// SPDX-License-Identifier: GPL-2.0-or-later /* * rtc-tps65910.c -- TPS65910 Real Time Clock interface * * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. * Author: Venu Byravarasu <vbyravarasu@nvidia.com> * * Based on original TI driver rtc-twl.c * Copyright (C) 2007 MontaVista Software, Inc * Author: Alexandre Rusev <source@mvista.com> */ #include <linux/kernel.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/module.h> #include <linux/types.h> #include <linux/rtc.h> #include <linux/bcd.h> #include <linux/math64.h> #include <linux/platform_device.h> #include <linux/interrupt.h> #include <linux/mfd/tps65910.h> struct tps65910_rtc { struct rtc_device *rtc; int irq; }; /* Total number of RTC registers needed to set time*/ #define NUM_TIME_REGS (TPS65910_YEARS - TPS65910_SECONDS + 1) /* Total number of RTC registers needed to set compensation registers */ #define NUM_COMP_REGS (TPS65910_RTC_COMP_MSB - TPS65910_RTC_COMP_LSB + 1) /* Min and max values supported with 'offset' interface (swapped sign) */ #define MIN_OFFSET (-277761) #define MAX_OFFSET (277778) /* Number of ticks per hour */ #define TICKS_PER_HOUR (32768 * 3600) /* Multiplier for ppb conversions */ #define PPB_MULT (1000000000LL) static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct tps65910 *tps = dev_get_drvdata(dev->parent); u8 val = 0; if (enabled) val = TPS65910_RTC_INTERRUPTS_IT_ALARM; return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val); } /* * Gets current tps65910 RTC time and date parameters. * * The RTC's time/alarm representation is not what gmtime(3) requires * Linux to use: * * - Months are 1..12 vs Linux 0-11 * - Years are 0..99 vs Linux 1900..N (we assume 21st century) */ static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm) { unsigned char rtc_data[NUM_TIME_REGS]; struct tps65910 *tps = dev_get_drvdata(dev->parent); int ret; /* Copy RTC counting registers to static registers or latches */ ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME); if (ret < 0) { dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret); return ret; } ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data, NUM_TIME_REGS); if (ret < 0) { dev_err(dev, "reading from RTC failed with err:%d\n", ret); return ret; } tm->tm_sec = bcd2bin(rtc_data[0]); tm->tm_min = bcd2bin(rtc_data[1]); tm->tm_hour = bcd2bin(rtc_data[2]); tm->tm_mday = bcd2bin(rtc_data[3]); tm->tm_mon = bcd2bin(rtc_data[4]) - 1; tm->tm_year = bcd2bin(rtc_data[5]) + 100; return ret; } static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm) { unsigned char rtc_data[NUM_TIME_REGS]; struct tps65910 *tps = dev_get_drvdata(dev->parent); int ret; rtc_data[0] = bin2bcd(tm->tm_sec); rtc_data[1] = bin2bcd(tm->tm_min); rtc_data[2] = bin2bcd(tm->tm_hour); rtc_data[3] = bin2bcd(tm->tm_mday); rtc_data[4] = bin2bcd(tm->tm_mon + 1); rtc_data[5] = bin2bcd(tm->tm_year - 100); /* Stop RTC while updating the RTC time registers */ ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, TPS65910_RTC_CTRL_STOP_RTC, 0); if (ret < 0) { dev_err(dev, "RTC stop failed with err:%d\n", ret); return ret; } /* update all the time registers in one shot */ ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data, NUM_TIME_REGS); if (ret < 0) { dev_err(dev, "rtc_set_time error %d\n", ret); return ret; } /* Start back RTC */ ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, TPS65910_RTC_CTRL_STOP_RTC, 1); if (ret < 0) dev_err(dev, "RTC start failed with err:%d\n", ret); return ret; } /* * Gets current tps65910 RTC alarm time. */ static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) { unsigned char alarm_data[NUM_TIME_REGS]; u32 int_val; struct tps65910 *tps = dev_get_drvdata(dev->parent); int ret; ret = regmap_bulk_read(tps->regmap, TPS65910_ALARM_SECONDS, alarm_data, NUM_TIME_REGS); if (ret < 0) { dev_err(dev, "rtc_read_alarm error %d\n", ret); return ret; } alm->time.tm_sec = bcd2bin(alarm_data[0]); alm->time.tm_min = bcd2bin(alarm_data[1]); alm->time.tm_hour = bcd2bin(alarm_data[2]); alm->time.tm_mday = bcd2bin(alarm_data[3]); alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1; alm->time.tm_year = bcd2bin(alarm_data[5]) + 100; ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val); if (ret < 0) return ret; if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM) alm->enabled = 1; return ret; } static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) { unsigned char alarm_data[NUM_TIME_REGS]; struct tps65910 *tps = dev_get_drvdata(dev->parent); int ret; ret = tps65910_rtc_alarm_irq_enable(dev, 0); if (ret) return ret; alarm_data[0] = bin2bcd(alm->time.tm_sec); alarm_data[1] = bin2bcd(alm->time.tm_min); alarm_data[2] = bin2bcd(alm->time.tm_hour); alarm_data[3] = bin2bcd(alm->time.tm_mday); alarm_data[4] = bin2bcd(alm->time.tm_mon + 1); alarm_data[5] = bin2bcd(alm->time.tm_year - 100); /* update all the alarm registers in one shot */ ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS, alarm_data, NUM_TIME_REGS); if (ret) { dev_err(dev, "rtc_set_alarm error %d\n", ret); return ret; } if (alm->enabled) ret = tps65910_rtc_alarm_irq_enable(dev, 1); return ret; } static int tps65910_rtc_set_calibration(struct device *dev, int calibration) { unsigned char comp_data[NUM_COMP_REGS]; struct tps65910 *tps = dev_get_drvdata(dev->parent); s16 value; int ret; /* * TPS65910 uses two's complement 16 bit value for compensation for RTC * crystal inaccuracies. One time every hour when seconds counter * increments from 0 to 1 compensation value will be added to internal * RTC counter value. * * Compensation value 0x7FFF is prohibited value. * * Valid range for compensation value: [-32768 .. 32766] */ if ((calibration < -32768) || (calibration > 32766)) { dev_err(dev, "RTC calibration value out of range: %d\n", calibration); return -EINVAL; } value = (s16)calibration; comp_data[0] = (u16)value & 0xFF; comp_data[1] = ((u16)value >> 8) & 0xFF; /* Update all the compensation registers in one shot */ ret = regmap_bulk_write(tps->regmap, TPS65910_RTC_COMP_LSB, comp_data, NUM_COMP_REGS); if (ret < 0) { dev_err(dev, "rtc_set_calibration error: %d\n", ret); return ret; } /* Enable automatic compensation */ ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, TPS65910_RTC_CTRL_AUTO_COMP, TPS65910_RTC_CTRL_AUTO_COMP); if (ret < 0) dev_err(dev, "auto_comp enable failed with error: %d\n", ret); return ret; } static int tps65910_rtc_get_calibration(struct device *dev, int *calibration) { unsigned char comp_data[NUM_COMP_REGS]; struct tps65910 *tps = dev_get_drvdata(dev->parent); unsigned int ctrl; u16 value; int ret; ret = regmap_read(tps->regmap, TPS65910_RTC_CTRL, &ctrl); if (ret < 0) return ret; /* If automatic compensation is not enabled report back zero */ if (!(ctrl & TPS65910_RTC_CTRL_AUTO_COMP)) { *calibration = 0; return 0; } ret = regmap_bulk_read(tps->regmap, TPS65910_RTC_COMP_LSB, comp_data, NUM_COMP_REGS); if (ret < 0) { dev_err(dev, "rtc_get_calibration error: %d\n", ret); return ret; } value = (u16)comp_data[0] | ((u16)comp_data[1] << 8); *calibration = (s16)value; return 0; } static int tps65910_read_offset(struct device *dev, long *offset) { int calibration; s64 tmp; int ret; ret = tps65910_rtc_get_calibration(dev, &calibration); if (ret < 0) return ret; /* Convert from RTC calibration register format to ppb format */ tmp = calibration * (s64)PPB_MULT; if (tmp < 0) tmp -= TICKS_PER_HOUR / 2LL; else tmp += TICKS_PER_HOUR / 2LL; tmp = div_s64(tmp, TICKS_PER_HOUR); /* Offset value operates in negative way, so swap sign */ *offset = (long)-tmp; return 0; } static int tps65910_set_offset(struct device *dev, long offset) { int calibration; s64 tmp; int ret; /* Make sure offset value is within supported range */ if (offset < MIN_OFFSET || offset > MAX_OFFSET) return -ERANGE; /* Convert from ppb format to RTC calibration register format */ tmp = offset * (s64)TICKS_PER_HOUR; if (tmp < 0) tmp -= PPB_MULT / 2LL; else tmp += PPB_MULT / 2LL; tmp = div_s64(tmp, PPB_MULT); /* Offset value operates in negative way, so swap sign */ calibration = (int)-tmp; ret = tps65910_rtc_set_calibration(dev, calibration); return ret; } static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc) { struct device *dev = rtc; unsigned long events = 0; struct tps65910 *tps = dev_get_drvdata(dev->parent); struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); int ret; u32 rtc_reg; ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg); if (ret) return IRQ_NONE; if (rtc_reg & TPS65910_RTC_STATUS_ALARM) events = RTC_IRQF | RTC_AF; ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg); if (ret) return IRQ_NONE; /* Notify RTC core on event */ rtc_update_irq(tps_rtc->rtc, 1, events); return IRQ_HANDLED; } static const struct rtc_class_ops tps65910_rtc_ops = { .read_time = tps65910_rtc_read_time, .set_time = tps65910_rtc_set_time, .read_alarm = tps65910_rtc_read_alarm, .set_alarm = tps65910_rtc_set_alarm, .alarm_irq_enable = tps65910_rtc_alarm_irq_enable, .read_offset = tps65910_read_offset, .set_offset = tps65910_set_offset, }; static const struct rtc_class_ops tps65910_rtc_ops_noirq = { .read_time = tps65910_rtc_read_time, .set_time = tps65910_rtc_set_time, .read_offset = tps65910_read_offset, .set_offset = tps65910_set_offset, }; static int tps65910_rtc_probe(struct platform_device *pdev) { struct tps65910 *tps65910 = NULL; struct tps65910_rtc *tps_rtc = NULL; int ret; int irq; u32 rtc_reg; tps65910 = dev_get_drvdata(pdev->dev.parent); tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc), GFP_KERNEL); if (!tps_rtc) return -ENOMEM; tps_rtc->rtc = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(tps_rtc->rtc)) return PTR_ERR(tps_rtc->rtc); /* Clear pending interrupts */ ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg); if (ret < 0) return ret; ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg); if (ret < 0) return ret; dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n"); /* Enable RTC digital power domain */ ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL, DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT); if (ret < 0) return ret; rtc_reg = TPS65910_RTC_CTRL_STOP_RTC; ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg); if (ret < 0) return ret; platform_set_drvdata(pdev, tps_rtc); irq = platform_get_irq(pdev, 0); if (irq <= 0) { dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n", irq); return -ENXIO; } ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, tps65910_rtc_interrupt, IRQF_TRIGGER_LOW, dev_name(&pdev->dev), &pdev->dev); if (ret < 0) irq = -1; tps_rtc->irq = irq; if (irq != -1) { device_set_wakeup_capable(&pdev->dev, 1); tps_rtc->rtc->ops = &tps65910_rtc_ops; } else tps_rtc->rtc->ops = &tps65910_rtc_ops_noirq; tps_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; tps_rtc->rtc->range_max = RTC_TIMESTAMP_END_2099; return rtc_register_device(tps_rtc->rtc); } #ifdef CONFIG_PM_SLEEP static int tps65910_rtc_suspend(struct device *dev) { struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); if (device_may_wakeup(dev)) enable_irq_wake(tps_rtc->irq); return 0; } static int tps65910_rtc_resume(struct device *dev) { struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); if (device_may_wakeup(dev)) disable_irq_wake(tps_rtc->irq); return 0; } #endif static SIMPLE_DEV_PM_OPS(tps65910_rtc_pm_ops, tps65910_rtc_suspend, tps65910_rtc_resume); static struct platform_driver tps65910_rtc_driver = { .probe = tps65910_rtc_probe, .driver = { .name = "tps65910-rtc", .pm = &tps65910_rtc_pm_ops, }, }; module_platform_driver(tps65910_rtc_driver); MODULE_ALIAS("platform:rtc-tps65910"); MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>"); MODULE_LICENSE("GPL");