Re: [PATCH 18/19] clocksource: add timer-nationalchip.c

From: Guo Ren
Date: Mon Mar 19 2018 - 03:00:43 EST


Hi Daniel,

On Sun, Mar 18, 2018 at 11:07:12PM +0100, Daniel Lezcano wrote:
>
> This patch is a new driver. Please add the hardware details of this
> timer and optionally a link to the documentation. No need to write a
> book, just a quick summary of it.
>
OK

> > +#include <linux/kernel.h>
> > +#include <linux/sched.h>
> > +#include <linux/param.h>
>
> sched ? param ?
>
I'll cleanup the headers.

> > +#include <linux/init.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/profile.h>
>
> profile ?
>
I'll cleanup the headers.

> > +#include <linux/irq.h>
> > +#include <linux/rtc.h>
> > +#include <linux/sizes.h>
>
> rtc ? sizes ?
>
I'll cleanup the headers.

> > +#include <linux/clocksource.h>
> > +#include <linux/clockchips.h>
> > +#include <asm/irq.h>
> > +#include <asm/io.h>
> > +#include <asm/delay.h>
>
> Is the delay API defined for this architecture ? I don't see it used below.
>
I'll cleanup the headers.

> > +#define NC_VA_COUNTER_3_CONFIG (void *)(timer_reg + 0xa0)
> > +#define NC_VA_COUNTER_3_PRE (void *)(timer_reg + 0xa4)
> > +#define NC_VA_COUNTER_3_INI (void *)(timer_reg + 0xa8)
> > +
> > +static unsigned int timer_reg;
> > +
> > +static inline void timer_reset(void)
> > +{
> > + __raw_writel(0x1, NC_VA_COUNTER_1_CONTROL);
> > + __raw_writel(0x0, NC_VA_COUNTER_1_CONTROL);
> > + __raw_writel(0x3, NC_VA_COUNTER_1_CONFIG);
> > + __raw_writel(26, NC_VA_COUNTER_1_PRE);
>
> Why are you using the __raw_writel instead of writel ?
>
> No values, explicit macros please.
>
OK

> > +}
> > +
> > +static irqreturn_t timer_interrupt(int irq, void *dev_id)
>
> timer_interrupt is a too generic name, at least nc_timer_interrupt would
> be more accurate.
>
OK

> > +static u64 notrace nc_sched_clock_read(void)
> > +{
> > + return (u64) __raw_readl(NC_VA_COUNTER_2_VALUE);
> > +}
> > +
> > +static void nc_csd_enable(void)
>
> Can you choose a more explicit name than 'csd'?
>
OK, change to nc_clocksource_dev_enable

> > + /* setup irq */
> > + if (request_irq(irq, timer_interrupt, IRQF_TIMER, np->name, &nc_ced))
> > + panic("%s timer_interrupt error.\n", __func__);
>
> Replace the "clock-frequency" property to a clock phandle and use the
> timer-of API.
>
> That will result on something like that:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clocksource/timer-sprd.c#n124
>
> No panic in init function.
>
OK

> > + /* register */
> > + clockevents_config_and_register(&nc_ced, freq, 1, ULONG_MAX);
> > +
> > + nc_csd_enable();
> > + clocksource_mmio_init(NC_VA_COUNTER_2_VALUE, "nationalchip-clksource", freq, 200, 32, clocksource_mmio_readl_up);
>
> s/nationalchip-clksource/nationalchip/
>
> line wrap
>
OK

> > + sched_clock_register(nc_sched_clock_read, 32, freq);
> > +
> > + return 0;
> > +}
> > +CLOCKSOURCE_OF_DECLARE(nc_timer, "nationalchip,timer-v1", nc_timer_init);
>
> s/CLOCKSOURCE_OF_DECLARE/TIMER_OF_DECLARE/
>
OK

Best Regards
Guo Ren