diff options
Diffstat (limited to 'drivers/clocksource/tango_xtal.c')
-rw-r--r-- | drivers/clocksource/tango_xtal.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/clocksource/tango_xtal.c b/drivers/clocksource/tango_xtal.c new file mode 100644 index 0000000..d297b30 --- /dev/null +++ b/drivers/clocksource/tango_xtal.c @@ -0,0 +1,66 @@ +#include <linux/clocksource.h> +#include <linux/sched_clock.h> +#include <linux/of_address.h> +#include <linux/printk.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/clk.h> + +static void __iomem *xtal_in_cnt; +static struct delay_timer delay_timer; + +static unsigned long notrace read_xtal_counter(void) +{ + return readl_relaxed(xtal_in_cnt); +} + +static u64 notrace read_sched_clock(void) +{ + return read_xtal_counter(); +} + +static cycle_t read_clocksource(struct clocksource *cs) +{ + return read_xtal_counter(); +} + +static struct clocksource tango_xtal = { + .name = "tango-xtal", + .rating = 350, + .read = read_clocksource, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static void __init tango_clocksource_init(struct device_node *np) +{ + struct clk *clk; + int xtal_freq, ret; + + xtal_in_cnt = of_iomap(np, 0); + if (xtal_in_cnt == NULL) { + pr_err("%s: invalid address\n", np->full_name); + return; + } + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) { + pr_err("%s: invalid clock\n", np->full_name); + return; + } + + xtal_freq = clk_get_rate(clk); + delay_timer.freq = xtal_freq; + delay_timer.read_current_timer = read_xtal_counter; + + ret = clocksource_register_hz(&tango_xtal, xtal_freq); + if (ret != 0) { + pr_err("%s: registration failed\n", np->full_name); + return; + } + + sched_clock_register(read_sched_clock, 32, xtal_freq); + register_current_timer_delay(&delay_timer); +} + +CLOCKSOURCE_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init); |