diff options
Diffstat (limited to 'drivers/rtc/rtc-pm8xxx.c')
| -rw-r--r-- | drivers/rtc/rtc-pm8xxx.c | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c new file mode 100644 index 000000000..3417eef0a --- /dev/null +++ b/drivers/rtc/rtc-pm8xxx.c @@ -0,0 +1,550 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + */ +#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. + * @regs: rtc registers description. + * @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; + + secs = rtc_tm_to_time64(tm); + + 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_time64_to_tm(secs, tm); + + dev_dbg(dev, "secs = %lu, h:m:s == %ptRt, y-m-d = %ptRdr\n", secs, tm, tm); + + 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 long secs, irq_flags; + struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); + const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; + + secs = rtc_tm_to_time64(&alarm->time); + + for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) { + value[i] = secs & 0xFF; + secs >>= 8; + } + + rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, + regs->alarm_en, 0); + if (rc) + return rc; + + 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; + } + + if (alarm->enabled) { + rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, + regs->alarm_en, regs->alarm_en); + if (rc) + goto rtc_rw_fail; + } + + dev_dbg(dev, "Alarm Set for h:m:s=%ptRt, y-m-d=%ptRdr\n", + &alarm->time, &alarm->time); +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_time64_to_tm(secs, &alarm->time); + + dev_dbg(dev, "Alarm set for - h:m:s=%ptRt, y-m-d=%ptRdr\n", + &alarm->time, &alarm->time); + + 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; + u8 value[NUM_8_BIT_RTC_REGS] = {0}; + + 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; + } + + /* Clear Alarm register */ + if (!enable) { + rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value, + sizeof(value)); + if (rc) { + dev_err(dev, "Clear RTC ALARM 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) + 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_allocate_device(&pdev->dev); + if (IS_ERR(rtc_dd->rtc)) + return PTR_ERR(rtc_dd->rtc); + + rtc_dd->rtc->ops = &pm8xxx_rtc_ops; + rtc_dd->rtc->range_max = U32_MAX; + + /* 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; + } + + return rtc_register_device(rtc_dd->rtc); +} + +#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>"); |