/* 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>");