| /* |
| * drivers/rtc/rtc_tps6591x.c |
| * |
| * RTC driver for TI TPS6591x |
| * |
| * Copyright (c) 2011-2012, NVIDIA Corporation. |
| * |
| * 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; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * 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. |
| * |
| * 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., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| */ |
| |
| /* #define DEBUG 1 */ |
| /* #define VERBOSE_DEBUG 1 */ |
| |
| #include <linux/device.h> |
| #include <linux/err.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/mfd/tps6591x.h> |
| #include <linux/platform_device.h> |
| #include <linux/rtc.h> |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| |
| #define RTC_CTRL 0x10 |
| #define RTC_STATUS 0x11 |
| #define RTC_SECONDS_REG 0x0 |
| #define RTC_ALARM 0x8 |
| #define RTC_INT 0x12 |
| #define RTC_RESET_STATUS 0x16 |
| #define RTC_BBCH_REG 0x39 |
| |
| #define RTC_BBCH_SEL 0x02 |
| #define RTC_BBCH_EN 0x01 |
| #define ENABLE_ALARM_INT 0x8 |
| #define RTC_RESET_VALUE 0x80 |
| #define ALARM_INT_STATUS 0x40 |
| |
| /* |
| Linux RTC driver refers 1900 as base year in many calculations. |
| (e.g. refer drivers/rtc/rtc-lib.c) |
| */ |
| #define OS_REF_YEAR 1900 |
| |
| /* |
| 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 tps6591x_rtc { |
| unsigned long epoch_start; |
| int irq; |
| struct rtc_device *rtc; |
| bool irq_en; |
| }; |
| |
| static int tps6591x_read_regs(struct device *dev, int reg, int len, |
| uint8_t *val) |
| { |
| int ret; |
| |
| /* dummy read of STATUS_REG as per data sheet */ |
| ret = tps6591x_reads(dev->parent, RTC_STATUS, 1, val); |
| if (ret < 0) { |
| dev_err(dev->parent, "\n %s failed reading from RTC_STATUS\n", |
| __func__); |
| WARN_ON(1); |
| return ret; |
| } |
| |
| ret = tps6591x_reads(dev->parent, reg, len, val); |
| if (ret < 0) { |
| dev_err(dev->parent, "\n %s failed reading from 0x%02x\n", |
| __func__, reg); |
| WARN_ON(1); |
| return ret; |
| } |
| return 0; |
| } |
| |
| static int tps6591x_write_regs(struct device *dev, int reg, int len, |
| uint8_t *val) |
| { |
| int ret; |
| ret = tps6591x_writes(dev->parent, reg, len, val); |
| if (ret < 0) { |
| dev_err(dev->parent, "\n %s failed writing\n", __func__); |
| WARN_ON(1); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int tps6591x_rtc_valid_tm(struct rtc_time *tm) |
| { |
| if (tm->tm_year >= (RTC_YEAR_OFFSET + 99) |
| || tm->tm_year < (RTC_YEAR_OFFSET) |
| || tm->tm_mon >= 12 |
| || tm->tm_mday < 1 |
| || tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + OS_REF_YEAR) |
| || tm->tm_hour >= 24 |
| || tm->tm_min >= 60 |
| || tm->tm_sec >= 60) |
| return -EINVAL; |
| return 0; |
| } |
| |
| static u8 dec2bcd(u8 dec) |
| { |
| return ((dec/10)<<4)+(dec%10); |
| } |
| |
| static u8 bcd2dec(u8 bcd) |
| { |
| return (bcd >> 4)*10+(bcd & 0xF); |
| } |
| |
| static void convert_bcd_to_decimal(u8 *buf, u8 len) |
| { |
| int i = 0; |
| for (i = 0; i < len; i++) |
| buf[i] = bcd2dec(buf[i]); |
| } |
| |
| static void convert_decimal_to_bcd(u8 *buf, u8 len) |
| { |
| int i = 0; |
| for (i = 0; i < len; i++) |
| buf[i] = dec2bcd(buf[i]); |
| } |
| |
| static void print_time(struct device *dev, struct rtc_time *tm) |
| { |
| dev_info(dev, "RTC Time : %d/%d/%d %d:%d:%d\n", |
| (tm->tm_mon + 1), tm->tm_mday, (tm->tm_year + OS_REF_YEAR), |
| tm->tm_hour, tm->tm_min , tm->tm_sec); |
| } |
| |
| static int tps6591x_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| { |
| u8 buff[7]; |
| int err; |
| err = tps6591x_read_regs(dev, RTC_SECONDS_REG, sizeof(buff), buff); |
| if (err < 0) { |
| dev_err(dev, "\n %s :: failed to read time\n", __FILE__); |
| return err; |
| } |
| convert_bcd_to_decimal(buff, sizeof(buff)); |
| tm->tm_sec = buff[0]; |
| tm->tm_min = buff[1]; |
| tm->tm_hour = buff[2]; |
| tm->tm_mday = buff[3]; |
| tm->tm_mon = buff[4] - 1; |
| tm->tm_year = buff[5] + RTC_YEAR_OFFSET; |
| tm->tm_wday = buff[6]; |
| print_time(dev, tm); |
| return tps6591x_rtc_valid_tm(tm); |
| } |
| |
| static int tps6591x_rtc_stop(struct device *dev) |
| { |
| u8 reg = 0; |
| u8 retries = 0; |
| int err; |
| do { |
| err = tps6591x_read_regs(dev, RTC_CTRL, 1, ®); |
| if (err < 0) { |
| dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n"); |
| return err; |
| } |
| |
| /* clear STOP bit alone */ |
| reg &= ~0x1; |
| |
| err = tps6591x_write_regs(dev, RTC_CTRL, 1, ®); |
| if (err < 0) { |
| dev_err(dev->parent, "\n failed to program RTC_CTRL reg\n"); |
| return err; |
| } |
| |
| err = tps6591x_read_regs(dev, RTC_STATUS, 1, ®); |
| if (err < 0) { |
| dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n"); |
| return err; |
| } |
| /* FixMe: Is allowing up to 5 retries sufficient?? */ |
| if (retries++ == 5) { |
| dev_err(dev->parent, "\n failed to stop RTC\n"); |
| return -EBUSY; |
| } |
| } while (reg & 2); |
| return 0; |
| } |
| |
| static int tps6591x_rtc_start(struct device *dev) |
| { |
| u8 reg = 0; |
| u8 retries = 0; |
| int err; |
| |
| do { |
| err = tps6591x_read_regs(dev, RTC_CTRL, 1, ®); |
| if (err < 0) { |
| dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n"); |
| return err; |
| } |
| |
| /* set STOP bit alone */ |
| reg |= 0x1; |
| |
| err = tps6591x_write_regs(dev, RTC_CTRL, 1, ®); |
| if (err < 0) { |
| dev_err(dev->parent, "\n failed to program RTC_CTRL reg\n"); |
| return err; |
| } |
| |
| err = tps6591x_read_regs(dev, RTC_STATUS, 1, ®); |
| if (err < 0) { |
| dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n"); |
| return err; |
| } |
| /* FixMe: Is allowing up to 5 retries sufficient?? */ |
| if (retries++ == 5) { |
| dev_err(dev->parent, "\n failed to stop RTC\n"); |
| return -EBUSY; |
| } |
| } while (!(reg & 2)); |
| return 0; |
| } |
| |
| |
| static int tps6591x_rtc_set_time(struct device *dev, struct rtc_time *tm) |
| { |
| u8 buff[7]; |
| int err; |
| |
| err = tps6591x_rtc_valid_tm(tm); |
| if (err < 0) { |
| dev_err(dev->parent, "\n Invalid Time\n"); |
| return err; |
| } |
| |
| buff[0] = tm->tm_sec; |
| buff[1] = tm->tm_min; |
| buff[2] = tm->tm_hour; |
| buff[3] = tm->tm_mday; |
| buff[4] = tm->tm_mon + 1; |
| buff[5] = tm->tm_year % RTC_YEAR_OFFSET; |
| buff[6] = tm->tm_wday; |
| |
| print_time(dev, tm); |
| convert_decimal_to_bcd(buff, sizeof(buff)); |
| err = tps6591x_rtc_stop(dev); |
| if (err < 0) { |
| dev_err(dev->parent, "\n failed to clear RTC_ENABLE\n"); |
| return err; |
| } |
| |
| err = tps6591x_write_regs(dev, RTC_SECONDS_REG, sizeof(buff), buff); |
| if (err < 0) { |
| dev_err(dev->parent, "\n failed to program new time\n"); |
| return err; |
| } |
| |
| err = tps6591x_rtc_start(dev); |
| if (err < 0) { |
| dev_err(dev->parent, "\n failed to set RTC_ENABLE\n"); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static int tps6591x_rtc_alarm_irq_enable(struct device *dev, |
| unsigned int enable) |
| { |
| struct tps6591x_rtc *rtc = dev_get_drvdata(dev); |
| u8 reg; |
| int err; |
| |
| if (rtc->irq == -1) |
| return -EIO; |
| |
| if (enable) { |
| if (rtc->irq_en == true) |
| return 0; |
| err = tps6591x_read_regs(dev, RTC_INT, 1, ®); |
| if (err) |
| return err; |
| reg |= 0x8; |
| err = tps6591x_write_regs(dev, RTC_INT, 1, ®); |
| if (err) |
| return err; |
| rtc->irq_en = true; |
| } else { |
| if (rtc->irq_en == false) |
| return 0; |
| err = tps6591x_read_regs(dev, RTC_INT, 1, ®); |
| if (err) |
| return err; |
| reg &= ~0x8; |
| err = tps6591x_write_regs(dev, RTC_INT, 1, ®); |
| if (err) |
| return err; |
| rtc->irq_en = false; |
| } |
| return 0; |
| } |
| |
| static int tps6591x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
| { |
| struct tps6591x_rtc *rtc = dev_get_drvdata(dev); |
| unsigned long seconds; |
| u8 buff[6]; |
| int err; |
| struct rtc_time tm; |
| |
| if (rtc->irq == -1) |
| return -EIO; |
| |
| err = tps6591x_rtc_valid_tm(&alrm->time); |
| if (err < 0) { |
| dev_err(dev->parent, "\n Invalid alarm time\n"); |
| return err; |
| } |
| |
| dev_info(dev->parent, "\n setting alarm to requested time::\n"); |
| print_time(dev->parent, &alrm->time); |
| rtc_tm_to_time(&alrm->time, &seconds); |
| tps6591x_rtc_read_time(dev, &tm); |
| rtc_tm_to_time(&tm, &rtc->epoch_start); |
| |
| if (WARN_ON(alrm->enabled && (seconds < rtc->epoch_start))) { |
| dev_err(dev->parent, "\n can't set alarm to requested time\n"); |
| return -EINVAL; |
| } |
| |
| err = tps6591x_rtc_alarm_irq_enable(dev, alrm->enabled); |
| if(err) { |
| dev_err(dev->parent, "\n can't set alarm irq\n"); |
| return err; |
| } |
| |
| buff[0] = alrm->time.tm_sec; |
| buff[1] = alrm->time.tm_min; |
| buff[2] = alrm->time.tm_hour; |
| buff[3] = alrm->time.tm_mday; |
| buff[4] = alrm->time.tm_mon + 1; |
| buff[5] = alrm->time.tm_year % RTC_YEAR_OFFSET; |
| convert_decimal_to_bcd(buff, sizeof(buff)); |
| err = tps6591x_write_regs(dev, RTC_ALARM, sizeof(buff), buff); |
| if (err) |
| dev_err(dev->parent, "\n unable to program alarm\n"); |
| |
| return err; |
| } |
| |
| static int tps6591x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
| { |
| u8 buff[6]; |
| int err; |
| |
| err = tps6591x_read_regs(dev, RTC_ALARM, sizeof(buff), buff); |
| if (err) |
| return err; |
| convert_bcd_to_decimal(buff, sizeof(buff)); |
| |
| alrm->time.tm_sec = buff[0]; |
| alrm->time.tm_min = buff[1]; |
| alrm->time.tm_hour = buff[2]; |
| alrm->time.tm_mday = buff[3]; |
| alrm->time.tm_mon = buff[4] - 1; |
| alrm->time.tm_year = buff[5] + RTC_YEAR_OFFSET; |
| |
| dev_info(dev->parent, "\n getting alarm time::\n"); |
| print_time(dev, &alrm->time); |
| |
| return 0; |
| } |
| |
| static const struct rtc_class_ops tps6591x_rtc_ops = { |
| .read_time = tps6591x_rtc_read_time, |
| .set_time = tps6591x_rtc_set_time, |
| .set_alarm = tps6591x_rtc_set_alarm, |
| .read_alarm = tps6591x_rtc_read_alarm, |
| .alarm_irq_enable = tps6591x_rtc_alarm_irq_enable, |
| }; |
| |
| static irqreturn_t tps6591x_rtc_irq(int irq, void *data) |
| { |
| struct device *dev = data; |
| struct tps6591x_rtc *rtc = dev_get_drvdata(dev); |
| u8 reg; |
| int err; |
| |
| /* clear Alarm status bits.*/ |
| err = tps6591x_read_regs(dev, RTC_STATUS, 1, ®); |
| if (err) { |
| dev_err(dev->parent, "unable to read RTC_STATUS reg\n"); |
| return -EBUSY; |
| } |
| |
| reg = ALARM_INT_STATUS; |
| err = tps6591x_write_regs(dev, RTC_STATUS, 1, ®); |
| if (err) { |
| dev_err(dev->parent, "unable to program RTC_STATUS reg\n"); |
| return -EBUSY; |
| } |
| |
| rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); |
| return IRQ_HANDLED; |
| } |
| |
| static int tps6591x_rtc_probe(struct platform_device *pdev) |
| { |
| struct tps6591x_rtc_platform_data *pdata = pdev->dev.platform_data; |
| struct tps6591x_rtc *rtc; |
| struct rtc_time tm; |
| int err; |
| u8 reg; |
| |
| rtc = kzalloc(sizeof(*rtc), GFP_KERNEL); |
| |
| if (!rtc) |
| return -ENOMEM; |
| |
| rtc->irq = -1; |
| |
| if (!pdata) { |
| dev_err(&pdev->dev, "no platform_data specified\n"); |
| return -EINVAL; |
| } |
| |
| if (pdata->irq < 0) |
| dev_err(&pdev->dev, "\n no IRQ specified, wakeup is disabled\n"); |
| |
| dev_set_drvdata(&pdev->dev, rtc); |
| device_init_wakeup(&pdev->dev, 1); |
| rtc->rtc = rtc_device_register(pdev->name, &pdev->dev, |
| &tps6591x_rtc_ops, THIS_MODULE); |
| |
| if (IS_ERR(rtc->rtc)) { |
| err = PTR_ERR(rtc->rtc); |
| goto fail; |
| } |
| |
| if ((int)pdev && (int)&pdev->dev) |
| err = tps6591x_read_regs(&pdev->dev, RTC_STATUS, 1, ®); |
| else { |
| dev_err(&pdev->dev, "\n %s Input params incorrect\n", __func__); |
| return -EBUSY; |
| } |
| if (err) { |
| dev_err(&pdev->dev, "\n %s unable to read status\n", __func__); |
| return -EBUSY; |
| } |
| |
| reg = RTC_BBCH_SEL | RTC_BBCH_EN; |
| tps6591x_write_regs(&pdev->dev, RTC_BBCH_REG, 1, ®); |
| if (err) { |
| dev_err(&pdev->dev, "unable to program Charger reg\n"); |
| return -EBUSY; |
| } |
| |
| err = tps6591x_rtc_start(&pdev->dev); |
| if (err) { |
| dev_err(&pdev->dev, "unable to start RTC\n"); |
| return -EBUSY; |
| } |
| |
| tps6591x_rtc_read_time(&pdev->dev, &tm); |
| |
| if (tps6591x_rtc_valid_tm(&tm) < 0) { |
| if (pdata->time.tm_year < 2000 || pdata->time.tm_year >= 2100) { |
| memset(&pdata->time, 0, sizeof(pdata->time)); |
| pdata->time.tm_year = 2000; |
| pdata->time.tm_mday = 1; |
| } |
| pdata->time.tm_year -= OS_REF_YEAR; |
| tps6591x_rtc_set_time(&pdev->dev, &pdata->time); |
| } |
| |
| reg = ALARM_INT_STATUS; |
| err = tps6591x_write_regs(&pdev->dev, RTC_STATUS, 1, ®); |
| if (err) { |
| dev_err(&pdev->dev, "unable to program RTC_STATUS reg\n"); |
| return -EBUSY; |
| } |
| |
| reg = ENABLE_ALARM_INT; |
| tps6591x_write_regs(&pdev->dev, RTC_INT, 1, ®); |
| if (err) { |
| dev_err(&pdev->dev, "unable to program Interrupt Mask reg\n"); |
| return -EBUSY; |
| } |
| |
| if (pdata && (pdata->irq >= 0)) { |
| rtc->irq = pdata->irq; |
| err = request_threaded_irq(pdata->irq, NULL, tps6591x_rtc_irq, |
| IRQF_ONESHOT, "rtc_tps6591x", |
| &pdev->dev); |
| if (err) { |
| dev_err(&pdev->dev, "request IRQ:%d fail\n", rtc->irq); |
| rtc->irq = -1; |
| } else { |
| device_init_wakeup(&pdev->dev, 1); |
| enable_irq_wake(rtc->irq); |
| } |
| } |
| return 0; |
| |
| fail: |
| if (!IS_ERR_OR_NULL(rtc->rtc)) |
| rtc_device_unregister(rtc->rtc); |
| kfree(rtc); |
| return err; |
| } |
| |
| static int tps6591x_rtc_remove(struct platform_device *pdev) |
| { |
| struct tps6591x_rtc *rtc = dev_get_drvdata(&pdev->dev); |
| |
| if (rtc->irq != -1) |
| free_irq(rtc->irq, rtc); |
| rtc_device_unregister(rtc->rtc); |
| kfree(rtc); |
| return 0; |
| } |
| |
| static struct platform_driver tps6591x_rtc_driver = { |
| .driver = { |
| .name = "rtc_tps6591x", |
| .owner = THIS_MODULE, |
| }, |
| .probe = tps6591x_rtc_probe, |
| .remove = tps6591x_rtc_remove, |
| }; |
| |
| static int __init tps6591x_rtc_init(void) |
| { |
| return platform_driver_register(&tps6591x_rtc_driver); |
| } |
| module_init(tps6591x_rtc_init); |
| |
| static void __exit tps6591x_rtc_exit(void) |
| { |
| platform_driver_unregister(&tps6591x_rtc_driver); |
| } |
| module_exit(tps6591x_rtc_exit); |
| |
| MODULE_DESCRIPTION("TI TPS6591x RTC driver"); |
| MODULE_AUTHOR("NVIDIA Corporation"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:rtc_tps6591x"); |