linux-imx

    struct pit_data *data;

​

    data = kzalloc(sizeof(*data), GFP_KERNEL);

    if (!data)

        return -ENOMEM;

​

    data->base = of_iomap(node, 0);

    if (!data->base) {

        pr_err("Could not map PIT address\n");

    }

​

    data->mck = of_clk_get(node, 0);

    if (IS_ERR(data->mck)) {

        pr_err("Unable to get mck clk\n");

    }

​

    ret = clk_prepare_enable(data->mck);

    if (ret) {

        pr_err("Unable to enable mck\n");

    }

​

    /* Get the interrupts property */

    data->irq = irq_of_parse_and_map(node, 0);

    if (!data->irq) {

        pr_err("Unable to get IRQ from DT\n");

    }

​

    /*

     * Use our actual MCK to figure out how many MCK/16 ticks per

     * 1/HZ period (instead of a compile-time constant LATCH).

     */

    pit_rate = clk_get_rate(data->mck) / 16;

    data->cycle = DIV_ROUND_CLOSEST(pit_rate, HZ);

    WARN_ON(((data->cycle - 1) & ~AT91_PIT_PIV) != 0);

​

    data->clksrc.mask = CLOCKSOURCE_MASK(bits);

    data->clksrc.name = "pit";

    data->clksrc.rating = 175;

    data->clksrc.read = read_pit_clk;

    data->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;

    ret = clocksource_register_hz(&data->clksrc, pit_rate);

    if (ret) {

        pr_err("Failed to register clocksource\n");

    }

​

    /* Set up irq handler */

    ret = request_irq(data->irq, at91sam926x_pit_interrupt,

              IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,

              "at91_tick", data);

    if (ret) {

        pr_err("Unable to setup IRQ\n");

    }

​

    /* Set up and register clockevents */

    data->clkevt.name = "pit";

    data->clkevt.features = CLOCK_EVT_FEAT_PERIODIC;

    data->clkevt.shift = 32;

    data->clkevt.mult = div_sc(pit_rate, NSEC_PER_SEC, data->clkevt.shift);

    data->clkevt.rating = 100;

    data->clkevt.cpumask = cpumask_of(0);

​

    data->clkevt.set_state_shutdown = pit_clkevt_shutdown;

    data->clkevt.set_state_periodic = pit_clkevt_set_periodic;

    data->clkevt.resume = at91sam926x_pit_resume;

    data->clkevt.suspend = at91sam926x_pit_suspend;

    clockevents_register_device(&data->clkevt);

​

    return 0;

}

TIMER_OF_DECLARE(at91sam926x_pit, "atmel,at91sam9260-pit",

               at91sam926x_pit_dt_init);