diff options
Diffstat (limited to 'drivers/rtc/rtc-max8998.c')
| -rw-r--r-- | drivers/rtc/rtc-max8998.c | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-max8998.c b/drivers/rtc/rtc-max8998.c new file mode 100644 index 000000000..c873b4509 --- /dev/null +++ b/drivers/rtc/rtc-max8998.c @@ -0,0 +1,321 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// RTC driver for Maxim MAX8998 +// +// Copyright (C) 2010 Samsung Electronics Co.Ltd +// Author: Minkyu Kang <mk7.kang@samsung.com> +// Author: Joonyoung Shim <jy0922.shim@samsung.com> + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/slab.h> +#include <linux/bcd.h> +#include <linux/irqdomain.h> +#include <linux/rtc.h> +#include <linux/platform_device.h> +#include <linux/mfd/max8998.h> +#include <linux/mfd/max8998-private.h> +#include <linux/delay.h> + +#define MAX8998_RTC_SEC 0x00 +#define MAX8998_RTC_MIN 0x01 +#define MAX8998_RTC_HOUR 0x02 +#define MAX8998_RTC_WEEKDAY 0x03 +#define MAX8998_RTC_DATE 0x04 +#define MAX8998_RTC_MONTH 0x05 +#define MAX8998_RTC_YEAR1 0x06 +#define MAX8998_RTC_YEAR2 0x07 +#define MAX8998_ALARM0_SEC 0x08 +#define MAX8998_ALARM0_MIN 0x09 +#define MAX8998_ALARM0_HOUR 0x0a +#define MAX8998_ALARM0_WEEKDAY 0x0b +#define MAX8998_ALARM0_DATE 0x0c +#define MAX8998_ALARM0_MONTH 0x0d +#define MAX8998_ALARM0_YEAR1 0x0e +#define MAX8998_ALARM0_YEAR2 0x0f +#define MAX8998_ALARM1_SEC 0x10 +#define MAX8998_ALARM1_MIN 0x11 +#define MAX8998_ALARM1_HOUR 0x12 +#define MAX8998_ALARM1_WEEKDAY 0x13 +#define MAX8998_ALARM1_DATE 0x14 +#define MAX8998_ALARM1_MONTH 0x15 +#define MAX8998_ALARM1_YEAR1 0x16 +#define MAX8998_ALARM1_YEAR2 0x17 +#define MAX8998_ALARM0_CONF 0x18 +#define MAX8998_ALARM1_CONF 0x19 +#define MAX8998_RTC_STATUS 0x1a +#define MAX8998_WTSR_SMPL_CNTL 0x1b +#define MAX8998_TEST 0x1f + +#define HOUR_12 (1 << 7) +#define HOUR_PM (1 << 5) +#define ALARM0_STATUS (1 << 1) +#define ALARM1_STATUS (1 << 2) + +enum { + RTC_SEC = 0, + RTC_MIN, + RTC_HOUR, + RTC_WEEKDAY, + RTC_DATE, + RTC_MONTH, + RTC_YEAR1, + RTC_YEAR2, +}; + +struct max8998_rtc_info { + struct device *dev; + struct max8998_dev *max8998; + struct i2c_client *rtc; + struct rtc_device *rtc_dev; + int irq; + bool lp3974_bug_workaround; +}; + +static void max8998_data_to_tm(u8 *data, struct rtc_time *tm) +{ + tm->tm_sec = bcd2bin(data[RTC_SEC]); + tm->tm_min = bcd2bin(data[RTC_MIN]); + if (data[RTC_HOUR] & HOUR_12) { + tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f); + if (data[RTC_HOUR] & HOUR_PM) + tm->tm_hour += 12; + } else + tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f); + + tm->tm_wday = data[RTC_WEEKDAY] & 0x07; + tm->tm_mday = bcd2bin(data[RTC_DATE]); + tm->tm_mon = bcd2bin(data[RTC_MONTH]); + tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100; + tm->tm_year -= 1900; +} + +static void max8998_tm_to_data(struct rtc_time *tm, u8 *data) +{ + data[RTC_SEC] = bin2bcd(tm->tm_sec); + data[RTC_MIN] = bin2bcd(tm->tm_min); + data[RTC_HOUR] = bin2bcd(tm->tm_hour); + data[RTC_WEEKDAY] = tm->tm_wday; + data[RTC_DATE] = bin2bcd(tm->tm_mday); + data[RTC_MONTH] = bin2bcd(tm->tm_mon); + data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100); + data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100); +} + +static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct max8998_rtc_info *info = dev_get_drvdata(dev); + u8 data[8]; + int ret; + + ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data); + if (ret < 0) + return ret; + + max8998_data_to_tm(data, tm); + + return 0; +} + +static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct max8998_rtc_info *info = dev_get_drvdata(dev); + u8 data[8]; + int ret; + + max8998_tm_to_data(tm, data); + + ret = max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data); + + if (info->lp3974_bug_workaround) + msleep(2000); + + return ret; +} + +static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct max8998_rtc_info *info = dev_get_drvdata(dev); + u8 data[8]; + u8 val; + int ret; + + ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data); + if (ret < 0) + return ret; + + max8998_data_to_tm(data, &alrm->time); + + ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val); + if (ret < 0) + return ret; + + alrm->enabled = !!val; + + ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val); + if (ret < 0) + return ret; + + if (val & ALARM0_STATUS) + alrm->pending = 1; + else + alrm->pending = 0; + + return 0; +} + +static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info) +{ + int ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0); + + if (info->lp3974_bug_workaround) + msleep(2000); + + return ret; +} + +static int max8998_rtc_start_alarm(struct max8998_rtc_info *info) +{ + int ret; + u8 alarm0_conf = 0x77; + + /* LP3974 with delay bug chips has rtc alarm bugs with "MONTH" field */ + if (info->lp3974_bug_workaround) + alarm0_conf = 0x57; + + ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, alarm0_conf); + + if (info->lp3974_bug_workaround) + msleep(2000); + + return ret; +} + +static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct max8998_rtc_info *info = dev_get_drvdata(dev); + u8 data[8]; + int ret; + + max8998_tm_to_data(&alrm->time, data); + + ret = max8998_rtc_stop_alarm(info); + if (ret < 0) + return ret; + + ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data); + if (ret < 0) + return ret; + + if (info->lp3974_bug_workaround) + msleep(2000); + + if (alrm->enabled) + ret = max8998_rtc_start_alarm(info); + + return ret; +} + +static int max8998_rtc_alarm_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct max8998_rtc_info *info = dev_get_drvdata(dev); + + if (enabled) + return max8998_rtc_start_alarm(info); + else + return max8998_rtc_stop_alarm(info); +} + +static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data) +{ + struct max8998_rtc_info *info = data; + + rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF); + + return IRQ_HANDLED; +} + +static const struct rtc_class_ops max8998_rtc_ops = { + .read_time = max8998_rtc_read_time, + .set_time = max8998_rtc_set_time, + .read_alarm = max8998_rtc_read_alarm, + .set_alarm = max8998_rtc_set_alarm, + .alarm_irq_enable = max8998_rtc_alarm_irq_enable, +}; + +static int max8998_rtc_probe(struct platform_device *pdev) +{ + struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent); + struct max8998_platform_data *pdata = max8998->pdata; + struct max8998_rtc_info *info; + int ret; + + info = devm_kzalloc(&pdev->dev, sizeof(struct max8998_rtc_info), + GFP_KERNEL); + if (!info) + return -ENOMEM; + + info->dev = &pdev->dev; + info->max8998 = max8998; + info->rtc = max8998->rtc; + + platform_set_drvdata(pdev, info); + + info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8998-rtc", + &max8998_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; + } + + if (!max8998->irq_domain) + goto no_irq; + + info->irq = irq_create_mapping(max8998->irq_domain, MAX8998_IRQ_ALARM0); + if (!info->irq) { + dev_warn(&pdev->dev, "Failed to map alarm IRQ\n"); + goto no_irq; + } + + ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, + max8998_rtc_alarm_irq, 0, "rtc-alarm0", info); + + if (ret < 0) + dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n", + info->irq, ret); + +no_irq: + dev_info(&pdev->dev, "RTC CHIP NAME: %s\n", pdev->id_entry->name); + if (pdata && pdata->rtc_delay) { + info->lp3974_bug_workaround = true; + dev_warn(&pdev->dev, "LP3974 with RTC REGERR option." + " RTC updates will be extremely slow.\n"); + } + + return 0; +} + +static const struct platform_device_id max8998_rtc_id[] = { + { "max8998-rtc", TYPE_MAX8998 }, + { "lp3974-rtc", TYPE_LP3974 }, + { } +}; +MODULE_DEVICE_TABLE(platform, max8998_rtc_id); + +static struct platform_driver max8998_rtc_driver = { + .driver = { + .name = "max8998-rtc", + }, + .probe = max8998_rtc_probe, + .id_table = max8998_rtc_id, +}; + +module_platform_driver(max8998_rtc_driver); + +MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>"); +MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>"); +MODULE_DESCRIPTION("Maxim MAX8998 RTC driver"); +MODULE_LICENSE("GPL"); |