLOCK_FREQUENCY or TIMER_OF_CLOCK > flag if want to use timer-of driver to initialize the clock rate. > > Signed-off-by: Anson Huang > --- > Changes since V3: > - use hardcoded "clock-frequency" instead of adding new variable prop_name; > - add pre-condition check for TIMER_OF_CLOCK and TIMER_OF_CLOCK_FREQUENCY, they MUST be exclusive. > --- > drivers/clocksource/timer-of.c | 29 +++++++++++++++++++++++++++++ > drivers/clocksource/timer-of.h | 7 ++++--- > 2 files changed, 33 insertions(+), 3 deletions(-) > > diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c > index 8054228..858f684 100644 > --- a/drivers/clocksource/timer-of.c > +++ b/drivers/clocksource/timer-of.c > @@ -161,11 +161,30 @@ static __init int timer_of_base_init(struct device_node *np, > return 0; > } > > +static __init int timer_of_clk_frequency_init(struct device_node *np, > + struct of_timer_clk *of_clk) > +{ > + int ret; > + u32 rate; > + > + ret = of_property_read_u32(np, "clock-frequency", &rate); > + if (!ret) { > + of_clk->rate = rate; > + of_clk->period = DIV_ROUND_UP(rate, HZ); > + } > + > + return ret; > +} > + > int __init timer_of_init(struct device_node *np, struct timer_of *to) > { > + unsigned long clock_flags = TIMER_OF_CLOCK | TIMER_OF_CLOCK_FREQUENCY; > int ret = -EINVAL; > int flags = 0; > > + if ((to->flags & clock_flags) == clock_flags) > + return ret; > + > if (to->flags & TIMER_OF_BASE) { > ret = timer_of_base_init(np, &to->of_base); > if (ret) > @@ -180,6 +199,13 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to) > flags |= TIMER_OF_CLOCK; > } > > + if (to->flags & TIMER_OF_CLOCK_FREQUENCY) { > + ret = timer_of_clk_frequency_init(np, &to->of_clk); > + if (ret) > + goto out_fail; > + flags |= TIMER_OF_CLOCK_FREQUENCY; > + } > + > if (to->flags & TIMER_OF_IRQ) { > ret = timer_of_irq_init(np, &to->of_irq); > if (ret) > @@ -201,6 +227,9 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to) > if (flags & TIMER_OF_CLOCK) > timer_of_clk_exit(&to->of_clk); > > + if (flags & TIMER_OF_CLOCK_FREQUENCY) > + to->of_clk.rate = 0; > + > if (flags & TIMER_OF_BASE) > timer_of_base_exit(&to->of_base); > return ret; > diff --git a/drivers/clocksource/timer-of.h b/drivers/clocksource/timer-of.h > index a5478f3..a08e108 100644 > --- a/drivers/clocksource/timer-of.h > +++ b/drivers/clocksource/timer-of.h > @@ -4,9 +4,10 @@ > > #include > > -#define TIMER_OF_BASE 0x1 > -#define TIMER_OF_CLOCK 0x2 > -#define TIMER_OF_IRQ 0x4 > +#define TIMER_OF_BASE 0x1 > +#define TIMER_OF_CLOCK 0x2 > +#define TIMER_OF_IRQ 0x4 > +#define TIMER_OF_CLOCK_FREQUENCY 0x8 > > struct of_timer_irq { > int irq; > -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog