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- /* 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. Disable rtc if enabled.
- * 3. Write 0x00 to LSB.
- * 4. Write Byte[1], Byte[2], Byte[3] then Byte[0].
- * 5. Enable rtc if disabled in step 2.
- * 6. 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, rtc_disabled = 0;
- unsigned int ctrl_reg, rtc_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);
- dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", 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_read(rtc_dd->regmap, regs->alarm_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->alarm_ctrl, ctrl_reg);
- if (rc) {
- dev_err(dev, "Write to RTC Alarm control register failed\n");
- goto rtc_rw_fail;
- }
- }
- /* Disable RTC H/w before writing on RTC register */
- rc = regmap_read(rtc_dd->regmap, regs->ctrl, &rtc_ctrl_reg);
- if (rc)
- goto rtc_rw_fail;
- if (rtc_ctrl_reg & PM8xxx_RTC_ENABLE) {
- rtc_disabled = 1;
- rtc_ctrl_reg &= ~PM8xxx_RTC_ENABLE;
- rc = regmap_write(rtc_dd->regmap, regs->ctrl, rtc_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;
- }
- /* Enable RTC H/w after writing on RTC register */
- if (rtc_disabled) {
- rtc_ctrl_reg |= PM8xxx_RTC_ENABLE;
- rc = regmap_write(rtc_dd->regmap, regs->ctrl, rtc_ctrl_reg);
- if (rc) {
- dev_err(dev, "Write to RTC control register failed\n");
- goto rtc_rw_fail;
- }
- }
- if (alarm_enabled) {
- 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;
- }
- }
- 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) |
- ((unsigned long)value[3] << 24);
- rtc_time_to_tm(secs, tm);
- 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) |
- ((unsigned long)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,pm8018-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>");
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