--- /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/module.h>
+#include <linux/init.h>
+#include <linux/rtc.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <linux/mfd/pm8xxx/core.h>
+#include <linux/mfd/pm8xxx/rtc.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_ENABLE BIT(1)
+#define PM8xxx_RTC_ALARM_CLEAR BIT(0)
+
+#define NUM_8_BIT_RTC_REGS 0x4
+
+/**
+ * struct pm8xxx_rtc - rtc driver internal structure
+ * @rtc: rtc device for this driver.
+ * @rtc_alarm_irq: rtc alarm irq number.
+ * @rtc_base: address of rtc control register.
+ * @rtc_read_base: base address of read registers.
+ * @rtc_write_base: base address of write registers.
+ * @alarm_rw_base: base address of alarm registers.
+ * @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;
+ int rtc_alarm_irq;
+ int rtc_base;
+ int rtc_read_base;
+ int rtc_write_base;
+ int alarm_rw_base;
+ u8 ctrl_reg;
+ struct device *rtc_dev;
+ spinlock_t ctrl_reg_lock;
+};
+
+/*
+ * The RTC registers need to be read/written one byte at a time. This is a
+ * hardware limitation.
+ */
+static int pm8xxx_read_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
+ int base, int count)
+{
+ int i, rc;
+ struct device *parent = rtc_dd->rtc_dev->parent;
+
+ for (i = 0; i < count; i++) {
+ rc = pm8xxx_readb(parent, base + i, &rtc_val[i]);
+ if (rc < 0) {
+ dev_err(rtc_dd->rtc_dev, "PMIC read failed\n");
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+static int pm8xxx_write_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
+ int base, int count)
+{
+ int i, rc;
+ struct device *parent = rtc_dd->rtc_dev->parent;
+
+ for (i = 0; i < count; i++) {
+ rc = pm8xxx_writeb(parent, base + i, rtc_val[i]);
+ if (rc < 0) {
+ dev_err(rtc_dd->rtc_dev, "PMIC write failed\n");
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * 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], reg = 0, alarm_enabled = 0, ctrl_reg;
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+ 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);
+ ctrl_reg = rtc_dd->ctrl_reg;
+
+ if (ctrl_reg & PM8xxx_RTC_ALARM_ENABLE) {
+ alarm_enabled = 1;
+ ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
+ 1);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC control register "
+ "failed\n");
+ goto rtc_rw_fail;
+ }
+ rtc_dd->ctrl_reg = ctrl_reg;
+ } else
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+ /* Write 0 to Byte[0] */
+ reg = 0;
+ rc = pm8xxx_write_wrapper(rtc_dd, ®, rtc_dd->rtc_write_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC write data register failed\n");
+ goto rtc_rw_fail;
+ }
+
+ /* Write Byte[1], Byte[2], Byte[3] */
+ rc = pm8xxx_write_wrapper(rtc_dd, value + 1,
+ rtc_dd->rtc_write_base + 1, 3);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC write data register failed\n");
+ goto rtc_rw_fail;
+ }
+
+ /* Write Byte[0] */
+ rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->rtc_write_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC write data register failed\n");
+ goto rtc_rw_fail;
+ }
+
+ if (alarm_enabled) {
+ ctrl_reg |= PM8xxx_RTC_ALARM_ENABLE;
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
+ 1);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC control register "
+ "failed\n");
+ goto rtc_rw_fail;
+ }
+ rtc_dd->ctrl_reg = ctrl_reg;
+ }
+
+rtc_rw_fail:
+ if (alarm_enabled)
+ 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], reg;
+ unsigned long secs;
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+ rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->rtc_read_base,
+ NUM_8_BIT_RTC_REGS);
+ if (rc < 0) {
+ 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 = pm8xxx_read_wrapper(rtc_dd, ®, rtc_dd->rtc_read_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "RTC read data register failed\n");
+ return rc;
+ }
+
+ if (unlikely(reg < value[0])) {
+ rc = pm8xxx_read_wrapper(rtc_dd, value,
+ rtc_dd->rtc_read_base, NUM_8_BIT_RTC_REGS);
+ if (rc < 0) {
+ 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], ctrl_reg;
+ unsigned long secs, irq_flags;
+ struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+
+ 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 = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
+ NUM_8_BIT_RTC_REGS);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC ALARM register failed\n");
+ goto rtc_rw_fail;
+ }
+
+ ctrl_reg = rtc_dd->ctrl_reg;
+ ctrl_reg = alarm->enabled ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
+ (ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
+
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC control register failed\n");
+ goto rtc_rw_fail;
+ }
+
+ rtc_dd->ctrl_reg = ctrl_reg;
+
+ 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);
+
+ rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
+ NUM_8_BIT_RTC_REGS);
+ if (rc < 0) {
+ 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);
+ u8 ctrl_reg;
+
+ spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+ ctrl_reg = rtc_dd->ctrl_reg;
+ ctrl_reg = (enable) ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
+ (ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
+
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
+ if (rc < 0) {
+ dev_err(dev, "Write to RTC control register failed\n");
+ goto rtc_rw_fail;
+ }
+
+ rtc_dd->ctrl_reg = ctrl_reg;
+
+rtc_rw_fail:
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+ return rc;
+}
+
+static struct rtc_class_ops pm8xxx_rtc_ops = {
+ .read_time = pm8xxx_rtc_read_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;
+ u8 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 */
+ ctrl_reg = rtc_dd->ctrl_reg;
+ ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
+
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
+ if (rc < 0) {
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+ dev_err(rtc_dd->rtc_dev, "Write to RTC control register "
+ "failed\n");
+ goto rtc_alarm_handled;
+ }
+
+ rtc_dd->ctrl_reg = ctrl_reg;
+ spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+
+ /* Clear RTC alarm register */
+ rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
+ PM8XXX_ALARM_CTRL_OFFSET, 1);
+ if (rc < 0) {
+ dev_err(rtc_dd->rtc_dev, "RTC Alarm control register read "
+ "failed\n");
+ goto rtc_alarm_handled;
+ }
+
+ ctrl_reg &= ~PM8xxx_RTC_ALARM_CLEAR;
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
+ PM8XXX_ALARM_CTRL_OFFSET, 1);
+ if (rc < 0)
+ dev_err(rtc_dd->rtc_dev, "Write to RTC Alarm control register"
+ " failed\n");
+
+rtc_alarm_handled:
+ return IRQ_HANDLED;
+}
+
+static int __devinit pm8xxx_rtc_probe(struct platform_device *pdev)
+{
+ int rc;
+ u8 ctrl_reg;
+ bool rtc_write_enable = false;
+ struct pm8xxx_rtc *rtc_dd;
+ struct resource *rtc_resource;
+ const struct pm8xxx_rtc_platform_data *pdata =
+ dev_get_platdata(&pdev->dev);
+
+ if (pdata != NULL)
+ rtc_write_enable = pdata->rtc_write_enable;
+
+ rtc_dd = kzalloc(sizeof(*rtc_dd), GFP_KERNEL);
+ if (rtc_dd == NULL) {
+ dev_err(&pdev->dev, "Unable to allocate memory!\n");
+ return -ENOMEM;
+ }
+
+ /* Initialise spinlock to protect RTC control register */
+ spin_lock_init(&rtc_dd->ctrl_reg_lock);
+
+ 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");
+ rc = -ENXIO;
+ goto fail_rtc_enable;
+ }
+
+ rtc_resource = platform_get_resource_byname(pdev, IORESOURCE_IO,
+ "pmic_rtc_base");
+ if (!(rtc_resource && rtc_resource->start)) {
+ dev_err(&pdev->dev, "RTC IO resource absent!\n");
+ rc = -ENXIO;
+ goto fail_rtc_enable;
+ }
+
+ rtc_dd->rtc_base = rtc_resource->start;
+
+ /* Setup RTC register addresses */
+ rtc_dd->rtc_write_base = rtc_dd->rtc_base + PM8XXX_RTC_WRITE_OFFSET;
+ rtc_dd->rtc_read_base = rtc_dd->rtc_base + PM8XXX_RTC_READ_OFFSET;
+ rtc_dd->alarm_rw_base = rtc_dd->rtc_base + PM8XXX_ALARM_RW_OFFSET;
+
+ rtc_dd->rtc_dev = &pdev->dev;
+
+ /* Check if the RTC is on, else turn it on */
+ rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "RTC control register read failed!\n");
+ goto fail_rtc_enable;
+ }
+
+ if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) {
+ ctrl_reg |= PM8xxx_RTC_ENABLE;
+ rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
+ 1);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Write to RTC control register "
+ "failed\n");
+ goto fail_rtc_enable;
+ }
+ }
+
+ rtc_dd->ctrl_reg = ctrl_reg;
+ if (rtc_write_enable == true)
+ pm8xxx_rtc_ops.set_time = pm8xxx_rtc_set_time;
+
+ platform_set_drvdata(pdev, rtc_dd);
+
+ /* Register the RTC device */
+ rtc_dd->rtc = rtc_device_register("pm8xxx_rtc", &pdev->dev,
+ &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));
+ rc = PTR_ERR(rtc_dd->rtc);
+ goto fail_rtc_enable;
+ }
+
+ /* Request the alarm IRQ */
+ rc = request_any_context_irq(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);
+ goto fail_req_irq;
+ }
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ dev_dbg(&pdev->dev, "Probe success !!\n");
+
+ return 0;
+
+fail_req_irq:
+ rtc_device_unregister(rtc_dd->rtc);
+fail_rtc_enable:
+ platform_set_drvdata(pdev, NULL);
+ kfree(rtc_dd);
+ return rc;
+}
+
+static int __devexit pm8xxx_rtc_remove(struct platform_device *pdev)
+{
+ struct pm8xxx_rtc *rtc_dd = platform_get_drvdata(pdev);
+
+ device_init_wakeup(&pdev->dev, 0);
+ free_irq(rtc_dd->rtc_alarm_irq, rtc_dd);
+ rtc_device_unregister(rtc_dd->rtc);
+ platform_set_drvdata(pdev, NULL);
+ kfree(rtc_dd);
+
+ 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
+
+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,
+ .remove = __devexit_p(pm8xxx_rtc_remove),
+ .driver = {
+ .name = PM8XXX_RTC_DEV_NAME,
+ .owner = THIS_MODULE,
+ .pm = &pm8xxx_rtc_pm_ops,
+ },
+};
+
+static int __init pm8xxx_rtc_init(void)
+{
+ return platform_driver_register(&pm8xxx_rtc_driver);
+}
+module_init(pm8xxx_rtc_init);
+
+static void __exit pm8xxx_rtc_exit(void)
+{
+ platform_driver_unregister(&pm8xxx_rtc_driver);
+}
+module_exit(pm8xxx_rtc_exit);
+
+MODULE_ALIAS("platform:rtc-pm8xxx");
+MODULE_DESCRIPTION("PMIC8xxx RTC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>");
projects / ~andy / linux / commitdiff