diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/clocksource/dw_apb_timer_of.c | 95 |
2 files changed, 65 insertions, 32 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index f151c6cf27c3..5871933c4e51 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -21,6 +21,8 @@ config DW_APB_TIMER config DW_APB_TIMER_OF bool + select DW_APB_TIMER + select CLKSRC_OF config ARMADA_370_XP_TIMER bool diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c index ab09ed3742ee..cef554432a33 100644 --- a/drivers/clocksource/dw_apb_timer_of.c +++ b/drivers/clocksource/dw_apb_timer_of.c @@ -20,6 +20,7 @@ #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> +#include <linux/clk.h> #include <asm/mach/time.h> #include <asm/sched_clock.h> @@ -27,14 +28,37 @@ static void timer_get_base_and_rate(struct device_node *np, void __iomem **base, u32 *rate) { + struct clk *timer_clk; + struct clk *pclk; + *base = of_iomap(np, 0); if (!*base) panic("Unable to map regs for %s", np->name); + /* + * Not all implementations use a periphal clock, so don't panic + * if it's not present + */ + pclk = of_clk_get_by_name(np, "pclk"); + if (!IS_ERR(pclk)) + if (clk_prepare_enable(pclk)) + pr_warn("pclk for %s is present, but could not be activated\n", + np->name); + + timer_clk = of_clk_get_by_name(np, "timer"); + if (IS_ERR(timer_clk)) + goto try_clock_freq; + + if (!clk_prepare_enable(timer_clk)) { + *rate = clk_get_rate(timer_clk); + return; + } + +try_clock_freq: if (of_property_read_u32(np, "clock-freq", rate) && of_property_read_u32(np, "clock-frequency", rate)) - panic("No clock-frequency property for %s", np->name); + panic("No clock nor clock-frequency property for %s", np->name); } static void add_clockevent(struct device_node *event_timer) @@ -57,6 +81,9 @@ static void add_clockevent(struct device_node *event_timer) dw_apb_clockevent_register(ced); } +static void __iomem *sched_io_base; +static u32 sched_rate; + static void add_clocksource(struct device_node *source_timer) { void __iomem *iobase; @@ -71,9 +98,15 @@ static void add_clocksource(struct device_node *source_timer) dw_apb_clocksource_start(cs); dw_apb_clocksource_register(cs); -} -static void __iomem *sched_io_base; + /* + * Fallback to use the clocksource as sched_clock if no separate + * timer is found. sched_io_base then points to the current_value + * register of the clocksource timer. + */ + sched_io_base = iobase + 0x04; + sched_rate = rate; +} static u32 read_sched_clock(void) { @@ -89,39 +122,37 @@ static const struct of_device_id sptimer_ids[] __initconst = { static void init_sched_clock(void) { struct device_node *sched_timer; - u32 rate; sched_timer = of_find_matching_node(NULL, sptimer_ids); - if (!sched_timer) - panic("No RTC for sched clock to use"); + if (sched_timer) { + timer_get_base_and_rate(sched_timer, &sched_io_base, + &sched_rate); + of_node_put(sched_timer); + } - timer_get_base_and_rate(sched_timer, &sched_io_base, &rate); - of_node_put(sched_timer); - - setup_sched_clock(read_sched_clock, 32, rate); + setup_sched_clock(read_sched_clock, 32, sched_rate); } -static const struct of_device_id osctimer_ids[] __initconst = { - { .compatible = "picochip,pc3x2-timer" }, - { .compatible = "snps,dw-apb-timer-osc" }, - {}, -}; - -void __init dw_apb_timer_init(void) +static int num_called; +static void __init dw_apb_timer_init(struct device_node *timer) { - struct device_node *event_timer, *source_timer; - - event_timer = of_find_matching_node(NULL, osctimer_ids); - if (!event_timer) - panic("No timer for clockevent"); - add_clockevent(event_timer); - - source_timer = of_find_matching_node(event_timer, osctimer_ids); - if (!source_timer) - panic("No timer for clocksource"); - add_clocksource(source_timer); - - of_node_put(source_timer); - - init_sched_clock(); + switch (num_called) { + case 0: + pr_debug("%s: found clockevent timer\n", __func__); + add_clockevent(timer); + of_node_put(timer); + break; + case 1: + pr_debug("%s: found clocksource timer\n", __func__); + add_clocksource(timer); + of_node_put(timer); + init_sched_clock(); + break; + default: + break; + } + + num_called++; } +CLOCKSOURCE_OF_DECLARE(pc3x2_timer, "picochip,pc3x2-timer", dw_apb_timer_init); +CLOCKSOURCE_OF_DECLARE(apb_timer, "snps,dw-apb-timer-osc", dw_apb_timer_init); |