diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/rtc/rtc-max8997.c | 533 |
1 files changed, 533 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-max8997.c b/drivers/rtc/rtc-max8997.c new file mode 100644 index 000000000..20e50d9fd --- /dev/null +++ b/drivers/rtc/rtc-max8997.c @@ -0,0 +1,533 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// RTC driver for Maxim MAX8997 +// +// Copyright (C) 2013 Samsung Electronics Co.Ltd +// +// based on rtc-max8998.c + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/slab.h> +#include <linux/rtc.h> +#include <linux/delay.h> +#include <linux/mutex.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/mfd/max8997-private.h> +#include <linux/irqdomain.h> + +/* Module parameter for WTSR function control */ +static int wtsr_en = 1; +module_param(wtsr_en, int, 0444); +MODULE_PARM_DESC(wtsr_en, "Watchdog Timeout & Software Reset (default=on)"); +/* Module parameter for SMPL function control */ +static int smpl_en = 1; +module_param(smpl_en, int, 0444); +MODULE_PARM_DESC(smpl_en, "Sudden Momentary Power Loss (default=on)"); + +/* RTC Control Register */ +#define BCD_EN_SHIFT 0 +#define BCD_EN_MASK (1 << BCD_EN_SHIFT) +#define MODEL24_SHIFT 1 +#define MODEL24_MASK (1 << MODEL24_SHIFT) +/* RTC Update Register1 */ +#define RTC_UDR_SHIFT 0 +#define RTC_UDR_MASK (1 << RTC_UDR_SHIFT) +/* WTSR and SMPL Register */ +#define WTSRT_SHIFT 0 +#define SMPLT_SHIFT 2 +#define WTSR_EN_SHIFT 6 +#define SMPL_EN_SHIFT 7 +#define WTSRT_MASK (3 << WTSRT_SHIFT) +#define SMPLT_MASK (3 << SMPLT_SHIFT) +#define WTSR_EN_MASK (1 << WTSR_EN_SHIFT) +#define SMPL_EN_MASK (1 << SMPL_EN_SHIFT) +/* RTC Hour register */ +#define HOUR_PM_SHIFT 6 +#define HOUR_PM_MASK (1 << HOUR_PM_SHIFT) +/* RTC Alarm Enable */ +#define ALARM_ENABLE_SHIFT 7 +#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT) + +enum { + RTC_SEC = 0, + RTC_MIN, + RTC_HOUR, + RTC_WEEKDAY, + RTC_MONTH, + RTC_YEAR, + RTC_DATE, + RTC_NR_TIME +}; + +struct max8997_rtc_info { + struct device *dev; + struct max8997_dev *max8997; + struct i2c_client *rtc; + struct rtc_device *rtc_dev; + struct mutex lock; + int virq; + int rtc_24hr_mode; +}; + +static void max8997_rtc_data_to_tm(u8 *data, struct rtc_time *tm, + int rtc_24hr_mode) +{ + tm->tm_sec = data[RTC_SEC] & 0x7f; + tm->tm_min = data[RTC_MIN] & 0x7f; + if (rtc_24hr_mode) + tm->tm_hour = data[RTC_HOUR] & 0x1f; + else { + tm->tm_hour = data[RTC_HOUR] & 0x0f; + if (data[RTC_HOUR] & HOUR_PM_MASK) + tm->tm_hour += 12; + } + + tm->tm_wday = fls(data[RTC_WEEKDAY] & 0x7f) - 1; + tm->tm_mday = data[RTC_DATE] & 0x1f; + tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1; + tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100; + tm->tm_yday = 0; + tm->tm_isdst = 0; +} + +static int max8997_rtc_tm_to_data(struct rtc_time *tm, u8 *data) +{ + data[RTC_SEC] = tm->tm_sec; + data[RTC_MIN] = tm->tm_min; + data[RTC_HOUR] = tm->tm_hour; + data[RTC_WEEKDAY] = 1 << tm->tm_wday; + data[RTC_DATE] = tm->tm_mday; + data[RTC_MONTH] = tm->tm_mon + 1; + data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0; + + if (tm->tm_year < 100) { + pr_warn("RTC cannot handle the year %d. Assume it's 2000.\n", + 1900 + tm->tm_year); + return -EINVAL; + } + return 0; +} + +static inline int max8997_rtc_set_update_reg(struct max8997_rtc_info *info) +{ + int ret; + + ret = max8997_write_reg(info->rtc, MAX8997_RTC_UPDATE1, + RTC_UDR_MASK); + if (ret < 0) + dev_err(info->dev, "%s: fail to write update reg(%d)\n", + __func__, ret); + else { + /* Minimum 16ms delay required before RTC update. + * Otherwise, we may read and update based on out-of-date + * value */ + msleep(20); + } + + return ret; +} + +static int max8997_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct max8997_rtc_info *info = dev_get_drvdata(dev); + u8 data[RTC_NR_TIME]; + int ret; + + mutex_lock(&info->lock); + ret = max8997_bulk_read(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data); + mutex_unlock(&info->lock); + + if (ret < 0) { + dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__, + ret); + return ret; + } + + max8997_rtc_data_to_tm(data, tm, info->rtc_24hr_mode); + + return 0; +} + +static int max8997_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct max8997_rtc_info *info = dev_get_drvdata(dev); + u8 data[RTC_NR_TIME]; + int ret; + + ret = max8997_rtc_tm_to_data(tm, data); + if (ret < 0) + return ret; + + mutex_lock(&info->lock); + + ret = max8997_bulk_write(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data); + if (ret < 0) { + dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__, + ret); + goto out; + } + + ret = max8997_rtc_set_update_reg(info); +out: + mutex_unlock(&info->lock); + return ret; +} + +static int max8997_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct max8997_rtc_info *info = dev_get_drvdata(dev); + u8 data[RTC_NR_TIME]; + u8 val; + int i, ret; + + mutex_lock(&info->lock); + + ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, + data); + if (ret < 0) { + dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n", + __func__, __LINE__, ret); + goto out; + } + + max8997_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode); + + alrm->enabled = 0; + for (i = 0; i < RTC_NR_TIME; i++) { + if (data[i] & ALARM_ENABLE_MASK) { + alrm->enabled = 1; + break; + } + } + + alrm->pending = 0; + ret = max8997_read_reg(info->max8997->i2c, MAX8997_REG_STATUS1, &val); + if (ret < 0) { + dev_err(info->dev, "%s:%d fail to read status1 reg(%d)\n", + __func__, __LINE__, ret); + goto out; + } + + if (val & (1 << 4)) /* RTCA1 */ + alrm->pending = 1; + +out: + mutex_unlock(&info->lock); + return ret; +} + +static int max8997_rtc_stop_alarm(struct max8997_rtc_info *info) +{ + u8 data[RTC_NR_TIME]; + int ret, i; + + if (!mutex_is_locked(&info->lock)) + dev_warn(info->dev, "%s: should have mutex locked\n", __func__); + + ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, + data); + if (ret < 0) { + dev_err(info->dev, "%s: fail to read alarm reg(%d)\n", + __func__, ret); + goto out; + } + + for (i = 0; i < RTC_NR_TIME; i++) + data[i] &= ~ALARM_ENABLE_MASK; + + ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, + data); + if (ret < 0) { + dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", + __func__, ret); + goto out; + } + + ret = max8997_rtc_set_update_reg(info); +out: + return ret; +} + +static int max8997_rtc_start_alarm(struct max8997_rtc_info *info) +{ + u8 data[RTC_NR_TIME]; + int ret; + + if (!mutex_is_locked(&info->lock)) + dev_warn(info->dev, "%s: should have mutex locked\n", __func__); + + ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, + data); + if (ret < 0) { + dev_err(info->dev, "%s: fail to read alarm reg(%d)\n", + __func__, ret); + goto out; + } + + data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT); + data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT); + data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT); + data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK; + if (data[RTC_MONTH] & 0xf) + data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT); + if (data[RTC_YEAR] & 0x7f) + data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT); + if (data[RTC_DATE] & 0x1f) + data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT); + + ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, + data); + if (ret < 0) { + dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", + __func__, ret); + goto out; + } + + ret = max8997_rtc_set_update_reg(info); +out: + return ret; +} +static int max8997_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct max8997_rtc_info *info = dev_get_drvdata(dev); + u8 data[RTC_NR_TIME]; + int ret; + + ret = max8997_rtc_tm_to_data(&alrm->time, data); + if (ret < 0) + return ret; + + dev_info(info->dev, "%s: %d-%02d-%02d %02d:%02d:%02d\n", __func__, + data[RTC_YEAR] + 2000, data[RTC_MONTH], data[RTC_DATE], + data[RTC_HOUR], data[RTC_MIN], data[RTC_SEC]); + + mutex_lock(&info->lock); + + ret = max8997_rtc_stop_alarm(info); + if (ret < 0) + goto out; + + ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, + data); + if (ret < 0) { + dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", + __func__, ret); + goto out; + } + + ret = max8997_rtc_set_update_reg(info); + if (ret < 0) + goto out; + + if (alrm->enabled) + ret = max8997_rtc_start_alarm(info); +out: + mutex_unlock(&info->lock); + return ret; +} + +static int max8997_rtc_alarm_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct max8997_rtc_info *info = dev_get_drvdata(dev); + int ret; + + mutex_lock(&info->lock); + if (enabled) + ret = max8997_rtc_start_alarm(info); + else + ret = max8997_rtc_stop_alarm(info); + mutex_unlock(&info->lock); + + return ret; +} + +static irqreturn_t max8997_rtc_alarm_irq(int irq, void *data) +{ + struct max8997_rtc_info *info = data; + + dev_info(info->dev, "%s:irq(%d)\n", __func__, irq); + + rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF); + + return IRQ_HANDLED; +} + +static const struct rtc_class_ops max8997_rtc_ops = { + .read_time = max8997_rtc_read_time, + .set_time = max8997_rtc_set_time, + .read_alarm = max8997_rtc_read_alarm, + .set_alarm = max8997_rtc_set_alarm, + .alarm_irq_enable = max8997_rtc_alarm_irq_enable, +}; + +static void max8997_rtc_enable_wtsr(struct max8997_rtc_info *info, bool enable) +{ + int ret; + u8 val, mask; + + if (!wtsr_en) + return; + + if (enable) + val = (1 << WTSR_EN_SHIFT) | (3 << WTSRT_SHIFT); + else + val = 0; + + mask = WTSR_EN_MASK | WTSRT_MASK; + + dev_info(info->dev, "%s: %s WTSR\n", __func__, + enable ? "enable" : "disable"); + + ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask); + if (ret < 0) { + dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n", + __func__, ret); + return; + } + + max8997_rtc_set_update_reg(info); +} + +static void max8997_rtc_enable_smpl(struct max8997_rtc_info *info, bool enable) +{ + int ret; + u8 val, mask; + + if (!smpl_en) + return; + + if (enable) + val = (1 << SMPL_EN_SHIFT) | (0 << SMPLT_SHIFT); + else + val = 0; + + mask = SMPL_EN_MASK | SMPLT_MASK; + + dev_info(info->dev, "%s: %s SMPL\n", __func__, + enable ? "enable" : "disable"); + + ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask); + if (ret < 0) { + dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n", + __func__, ret); + return; + } + + max8997_rtc_set_update_reg(info); + + val = 0; + max8997_read_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, &val); + pr_info("WTSR_SMPL(0x%02x)\n", val); +} + +static int max8997_rtc_init_reg(struct max8997_rtc_info *info) +{ + u8 data[2]; + int ret; + + /* Set RTC control register : Binary mode, 24hour mdoe */ + data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT); + data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT); + + info->rtc_24hr_mode = 1; + + ret = max8997_bulk_write(info->rtc, MAX8997_RTC_CTRLMASK, 2, data); + if (ret < 0) { + dev_err(info->dev, "%s: fail to write controlm reg(%d)\n", + __func__, ret); + return ret; + } + + ret = max8997_rtc_set_update_reg(info); + return ret; +} + +static int max8997_rtc_probe(struct platform_device *pdev) +{ + struct max8997_dev *max8997 = dev_get_drvdata(pdev->dev.parent); + struct max8997_rtc_info *info; + int ret, virq; + + info = devm_kzalloc(&pdev->dev, sizeof(struct max8997_rtc_info), + GFP_KERNEL); + if (!info) + return -ENOMEM; + + mutex_init(&info->lock); + info->dev = &pdev->dev; + info->max8997 = max8997; + info->rtc = max8997->rtc; + + platform_set_drvdata(pdev, info); + + ret = max8997_rtc_init_reg(info); + + if (ret < 0) { + dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret); + return ret; + } + + max8997_rtc_enable_wtsr(info, true); + max8997_rtc_enable_smpl(info, true); + + device_init_wakeup(&pdev->dev, 1); + + info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8997-rtc", + &max8997_rtc_ops, THIS_MODULE); + + if (IS_ERR(info->rtc_dev)) { + ret = PTR_ERR(info->rtc_dev); + dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); + return ret; + } + + virq = irq_create_mapping(max8997->irq_domain, MAX8997_PMICIRQ_RTCA1); + if (!virq) { + dev_err(&pdev->dev, "Failed to create mapping alarm IRQ\n"); + ret = -ENXIO; + goto err_out; + } + info->virq = virq; + + ret = devm_request_threaded_irq(&pdev->dev, virq, NULL, + max8997_rtc_alarm_irq, 0, + "rtc-alarm0", info); + if (ret < 0) + dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n", + info->virq, ret); + +err_out: + return ret; +} + +static void max8997_rtc_shutdown(struct platform_device *pdev) +{ + struct max8997_rtc_info *info = platform_get_drvdata(pdev); + + max8997_rtc_enable_wtsr(info, false); + max8997_rtc_enable_smpl(info, false); +} + +static const struct platform_device_id rtc_id[] = { + { "max8997-rtc", 0 }, + {}, +}; +MODULE_DEVICE_TABLE(platform, rtc_id); + +static struct platform_driver max8997_rtc_driver = { + .driver = { + .name = "max8997-rtc", + }, + .probe = max8997_rtc_probe, + .shutdown = max8997_rtc_shutdown, + .id_table = rtc_id, +}; + +module_platform_driver(max8997_rtc_driver); + +MODULE_DESCRIPTION("Maxim MAX8997 RTC driver"); +MODULE_AUTHOR("<ms925.kim@samsung.com>"); +MODULE_LICENSE("GPL"); |