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path: root/drivers/rtc/rtc-mxc.c
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Diffstat (limited to 'drivers/rtc/rtc-mxc.c')
-rw-r--r--drivers/rtc/rtc-mxc.c507
1 files changed, 507 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
new file mode 100644
index 000000000000..6bd5072d4eb7
--- /dev/null
+++ b/drivers/rtc/rtc-mxc.c
@@ -0,0 +1,507 @@
+/*
+ * Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/io.h>
+#include <linux/rtc.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include <mach/hardware.h>
+
+#define RTC_INPUT_CLK_32768HZ (0x00 << 5)
+#define RTC_INPUT_CLK_32000HZ (0x01 << 5)
+#define RTC_INPUT_CLK_38400HZ (0x02 << 5)
+
+#define RTC_SW_BIT (1 << 0)
+#define RTC_ALM_BIT (1 << 2)
+#define RTC_1HZ_BIT (1 << 4)
+#define RTC_2HZ_BIT (1 << 7)
+#define RTC_SAM0_BIT (1 << 8)
+#define RTC_SAM1_BIT (1 << 9)
+#define RTC_SAM2_BIT (1 << 10)
+#define RTC_SAM3_BIT (1 << 11)
+#define RTC_SAM4_BIT (1 << 12)
+#define RTC_SAM5_BIT (1 << 13)
+#define RTC_SAM6_BIT (1 << 14)
+#define RTC_SAM7_BIT (1 << 15)
+#define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
+ RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
+ RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
+
+#define RTC_ENABLE_BIT (1 << 7)
+
+#define MAX_PIE_NUM 9
+#define MAX_PIE_FREQ 512
+static const u32 PIE_BIT_DEF[MAX_PIE_NUM][2] = {
+ { 2, RTC_2HZ_BIT },
+ { 4, RTC_SAM0_BIT },
+ { 8, RTC_SAM1_BIT },
+ { 16, RTC_SAM2_BIT },
+ { 32, RTC_SAM3_BIT },
+ { 64, RTC_SAM4_BIT },
+ { 128, RTC_SAM5_BIT },
+ { 256, RTC_SAM6_BIT },
+ { MAX_PIE_FREQ, RTC_SAM7_BIT },
+};
+
+/* Those are the bits from a classic RTC we want to mimic */
+#define RTC_IRQF 0x80 /* any of the following 3 is active */
+#define RTC_PF 0x40 /* Periodic interrupt */
+#define RTC_AF 0x20 /* Alarm interrupt */
+#define RTC_UF 0x10 /* Update interrupt for 1Hz RTC */
+
+#define MXC_RTC_TIME 0
+#define MXC_RTC_ALARM 1
+
+#define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
+#define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
+#define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
+#define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
+#define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
+#define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
+#define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
+#define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
+#define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
+#define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
+#define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
+#define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
+#define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
+
+struct rtc_plat_data {
+ struct rtc_device *rtc;
+ void __iomem *ioaddr;
+ int irq;
+ struct clk *clk;
+ unsigned int irqen;
+ int alrm_sec;
+ int alrm_min;
+ int alrm_hour;
+ int alrm_mday;
+ struct timespec mxc_rtc_delta;
+ struct rtc_time g_rtc_alarm;
+};
+
+/*
+ * This function is used to obtain the RTC time or the alarm value in
+ * second.
+ */
+static u32 get_alarm_or_time(struct device *dev, int time_alarm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
+
+ switch (time_alarm) {
+ case MXC_RTC_TIME:
+ day = readw(ioaddr + RTC_DAYR);
+ hr_min = readw(ioaddr + RTC_HOURMIN);
+ sec = readw(ioaddr + RTC_SECOND);
+ break;
+ case MXC_RTC_ALARM:
+ day = readw(ioaddr + RTC_DAYALARM);
+ hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
+ sec = readw(ioaddr + RTC_ALRM_SEC);
+ break;
+ }
+
+ hr = hr_min >> 8;
+ min = hr_min & 0xff;
+
+ return (((day * 24 + hr) * 60) + min) * 60 + sec;
+}
+
+/*
+ * This function sets the RTC alarm value or the time value.
+ */
+static void set_alarm_or_time(struct device *dev, int time_alarm, u32 time)
+{
+ u32 day, hr, min, sec, temp;
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ day = time / 86400;
+ time -= day * 86400;
+
+ /* time is within a day now */
+ hr = time / 3600;
+ time -= hr * 3600;
+
+ /* time is within an hour now */
+ min = time / 60;
+ sec = time - min * 60;
+
+ temp = (hr << 8) + min;
+
+ switch (time_alarm) {
+ case MXC_RTC_TIME:
+ writew(day, ioaddr + RTC_DAYR);
+ writew(sec, ioaddr + RTC_SECOND);
+ writew(temp, ioaddr + RTC_HOURMIN);
+ break;
+ case MXC_RTC_ALARM:
+ writew(day, ioaddr + RTC_DAYALARM);
+ writew(sec, ioaddr + RTC_ALRM_SEC);
+ writew(temp, ioaddr + RTC_ALRM_HM);
+ break;
+ }
+}
+
+/*
+ * This function updates the RTC alarm registers and then clears all the
+ * interrupt status bits.
+ */
+static int rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
+{
+ struct rtc_time alarm_tm, now_tm;
+ unsigned long now, time;
+ int ret;
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ now = get_alarm_or_time(dev, MXC_RTC_TIME);
+ rtc_time_to_tm(now, &now_tm);
+ alarm_tm.tm_year = now_tm.tm_year;
+ alarm_tm.tm_mon = now_tm.tm_mon;
+ alarm_tm.tm_mday = now_tm.tm_mday;
+ alarm_tm.tm_hour = alrm->tm_hour;
+ alarm_tm.tm_min = alrm->tm_min;
+ alarm_tm.tm_sec = alrm->tm_sec;
+ rtc_tm_to_time(&now_tm, &now);
+ rtc_tm_to_time(&alarm_tm, &time);
+
+ if (time < now) {
+ time += 60 * 60 * 24;
+ rtc_time_to_tm(time, &alarm_tm);
+ }
+
+ ret = rtc_tm_to_time(&alarm_tm, &time);
+
+ /* clear all the interrupt status bits */
+ writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
+ set_alarm_or_time(dev, MXC_RTC_ALARM, time);
+
+ return ret;
+}
+
+/* This function is the RTC interrupt service routine. */
+static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
+{
+ struct platform_device *pdev = dev_id;
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ u32 status;
+ u32 events = 0;
+
+ spin_lock_irq(&pdata->rtc->irq_lock);
+ status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
+ /* clear interrupt sources */
+ writew(status, ioaddr + RTC_RTCISR);
+
+ /* clear alarm interrupt if it has occurred */
+ if (status & RTC_ALM_BIT)
+ status &= ~RTC_ALM_BIT;
+
+ /* update irq data & counter */
+ if (status & RTC_ALM_BIT)
+ events |= (RTC_AF | RTC_IRQF);
+
+ if (status & RTC_1HZ_BIT)
+ events |= (RTC_UF | RTC_IRQF);
+
+ if (status & PIT_ALL_ON)
+ events |= (RTC_PF | RTC_IRQF);
+
+ if ((status & RTC_ALM_BIT) && rtc_valid_tm(&pdata->g_rtc_alarm))
+ rtc_update_alarm(&pdev->dev, &pdata->g_rtc_alarm);
+
+ rtc_update_irq(pdata->rtc, 1, events);
+ spin_unlock_irq(&pdata->rtc->irq_lock);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * Clear all interrupts and release the IRQ
+ */
+static void mxc_rtc_release(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ spin_lock_irq(&pdata->rtc->irq_lock);
+
+ /* Disable all rtc interrupts */
+ writew(0, ioaddr + RTC_RTCIENR);
+
+ /* Clear all interrupt status */
+ writew(0xffffffff, ioaddr + RTC_RTCISR);
+
+ spin_unlock_irq(&pdata->rtc->irq_lock);
+}
+
+static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
+ unsigned int enabled)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ u32 reg;
+
+ spin_lock_irq(&pdata->rtc->irq_lock);
+ reg = readw(ioaddr + RTC_RTCIENR);
+
+ if (enabled)
+ reg |= bit;
+ else
+ reg &= ~bit;
+
+ writew(reg, ioaddr + RTC_RTCIENR);
+ spin_unlock_irq(&pdata->rtc->irq_lock);
+}
+
+static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
+ return 0;
+}
+
+static int mxc_rtc_update_irq_enable(struct device *dev, unsigned int enabled)
+{
+ mxc_rtc_irq_enable(dev, RTC_1HZ_BIT, enabled);
+ return 0;
+}
+
+/*
+ * This function reads the current RTC time into tm in Gregorian date.
+ */
+static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ u32 val;
+
+ /* Avoid roll-over from reading the different registers */
+ do {
+ val = get_alarm_or_time(dev, MXC_RTC_TIME);
+ } while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
+
+ rtc_time_to_tm(val, tm);
+
+ return 0;
+}
+
+/*
+ * This function sets the internal RTC time based on tm in Gregorian date.
+ */
+static int mxc_rtc_set_mmss(struct device *dev, unsigned long time)
+{
+ /* Avoid roll-over from reading the different registers */
+ do {
+ set_alarm_or_time(dev, MXC_RTC_TIME, time);
+ } while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
+
+ return 0;
+}
+
+/*
+ * This function reads the current alarm value into the passed in 'alrm'
+ * argument. It updates the alrm's pending field value based on the whether
+ * an alarm interrupt occurs or not.
+ */
+static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ rtc_time_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
+ alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
+
+ return 0;
+}
+
+/*
+ * This function sets the RTC alarm based on passed in alrm.
+ */
+static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ int ret;
+
+ if (rtc_valid_tm(&alrm->time)) {
+ if (alrm->time.tm_sec > 59 ||
+ alrm->time.tm_hour > 23 ||
+ alrm->time.tm_min > 59)
+ return -EINVAL;
+
+ ret = rtc_update_alarm(dev, &alrm->time);
+ } else {
+ ret = rtc_valid_tm(&alrm->time);
+ if (ret)
+ return ret;
+
+ ret = rtc_update_alarm(dev, &alrm->time);
+ }
+
+ if (ret)
+ return ret;
+
+ memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
+ mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
+
+ return 0;
+}
+
+/* RTC layer */
+static struct rtc_class_ops mxc_rtc_ops = {
+ .release = mxc_rtc_release,
+ .read_time = mxc_rtc_read_time,
+ .set_mmss = mxc_rtc_set_mmss,
+ .read_alarm = mxc_rtc_read_alarm,
+ .set_alarm = mxc_rtc_set_alarm,
+ .alarm_irq_enable = mxc_rtc_alarm_irq_enable,
+ .update_irq_enable = mxc_rtc_update_irq_enable,
+};
+
+static int __init mxc_rtc_probe(struct platform_device *pdev)
+{
+ struct clk *clk;
+ struct resource *res;
+ struct rtc_device *rtc;
+ struct rtc_plat_data *pdata = NULL;
+ u32 reg;
+ int ret, rate;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdata->ioaddr = ioremap(res->start, resource_size(res));
+
+ clk = clk_get(&pdev->dev, "ckil");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ rate = clk_get_rate(clk);
+ clk_put(clk);
+
+ if (rate == 32768)
+ reg = RTC_INPUT_CLK_32768HZ;
+ else if (rate == 32000)
+ reg = RTC_INPUT_CLK_32000HZ;
+ else if (rate == 38400)
+ reg = RTC_INPUT_CLK_38400HZ;
+ else {
+ dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n",
+ clk_get_rate(clk));
+ ret = -EINVAL;
+ goto exit_free_pdata;
+ }
+
+ reg |= RTC_ENABLE_BIT;
+ writew(reg, (pdata->ioaddr + RTC_RTCCTL));
+ if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
+ dev_err(&pdev->dev, "hardware module can't be enabled!\n");
+ ret = -EIO;
+ goto exit_free_pdata;
+ }
+
+ pdata->clk = clk_get(&pdev->dev, "rtc");
+ if (IS_ERR(pdata->clk)) {
+ dev_err(&pdev->dev, "unable to get clock!\n");
+ ret = PTR_ERR(pdata->clk);
+ goto exit_free_pdata;
+ }
+
+ clk_enable(pdata->clk);
+
+ rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops,
+ THIS_MODULE);
+ if (IS_ERR(rtc)) {
+ ret = PTR_ERR(rtc);
+ goto exit_put_clk;
+ }
+
+ pdata->rtc = rtc;
+ platform_set_drvdata(pdev, pdata);
+
+ /* Configure and enable the RTC */
+ pdata->irq = platform_get_irq(pdev, 0);
+
+ if (pdata->irq >= 0 &&
+ request_irq(pdata->irq, mxc_rtc_interrupt, IRQF_SHARED,
+ pdev->name, pdev) < 0) {
+ dev_warn(&pdev->dev, "interrupt not available.\n");
+ pdata->irq = -1;
+ }
+
+ return 0;
+
+exit_put_clk:
+ clk_put(pdata->clk);
+
+exit_free_pdata:
+ kfree(pdata);
+
+ return ret;
+}
+
+static int __exit mxc_rtc_remove(struct platform_device *pdev)
+{
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+
+ rtc_device_unregister(pdata->rtc);
+
+ if (pdata->irq >= 0)
+ free_irq(pdata->irq, pdev);
+
+ clk_disable(pdata->clk);
+ clk_put(pdata->clk);
+ kfree(pdata);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static struct platform_driver mxc_rtc_driver = {
+ .driver = {
+ .name = "mxc_rtc",
+ .owner = THIS_MODULE,
+ },
+ .remove = __exit_p(mxc_rtc_remove),
+};
+
+static int __init mxc_rtc_init(void)
+{
+ return platform_driver_probe(&mxc_rtc_driver, mxc_rtc_probe);
+}
+
+static void __exit mxc_rtc_exit(void)
+{
+ platform_driver_unregister(&mxc_rtc_driver);
+}
+
+module_init(mxc_rtc_init);
+module_exit(mxc_rtc_exit);
+
+MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
+MODULE_DESCRIPTION("RTC driver for Freescale MXC");
+MODULE_LICENSE("GPL");
+