277 lines
6.5 KiB
C
277 lines
6.5 KiB
C
/*
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* Copyright (C) 2013 Pengutronix
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* Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
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*
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* This program is free software; you can redistribute it and/or modify it under
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* the terms of the GNU General Public License version 2 as published by the
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* Free Software Foundation.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/clocksource.h>
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#include <linux/clockchips.h>
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#include <linux/irq.h>
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#include <linux/interrupt.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#include <linux/clk.h>
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#define TIMERn_CTRL 0x00
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#define TIMERn_CTRL_PRESC(val) (((val) & 0xf) << 24)
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#define TIMERn_CTRL_PRESC_1024 TIMERn_CTRL_PRESC(10)
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#define TIMERn_CTRL_CLKSEL(val) (((val) & 0x3) << 16)
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#define TIMERn_CTRL_CLKSEL_PRESCHFPERCLK TIMERn_CTRL_CLKSEL(0)
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#define TIMERn_CTRL_OSMEN 0x00000010
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#define TIMERn_CTRL_MODE(val) (((val) & 0x3) << 0)
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#define TIMERn_CTRL_MODE_UP TIMERn_CTRL_MODE(0)
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#define TIMERn_CTRL_MODE_DOWN TIMERn_CTRL_MODE(1)
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#define TIMERn_CMD 0x04
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#define TIMERn_CMD_START 0x00000001
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#define TIMERn_CMD_STOP 0x00000002
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#define TIMERn_IEN 0x0c
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#define TIMERn_IF 0x10
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#define TIMERn_IFS 0x14
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#define TIMERn_IFC 0x18
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#define TIMERn_IRQ_UF 0x00000002
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#define TIMERn_TOP 0x1c
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#define TIMERn_CNT 0x24
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struct efm32_clock_event_ddata {
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struct clock_event_device evtdev;
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void __iomem *base;
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unsigned periodic_top;
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};
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static void efm32_clock_event_set_mode(enum clock_event_mode mode,
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struct clock_event_device *evtdev)
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{
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struct efm32_clock_event_ddata *ddata =
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container_of(evtdev, struct efm32_clock_event_ddata, evtdev);
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switch (mode) {
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case CLOCK_EVT_MODE_PERIODIC:
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writel_relaxed(TIMERn_CMD_STOP, ddata->base + TIMERn_CMD);
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writel_relaxed(ddata->periodic_top, ddata->base + TIMERn_TOP);
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writel_relaxed(TIMERn_CTRL_PRESC_1024 |
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TIMERn_CTRL_CLKSEL_PRESCHFPERCLK |
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TIMERn_CTRL_MODE_DOWN,
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ddata->base + TIMERn_CTRL);
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writel_relaxed(TIMERn_CMD_START, ddata->base + TIMERn_CMD);
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break;
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case CLOCK_EVT_MODE_ONESHOT:
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writel_relaxed(TIMERn_CMD_STOP, ddata->base + TIMERn_CMD);
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writel_relaxed(TIMERn_CTRL_PRESC_1024 |
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TIMERn_CTRL_CLKSEL_PRESCHFPERCLK |
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TIMERn_CTRL_OSMEN |
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TIMERn_CTRL_MODE_DOWN,
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ddata->base + TIMERn_CTRL);
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break;
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case CLOCK_EVT_MODE_UNUSED:
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case CLOCK_EVT_MODE_SHUTDOWN:
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writel_relaxed(TIMERn_CMD_STOP, ddata->base + TIMERn_CMD);
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break;
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case CLOCK_EVT_MODE_RESUME:
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break;
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}
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}
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static int efm32_clock_event_set_next_event(unsigned long evt,
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struct clock_event_device *evtdev)
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{
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struct efm32_clock_event_ddata *ddata =
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container_of(evtdev, struct efm32_clock_event_ddata, evtdev);
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writel_relaxed(TIMERn_CMD_STOP, ddata->base + TIMERn_CMD);
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writel_relaxed(evt, ddata->base + TIMERn_CNT);
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writel_relaxed(TIMERn_CMD_START, ddata->base + TIMERn_CMD);
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return 0;
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}
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static irqreturn_t efm32_clock_event_handler(int irq, void *dev_id)
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{
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struct efm32_clock_event_ddata *ddata = dev_id;
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writel_relaxed(TIMERn_IRQ_UF, ddata->base + TIMERn_IFC);
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ddata->evtdev.event_handler(&ddata->evtdev);
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return IRQ_HANDLED;
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}
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static struct efm32_clock_event_ddata clock_event_ddata = {
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.evtdev = {
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.name = "efm32 clockevent",
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.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_MODE_PERIODIC,
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.set_mode = efm32_clock_event_set_mode,
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.set_next_event = efm32_clock_event_set_next_event,
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.rating = 200,
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},
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};
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static struct irqaction efm32_clock_event_irq = {
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.name = "efm32 clockevent",
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.flags = IRQF_TIMER,
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.handler = efm32_clock_event_handler,
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.dev_id = &clock_event_ddata,
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};
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static int __init efm32_clocksource_init(struct device_node *np)
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{
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struct clk *clk;
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void __iomem *base;
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unsigned long rate;
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int ret;
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clk = of_clk_get(np, 0);
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if (IS_ERR(clk)) {
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ret = PTR_ERR(clk);
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pr_err("failed to get clock for clocksource (%d)\n", ret);
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goto err_clk_get;
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}
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ret = clk_prepare_enable(clk);
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if (ret) {
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pr_err("failed to enable timer clock for clocksource (%d)\n",
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ret);
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goto err_clk_enable;
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}
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rate = clk_get_rate(clk);
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base = of_iomap(np, 0);
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if (!base) {
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ret = -EADDRNOTAVAIL;
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pr_err("failed to map registers for clocksource\n");
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goto err_iomap;
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}
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writel_relaxed(TIMERn_CTRL_PRESC_1024 |
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TIMERn_CTRL_CLKSEL_PRESCHFPERCLK |
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TIMERn_CTRL_MODE_UP, base + TIMERn_CTRL);
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writel_relaxed(TIMERn_CMD_START, base + TIMERn_CMD);
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ret = clocksource_mmio_init(base + TIMERn_CNT, "efm32 timer",
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DIV_ROUND_CLOSEST(rate, 1024), 200, 16,
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clocksource_mmio_readl_up);
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if (ret) {
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pr_err("failed to init clocksource (%d)\n", ret);
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goto err_clocksource_init;
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}
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return 0;
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err_clocksource_init:
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iounmap(base);
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err_iomap:
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clk_disable_unprepare(clk);
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err_clk_enable:
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clk_put(clk);
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err_clk_get:
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return ret;
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}
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static int __init efm32_clockevent_init(struct device_node *np)
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{
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struct clk *clk;
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void __iomem *base;
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unsigned long rate;
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int irq;
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int ret;
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clk = of_clk_get(np, 0);
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if (IS_ERR(clk)) {
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ret = PTR_ERR(clk);
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pr_err("failed to get clock for clockevent (%d)\n", ret);
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goto err_clk_get;
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}
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ret = clk_prepare_enable(clk);
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if (ret) {
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pr_err("failed to enable timer clock for clockevent (%d)\n",
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ret);
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goto err_clk_enable;
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}
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rate = clk_get_rate(clk);
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base = of_iomap(np, 0);
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if (!base) {
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ret = -EADDRNOTAVAIL;
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pr_err("failed to map registers for clockevent\n");
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goto err_iomap;
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}
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irq = irq_of_parse_and_map(np, 0);
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if (!irq) {
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ret = -ENOENT;
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pr_err("failed to get irq for clockevent\n");
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goto err_get_irq;
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}
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writel_relaxed(TIMERn_IRQ_UF, base + TIMERn_IEN);
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clock_event_ddata.base = base;
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clock_event_ddata.periodic_top = DIV_ROUND_CLOSEST(rate, 1024 * HZ);
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clockevents_config_and_register(&clock_event_ddata.evtdev,
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DIV_ROUND_CLOSEST(rate, 1024),
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0xf, 0xffff);
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setup_irq(irq, &efm32_clock_event_irq);
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return 0;
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err_get_irq:
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iounmap(base);
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err_iomap:
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clk_disable_unprepare(clk);
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err_clk_enable:
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clk_put(clk);
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err_clk_get:
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return ret;
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}
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/*
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* This function asserts that we have exactly one clocksource and one
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* clock_event_device in the end.
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*/
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static void __init efm32_timer_init(struct device_node *np)
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{
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static int has_clocksource, has_clockevent;
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int ret;
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if (!has_clocksource) {
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ret = efm32_clocksource_init(np);
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if (!ret) {
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has_clocksource = 1;
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return;
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}
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}
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if (!has_clockevent) {
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ret = efm32_clockevent_init(np);
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if (!ret) {
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has_clockevent = 1;
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return;
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}
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}
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}
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CLOCKSOURCE_OF_DECLARE(efm32compat, "efm32,timer", efm32_timer_init);
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CLOCKSOURCE_OF_DECLARE(efm32, "energymicro,efm32-timer", efm32_timer_init);
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