diff options
Diffstat (limited to 'kernel/drivers/rtc/rtc-tps80031.c')
| -rw-r--r-- | kernel/drivers/rtc/rtc-tps80031.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/kernel/drivers/rtc/rtc-tps80031.c b/kernel/drivers/rtc/rtc-tps80031.c new file mode 100644 index 000000000..27e254cde --- /dev/null +++ b/kernel/drivers/rtc/rtc-tps80031.c @@ -0,0 +1,337 @@ +/* + * 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 | IRQF_EARLY_RESUME, + 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"); |