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 <alexandre.bell...@free-electrons.com> --- drivers/clocksource/timer-atmel-st.c | 103 +++++++++++++---------------------- 1 file changed, 39 insertions(+), 64 deletions(-) diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c index ed0267f1c892..0a089b9fc3d2 100644 --- a/drivers/clocksource/timer-atmel-st.c +++ b/drivers/clocksource/timer-atmel-st.c @@ -24,20 +24,20 @@ #include <linux/irq.h> #include <linux/clockchips.h> #include <linux/export.h> -#include <linux/of.h> -#include <linux/of_address.h> +#include <linux/mfd/atmel-st.h> +#include <linux/mfd/syscon.h> #include <linux/of_irq.h> +#include <linux/regmap.h> #include <asm/mach/time.h> #include <asm/system_misc.h> -#include <mach/at91_st.h> -#include <mach/hardware.h> - static unsigned long last_crtr; static u32 irqmask; static struct clock_event_device clkevt; +static struct regmap *regmap_st; +#define AT91_SLOW_CLOCK 32768 /* DT compatibility */ #define RM9200_TIMER_LATCH ((AT91_SLOW_CLOCK + HZ/2) / HZ) /* @@ -47,11 +47,11 @@ static struct clock_event_device clkevt; */ static inline unsigned long read_CRTR(void) { - unsigned long x1, x2; + unsigned int x1, x2; - x1 = at91_st_read(AT91_ST_CRTR); + regmap_read(regmap_st, AT91_ST_CRTR, &x1); do { - x2 = at91_st_read(AT91_ST_CRTR); + regmap_read(regmap_st, AT91_ST_CRTR, &x2); if (x1 == x2) break; x1 = x2; @@ -64,7 +64,10 @@ static inline unsigned long read_CRTR(void) */ static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id) { - u32 sr = at91_st_read(AT91_ST_SR) & irqmask; + u32 sr; + + regmap_read(regmap_st, AT91_ST_SR, &sr); + sr &= irqmask; /* * irqs should be disabled here, but as the irq is shared they are only @@ -97,7 +100,7 @@ static struct irqaction at91rm9200_timer_irq = { .name = "at91_tick", .flags = IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL, .handler = at91rm9200_timer_interrupt, - .irq = NR_IRQS_LEGACY + AT91_ID_SYS, + .irq = 0, }; static cycle_t read_clk32k(struct clocksource *cs) @@ -116,23 +119,25 @@ static struct clocksource clk32k = { static void clkevt32k_mode(enum clock_event_mode mode, struct clock_event_device *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 = read_CRTR(); switch (mode) { case CLOCK_EVT_MODE_PERIODIC: /* PIT for periodic irqs; fixed rate of 1/HZ */ irqmask = 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 = 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: @@ -140,7 +145,7 @@ clkevt32k_mode(enum clock_event_mode mode, struct clock_event_device *dev) irqmask = 0; break; } - at91_st_write(AT91_ST_IER, irqmask); + regmap_write(regmap_st, AT91_ST_IER, irqmask); } static int @@ -148,6 +153,7 @@ clkevt32k_next_event(unsigned long delta, struct clock_event_device *dev) { u32 alm; int status = 0; + unsigned int val; BUG_ON(delta < 2); @@ -163,12 +169,12 @@ clkevt32k_next_event(unsigned long delta, struct clock_event_device *dev) alm = 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 += delta; - at91_st_write(AT91_ST_RTAR, alm); + regmap_write(regmap_st, AT91_ST_RTAR, alm); return status; } @@ -186,47 +192,8 @@ static void at91rm9200_restart(enum reboot_mode reboot_mode, const char *cmd) /* * Perform a hardware reset with the use of the Watchdog timer. */ - at91_st_write(AT91_ST_WDMR, AT91_ST_RSTEN | AT91_ST_EXTEN | 1); - at91_st_write(AT91_ST_CR, AT91_ST_WDRST); -} - -void __iomem *at91_st_base; -EXPORT_SYMBOL_GPL(at91_st_base); - -static struct of_device_id at91rm9200_st_timer_ids[] = { - { .compatible = "atmel,at91rm9200-st" }, - { /* sentinel */ } -}; - -static int __init of_at91rm9200_st_init(void) -{ - struct device_node *np; - int ret; - - np = of_find_matching_node(NULL, at91rm9200_st_timer_ids); - if (!np) - goto err; - - at91_st_base = of_iomap(np, 0); - if (!at91_st_base) - goto node_err; - - /* Get the interrupts property */ - ret = irq_of_parse_and_map(np, 0); - if (!ret) - goto ioremap_err; - at91rm9200_timer_irq.irq = ret; - - of_node_put(np); - - return 0; - -ioremap_err: - iounmap(at91_st_base); -node_err: - of_node_put(np); -err: - return -EINVAL; + regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_RSTEN | AT91_ST_EXTEN | 1); + regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST); } /* @@ -234,13 +201,21 @@ err: */ 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 = 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 = 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); @@ -249,7 +224,7 @@ static void __init atmel_st_timer_init(struct device_node *node) * directly for the clocksource and all clockevents, after adjusting * 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 = cpumask_of(0); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/