/* * rtc-tps80031.c -- TI TPS80031/TPS80032 RTC driver * * RTC driver for TI TPS80031/TPS80032 Fully Integrated * Power Management with Power Path and Battery Charger * * Copyright (c) 2012, NVIDIA Corporation. * * Author: Laxman Dewangan <ldewangan@nvidia.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation version 2. * * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind, * whether express or implied; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA * 02111-1307, USA */ #include <linux/bcd.h> #include <linux/device.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/mfd/tps80031.h> #include <linux/platform_device.h> #include <linux/pm.h> #include <linux/rtc.h> #include <linux/slab.h> #define ENABLE_ALARM_INT 0x08 #define ALARM_INT_STATUS 0x40 /** * Setting bit to 1 in STOP_RTC will run the RTC and * setting this bit to 0 will freeze RTC. */ #define STOP_RTC 0x1 /* Power on reset Values of RTC registers */ #define TPS80031_RTC_POR_YEAR 0 #define TPS80031_RTC_POR_MONTH 1 #define TPS80031_RTC_POR_DAY 1 /* Numbers of registers for time and alarms */ #define TPS80031_RTC_TIME_NUM_REGS 7 #define TPS80031_RTC_ALARM_NUM_REGS 6 /** * PMU RTC have only 2 nibbles to store year information, so using an * offset of 100 to set the base year as 2000 for our driver. */ #define RTC_YEAR_OFFSET 100 struct tps80031_rtc { struct rtc_device *rtc; int irq; }; static int tps80031_rtc_read_time(struct device *dev, struct rtc_time *tm) { u8 buff[TPS80031_RTC_TIME_NUM_REGS]; int ret; ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1, TPS80031_SECONDS_REG, TPS80031_RTC_TIME_NUM_REGS, buff); if (ret < 0) { dev_err(dev, "reading RTC_SECONDS_REG failed, err = %d\n", ret); return ret; } tm->tm_sec = bcd2bin(buff[0]); tm->tm_min = bcd2bin(buff[1]); tm->tm_hour = bcd2bin(buff[2]); tm->tm_mday = bcd2bin(buff[3]); tm->tm_mon = bcd2bin(buff[4]) - 1; tm->tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET; tm->tm_wday = bcd2bin(buff[6]); return 0; } static int tps80031_rtc_set_time(struct device *dev, struct rtc_time *tm) { u8 buff[7]; int ret; buff[0] = bin2bcd(tm->tm_sec); buff[1] = bin2bcd(tm->tm_min); buff[2] = bin2bcd(tm->tm_hour); buff[3] = bin2bcd(tm->tm_mday); buff[4] = bin2bcd(tm->tm_mon + 1); buff[5] = bin2bcd(tm->tm_year % RTC_YEAR_OFFSET); buff[6] = bin2bcd(tm->tm_wday); /* Stop RTC while updating the RTC time registers */ ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1, TPS80031_RTC_CTRL_REG, STOP_RTC); if (ret < 0) { dev_err(dev->parent, "Stop RTC failed, err = %d\n", ret); return ret; } ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1, TPS80031_SECONDS_REG, TPS80031_RTC_TIME_NUM_REGS, buff); if (ret < 0) { dev_err(dev, "writing RTC_SECONDS_REG failed, err %d\n", ret); return ret; } ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1, TPS80031_RTC_CTRL_REG, STOP_RTC); if (ret < 0) dev_err(dev->parent, "Start RTC failed, err = %d\n", ret); return ret; } static int tps80031_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) { int ret; if (enable) ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1, TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT); else ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1, TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT); if (ret < 0) { dev_err(dev, "Update on RTC_INT failed, err = %d\n", ret); return ret; } return 0; } static int tps80031_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { u8 buff[TPS80031_RTC_ALARM_NUM_REGS]; int ret; buff[0] = bin2bcd(alrm->time.tm_sec); buff[1] = bin2bcd(alrm->time.tm_min); buff[2] = bin2bcd(alrm->time.tm_hour); buff[3] = bin2bcd(alrm->time.tm_mday); buff[4] = bin2bcd(alrm->time.tm_mon + 1); buff[5] = bin2bcd(alrm->time.tm_year % RTC_YEAR_OFFSET); ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1, TPS80031_ALARM_SECONDS_REG, TPS80031_RTC_ALARM_NUM_REGS, buff); if (ret < 0) { dev_err(dev, "Writing RTC_ALARM failed, err %d\n", ret); return ret; } return tps80031_rtc_alarm_irq_enable(dev, alrm->enabled); } static int tps80031_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { u8 buff[6]; int ret; ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1, TPS80031_ALARM_SECONDS_REG, TPS80031_RTC_ALARM_NUM_REGS, buff); if (ret < 0) { dev_err(dev->parent, "reading RTC_ALARM failed, err = %d\n", ret); return ret; } alrm->time.tm_sec = bcd2bin(buff[0]); alrm->time.tm_min = bcd2bin(buff[1]); alrm->time.tm_hour = bcd2bin(buff[2]); alrm->time.tm_mday = bcd2bin(buff[3]); alrm->time.tm_mon = bcd2bin(buff[4]) - 1; alrm->time.tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET; return 0; } static int clear_alarm_int_status(struct device *dev, struct tps80031_rtc *rtc) { int ret; u8 buf; /** * As per datasheet, A dummy read of this RTC_STATUS_REG register * is necessary before each I2C read in order to update the status * register value. */ ret = tps80031_read(dev->parent, TPS80031_SLAVE_ID1, TPS80031_RTC_STATUS_REG, &buf); if (ret < 0) { dev_err(dev, "reading RTC_STATUS failed. err = %d\n", ret); return ret; } /* clear Alarm status bits.*/ ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1, TPS80031_RTC_STATUS_REG, ALARM_INT_STATUS); if (ret < 0) { dev_err(dev, "clear Alarm INT failed, err = %d\n", ret); return ret; } return 0; } static irqreturn_t tps80031_rtc_irq(int irq, void *data) { struct device *dev = data; struct tps80031_rtc *rtc = dev_get_drvdata(dev); int ret; ret = clear_alarm_int_status(dev, rtc); if (ret < 0) return ret; rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); return IRQ_HANDLED; } static const struct rtc_class_ops tps80031_rtc_ops = { .read_time = tps80031_rtc_read_time, .set_time = tps80031_rtc_set_time, .set_alarm = tps80031_rtc_set_alarm, .read_alarm = tps80031_rtc_read_alarm, .alarm_irq_enable = tps80031_rtc_alarm_irq_enable, }; static int tps80031_rtc_probe(struct platform_device *pdev) { struct tps80031_rtc *rtc; struct rtc_time tm; int ret; rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) return -ENOMEM; rtc->irq = platform_get_irq(pdev, 0); platform_set_drvdata(pdev, rtc); /* Start RTC */ ret = tps80031_set_bits(pdev->dev.parent, TPS80031_SLAVE_ID1, TPS80031_RTC_CTRL_REG, STOP_RTC); if (ret < 0) { dev_err(&pdev->dev, "failed to start RTC. err = %d\n", ret); return ret; } /* If RTC have POR values, set time 01:01:2000 */ tps80031_rtc_read_time(&pdev->dev, &tm); if ((tm.tm_year == RTC_YEAR_OFFSET + TPS80031_RTC_POR_YEAR) && (tm.tm_mon == (TPS80031_RTC_POR_MONTH - 1)) && (tm.tm_mday == TPS80031_RTC_POR_DAY)) { tm.tm_year = 2000; tm.tm_mday = 1; tm.tm_mon = 1; ret = tps80031_rtc_set_time(&pdev->dev, &tm); if (ret < 0) { dev_err(&pdev->dev, "RTC set time failed, err = %d\n", ret); return ret; } } /* Clear alarm intretupt status if it is there */ ret = clear_alarm_int_status(&pdev->dev, rtc); if (ret < 0) { dev_err(&pdev->dev, "Clear alarm int failed, err = %d\n", ret); return ret; } rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &tps80031_rtc_ops, THIS_MODULE); if (IS_ERR(rtc->rtc)) { ret = PTR_ERR(rtc->rtc); dev_err(&pdev->dev, "RTC registration failed, err %d\n", ret); return ret; } ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, tps80031_rtc_irq, IRQF_ONESHOT, dev_name(&pdev->dev), rtc); if (ret < 0) { dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n", rtc->irq, ret); return ret; } device_set_wakeup_capable(&pdev->dev, 1); return 0; } #ifdef CONFIG_PM_SLEEP static int tps80031_rtc_suspend(struct device *dev) { struct tps80031_rtc *rtc = dev_get_drvdata(dev); if (device_may_wakeup(dev)) enable_irq_wake(rtc->irq); return 0; } static int tps80031_rtc_resume(struct device *dev) { struct tps80031_rtc *rtc = dev_get_drvdata(dev); if (device_may_wakeup(dev)) disable_irq_wake(rtc->irq); return 0; }; #endif static SIMPLE_DEV_PM_OPS(tps80031_pm_ops, tps80031_rtc_suspend, tps80031_rtc_resume); static struct platform_driver tps80031_rtc_driver = { .driver = { .name = "tps80031-rtc", .pm = &tps80031_pm_ops, }, .probe = tps80031_rtc_probe, }; module_platform_driver(tps80031_rtc_driver); MODULE_ALIAS("platform:tps80031-rtc"); MODULE_DESCRIPTION("TI TPS80031/TPS80032 RTC driver"); MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); MODULE_LICENSE("GPL v2");