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");
+