From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH v4 8/9] clocksource: atmel-st: use syscon/regmap Date: Fri, 06 Mar 2015 09:43:02 +0100 Message-ID: <54F96896.6040204@linaro.org> References: <1425570594-13124-1-git-send-email-alexandre.belloni@free-electrons.com> <1425570594-13124-9-git-send-email-alexandre.belloni@free-electrons.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1425570594-13124-9-git-send-email-alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> Sender: linux-watchdog-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alexandre Belloni , Nicolas Ferre Cc: Boris Brezillon , Jean-Christophe Plagniol-Villard , Thomas Gleixner , Lee Jones , Wim Van Sebroeck , Guenter Roeck , Sebastian Reichel , Dmitry Eremin-Solenikov , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-pm@vger.kernel.org On 03/05/2015 04:49 PM, Alexandre Belloni wrote: > The register range from the system timer is also used by the watchdog= driver. > Use a regmap to handle concurrent accesses. > > Signed-off-by: Alexandre Belloni > Acked-by: Boris Brezillon > --- > drivers/clocksource/timer-atmel-st.c | 99 ++++++++++++++-----------= ----------- > 1 file changed, 37 insertions(+), 62 deletions(-) > > diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksour= ce/timer-atmel-st.c > index 7d062ab32674..c4a52e32675e 100644 > --- a/drivers/clocksource/timer-atmel-st.c > +++ b/drivers/clocksource/timer-atmel-st.c > @@ -24,19 +24,19 @@ > #include > #include > #include > -#include > -#include > +#include > +#include > #include > +#include > > #include > > -#include > -#include > - > static unsigned long last_crtr; > static u32 irqmask; > static struct clock_event_device clkevt; > +static struct regmap *regmap_st; > > +#define AT91_SLOW_CLOCK 32768 > #define RM9200_TIMER_LATCH ((AT91_SLOW_CLOCK + HZ/2) / HZ) > > /* > @@ -46,11 +46,11 @@ static struct clock_event_device clkevt; > */ > static inline unsigned long read_CRTR(void) > { > - unsigned long x1, x2; > + unsigned int x1, x2; > > - x1 =3D at91_st_read(AT91_ST_CRTR); > + regmap_read(regmap_st, AT91_ST_CRTR, &x1); > do { > - x2 =3D at91_st_read(AT91_ST_CRTR); > + regmap_read(regmap_st, AT91_ST_CRTR, &x2); > if (x1 =3D=3D x2) > break; > x1 =3D x2; > @@ -63,7 +63,10 @@ static inline unsigned long read_CRTR(void) > */ > static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id= ) > { > - u32 sr =3D at91_st_read(AT91_ST_SR) & irqmask; > + u32 sr; > + > + regmap_read(regmap_st, AT91_ST_SR, &sr); > + sr &=3D irqmask; > > /* > * irqs should be disabled here, but as the irq is shared they are= only > @@ -96,7 +99,7 @@ static struct irqaction at91rm9200_timer_irq =3D { > .name =3D "at91_tick", > .flags =3D IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL, > .handler =3D at91rm9200_timer_interrupt, > - .irq =3D NR_IRQS_LEGACY + AT91_ID_SYS, > + .irq =3D 0, Is this change related to regmap ? By the way, perhaps take the opportunity to replace setup_irq by=20 request_irq (and check the return value) ? > }; > > static cycle_t read_clk32k(struct clocksource *cs) > @@ -115,23 +118,25 @@ static struct clocksource clk32k =3D { > static void > clkevt32k_mode(enum clock_event_mode mode, struct clock_event_devic= e *dev) > { > + unsigned int val; > + > /* Disable and flush pending timer interrupts */ > - at91_st_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_ALMS); > - at91_st_read(AT91_ST_SR); > + regmap_write(regmap_st, AT91_ST_IDR, AT91_ST_PITS | AT91_ST_ALMS); > + regmap_read(regmap_st, AT91_ST_SR, &val); > > last_crtr =3D read_CRTR(); > switch (mode) { > case CLOCK_EVT_MODE_PERIODIC: > /* PIT for periodic irqs; fixed rate of 1/HZ */ > irqmask =3D AT91_ST_PITS; > - at91_st_write(AT91_ST_PIMR, RM9200_TIMER_LATCH); > + regmap_write(regmap_st, AT91_ST_PIMR, RM9200_TIMER_LATCH); > break; > case CLOCK_EVT_MODE_ONESHOT: > /* ALM for oneshot irqs, set by next_event() > * before 32 seconds have passed > */ > irqmask =3D AT91_ST_ALMS; > - at91_st_write(AT91_ST_RTAR, last_crtr); > + regmap_write(regmap_st, AT91_ST_RTAR, last_crtr); > break; > case CLOCK_EVT_MODE_SHUTDOWN: > case CLOCK_EVT_MODE_UNUSED: > @@ -139,7 +144,7 @@ clkevt32k_mode(enum clock_event_mode mode, struct= clock_event_device *dev) > irqmask =3D 0; > break; > } > - at91_st_write(AT91_ST_IER, irqmask); > + regmap_write(regmap_st, AT91_ST_IER, irqmask); > } > > static int > @@ -147,6 +152,7 @@ clkevt32k_next_event(unsigned long delta, struct = clock_event_device *dev) > { > u32 alm; > int status =3D 0; > + unsigned int val; > > BUG_ON(delta < 2); > > @@ -162,12 +168,12 @@ clkevt32k_next_event(unsigned long delta, struc= t clock_event_device *dev) > alm =3D read_CRTR(); > > /* Cancel any pending alarm; flush any pending IRQ */ > - at91_st_write(AT91_ST_RTAR, alm); > - at91_st_read(AT91_ST_SR); > + regmap_write(regmap_st, AT91_ST_RTAR, alm); > + regmap_read(regmap_st, AT91_ST_SR, &val); > > /* Schedule alarm by writing RTAR. */ > alm +=3D delta; > - at91_st_write(AT91_ST_RTAR, alm); > + regmap_write(regmap_st, AT91_ST_RTAR, alm); > > return status; > } > @@ -180,57 +186,26 @@ static struct clock_event_device clkevt =3D { > .set_mode =3D clkevt32k_mode, > }; > > -void __iomem *at91_st_base; > -EXPORT_SYMBOL_GPL(at91_st_base); > - > -static const struct of_device_id at91rm9200_st_timer_ids[] =3D { > - { .compatible =3D "atmel,at91rm9200-st" }, > - { /* sentinel */ } > -}; > - > -static int __init of_at91rm9200_st_init(void) > -{ > - struct device_node *np; > - int ret; > - > - np =3D of_find_matching_node(NULL, at91rm9200_st_timer_ids); > - if (!np) > - goto err; > - > - at91_st_base =3D of_iomap(np, 0); > - if (!at91_st_base) > - goto node_err; > - > - /* Get the interrupts property */ > - ret =3D irq_of_parse_and_map(np, 0); > - if (!ret) > - goto ioremap_err; > - at91rm9200_timer_irq.irq =3D ret; > - > - of_node_put(np); > - > - return 0; > - > -ioremap_err: > - iounmap(at91_st_base); > -node_err: > - of_node_put(np); > -err: > - return -EINVAL; > -} > - > /* > * ST (system timer) module supports both clockevents and clocksour= ce. > */ > static void __init atmel_st_timer_init(struct device_node *node) > { > - /* For device tree enabled device: initialize here */ > - of_at91rm9200_st_init(); > + unsigned int val; > + > + regmap_st =3D syscon_node_to_regmap(node); > + if (IS_ERR(regmap_st)) > + panic(pr_fmt("Unable to get regmap\n")); > > /* Disable all timer interrupts, and clear any pending ones */ > - at91_st_write(AT91_ST_IDR, > + regmap_write(regmap_st, AT91_ST_IDR, > AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS); > - at91_st_read(AT91_ST_SR); > + regmap_read(regmap_st, AT91_ST_SR, &val); > + > + /* Get the interrupts property */ > + at91rm9200_timer_irq.irq =3D irq_of_parse_and_map(node, 0); > + if (!at91rm9200_timer_irq.irq) > + panic(pr_fmt("Unable to get IRQ from DT\n")); > > /* Make IRQs happen for the system timer */ > setup_irq(at91rm9200_timer_irq.irq, &at91rm9200_timer_irq); > @@ -239,7 +214,7 @@ static void __init atmel_st_timer_init(struct dev= ice_node *node) > * directly for the clocksource and all clockevents, after adjusti= ng > * its prescaler from the 1 Hz default. > */ > - at91_st_write(AT91_ST_RTMR, 1); > + regmap_write(regmap_st, AT91_ST_RTMR, 1); > > /* Setup timer clockevent, with minimum of two ticks (important!!)= */ > clkevt.cpumask =3D cpumask_of(0); > --=20 Linaro.org =E2=94=82 Open source software fo= r ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-watchdo= g" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html