293 lines
7.6 KiB
C
293 lines
7.6 KiB
C
/*
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* Freescale STMP37XX/STMP378X Real Time Clock driver
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*
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* Copyright (c) 2007 Sigmatel, Inc.
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* Peter Hartley, <peter.hartley@sigmatel.com>
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*
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* Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
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* Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
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* Copyright 2011 Wolfram Sang, Pengutronix e.K.
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*/
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/*
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* The code contained herein is licensed under the GNU General Public
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* License. You may obtain a copy of the GNU General Public License
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* Version 2 or later at the following locations:
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*
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* http://www.opensource.org/licenses/gpl-license.html
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* http://www.gnu.org/copyleft/gpl.html
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/io.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/interrupt.h>
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#include <linux/rtc.h>
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#include <linux/slab.h>
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#include <linux/of_device.h>
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#include <mach/common.h>
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#define STMP3XXX_RTC_CTRL 0x0
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#define STMP3XXX_RTC_CTRL_SET 0x4
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#define STMP3XXX_RTC_CTRL_CLR 0x8
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#define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001
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#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002
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#define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004
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#define STMP3XXX_RTC_STAT 0x10
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#define STMP3XXX_RTC_STAT_STALE_SHIFT 16
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#define STMP3XXX_RTC_STAT_RTC_PRESENT 0x80000000
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#define STMP3XXX_RTC_SECONDS 0x30
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#define STMP3XXX_RTC_ALARM 0x40
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#define STMP3XXX_RTC_PERSISTENT0 0x60
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#define STMP3XXX_RTC_PERSISTENT0_SET 0x64
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#define STMP3XXX_RTC_PERSISTENT0_CLR 0x68
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#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN 0x00000002
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#define STMP3XXX_RTC_PERSISTENT0_ALARM_EN 0x00000004
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#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE 0x00000080
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struct stmp3xxx_rtc_data {
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struct rtc_device *rtc;
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void __iomem *io;
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int irq_alarm;
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};
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static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
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{
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/*
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* The datasheet doesn't say which way round the
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* NEW_REGS/STALE_REGS bitfields go. In fact it's 0x1=P0,
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* 0x2=P1, .., 0x20=P5, 0x40=ALARM, 0x80=SECONDS
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*/
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while (readl(rtc_data->io + STMP3XXX_RTC_STAT) &
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(0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT))
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cpu_relax();
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}
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/* Time read/write */
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static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
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{
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struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
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stmp3xxx_wait_time(rtc_data);
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rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm);
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return 0;
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}
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static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t)
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{
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struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
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writel(t, rtc_data->io + STMP3XXX_RTC_SECONDS);
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stmp3xxx_wait_time(rtc_data);
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return 0;
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}
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/* interrupt(s) handler */
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static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id)
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{
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struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id);
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u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL);
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if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) {
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writel(STMP3XXX_RTC_CTRL_ALARM_IRQ,
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rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
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rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF);
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return IRQ_HANDLED;
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}
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return IRQ_NONE;
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}
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static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled)
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{
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struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
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if (enabled) {
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writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
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STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
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rtc_data->io + STMP3XXX_RTC_PERSISTENT0_SET);
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writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
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rtc_data->io + STMP3XXX_RTC_CTRL_SET);
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} else {
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writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
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STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
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rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
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writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
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rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
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}
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return 0;
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}
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static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
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{
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struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
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rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time);
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return 0;
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}
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static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
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{
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unsigned long t;
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struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
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rtc_tm_to_time(&alm->time, &t);
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writel(t, rtc_data->io + STMP3XXX_RTC_ALARM);
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stmp3xxx_alarm_irq_enable(dev, alm->enabled);
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return 0;
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}
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static struct rtc_class_ops stmp3xxx_rtc_ops = {
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.alarm_irq_enable =
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stmp3xxx_alarm_irq_enable,
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.read_time = stmp3xxx_rtc_gettime,
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.set_mmss = stmp3xxx_rtc_set_mmss,
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.read_alarm = stmp3xxx_rtc_read_alarm,
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.set_alarm = stmp3xxx_rtc_set_alarm,
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};
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static int stmp3xxx_rtc_remove(struct platform_device *pdev)
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{
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struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev);
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if (!rtc_data)
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return 0;
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writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
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rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
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free_irq(rtc_data->irq_alarm, &pdev->dev);
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rtc_device_unregister(rtc_data->rtc);
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platform_set_drvdata(pdev, NULL);
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iounmap(rtc_data->io);
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kfree(rtc_data);
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return 0;
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}
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static int stmp3xxx_rtc_probe(struct platform_device *pdev)
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{
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struct stmp3xxx_rtc_data *rtc_data;
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struct resource *r;
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int err;
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rtc_data = kzalloc(sizeof *rtc_data, GFP_KERNEL);
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if (!rtc_data)
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return -ENOMEM;
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r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!r) {
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dev_err(&pdev->dev, "failed to get resource\n");
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err = -ENXIO;
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goto out_free;
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}
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rtc_data->io = ioremap(r->start, resource_size(r));
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if (!rtc_data->io) {
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dev_err(&pdev->dev, "ioremap failed\n");
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err = -EIO;
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goto out_free;
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}
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rtc_data->irq_alarm = platform_get_irq(pdev, 0);
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if (!(readl(STMP3XXX_RTC_STAT + rtc_data->io) &
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STMP3XXX_RTC_STAT_RTC_PRESENT)) {
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dev_err(&pdev->dev, "no device onboard\n");
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err = -ENODEV;
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goto out_remap;
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}
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platform_set_drvdata(pdev, rtc_data);
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mxs_reset_block(rtc_data->io);
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writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
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STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
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STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
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rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
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writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN |
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STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
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rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
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rtc_data->rtc = rtc_device_register(pdev->name, &pdev->dev,
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&stmp3xxx_rtc_ops, THIS_MODULE);
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if (IS_ERR(rtc_data->rtc)) {
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err = PTR_ERR(rtc_data->rtc);
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goto out_remap;
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}
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err = request_irq(rtc_data->irq_alarm, stmp3xxx_rtc_interrupt, 0,
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"RTC alarm", &pdev->dev);
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if (err) {
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dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
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rtc_data->irq_alarm);
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goto out_irq_alarm;
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}
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return 0;
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out_irq_alarm:
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rtc_device_unregister(rtc_data->rtc);
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out_remap:
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platform_set_drvdata(pdev, NULL);
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iounmap(rtc_data->io);
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out_free:
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kfree(rtc_data);
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return err;
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}
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#ifdef CONFIG_PM
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static int stmp3xxx_rtc_suspend(struct platform_device *dev, pm_message_t state)
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{
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return 0;
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}
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static int stmp3xxx_rtc_resume(struct platform_device *dev)
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{
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struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(dev);
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mxs_reset_block(rtc_data->io);
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writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
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STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
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STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
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rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
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return 0;
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}
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#else
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#define stmp3xxx_rtc_suspend NULL
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#define stmp3xxx_rtc_resume NULL
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#endif
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static const struct of_device_id rtc_dt_ids[] = {
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{ .compatible = "fsl,stmp3xxx-rtc", },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, rtc_dt_ids);
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static struct platform_driver stmp3xxx_rtcdrv = {
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.probe = stmp3xxx_rtc_probe,
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.remove = stmp3xxx_rtc_remove,
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.suspend = stmp3xxx_rtc_suspend,
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.resume = stmp3xxx_rtc_resume,
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.driver = {
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.name = "stmp3xxx-rtc",
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.owner = THIS_MODULE,
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.of_match_table = rtc_dt_ids,
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},
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};
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module_platform_driver(stmp3xxx_rtcdrv);
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MODULE_DESCRIPTION("STMP3xxx RTC Driver");
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MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com> and "
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"Wolfram Sang <w.sang@pengutronix.de>");
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MODULE_LICENSE("GPL");
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