This patch adds support to the sp804 code for retrieving timer configuration from the device tree. sp804 channels can be used as a clock event device or a clock source.
Signed-off-by: Grant Likely <[email protected]> Cc: Russell King <[email protected]> --- arch/arm/common/timer-sp.c | 72 ++++++++++++++++++++++++++--- arch/arm/include/asm/hardware/timer-sp.h | 2 + 2 files changed, 66 insertions(+), 8 deletions(-) diff --git a/arch/arm/common/timer-sp.c b/arch/arm/common/timer-sp.c index 2393b5b..93aed48 100644 --- a/arch/arm/common/timer-sp.c +++ b/arch/arm/common/timer-sp.c @@ -25,16 +25,18 @@ #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_clk.h> +#include <linux/of_irq.h> #include <asm/hardware/arm_timer.h> -static long __init sp804_get_clock_rate(const char *name) +static long __init sp804_get_clock_rate(struct clk *clk, const char *name) { - struct clk *clk; long rate; int err; - clk = clk_get_sys("sp804", name); if (IS_ERR(clk)) { pr_err("sp804: %s clock not found: %d\n", name, (int)PTR_ERR(clk)); @@ -67,9 +69,10 @@ static long __init sp804_get_clock_rate(const char *name) return rate; } -void __init sp804_clocksource_init(void __iomem *base, const char *name) +static void __init __sp804_clocksource_init(void __iomem *base, + const char *name, struct clk *clk) { - long rate = sp804_get_clock_rate(name); + long rate = sp804_get_clock_rate(clk, name); if (rate < 0) return; @@ -85,6 +88,10 @@ void __init sp804_clocksource_init(void __iomem *base, const char *name) rate, 200, 32, clocksource_mmio_readl_down); } +void __init sp804_clocksource_init(void __iomem *base, const char *name) +{ + __sp804_clocksource_init(base, name, clk_get_sys("sp804", name)); +} static void __iomem *clkevt_base; static unsigned long clkevt_reload; @@ -158,11 +165,11 @@ static struct irqaction sp804_timer_irq = { .dev_id = &sp804_clockevent, }; -void __init sp804_clockevents_init(void __iomem *base, unsigned int irq, - const char *name) +static void __init __sp804_clockevents_init(void __iomem *base, + unsigned int irq, const char *name, struct clk *clk) { struct clock_event_device *evt = &sp804_clockevent; - long rate = sp804_get_clock_rate(name); + long rate = sp804_get_clock_rate(clk, name); if (rate < 0) return; @@ -179,3 +186,52 @@ void __init sp804_clockevents_init(void __iomem *base, unsigned int irq, setup_irq(irq, &sp804_timer_irq); clockevents_register_device(evt); } + +void __init sp804_clockevents_init(void __iomem *base, unsigned int irq, + const char *name) +{ + __sp804_clockevents_init(base, irq, name, clk_get_sys("sp804", name)); +} + +#ifdef CONFIG_OF +void __init sp804_dt_setup(struct device_node *node) +{ + struct clk *clk; + unsigned int irq; + __iomem void * base; + + pr_debug("%s(): Setting up sp804 clock %s\n", __func__, node->name); + + /* Find the base address of the clock */ + base = of_iomap(node, 0); + if (!base) { + pr_err("ERROR: Cannot get base address of sp804 %s\n", + node->full_name); + return; + } + + writel(0, base + TIMER_CTRL); /* Disable the clock */ + + clk = of_clk_get(node, 0); + if (!clk) { + pr_err("ERROR: Cannot get clock for sp804 %s\n", node->name); + return; + } + + /* + * Figure out how to use this clock + * + * Note: This is kind of ugly since it requires linux-specific + * properties in the device tree so that Linux knows which sp804 + * channels can be used as the clock source and the clock events + * trigger. Something OS agnostic would be nicer, but it isn't + * obvious what that should look like. + */ + if (of_get_property(node, "linux,clock-source", NULL)) { + __sp804_clocksource_init(base, node->full_name, clk); + } else if (of_get_property(node, "linux,clockevents-device", NULL)) { + irq = irq_of_parse_and_map(node, 0); + __sp804_clockevents_init(base, irq, node->full_name, clk); + }; +} +#endif /* CONFIG_OF */ diff --git a/arch/arm/include/asm/hardware/timer-sp.h b/arch/arm/include/asm/hardware/timer-sp.h index 4384d81..edd0ec3 100644 --- a/arch/arm/include/asm/hardware/timer-sp.h +++ b/arch/arm/include/asm/hardware/timer-sp.h @@ -1,2 +1,4 @@ +struct device_node; void sp804_clocksource_init(void __iomem *, const char *); void sp804_clockevents_init(void __iomem *, unsigned int, const char *); +void sp804_dt_setup(struct device_node *node); -- 1.7.5.4 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
