--- /dev/null
+/* 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, ®);
+ 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>");
Code Review / kvmfornfv.git / blobdiff