// SPDX-License-Identifier: GPL-2.0-only /* * I2C client/driver for the ST M41T80 family of i2c rtc chips. * * Author: Alexander Bigga <[email protected]> * * Based on m41t00.c by Mark A. Greer <[email protected]> * * 2006 (c) mycable GmbH */ #define pr_fmt(fmt) … #include <linux/bcd.h> #include <linux/clk-provider.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/rtc.h> #include <linux/slab.h> #include <linux/mutex.h> #include <linux/string.h> #ifdef CONFIG_RTC_DRV_M41T80_WDT #include <linux/fs.h> #include <linux/ioctl.h> #include <linux/miscdevice.h> #include <linux/reboot.h> #include <linux/watchdog.h> #endif #define M41T80_REG_SSEC … #define M41T80_REG_SEC … #define M41T80_REG_MIN … #define M41T80_REG_HOUR … #define M41T80_REG_WDAY … #define M41T80_REG_DAY … #define M41T80_REG_MON … #define M41T80_REG_YEAR … #define M41T80_REG_ALARM_MON … #define M41T80_REG_ALARM_DAY … #define M41T80_REG_ALARM_HOUR … #define M41T80_REG_ALARM_MIN … #define M41T80_REG_ALARM_SEC … #define M41T80_REG_FLAGS … #define M41T80_REG_SQW … #define M41T80_DATETIME_REG_SIZE … #define M41T80_ALARM_REG_SIZE … #define M41T80_SQW_MAX_FREQ … #define M41T80_SEC_ST … #define M41T80_ALMON_AFE … #define M41T80_ALMON_SQWE … #define M41T80_ALHOUR_HT … #define M41T80_FLAGS_OF … #define M41T80_FLAGS_AF … #define M41T80_FLAGS_BATT_LOW … #define M41T80_WATCHDOG_RB2 … #define M41T80_WATCHDOG_RB1 … #define M41T80_WATCHDOG_RB0 … #define M41T80_FEATURE_HT … #define M41T80_FEATURE_BL … #define M41T80_FEATURE_SQ … #define M41T80_FEATURE_WD … #define M41T80_FEATURE_SQ_ALT … static const struct i2c_device_id m41t80_id[] = …; MODULE_DEVICE_TABLE(i2c, m41t80_id); static const __maybe_unused struct of_device_id m41t80_of_match[] = …; MODULE_DEVICE_TABLE(of, m41t80_of_match); struct m41t80_data { … }; static irqreturn_t m41t80_handle_irq(int irq, void *dev_id) { … } static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm) { … } static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm) { … } static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq) { … } static int m41t80_alarm_irq_enable(struct device *dev, unsigned int enabled) { … } static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { … } static int m41t80_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { … } static const struct rtc_class_ops m41t80_rtc_ops = …; #ifdef CONFIG_PM_SLEEP static int m41t80_suspend(struct device *dev) { … } static int m41t80_resume(struct device *dev) { … } #endif static SIMPLE_DEV_PM_OPS(m41t80_pm, m41t80_suspend, m41t80_resume); #ifdef CONFIG_COMMON_CLK #define sqw_to_m41t80_data(_hw) … static unsigned long m41t80_decode_freq(int setting) { … } static unsigned long m41t80_get_freq(struct m41t80_data *m41t80) { … } static unsigned long m41t80_sqw_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { … } static long m41t80_sqw_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { … } static int m41t80_sqw_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { … } static int m41t80_sqw_control(struct clk_hw *hw, bool enable) { … } static int m41t80_sqw_prepare(struct clk_hw *hw) { … } static void m41t80_sqw_unprepare(struct clk_hw *hw) { … } static int m41t80_sqw_is_prepared(struct clk_hw *hw) { … } static const struct clk_ops m41t80_sqw_ops = …; static struct clk *m41t80_sqw_register_clk(struct m41t80_data *m41t80) { … } #endif #ifdef CONFIG_RTC_DRV_M41T80_WDT /* ***************************************************************************** * * Watchdog Driver * ***************************************************************************** */ static DEFINE_MUTEX(m41t80_rtc_mutex); static struct i2c_client *save_client; /* Default margin */ #define WD_TIMO … static int wdt_margin = …; module_param(wdt_margin, int, 0); MODULE_PARM_DESC(…) …; static unsigned long wdt_is_open; static int boot_flag; /** * wdt_ping - Reload counter one with the watchdog timeout. * We don't bother reloading the cascade counter. */ static void wdt_ping(void) { … } /** * wdt_disable - disables watchdog. */ static void wdt_disable(void) { … } /** * wdt_write - write to watchdog. * @file: file handle to the watchdog * @buf: buffer to write (unused as data does not matter here * @count: count of bytes * @ppos: pointer to the position to write. No seeks allowed * * A write to a watchdog device is defined as a keepalive signal. Any * write of data will do, as we don't define content meaning. */ static ssize_t wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { … } static ssize_t wdt_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { … } /** * wdt_ioctl - ioctl handler to set watchdog. * @file: file handle to the device * @cmd: watchdog command * @arg: argument pointer * * The watchdog API defines a common set of functions for all watchdogs * according to their available features. We only actually usefully support * querying capabilities and current status. */ static int wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { … } static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { … } /** * wdt_open - open a watchdog. * @inode: inode of device * @file: file handle to device * */ static int wdt_open(struct inode *inode, struct file *file) { … } /** * wdt_release - release a watchdog. * @inode: inode to board * @file: file handle to board * */ static int wdt_release(struct inode *inode, struct file *file) { … } /** * wdt_notify_sys - notify to watchdog. * @this: our notifier block * @code: the event being reported * @unused: unused * * Our notifier is called on system shutdowns. We want to turn the card * off at reboot otherwise the machine will reboot again during memory * test or worse yet during the following fsck. This would suck, in fact * trust me - if it happens it does suck. */ static int wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { … } static const struct file_operations wdt_fops = …; static struct miscdevice wdt_dev = …; /* * The WDT card needs to learn about soft shutdowns in order to * turn the timebomb registers off. */ static struct notifier_block wdt_notifier = …; #endif /* CONFIG_RTC_DRV_M41T80_WDT */ /* ***************************************************************************** * * Driver Interface * ***************************************************************************** */ static int m41t80_probe(struct i2c_client *client) { … } static void m41t80_remove(struct i2c_client *client) { … } static struct i2c_driver m41t80_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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