// 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");