Initial import

1 files changed, 544 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
new file mode 100644
index 000000000..795fcbd02
--- /dev/null
+++ b/drivers/rtc/rtc-pm8xxx.c
@@ -0,0 +1,544 @@
+/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+/* RTC Register offsets from RTC CTRL REG */
+#define PM8XXX_ALARM_CTRL_OFFSET	0x01
+#define PM8XXX_RTC_WRITE_OFFSET		0x02
+#define PM8XXX_RTC_READ_OFFSET		0x06
+#define PM8XXX_ALARM_RW_OFFSET		0x0A
+
+/* RTC_CTRL register bit fields */
+#define PM8xxx_RTC_ENABLE		BIT(7)
+#define PM8xxx_RTC_ALARM_CLEAR		BIT(0)
+
+#define NUM_8_BIT_RTC_REGS		0x4
+
+/**
+ * struct pm8xxx_rtc_regs - describe RTC registers per PMIC versions
+ * @ctrl: base address of control register
+ * @write: base address of write register
+ * @read: base address of read register
+ * @alarm_ctrl: base address of alarm control register
+ * @alarm_ctrl2: base address of alarm control2 register
+ * @alarm_rw: base address of alarm read-write register
+ * @alarm_en: alarm enable mask
+ */
+struct pm8xxx_rtc_regs {
+	unsigned int ctrl;
+	unsigned int write;
+	unsigned int read;
+	unsigned int alarm_ctrl;
+	unsigned int alarm_ctrl2;
+	unsigned int alarm_rw;
+	unsigned int alarm_en;
+};
+
+/**
+ * struct pm8xxx_rtc -  rtc driver internal structure
+ * @rtc:		rtc device for this driver.
+ * @regmap:		regmap used to access RTC registers
+ * @allow_set_time:	indicates whether writing to the RTC is allowed
+ * @rtc_alarm_irq:	rtc alarm irq number.
+ * @ctrl_reg:		rtc control register.
+ * @rtc_dev:		device structure.
+ * @ctrl_reg_lock:	spinlock protecting access to ctrl_reg.
+ */
+struct pm8xxx_rtc {
+	struct rtc_device *rtc;
+	struct regmap *regmap;
+	bool allow_set_time;
+	int rtc_alarm_irq;
+	const struct pm8xxx_rtc_regs *regs;
+	struct device *rtc_dev;
+	spinlock_t ctrl_reg_lock;
+};
+
+/*
+ * Steps to write the RTC registers.
+ * 1. Disable alarm if enabled.
+ * 2. Write 0x00 to LSB.
+ * 3. Write Byte[1], Byte[2], Byte[3] then Byte[0].
+ * 4. Enable alarm if disabled in step 1.
+ */
+static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	int rc, i;
+	unsigned long secs, irq_flags;
+	u8 value[NUM_8_BIT_RTC_REGS], alarm_enabled = 0;
+	unsigned int ctrl_reg;
+	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+
+	if (!rtc_dd->allow_set_time)
+		return -EACCES;
+
+	rtc_tm_to_time(tm, &secs);
+
+	for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) {
+		value[i] = secs & 0xFF;
+		secs >>= 8;
+	}
+
+	dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
+
+	spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+	rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg);
+	if (rc)
+		goto rtc_rw_fail;
+
+	if (ctrl_reg & regs->alarm_en) {
+		alarm_enabled = 1;
+		ctrl_reg &= ~regs->alarm_en;
+		rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
+		if (rc) {
+			dev_err(dev, "Write to RTC control register failed\n");
+			goto rtc_rw_fail;
+		}
+	}
+
+	/* Write 0 to Byte[0] */
+	rc = regmap_write(rtc_dd->regmap, regs->write, 0);
+	if (rc) {
+		dev_err(dev, "Write to RTC write data register failed\n");
+		goto rtc_rw_fail;
+	}
+
+	/* Write Byte[1], Byte[2], Byte[3] */
+	rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1,
+			       &value[1], sizeof(value) - 1);
+	if (rc) {
+		dev_err(dev, "Write to RTC write data register failed\n");
+		goto rtc_rw_fail;
+	}
+
+	/* Write Byte[0] */
+	rc = regmap_write(rtc_dd->regmap, regs->write, value[0]);
+	if (rc) {
+		dev_err(dev, "Write to RTC write data register failed\n");
+		goto rtc_rw_fail;
+	}
+
+	if (alarm_enabled) {
+		ctrl_reg |= regs->alarm_en;
+		rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
+		if (rc) {
+			dev_err(dev, "Write to RTC control register failed\n");
+			goto rtc_rw_fail;
+		}
+	}
+
+rtc_rw_fail:
+	spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+	return rc;
+}
+
+static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	int rc;
+	u8 value[NUM_8_BIT_RTC_REGS];
+	unsigned long secs;
+	unsigned int reg;
+	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+
+	rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, sizeof(value));
+	if (rc) {
+		dev_err(dev, "RTC read data register failed\n");
+		return rc;
+	}
+
+	/*
+	 * Read the LSB again and check if there has been a carry over.
+	 * If there is, redo the read operation.
+	 */
+	rc = regmap_read(rtc_dd->regmap, regs->read, &reg);
+	if (rc < 0) {
+		dev_err(dev, "RTC read data register failed\n");
+		return rc;
+	}
+
+	if (unlikely(reg < value[0])) {
+		rc = regmap_bulk_read(rtc_dd->regmap, regs->read,
+				      value, sizeof(value));
+		if (rc) {
+			dev_err(dev, "RTC read data register failed\n");
+			return rc;
+		}
+	}
+
+	secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24);
+
+	rtc_time_to_tm(secs, tm);
+
+	rc = rtc_valid_tm(tm);
+	if (rc < 0) {
+		dev_err(dev, "Invalid time read from RTC\n");
+		return rc;
+	}
+
+	dev_dbg(dev, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n",
+		secs, tm->tm_hour, tm->tm_min, tm->tm_sec,
+		tm->tm_mday, tm->tm_mon, tm->tm_year);
+
+	return 0;
+}
+
+static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	int rc, i;
+	u8 value[NUM_8_BIT_RTC_REGS];
+	unsigned int ctrl_reg;
+	unsigned long secs, irq_flags;
+	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+
+	rtc_tm_to_time(&alarm->time, &secs);
+
+	for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) {
+		value[i] = secs & 0xFF;
+		secs >>= 8;
+	}
+
+	spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+	rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
+			       sizeof(value));
+	if (rc) {
+		dev_err(dev, "Write to RTC ALARM register failed\n");
+		goto rtc_rw_fail;
+	}
+
+	rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
+	if (rc)
+		goto rtc_rw_fail;
+
+	if (alarm->enabled)
+		ctrl_reg |= regs->alarm_en;
+	else
+		ctrl_reg &= ~regs->alarm_en;
+
+	rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
+	if (rc) {
+		dev_err(dev, "Write to RTC alarm control register failed\n");
+		goto rtc_rw_fail;
+	}
+
+	dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
+		alarm->time.tm_hour, alarm->time.tm_min,
+		alarm->time.tm_sec, alarm->time.tm_mday,
+		alarm->time.tm_mon, alarm->time.tm_year);
+rtc_rw_fail:
+	spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+	return rc;
+}
+
+static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	int rc;
+	u8 value[NUM_8_BIT_RTC_REGS];
+	unsigned long secs;
+	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+
+	rc = regmap_bulk_read(rtc_dd->regmap, regs->alarm_rw, value,
+			      sizeof(value));
+	if (rc) {
+		dev_err(dev, "RTC alarm time read failed\n");
+		return rc;
+	}
+
+	secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24);
+
+	rtc_time_to_tm(secs, &alarm->time);
+
+	rc = rtc_valid_tm(&alarm->time);
+	if (rc < 0) {
+		dev_err(dev, "Invalid alarm time read from RTC\n");
+		return rc;
+	}
+
+	dev_dbg(dev, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
+		alarm->time.tm_hour, alarm->time.tm_min,
+		alarm->time.tm_sec, alarm->time.tm_mday,
+		alarm->time.tm_mon, alarm->time.tm_year);
+
+	return 0;
+}
+
+static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+	int rc;
+	unsigned long irq_flags;
+	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+	unsigned int ctrl_reg;
+
+	spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+	rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
+	if (rc)
+		goto rtc_rw_fail;
+
+	if (enable)
+		ctrl_reg |= regs->alarm_en;
+	else
+		ctrl_reg &= ~regs->alarm_en;
+
+	rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
+	if (rc) {
+		dev_err(dev, "Write to RTC control register failed\n");
+		goto rtc_rw_fail;
+	}
+
+rtc_rw_fail:
+	spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+	return rc;
+}
+
+static const struct rtc_class_ops pm8xxx_rtc_ops = {
+	.read_time	= pm8xxx_rtc_read_time,
+	.set_time	= pm8xxx_rtc_set_time,
+	.set_alarm	= pm8xxx_rtc_set_alarm,
+	.read_alarm	= pm8xxx_rtc_read_alarm,
+	.alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
+{
+	struct pm8xxx_rtc *rtc_dd = dev_id;
+	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+	unsigned int ctrl_reg;
+	int rc;
+	unsigned long irq_flags;
+
+	rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
+
+	spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+	/* Clear the alarm enable bit */
+	rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
+	if (rc) {
+		spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+		goto rtc_alarm_handled;
+	}
+
+	ctrl_reg &= ~regs->alarm_en;
+
+	rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
+	if (rc) {
+		spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+		dev_err(rtc_dd->rtc_dev,
+			"Write to alarm control register failed\n");
+		goto rtc_alarm_handled;
+	}
+
+	spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+	/* Clear RTC alarm register */
+	rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl2, &ctrl_reg);
+	if (rc) {
+		dev_err(rtc_dd->rtc_dev,
+			"RTC Alarm control2 register read failed\n");
+		goto rtc_alarm_handled;
+	}
+
+	ctrl_reg |= PM8xxx_RTC_ALARM_CLEAR;
+	rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl2, ctrl_reg);
+	if (rc)
+		dev_err(rtc_dd->rtc_dev,
+			"Write to RTC Alarm control2 register failed\n");
+
+rtc_alarm_handled:
+	return IRQ_HANDLED;
+}
+
+static int pm8xxx_rtc_enable(struct pm8xxx_rtc *rtc_dd)
+{
+	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+	unsigned int ctrl_reg;
+	int rc;
+
+	/* Check if the RTC is on, else turn it on */
+	rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg);
+	if (rc)
+		return rc;
+
+	if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) {
+		ctrl_reg |= PM8xxx_RTC_ENABLE;
+		rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}
+
+static const struct pm8xxx_rtc_regs pm8921_regs = {
+	.ctrl		= 0x11d,
+	.write		= 0x11f,
+	.read		= 0x123,
+	.alarm_rw	= 0x127,
+	.alarm_ctrl	= 0x11d,
+	.alarm_ctrl2	= 0x11e,
+	.alarm_en	= BIT(1),
+};
+
+static const struct pm8xxx_rtc_regs pm8058_regs = {
+	.ctrl		= 0x1e8,
+	.write		= 0x1ea,
+	.read		= 0x1ee,
+	.alarm_rw	= 0x1f2,
+	.alarm_ctrl	= 0x1e8,
+	.alarm_ctrl2	= 0x1e9,
+	.alarm_en	= BIT(1),
+};
+
+static const struct pm8xxx_rtc_regs pm8941_regs = {
+	.ctrl		= 0x6046,
+	.write		= 0x6040,
+	.read		= 0x6048,
+	.alarm_rw	= 0x6140,
+	.alarm_ctrl	= 0x6146,
+	.alarm_ctrl2	= 0x6148,
+	.alarm_en	= BIT(7),
+};
+
+/*
+ * Hardcoded RTC bases until IORESOURCE_REG mapping is figured out
+ */
+static const struct of_device_id pm8xxx_id_table[] = {
+	{ .compatible = "qcom,pm8921-rtc", .data = &pm8921_regs },
+	{ .compatible = "qcom,pm8058-rtc", .data = &pm8058_regs },
+	{ .compatible = "qcom,pm8941-rtc", .data = &pm8941_regs },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, pm8xxx_id_table);
+
+static int pm8xxx_rtc_probe(struct platform_device *pdev)
+{
+	int rc;
+	struct pm8xxx_rtc *rtc_dd;
+	const struct of_device_id *match;
+
+	match = of_match_node(pm8xxx_id_table, pdev->dev.of_node);
+	if (!match)
+		return -ENXIO;
+
+	rtc_dd = devm_kzalloc(&pdev->dev, sizeof(*rtc_dd), GFP_KERNEL);
+	if (rtc_dd == NULL)
+		return -ENOMEM;
+
+	/* Initialise spinlock to protect RTC control register */
+	spin_lock_init(&rtc_dd->ctrl_reg_lock);
+
+	rtc_dd->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!rtc_dd->regmap) {
+		dev_err(&pdev->dev, "Parent regmap unavailable.\n");
+		return -ENXIO;
+	}
+
+	rtc_dd->rtc_alarm_irq = platform_get_irq(pdev, 0);
+	if (rtc_dd->rtc_alarm_irq < 0) {
+		dev_err(&pdev->dev, "Alarm IRQ resource absent!\n");
+		return -ENXIO;
+	}
+
+	rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node,
+						      "allow-set-time");
+
+	rtc_dd->regs = match->data;
+	rtc_dd->rtc_dev = &pdev->dev;
+
+	rc = pm8xxx_rtc_enable(rtc_dd);
+	if (rc)
+		return rc;
+
+	platform_set_drvdata(pdev, rtc_dd);
+
+	device_init_wakeup(&pdev->dev, 1);
+
+	/* Register the RTC device */
+	rtc_dd->rtc = devm_rtc_device_register(&pdev->dev, "pm8xxx_rtc",
+					       &pm8xxx_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc_dd->rtc)) {
+		dev_err(&pdev->dev, "%s: RTC registration failed (%ld)\n",
+			__func__, PTR_ERR(rtc_dd->rtc));
+		return PTR_ERR(rtc_dd->rtc);
+	}
+
+	/* Request the alarm IRQ */
+	rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->rtc_alarm_irq,
+					  pm8xxx_alarm_trigger,
+					  IRQF_TRIGGER_RISING,
+					  "pm8xxx_rtc_alarm", rtc_dd);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Request IRQ failed (%d)\n", rc);
+		return rc;
+	}
+
+	dev_dbg(&pdev->dev, "Probe success !!\n");
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pm8xxx_rtc_resume(struct device *dev)
+{
+	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(rtc_dd->rtc_alarm_irq);
+
+	return 0;
+}
+
+static int pm8xxx_rtc_suspend(struct device *dev)
+{
+	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(rtc_dd->rtc_alarm_irq);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(pm8xxx_rtc_pm_ops,
+			 pm8xxx_rtc_suspend,
+			 pm8xxx_rtc_resume);
+
+static struct platform_driver pm8xxx_rtc_driver = {
+	.probe		= pm8xxx_rtc_probe,
+	.driver	= {
+		.name		= "rtc-pm8xxx",
+		.pm		= &pm8xxx_rtc_pm_ops,
+		.of_match_table	= pm8xxx_id_table,
+	},
+};
+
+module_platform_driver(pm8xxx_rtc_driver);
+
+MODULE_ALIAS("platform:rtc-pm8xxx");
+MODULE_DESCRIPTION("PMIC8xxx RTC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>");