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path: root/drivers/rtc/rtc-mxc.c
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-rw-r--r--drivers/rtc/rtc-mxc.c806
1 files changed, 806 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
new file mode 100644
index 000000000000..b6b168d8ac6b
--- /dev/null
+++ b/drivers/rtc/rtc-mxc.c
@@ -0,0 +1,806 @@
+/*
+ * Copyright 2004-2009 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
+ */
+/*
+ * Implementation based on rtc-ds1553.c
+ */
+
+/*!
+ * @defgroup RTC Real Time Clock (RTC) Driver
+ */
+/*!
+ * @file rtc-mxc.c
+ * @brief Real Time Clock interface
+ *
+ * This file contains Real Time Clock interface for Linux.
+ *
+ * @ingroup RTC
+ */
+
+#include <linux/rtc.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/uaccess.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
+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;
+ unsigned long baseaddr;
+ int irq;
+ struct clk *clk;
+ unsigned int irqen;
+ int alrm_sec;
+ int alrm_min;
+ int alrm_hour;
+ int alrm_mday;
+};
+
+/*!
+ * @defgroup RTC Real Time Clock (RTC) Driver
+ */
+/*!
+ * @file rtc-mxc.c
+ * @brief Real Time Clock interface
+ *
+ * This file contains Real Time Clock interface for Linux.
+ *
+ * @ingroup RTC
+ */
+
+#if defined(CONFIG_MXC_PMIC_SC55112_RTC) || defined(CONFIG_MXC_MC13783_RTC) ||\
+ defined(CONFIG_MXC_MC9SDZ60_RTC)
+#include <linux/pmic_rtc.h>
+#else
+#define pmic_rtc_get_time(args) MXC_EXTERNAL_RTC_NONE
+#define pmic_rtc_set_time(args) MXC_EXTERNAL_RTC_NONE
+#define pmic_rtc_loaded() 0
+#endif
+
+#define RTC_VERSION "1.0"
+#define MXC_EXTERNAL_RTC_OK 0
+#define MXC_EXTERNAL_RTC_ERR -1
+#define MXC_EXTERNAL_RTC_NONE -2
+
+/*!
+ * This function reads the RTC value from some external source.
+ *
+ * @param second pointer to the returned value in second
+ *
+ * @return 0 if successful; non-zero otherwise
+ */
+int get_ext_rtc_time(u32 * second)
+{
+ int ret = 0;
+ struct timeval tmp;
+ if (!pmic_rtc_loaded()) {
+ return MXC_EXTERNAL_RTC_NONE;
+ }
+
+ ret = pmic_rtc_get_time(&tmp);
+
+ if (0 == ret)
+ *second = tmp.tv_sec;
+ else
+ ret = MXC_EXTERNAL_RTC_ERR;
+
+ return ret;
+}
+
+/*!
+ * This function sets external RTC
+ *
+ * @param second value in second to be set to external RTC
+ *
+ * @return 0 if successful; non-zero otherwise
+ */
+int set_ext_rtc_time(u32 second)
+{
+ int ret = 0;
+ struct timeval tmp;
+
+ if (!pmic_rtc_loaded()) {
+ return MXC_EXTERNAL_RTC_NONE;
+ }
+
+ tmp.tv_sec = second;
+
+ ret = pmic_rtc_set_time(&tmp);
+
+ if (0 != ret)
+ ret = MXC_EXTERNAL_RTC_ERR;
+
+ return ret;
+}
+
+static u32 rtc_freq = 2; /* minimun value for PIE */
+static unsigned long rtc_status;
+
+static struct rtc_time g_rtc_alarm = {
+ .tm_year = 0,
+ .tm_mon = 0,
+ .tm_mday = 0,
+ .tm_hour = 0,
+ .tm_mon = 0,
+ .tm_sec = 0,
+};
+
+static DEFINE_SPINLOCK(rtc_lock);
+
+/*!
+ * This function is used to obtain the RTC time or the alarm value in
+ * second.
+ *
+ * @param time_alarm use MXC_RTC_TIME for RTC time value; MXC_RTC_ALARM for alarm value
+ *
+ * @return The RTC time or alarm time 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, hr, min, sec, hr_min;
+ if (time_alarm == MXC_RTC_TIME) {
+ day = readw(ioaddr + RTC_DAYR);
+ hr_min = readw(ioaddr + RTC_HOURMIN);
+ sec = readw(ioaddr + RTC_SECOND);
+ } else if (time_alarm == MXC_RTC_ALARM) {
+ day = readw(ioaddr + RTC_DAYALARM);
+ hr_min = (0x0000FFFF) & readw(ioaddr + RTC_ALRM_HM);
+ sec = readw(ioaddr + RTC_ALRM_SEC);
+ } else {
+ panic("wrong value for time_alarm=%d\n", time_alarm);
+ }
+
+ hr = hr_min >> 8;
+ min = hr_min & 0x00FF;
+
+ return ((((day * 24 + hr) * 60) + min) * 60 + sec);
+}
+
+/*!
+ * This function sets the RTC alarm value or the time value.
+ *
+ * @param time_alarm the new alarm value to be updated in the RTC
+ * @param time use MXC_RTC_TIME for RTC time value; MXC_RTC_ALARM for alarm 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;
+
+ if (time_alarm == MXC_RTC_TIME) {
+ writew(day, ioaddr + RTC_DAYR);
+ writew(sec, ioaddr + RTC_SECOND);
+ writew(temp, ioaddr + RTC_HOURMIN);
+ } else if (time_alarm == MXC_RTC_ALARM) {
+ writew(day, ioaddr + RTC_DAYALARM);
+ writew(sec, ioaddr + RTC_ALRM_SEC);
+ writew(temp, ioaddr + RTC_ALRM_HM);
+ } else {
+ panic("wrong value for time_alarm=%d\n", time_alarm);
+ }
+}
+
+/*!
+ * This function updates the RTC alarm registers and then clears all the
+ * interrupt status bits.
+ *
+ * @param alrm the new alarm value to be updated in the RTC
+ *
+ * @return 0 if successful; non-zero otherwise.
+ */
+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.
+ *
+ * @param irq RTC IRQ number
+ * @param dev_id device ID which is not used
+ *
+ * @return IRQ_HANDLED as defined in the include/linux/interrupt.h file.
+ */
+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(&rtc_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(&g_rtc_alarm)) {
+ rtc_update_alarm(&pdev->dev, &g_rtc_alarm);
+ }
+
+ spin_unlock(&rtc_lock);
+ rtc_update_irq(pdata->rtc, 1, events);
+ return IRQ_HANDLED;
+}
+
+/*!
+ * This function is used to open the RTC driver by registering the RTC
+ * interrupt service routine.
+ *
+ * @return 0 if successful; non-zero otherwise.
+ */
+static int mxc_rtc_open(struct device *dev)
+{
+ if (test_and_set_bit(1, &rtc_status))
+ return -EBUSY;
+ return 0;
+}
+
+/*!
+ * 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(&rtc_lock);
+ writew(0, ioaddr + RTC_RTCIENR); /* Disable all rtc interrupts */
+ writew(0xFFFFFFFF, ioaddr + RTC_RTCISR); /* Clear all interrupt status */
+ spin_unlock_irq(&rtc_lock);
+ rtc_status = 0;
+}
+
+/*!
+ * This function is used to support some ioctl calls directly.
+ * Other ioctl calls are supported indirectly through the
+ * arm/common/rtctime.c file.
+ *
+ * @param cmd ioctl command as defined in include/linux/rtc.h
+ * @param arg value for the ioctl command
+ *
+ * @return 0 if successful or negative value otherwise.
+ */
+static int mxc_rtc_ioctl(struct device *dev, unsigned int cmd,
+ unsigned long arg)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ int i;
+ switch (cmd) {
+ case RTC_PIE_OFF:
+ writew((readw(ioaddr + RTC_RTCIENR) & ~PIT_ALL_ON),
+ ioaddr + RTC_RTCIENR);
+ return 0;
+ case RTC_IRQP_SET:
+ if (arg < 2 || arg > MAX_PIE_FREQ || (arg % 2) != 0)
+ return -EINVAL; /* Also make sure a power of 2Hz */
+ if ((arg > 64) && (!capable(CAP_SYS_RESOURCE)))
+ return -EACCES;
+ rtc_freq = arg;
+ return 0;
+ case RTC_IRQP_READ:
+ return put_user(rtc_freq, (u32 *) arg);
+ case RTC_PIE_ON:
+ for (i = 0; i < MAX_PIE_NUM; i++) {
+ if (PIE_BIT_DEF[i][0] == rtc_freq) {
+ break;
+ }
+ }
+ if (i == MAX_PIE_NUM) {
+ return -EACCES;
+ }
+ spin_lock_irq(&rtc_lock);
+ writew((readw(ioaddr + RTC_RTCIENR) | PIE_BIT_DEF[i][1]),
+ ioaddr + RTC_RTCIENR);
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+ case RTC_AIE_OFF:
+ spin_lock_irq(&rtc_lock);
+ writew((readw(ioaddr + RTC_RTCIENR) & ~RTC_ALM_BIT),
+ ioaddr + RTC_RTCIENR);
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+
+ case RTC_AIE_ON:
+ spin_lock_irq(&rtc_lock);
+ writew((readw(ioaddr + RTC_RTCIENR) | RTC_ALM_BIT),
+ ioaddr + RTC_RTCIENR);
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+
+ case RTC_UIE_OFF: /* UIE is for the 1Hz interrupt */
+ spin_lock_irq(&rtc_lock);
+ writew((readw(ioaddr + RTC_RTCIENR) & ~RTC_1HZ_BIT),
+ ioaddr + RTC_RTCIENR);
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+
+ case RTC_UIE_ON:
+ spin_lock_irq(&rtc_lock);
+ writew((readw(ioaddr + RTC_RTCIENR) | RTC_1HZ_BIT),
+ ioaddr + RTC_RTCIENR);
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+ }
+ return -ENOIOCTLCMD;
+}
+
+/*!
+ * This function reads the current RTC time into tm in Gregorian date.
+ *
+ * @param tm contains the RTC time value upon return
+ *
+ * @return 0 if successful; non-zero otherwise.
+ */
+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.
+ *
+ * @param tm the time value to be set in the RTC
+ *
+ * @return 0 if successful; non-zero otherwise.
+ */
+static int mxc_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ unsigned long time;
+ int ret;
+ ret = rtc_tm_to_time(tm, &time);
+ if (ret != 0) {
+ return ret;
+ }
+
+ /* 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));
+
+ ret = set_ext_rtc_time(time);
+
+ if (ret != MXC_EXTERNAL_RTC_OK) {
+ if (ret == MXC_EXTERNAL_RTC_NONE) {
+ pr_info("No external RTC\n");
+ ret = 0;
+ } else
+ pr_info("Failed to set external RTC\n");
+ }
+
+ return ret;
+}
+
+/*!
+ * This function reads the current alarm value into the passed in \b alrm
+ * argument. It updates the \b alrm's pending field value based on the whether
+ * an alarm interrupt occurs or not.
+ *
+ * @param alrm contains the RTC alarm value upon return
+ *
+ * @return 0 if successful; non-zero otherwise.
+ */
+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) != 0) ? 1 : 0;
+
+ return 0;
+}
+
+/*!
+ * This function sets the RTC alarm based on passed in alrm.
+ *
+ * @param alrm the alarm value to be set in the RTC
+ *
+ * @return 0 if successful; non-zero otherwise.
+ */
+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);
+ void __iomem *ioaddr = pdata->ioaddr;
+ int ret;
+
+ spin_lock_irq(&rtc_lock);
+ if (rtc_valid_tm(&alrm->time)) {
+ if (alrm->time.tm_sec > 59 ||
+ alrm->time.tm_hour > 23 || alrm->time.tm_min > 59) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = rtc_update_alarm(dev, &alrm->time);
+ } else {
+ if ((ret = rtc_valid_tm(&alrm->time)))
+ goto out;
+ ret = rtc_update_alarm(dev, &alrm->time);
+ }
+
+ if (ret == 0) {
+ memcpy(&g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
+
+ if (alrm->enabled) {
+ writew((readw(ioaddr + RTC_RTCIENR) | RTC_ALM_BIT),
+ ioaddr + RTC_RTCIENR);
+ } else {
+ writew((readw(ioaddr + RTC_RTCIENR) & ~RTC_ALM_BIT),
+ ioaddr + RTC_RTCIENR);
+ }
+ }
+ out:
+ spin_unlock_irq(&rtc_lock);
+
+ return ret;
+}
+
+/*!
+ * This function is used to provide the content for the /proc/driver/rtc
+ * file.
+ *
+ * @param buf the buffer to hold the information that the driver wants to write
+ *
+ * @return The number of bytes written into the rtc file.
+ */
+static int mxc_rtc_proc(struct device *dev, struct seq_file *sq)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ char *p = sq->buf;
+
+ p += sprintf(p, "alarm_IRQ\t: %s\n",
+ (((readw(ioaddr + RTC_RTCIENR)) & RTC_ALM_BIT) !=
+ 0) ? "yes" : "no");
+ p += sprintf(p, "update_IRQ\t: %s\n",
+ (((readw(ioaddr + RTC_RTCIENR)) & RTC_1HZ_BIT) !=
+ 0) ? "yes" : "no");
+ p += sprintf(p, "periodic_IRQ\t: %s\n",
+ (((readw(ioaddr + RTC_RTCIENR)) & PIT_ALL_ON) !=
+ 0) ? "yes" : "no");
+ p += sprintf(p, "periodic_freq\t: %d\n", rtc_freq);
+
+ return p - (sq->buf);
+}
+
+/*!
+ * The RTC driver structure
+ */
+static struct rtc_class_ops mxc_rtc_ops = {
+ .open = mxc_rtc_open,
+ .release = mxc_rtc_release,
+ .ioctl = mxc_rtc_ioctl,
+ .read_time = mxc_rtc_read_time,
+ .set_time = mxc_rtc_set_time,
+ .read_alarm = mxc_rtc_read_alarm,
+ .set_alarm = mxc_rtc_set_alarm,
+ .proc = mxc_rtc_proc,
+};
+
+/*! MXC RTC Power management control */
+
+static struct timespec mxc_rtc_delta;
+
+static int mxc_rtc_probe(struct platform_device *pdev)
+{
+ struct clk *clk;
+ struct timespec tv;
+ struct resource *res;
+ struct rtc_device *rtc;
+ struct rtc_plat_data *pdata = NULL;
+ u32 reg;
+ int ret = 0;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdata->clk = clk_get(&pdev->dev, "rtc_clk");
+ clk_enable(pdata->clk);
+
+ pdata->baseaddr = res->start;
+ pdata->ioaddr = ((void *)(IO_ADDRESS(pdata->baseaddr)));
+ /* Configure and enable the RTC */
+ pdata->irq = platform_get_irq(pdev, 0);
+ if (pdata->irq >= 0) {
+ if (request_irq(pdata->irq, mxc_rtc_interrupt, IRQF_SHARED,
+ pdev->name, pdev) < 0) {
+ dev_warn(&pdev->dev, "interrupt not available.\n");
+ pdata->irq = -1;
+ }
+ }
+ rtc =
+ rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops,
+ THIS_MODULE);
+ if (IS_ERR(rtc)) {
+ ret = PTR_ERR(rtc);
+ if (pdata->irq >= 0)
+ free_irq(pdata->irq, pdev);
+ kfree(pdata);
+ return ret;
+ }
+ pdata->rtc = rtc;
+ platform_set_drvdata(pdev, pdata);
+ tv.tv_nsec = 0;
+ tv.tv_sec = get_alarm_or_time(&pdev->dev, MXC_RTC_TIME);
+ clk = clk_get(NULL, "ckil");
+ if (clk_get_rate(clk) == 32768)
+ reg = RTC_INPUT_CLK_32768HZ;
+ else if (clk_get_rate(clk) == 32000)
+ reg = RTC_INPUT_CLK_32000HZ;
+ else if (clk_get_rate(clk) == 38400)
+ reg = RTC_INPUT_CLK_38400HZ;
+ else {
+ printk(KERN_ALERT "rtc clock is not valid");
+ return -EINVAL;
+ }
+ clk_put(clk);
+ reg |= RTC_ENABLE_BIT;
+ writew(reg, (pdata->ioaddr + RTC_RTCCTL));
+ if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
+ printk(KERN_ALERT "rtc : hardware module can't be enabled!\n");
+ return -EPERM;
+ }
+ printk("Real TIme clock Driver v%s \n", RTC_VERSION);
+ 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);
+ mxc_rtc_release(NULL);
+ return 0;
+}
+
+/*!
+ * This function is called to save the system time delta relative to
+ * the MXC RTC when enterring a low power state. This time delta is
+ * then used on resume to adjust the system time to account for time
+ * loss while suspended.
+ *
+ * @param pdev not used
+ * @param state Power state to enter.
+ *
+ * @return The function always returns 0.
+ */
+static int mxc_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct timespec tv;
+
+ /* calculate time delta for suspend */
+ /* RTC precision is 1 second; adjust delta for avg 1/2 sec err */
+ tv.tv_nsec = NSEC_PER_SEC >> 1;
+ tv.tv_sec = get_alarm_or_time(&pdev->dev, MXC_RTC_TIME);
+ set_normalized_timespec(&mxc_rtc_delta,
+ xtime.tv_sec - tv.tv_sec,
+ xtime.tv_nsec - tv.tv_nsec);
+
+ return 0;
+}
+
+/*!
+ * This function is called to correct the system time based on the
+ * current MXC RTC time relative to the time delta saved during
+ * suspend.
+ *
+ * @param pdev not used
+ *
+ * @return The function always returns 0.
+ */
+static int mxc_rtc_resume(struct platform_device *pdev)
+{
+ struct timespec tv;
+ struct timespec ts;
+
+ tv.tv_nsec = 0;
+ tv.tv_sec = get_alarm_or_time(&pdev->dev, MXC_RTC_TIME);
+
+ /* restore wall clock using delta against this RTC;
+ * adjust again for avg 1/2 second RTC sampling error
+ */
+ set_normalized_timespec(&ts,
+ tv.tv_sec + mxc_rtc_delta.tv_sec,
+ (NSEC_PER_SEC >> 1) + mxc_rtc_delta.tv_nsec);
+ do_settimeofday(&ts);
+
+ return 0;
+}
+
+/*!
+ * Contains pointers to the power management callback functions.
+ */
+static struct platform_driver mxc_rtc_driver = {
+ .driver = {
+ .name = "mxc_rtc",
+ },
+ .probe = mxc_rtc_probe,
+ .remove = __exit_p(mxc_rtc_remove),
+ .suspend = mxc_rtc_suspend,
+ .resume = mxc_rtc_resume,
+};
+
+/*!
+ * This function creates the /proc/driver/rtc file and registers the device RTC
+ * in the /dev/misc directory. It also reads the RTC value from external source
+ * and setup the internal RTC properly.
+ *
+ * @return -1 if RTC is failed to initialize; 0 is successful.
+ */
+static int __init mxc_rtc_init(void)
+{
+ return platform_driver_register(&mxc_rtc_driver);
+}
+
+/*!
+ * This function removes the /proc/driver/rtc file and un-registers the
+ * device RTC from the /dev/misc directory.
+ */
+static void __exit mxc_rtc_exit(void)
+{
+ platform_driver_unregister(&mxc_rtc_driver);
+
+}
+
+device_initcall_sync(mxc_rtc_init);
+module_exit(mxc_rtc_exit);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("Realtime Clock Driver (RTC)");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-04 23:51:20 +0000