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-rw-r--r--drivers/rtc/rtc-mxc.c405
1 files changed, 405 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
new file mode 100644
index 000000000..762cf0334
--- /dev/null
+++ b/drivers/rtc/rtc-mxc.c
@@ -0,0 +1,405 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
+
+#include <linux/io.h>
+#include <linux/rtc.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/of_device.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
+
+#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 */
+
+enum imx_rtc_type {
+ IMX1_RTC,
+ IMX21_RTC,
+};
+
+struct rtc_plat_data {
+ struct rtc_device *rtc;
+ void __iomem *ioaddr;
+ int irq;
+ struct clk *clk_ref;
+ struct clk *clk_ipg;
+ struct rtc_time g_rtc_alarm;
+ enum imx_rtc_type devtype;
+};
+
+static const struct of_device_id imx_rtc_dt_ids[] = {
+ { .compatible = "fsl,imx1-rtc", .data = (const void *)IMX1_RTC },
+ { .compatible = "fsl,imx21-rtc", .data = (const void *)IMX21_RTC },
+ {}
+};
+MODULE_DEVICE_TABLE(of, imx_rtc_dt_ids);
+
+static inline int is_imx1_rtc(struct rtc_plat_data *data)
+{
+ return data->devtype == IMX1_RTC;
+}
+
+/*
+ * This function is used to obtain the RTC time or the alarm value in
+ * second.
+ */
+static time64_t get_alarm_or_time(struct device *dev, int time_alarm)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ 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 ((((time64_t)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, time64_t time)
+{
+ u32 tod, day, hr, min, sec, temp;
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ day = div_s64_rem(time, 86400, &tod);
+
+ /* time is within a day now */
+ hr = tod / 3600;
+ tod -= hr * 3600;
+
+ /* time is within an hour now */
+ min = tod / 60;
+ sec = tod - 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 void rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
+{
+ time64_t time;
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ time = rtc_tm_to_time64(alrm);
+
+ /* clear all the interrupt status bits */
+ writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
+ set_alarm_or_time(dev, MXC_RTC_ALARM, time);
+}
+
+static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
+ unsigned int enabled)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ u32 reg;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
+ reg = readw(ioaddr + RTC_RTCIENR);
+
+ if (enabled)
+ reg |= bit;
+ else
+ reg &= ~bit;
+
+ writew(reg, ioaddr + RTC_RTCIENR);
+ spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
+}
+
+/* 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(&pdata->rtc->irq_lock);
+ status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
+ /* clear interrupt sources */
+ writew(status, ioaddr + RTC_RTCISR);
+
+ /* update irq data & counter */
+ if (status & RTC_ALM_BIT) {
+ events |= (RTC_AF | RTC_IRQF);
+ /* RTC alarm should be one-shot */
+ mxc_rtc_irq_enable(&pdev->dev, RTC_ALM_BIT, 0);
+ }
+
+ if (status & PIT_ALL_ON)
+ events |= (RTC_PF | RTC_IRQF);
+
+ rtc_update_irq(pdata->rtc, 1, events);
+ spin_unlock(&pdata->rtc->irq_lock);
+
+ return IRQ_HANDLED;
+}
+
+static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ mxc_rtc_irq_enable(dev, RTC_ALM_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)
+{
+ time64_t 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_time64_to_tm(val, tm);
+
+ return 0;
+}
+
+/*
+ * This function sets the internal RTC time based on tm in Gregorian date.
+ */
+static int mxc_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ time64_t time = rtc_tm_to_time64(tm);
+
+ /* 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 rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ rtc_time64_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 rtc_plat_data *pdata = dev_get_drvdata(dev);
+
+ rtc_update_alarm(dev, &alrm->time);
+
+ 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 const struct rtc_class_ops mxc_rtc_ops = {
+ .read_time = mxc_rtc_read_time,
+ .set_time = mxc_rtc_set_time,
+ .read_alarm = mxc_rtc_read_alarm,
+ .set_alarm = mxc_rtc_set_alarm,
+ .alarm_irq_enable = mxc_rtc_alarm_irq_enable,
+};
+
+static int mxc_rtc_probe(struct platform_device *pdev)
+{
+ struct rtc_device *rtc;
+ struct rtc_plat_data *pdata = NULL;
+ u32 reg;
+ unsigned long rate;
+ int ret;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdata->devtype = (uintptr_t)of_device_get_match_data(&pdev->dev);
+
+ pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(pdata->ioaddr))
+ return PTR_ERR(pdata->ioaddr);
+
+ rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ pdata->rtc = rtc;
+ rtc->ops = &mxc_rtc_ops;
+ if (is_imx1_rtc(pdata)) {
+ struct rtc_time tm;
+
+ /* 9bit days + hours minutes seconds */
+ rtc->range_max = (1 << 9) * 86400 - 1;
+
+ /*
+ * Set the start date as beginning of the current year. This can
+ * be overridden using device tree.
+ */
+ rtc_time64_to_tm(ktime_get_real_seconds(), &tm);
+ rtc->start_secs = mktime64(tm.tm_year, 1, 1, 0, 0, 0);
+ rtc->set_start_time = true;
+ } else {
+ /* 16bit days + hours minutes seconds */
+ rtc->range_max = (1 << 16) * 86400ULL - 1;
+ }
+
+ pdata->clk_ipg = devm_clk_get_enabled(&pdev->dev, "ipg");
+ if (IS_ERR(pdata->clk_ipg)) {
+ dev_err(&pdev->dev, "unable to get ipg clock!\n");
+ return PTR_ERR(pdata->clk_ipg);
+ }
+
+ pdata->clk_ref = devm_clk_get_enabled(&pdev->dev, "ref");
+ if (IS_ERR(pdata->clk_ref)) {
+ dev_err(&pdev->dev, "unable to get ref clock!\n");
+ return PTR_ERR(pdata->clk_ref);
+ }
+
+ rate = clk_get_rate(pdata->clk_ref);
+
+ 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", rate);
+ return -EINVAL;
+ }
+
+ 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");
+ return -EIO;
+ }
+
+ platform_set_drvdata(pdev, pdata);
+
+ /* Configure and enable the RTC */
+ pdata->irq = platform_get_irq(pdev, 0);
+
+ if (pdata->irq >= 0 &&
+ devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt,
+ IRQF_SHARED, pdev->name, pdev) < 0) {
+ dev_warn(&pdev->dev, "interrupt not available.\n");
+ pdata->irq = -1;
+ }
+
+ if (pdata->irq >= 0) {
+ device_init_wakeup(&pdev->dev, 1);
+ ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
+ if (ret)
+ dev_err(&pdev->dev, "failed to enable irq wake\n");
+ }
+
+ ret = devm_rtc_register_device(rtc);
+
+ return ret;
+}
+
+static struct platform_driver mxc_rtc_driver = {
+ .driver = {
+ .name = "mxc_rtc",
+ .of_match_table = imx_rtc_dt_ids,
+ },
+ .probe = mxc_rtc_probe,
+};
+
+module_platform_driver(mxc_rtc_driver)
+
+MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
+MODULE_DESCRIPTION("RTC driver for Freescale MXC");
+MODULE_LICENSE("GPL");
+