Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 424 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-stmp3xxx.c b/drivers/rtc/rtc-stmp3xxx.c
new file mode 100644
index 000000000..b76318fd5
--- /dev/null
+++ b/drivers/rtc/rtc-stmp3xxx.c
@@ -0,0 +1,424 @@
+/*
+ * Freescale STMP37XX/STMP378X Real Time Clock driver
+ *
+ * Copyright (c) 2007 Sigmatel, Inc.
+ * Peter Hartley, <peter.hartley@sigmatel.com>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ * Copyright 2011 Wolfram Sang, Pengutronix e.K.
+ */
+
+/*
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/stmp_device.h>
+#include <linux/stmp3xxx_rtc_wdt.h>
+
+#define STMP3XXX_RTC_CTRL			0x0
+#define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN		0x00000001
+#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN	0x00000002
+#define STMP3XXX_RTC_CTRL_ALARM_IRQ		0x00000004
+#define STMP3XXX_RTC_CTRL_WATCHDOGEN		0x00000010
+
+#define STMP3XXX_RTC_STAT			0x10
+#define STMP3XXX_RTC_STAT_STALE_SHIFT		16
+#define STMP3XXX_RTC_STAT_RTC_PRESENT		0x80000000
+#define STMP3XXX_RTC_STAT_XTAL32000_PRESENT	0x10000000
+#define STMP3XXX_RTC_STAT_XTAL32768_PRESENT	0x08000000
+
+#define STMP3XXX_RTC_SECONDS			0x30
+
+#define STMP3XXX_RTC_ALARM			0x40
+
+#define STMP3XXX_RTC_WATCHDOG			0x50
+
+#define STMP3XXX_RTC_PERSISTENT0		0x60
+#define STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE		(1 << 0)
+#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN		(1 << 1)
+#define STMP3XXX_RTC_PERSISTENT0_ALARM_EN		(1 << 2)
+#define STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP	(1 << 4)
+#define STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP	(1 << 5)
+#define STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ		(1 << 6)
+#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE		(1 << 7)
+
+#define STMP3XXX_RTC_PERSISTENT1		0x70
+/* missing bitmask in headers */
+#define STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER	0x80000000
+
+struct stmp3xxx_rtc_data {
+	struct rtc_device *rtc;
+	void __iomem *io;
+	int irq_alarm;
+};
+
+#if IS_ENABLED(CONFIG_STMP3XXX_RTC_WATCHDOG)
+/**
+ * stmp3xxx_wdt_set_timeout - configure the watchdog inside the STMP3xxx RTC
+ * @dev: the parent device of the watchdog (= the RTC)
+ * @timeout: the desired value for the timeout register of the watchdog.
+ *           0 disables the watchdog
+ *
+ * The watchdog needs one register and two bits which are in the RTC domain.
+ * To handle the resource conflict, the RTC driver will create another
+ * platform_device for the watchdog driver as a child of the RTC device.
+ * The watchdog driver is passed the below accessor function via platform_data
+ * to configure the watchdog. Locking is not needed because accessing SET/CLR
+ * registers is atomic.
+ */
+
+static void stmp3xxx_wdt_set_timeout(struct device *dev, u32 timeout)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	if (timeout) {
+		writel(timeout, rtc_data->io + STMP3XXX_RTC_WATCHDOG);
+		writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
+		       rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
+		writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
+		       rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_SET);
+	} else {
+		writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
+		       rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+		writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
+		       rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_CLR);
+	}
+}
+
+static struct stmp3xxx_wdt_pdata wdt_pdata = {
+	.wdt_set_timeout = stmp3xxx_wdt_set_timeout,
+};
+
+static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
+{
+	int rc = -1;
+	struct platform_device *wdt_pdev =
+		platform_device_alloc("stmp3xxx_rtc_wdt", rtc_pdev->id);
+
+	if (wdt_pdev) {
+		wdt_pdev->dev.parent = &rtc_pdev->dev;
+		wdt_pdev->dev.platform_data = &wdt_pdata;
+		rc = platform_device_add(wdt_pdev);
+	}
+
+	if (rc)
+		dev_err(&rtc_pdev->dev,
+			"failed to register stmp3xxx_rtc_wdt\n");
+}
+#else
+static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
+{
+}
+#endif /* CONFIG_STMP3XXX_RTC_WATCHDOG */
+
+static int stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
+{
+	int timeout = 5000; /* 3ms according to i.MX28 Ref Manual */
+	/*
+	 * The i.MX28 Applications Processor Reference Manual, Rev. 1, 2010
+	 * states:
+	 * | The order in which registers are updated is
+	 * | Persistent 0, 1, 2, 3, 4, 5, Alarm, Seconds.
+	 * | (This list is in bitfield order, from LSB to MSB, as they would
+	 * | appear in the STALE_REGS and NEW_REGS bitfields of the HW_RTC_STAT
+	 * | register. For example, the Seconds register corresponds to
+	 * | STALE_REGS or NEW_REGS containing 0x80.)
+	 */
+	do {
+		if (!(readl(rtc_data->io + STMP3XXX_RTC_STAT) &
+				(0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)))
+			return 0;
+		udelay(1);
+	} while (--timeout > 0);
+	return (readl(rtc_data->io + STMP3XXX_RTC_STAT) &
+		(0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)) ? -ETIME : 0;
+}
+
+/* Time read/write */
+static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
+{
+	int ret;
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	ret = stmp3xxx_wait_time(rtc_data);
+	if (ret)
+		return ret;
+
+	rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm);
+	return 0;
+}
+
+static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	writel(t, rtc_data->io + STMP3XXX_RTC_SECONDS);
+	return stmp3xxx_wait_time(rtc_data);
+}
+
+/* interrupt(s) handler */
+static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id);
+	u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL);
+
+	if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) {
+		writel(STMP3XXX_RTC_CTRL_ALARM_IRQ,
+			rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+		rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	if (enabled) {
+		writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
+				STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
+			rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
+				STMP_OFFSET_REG_SET);
+		writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
+			rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
+	} else {
+		writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
+				STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
+			rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
+				STMP_OFFSET_REG_CLR);
+		writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
+			rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+	}
+	return 0;
+}
+
+static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time);
+	return 0;
+}
+
+static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	unsigned long t;
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	rtc_tm_to_time(&alm->time, &t);
+	writel(t, rtc_data->io + STMP3XXX_RTC_ALARM);
+
+	stmp3xxx_alarm_irq_enable(dev, alm->enabled);
+
+	return 0;
+}
+
+static const struct rtc_class_ops stmp3xxx_rtc_ops = {
+	.alarm_irq_enable =
+			  stmp3xxx_alarm_irq_enable,
+	.read_time	= stmp3xxx_rtc_gettime,
+	.set_mmss	= stmp3xxx_rtc_set_mmss,
+	.read_alarm	= stmp3xxx_rtc_read_alarm,
+	.set_alarm	= stmp3xxx_rtc_set_alarm,
+};
+
+static int stmp3xxx_rtc_remove(struct platform_device *pdev)
+{
+	struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev);
+
+	if (!rtc_data)
+		return 0;
+
+	writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
+		rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+
+	return 0;
+}
+
+static int stmp3xxx_rtc_probe(struct platform_device *pdev)
+{
+	struct stmp3xxx_rtc_data *rtc_data;
+	struct resource *r;
+	u32 rtc_stat;
+	u32 pers0_set, pers0_clr;
+	u32 crystalfreq = 0;
+	int err;
+
+	rtc_data = devm_kzalloc(&pdev->dev, sizeof(*rtc_data), GFP_KERNEL);
+	if (!rtc_data)
+		return -ENOMEM;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r) {
+		dev_err(&pdev->dev, "failed to get resource\n");
+		return -ENXIO;
+	}
+
+	rtc_data->io = devm_ioremap(&pdev->dev, r->start, resource_size(r));
+	if (!rtc_data->io) {
+		dev_err(&pdev->dev, "ioremap failed\n");
+		return -EIO;
+	}
+
+	rtc_data->irq_alarm = platform_get_irq(pdev, 0);
+
+	rtc_stat = readl(rtc_data->io + STMP3XXX_RTC_STAT);
+	if (!(rtc_stat & STMP3XXX_RTC_STAT_RTC_PRESENT)) {
+		dev_err(&pdev->dev, "no device onboard\n");
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, rtc_data);
+
+	/*
+	 * Resetting the rtc stops the watchdog timer that is potentially
+	 * running. So (assuming it is running on purpose) don't reset if the
+	 * watchdog is enabled.
+	 */
+	if (readl(rtc_data->io + STMP3XXX_RTC_CTRL) &
+	    STMP3XXX_RTC_CTRL_WATCHDOGEN) {
+		dev_info(&pdev->dev,
+			 "Watchdog is running, skip resetting rtc\n");
+	} else {
+		err = stmp_reset_block(rtc_data->io);
+		if (err) {
+			dev_err(&pdev->dev, "stmp_reset_block failed: %d\n",
+				err);
+			return err;
+		}
+	}
+
+	/*
+	 * Obviously the rtc needs a clock input to be able to run.
+	 * This clock can be provided by an external 32k crystal. If that one is
+	 * missing XTAL must not be disabled in suspend which consumes a
+	 * lot of power. Normally the presence and exact frequency (supported
+	 * are 32000 Hz and 32768 Hz) is detectable from fuses, but as reality
+	 * proves these fuses are not blown correctly on all machines, so the
+	 * frequency can be overridden in the device tree.
+	 */
+	if (rtc_stat & STMP3XXX_RTC_STAT_XTAL32000_PRESENT)
+		crystalfreq = 32000;
+	else if (rtc_stat & STMP3XXX_RTC_STAT_XTAL32768_PRESENT)
+		crystalfreq = 32768;
+
+	of_property_read_u32(pdev->dev.of_node, "stmp,crystal-freq",
+			     &crystalfreq);
+
+	switch (crystalfreq) {
+	case 32000:
+		/* keep 32kHz crystal running in low-power mode */
+		pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ |
+			STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
+			STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
+		pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP;
+		break;
+	case 32768:
+		/* keep 32.768kHz crystal running in low-power mode */
+		pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
+			STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
+		pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP |
+			STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ;
+		break;
+	default:
+		dev_warn(&pdev->dev,
+			 "invalid crystal-freq specified in device-tree. Assuming no crystal\n");
+		/* fall-through */
+	case 0:
+		/* keep XTAL on in low-power mode */
+		pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP;
+		pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
+			STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
+	}
+
+	writel(pers0_set, rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
+			STMP_OFFSET_REG_SET);
+
+	writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
+			STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
+			STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE | pers0_clr,
+		rtc_data->io + STMP3XXX_RTC_PERSISTENT0 + STMP_OFFSET_REG_CLR);
+
+	writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN |
+			STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
+		rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
+
+	rtc_data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+				&stmp3xxx_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc_data->rtc))
+		return PTR_ERR(rtc_data->rtc);
+
+	err = devm_request_irq(&pdev->dev, rtc_data->irq_alarm,
+			stmp3xxx_rtc_interrupt, 0, "RTC alarm", &pdev->dev);
+	if (err) {
+		dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
+			rtc_data->irq_alarm);
+		return err;
+	}
+
+	stmp3xxx_wdt_register(pdev);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stmp3xxx_rtc_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int stmp3xxx_rtc_resume(struct device *dev)
+{
+	struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
+
+	stmp_reset_block(rtc_data->io);
+	writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
+			STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
+			STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
+		rtc_data->io + STMP3XXX_RTC_PERSISTENT0 + STMP_OFFSET_REG_CLR);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(stmp3xxx_rtc_pm_ops, stmp3xxx_rtc_suspend,
+			stmp3xxx_rtc_resume);
+
+static const struct of_device_id rtc_dt_ids[] = {
+	{ .compatible = "fsl,stmp3xxx-rtc", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rtc_dt_ids);
+
+static struct platform_driver stmp3xxx_rtcdrv = {
+	.probe		= stmp3xxx_rtc_probe,
+	.remove		= stmp3xxx_rtc_remove,
+	.driver		= {
+		.name	= "stmp3xxx-rtc",
+		.pm	= &stmp3xxx_rtc_pm_ops,
+		.of_match_table = rtc_dt_ids,
+	},
+};
+
+module_platform_driver(stmp3xxx_rtcdrv);
+
+MODULE_DESCRIPTION("STMP3xxx RTC Driver");
+MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com> and "
+		"Wolfram Sang <w.sang@pengutronix.de>");
+MODULE_LICENSE("GPL");