diff options
Diffstat (limited to 'drivers/rtc/rtc-rc5t583.c')
| -rw-r--r-- | drivers/rtc/rtc-rc5t583.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rc5t583.c b/drivers/rtc/rtc-rc5t583.c new file mode 100644 index 000000000..68ce77414 --- /dev/null +++ b/drivers/rtc/rtc-rc5t583.c @@ -0,0 +1,322 @@ +/* + * rtc-rc5t583.c -- RICOH RC5T583 Real Time Clock + * + * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. + * Author: Venu Byravarasu <vbyravarasu@nvidia.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>. */ + +#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/platform_device.h> +#include <linux/interrupt.h> +#include <linux/mfd/rc5t583.h> + +struct rc5t583_rtc { + struct rtc_device *rtc; + /* To store the list of enabled interrupts, during system suspend */ + u32 irqen; +}; + +/* Total number of RTC registers needed to set time*/ +#define NUM_TIME_REGS (RC5T583_RTC_YEAR - RC5T583_RTC_SEC + 1) + +/* Total number of RTC registers needed to set Y-Alarm*/ +#define NUM_YAL_REGS (RC5T583_RTC_AY_YEAR - RC5T583_RTC_AY_MIN + 1) + +/* Set Y-Alarm interrupt */ +#define SET_YAL BIT(5) + +/* Get Y-Alarm interrupt status*/ +#define GET_YAL_STATUS BIT(3) + +static int rc5t583_rtc_alarm_irq_enable(struct device *dev, unsigned enabled) +{ + struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent); + u8 val; + + /* Set Y-Alarm, based on 'enabled' */ + val = enabled ? SET_YAL : 0; + + return regmap_update_bits(rc5t583->regmap, RC5T583_RTC_CTL1, SET_YAL, + val); +} + +/* + * Gets current rc5t583 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 rc5t583_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent); + u8 rtc_data[NUM_TIME_REGS]; + int ret; + + ret = regmap_bulk_read(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data, + NUM_TIME_REGS); + if (ret < 0) { + dev_err(dev, "RTC read time 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_wday = bcd2bin(rtc_data[3]); + tm->tm_mday = bcd2bin(rtc_data[4]); + tm->tm_mon = bcd2bin(rtc_data[5]) - 1; + tm->tm_year = bcd2bin(rtc_data[6]) + 100; + + return ret; +} + +static int rc5t583_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent); + unsigned char rtc_data[NUM_TIME_REGS]; + 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_wday); + rtc_data[4] = bin2bcd(tm->tm_mday); + rtc_data[5] = bin2bcd(tm->tm_mon + 1); + rtc_data[6] = bin2bcd(tm->tm_year - 100); + + ret = regmap_bulk_write(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data, + NUM_TIME_REGS); + if (ret < 0) { + dev_err(dev, "RTC set time failed with error %d\n", ret); + return ret; + } + + return ret; +} + +static int rc5t583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent); + unsigned char alarm_data[NUM_YAL_REGS]; + u32 interrupt_enable; + int ret; + + ret = regmap_bulk_read(rc5t583->regmap, RC5T583_RTC_AY_MIN, alarm_data, + NUM_YAL_REGS); + if (ret < 0) { + dev_err(dev, "rtc_read_alarm error %d\n", ret); + return ret; + } + + alm->time.tm_sec = 0; + alm->time.tm_min = bcd2bin(alarm_data[0]); + alm->time.tm_hour = bcd2bin(alarm_data[1]); + alm->time.tm_mday = bcd2bin(alarm_data[2]); + alm->time.tm_mon = bcd2bin(alarm_data[3]) - 1; + alm->time.tm_year = bcd2bin(alarm_data[4]) + 100; + + ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL1, &interrupt_enable); + if (ret < 0) + return ret; + + /* check if YALE is set */ + if (interrupt_enable & SET_YAL) + alm->enabled = 1; + + return ret; +} + +static int rc5t583_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent); + unsigned char alarm_data[NUM_YAL_REGS]; + int ret; + + ret = rc5t583_rtc_alarm_irq_enable(dev, 0); + if (ret) + return ret; + + alarm_data[0] = bin2bcd(alm->time.tm_min); + alarm_data[1] = bin2bcd(alm->time.tm_hour); + alarm_data[2] = bin2bcd(alm->time.tm_mday); + alarm_data[3] = bin2bcd(alm->time.tm_mon + 1); + alarm_data[4] = bin2bcd(alm->time.tm_year - 100); + + ret = regmap_bulk_write(rc5t583->regmap, RC5T583_RTC_AY_MIN, alarm_data, + NUM_YAL_REGS); + if (ret) { + dev_err(dev, "rtc_set_alarm error %d\n", ret); + return ret; + } + + if (alm->enabled) + ret = rc5t583_rtc_alarm_irq_enable(dev, 1); + + return ret; +} + +static irqreturn_t rc5t583_rtc_interrupt(int irq, void *rtc) +{ + struct device *dev = rtc; + struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent); + struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev); + unsigned long events = 0; + int ret; + u32 rtc_reg; + + ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL2, &rtc_reg); + if (ret < 0) + return IRQ_NONE; + + if (rtc_reg & GET_YAL_STATUS) { + events = RTC_IRQF | RTC_AF; + /* clear pending Y-alarm interrupt bit */ + rtc_reg &= ~GET_YAL_STATUS; + } + + ret = regmap_write(rc5t583->regmap, RC5T583_RTC_CTL2, rtc_reg); + if (ret) + return IRQ_NONE; + + /* Notify RTC core on event */ + rtc_update_irq(rc5t583_rtc->rtc, 1, events); + + return IRQ_HANDLED; +} + +static const struct rtc_class_ops rc5t583_rtc_ops = { + .read_time = rc5t583_rtc_read_time, + .set_time = rc5t583_rtc_set_time, + .read_alarm = rc5t583_rtc_read_alarm, + .set_alarm = rc5t583_rtc_set_alarm, + .alarm_irq_enable = rc5t583_rtc_alarm_irq_enable, +}; + +static int rc5t583_rtc_probe(struct platform_device *pdev) +{ + struct rc5t583 *rc5t583 = dev_get_drvdata(pdev->dev.parent); + struct rc5t583_rtc *ricoh_rtc; + struct rc5t583_platform_data *pmic_plat_data; + int ret; + int irq; + + ricoh_rtc = devm_kzalloc(&pdev->dev, sizeof(struct rc5t583_rtc), + GFP_KERNEL); + if (!ricoh_rtc) + return -ENOMEM; + + platform_set_drvdata(pdev, ricoh_rtc); + + /* Clear pending interrupts */ + ret = regmap_write(rc5t583->regmap, RC5T583_RTC_CTL2, 0); + if (ret < 0) + return ret; + + /* clear RTC Adjust register */ + ret = regmap_write(rc5t583->regmap, RC5T583_RTC_ADJ, 0); + if (ret < 0) { + dev_err(&pdev->dev, "unable to program rtc_adjust reg\n"); + return -EBUSY; + } + + pmic_plat_data = dev_get_platdata(rc5t583->dev); + irq = pmic_plat_data->irq_base; + if (irq <= 0) { + dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n", + irq); + return ret; + } + + irq += RC5T583_IRQ_YALE; + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, + rc5t583_rtc_interrupt, IRQF_TRIGGER_LOW, + "rtc-rc5t583", &pdev->dev); + if (ret < 0) { + dev_err(&pdev->dev, "IRQ is not free.\n"); + return ret; + } + device_init_wakeup(&pdev->dev, 1); + + ricoh_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, + &rc5t583_rtc_ops, THIS_MODULE); + if (IS_ERR(ricoh_rtc->rtc)) { + ret = PTR_ERR(ricoh_rtc->rtc); + dev_err(&pdev->dev, "RTC device register: err %d\n", ret); + return ret; + } + + return 0; +} + +/* + * Disable rc5t583 RTC interrupts. + * Sets status flag to free. + */ +static int rc5t583_rtc_remove(struct platform_device *pdev) +{ + struct rc5t583_rtc *rc5t583_rtc = platform_get_drvdata(pdev); + + rc5t583_rtc_alarm_irq_enable(&rc5t583_rtc->rtc->dev, 0); + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int rc5t583_rtc_suspend(struct device *dev) +{ + struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent); + struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev); + int ret; + + /* Store current list of enabled interrupts*/ + ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL1, + &rc5t583_rtc->irqen); + return ret; +} + +static int rc5t583_rtc_resume(struct device *dev) +{ + struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent); + struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev); + + /* Restore list of enabled interrupts before suspend */ + return regmap_write(rc5t583->regmap, RC5T583_RTC_CTL1, + rc5t583_rtc->irqen); +} +#endif + +static SIMPLE_DEV_PM_OPS(rc5t583_rtc_pm_ops, rc5t583_rtc_suspend, + rc5t583_rtc_resume); + +static struct platform_driver rc5t583_rtc_driver = { + .probe = rc5t583_rtc_probe, + .remove = rc5t583_rtc_remove, + .driver = { + .name = "rtc-rc5t583", + .pm = &rc5t583_rtc_pm_ops, + }, +}; + +module_platform_driver(rc5t583_rtc_driver); +MODULE_ALIAS("platform:rtc-rc5t583"); +MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>"); +MODULE_LICENSE("GPL v2"); |