57 lines
1.3 KiB
C
57 lines
1.3 KiB
C
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#include <linux/clocksource.h>
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#include <linux/sched_clock.h>
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#include <linux/of_address.h>
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#include <linux/printk.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/clk.h>
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static void __iomem *xtal_in_cnt;
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static struct delay_timer delay_timer;
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static unsigned long notrace read_xtal_counter(void)
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{
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return readl_relaxed(xtal_in_cnt);
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}
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static u64 notrace read_sched_clock(void)
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{
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return read_xtal_counter();
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}
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static int __init tango_clocksource_init(struct device_node *np)
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{
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struct clk *clk;
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int xtal_freq, ret;
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xtal_in_cnt = of_iomap(np, 0);
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if (xtal_in_cnt == NULL) {
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pr_err("%s: invalid address\n", np->full_name);
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return -ENXIO;
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}
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clk = of_clk_get(np, 0);
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if (IS_ERR(clk)) {
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pr_err("%s: invalid clock\n", np->full_name);
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return PTR_ERR(clk);
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}
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xtal_freq = clk_get_rate(clk);
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delay_timer.freq = xtal_freq;
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delay_timer.read_current_timer = read_xtal_counter;
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ret = clocksource_mmio_init(xtal_in_cnt, "tango-xtal", xtal_freq, 350,
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32, clocksource_mmio_readl_up);
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if (ret) {
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pr_err("%s: registration failed\n", np->full_name);
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return ret;
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}
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sched_clock_register(read_sched_clock, 32, xtal_freq);
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register_current_timer_delay(&delay_timer);
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return 0;
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}
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CLOCKSOURCE_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init);
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