diff options
Diffstat (limited to 'drivers/rtc/rtc-rv8803.c')
| -rw-r--r-- | drivers/rtc/rtc-rv8803.c | 521 |
1 files changed, 521 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c new file mode 100644 index 000000000..e7329e21b --- /dev/null +++ b/drivers/rtc/rtc-rv8803.c @@ -0,0 +1,521 @@ +/* + * RTC driver for the Micro Crystal RV8803 + * + * Copyright (C) 2015 Micro Crystal SA + * + * Alexandre Belloni <alexandre.belloni@free-electrons.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/bcd.h> +#include <linux/bitops.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/rtc.h> + +#define RV8803_SEC 0x00 +#define RV8803_MIN 0x01 +#define RV8803_HOUR 0x02 +#define RV8803_WEEK 0x03 +#define RV8803_DAY 0x04 +#define RV8803_MONTH 0x05 +#define RV8803_YEAR 0x06 +#define RV8803_RAM 0x07 +#define RV8803_ALARM_MIN 0x08 +#define RV8803_ALARM_HOUR 0x09 +#define RV8803_ALARM_WEEK_OR_DAY 0x0A +#define RV8803_EXT 0x0D +#define RV8803_FLAG 0x0E +#define RV8803_CTRL 0x0F + +#define RV8803_EXT_WADA BIT(6) + +#define RV8803_FLAG_V1F BIT(0) +#define RV8803_FLAG_V2F BIT(1) +#define RV8803_FLAG_AF BIT(3) +#define RV8803_FLAG_TF BIT(4) +#define RV8803_FLAG_UF BIT(5) + +#define RV8803_CTRL_RESET BIT(0) + +#define RV8803_CTRL_EIE BIT(2) +#define RV8803_CTRL_AIE BIT(3) +#define RV8803_CTRL_TIE BIT(4) +#define RV8803_CTRL_UIE BIT(5) + +struct rv8803_data { + struct i2c_client *client; + struct rtc_device *rtc; + spinlock_t flags_lock; + u8 ctrl; +}; + +static irqreturn_t rv8803_handle_irq(int irq, void *dev_id) +{ + struct i2c_client *client = dev_id; + struct rv8803_data *rv8803 = i2c_get_clientdata(client); + unsigned long events = 0; + u8 flags; + + spin_lock(&rv8803->flags_lock); + + flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + if (flags <= 0) { + spin_unlock(&rv8803->flags_lock); + return IRQ_NONE; + } + + if (flags & RV8803_FLAG_V1F) + dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); + + if (flags & RV8803_FLAG_V2F) + dev_warn(&client->dev, "Voltage low, data loss detected.\n"); + + if (flags & RV8803_FLAG_TF) { + flags &= ~RV8803_FLAG_TF; + rv8803->ctrl &= ~RV8803_CTRL_TIE; + events |= RTC_PF; + } + + if (flags & RV8803_FLAG_AF) { + flags &= ~RV8803_FLAG_AF; + rv8803->ctrl &= ~RV8803_CTRL_AIE; + events |= RTC_AF; + } + + if (flags & RV8803_FLAG_UF) { + flags &= ~RV8803_FLAG_UF; + rv8803->ctrl &= ~RV8803_CTRL_UIE; + events |= RTC_UF; + } + + if (events) { + rtc_update_irq(rv8803->rtc, 1, events); + i2c_smbus_write_byte_data(client, RV8803_FLAG, flags); + i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL, + rv8803->ctrl); + } + + spin_unlock(&rv8803->flags_lock); + + return IRQ_HANDLED; +} + +static int rv8803_get_time(struct device *dev, struct rtc_time *tm) +{ + struct rv8803_data *rv8803 = dev_get_drvdata(dev); + u8 date1[7]; + u8 date2[7]; + u8 *date = date1; + int ret, flags; + + flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG); + if (flags < 0) + return flags; + + if (flags & RV8803_FLAG_V2F) { + dev_warn(dev, "Voltage low, data is invalid.\n"); + return -EINVAL; + } + + ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC, + 7, date); + if (ret != 7) + return ret < 0 ? ret : -EIO; + + if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) { + ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC, + 7, date2); + if (ret != 7) + return ret < 0 ? ret : -EIO; + + if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59)) + date = date2; + } + + tm->tm_sec = bcd2bin(date[RV8803_SEC] & 0x7f); + tm->tm_min = bcd2bin(date[RV8803_MIN] & 0x7f); + tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f); + tm->tm_wday = ffs(date[RV8803_WEEK] & 0x7f); + tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f); + tm->tm_mon = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1; + tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100; + + return rtc_valid_tm(tm); +} + +static int rv8803_set_time(struct device *dev, struct rtc_time *tm) +{ + struct rv8803_data *rv8803 = dev_get_drvdata(dev); + u8 date[7]; + int flags, ret; + unsigned long irqflags; + + if ((tm->tm_year < 100) || (tm->tm_year > 199)) + return -EINVAL; + + date[RV8803_SEC] = bin2bcd(tm->tm_sec); + date[RV8803_MIN] = bin2bcd(tm->tm_min); + date[RV8803_HOUR] = bin2bcd(tm->tm_hour); + date[RV8803_WEEK] = 1 << (tm->tm_wday); + date[RV8803_DAY] = bin2bcd(tm->tm_mday); + date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1); + date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100); + + ret = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_SEC, + 7, date); + if (ret < 0) + return ret; + + spin_lock_irqsave(&rv8803->flags_lock, irqflags); + + flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG); + if (flags < 0) { + spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + return flags; + } + + ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, + flags & ~RV8803_FLAG_V2F); + + spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + + return ret; +} + +static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct rv8803_data *rv8803 = dev_get_drvdata(dev); + struct i2c_client *client = rv8803->client; + u8 alarmvals[3]; + int flags, ret; + + ret = i2c_smbus_read_i2c_block_data(client, RV8803_ALARM_MIN, + 3, alarmvals); + if (ret != 3) + return ret < 0 ? ret : -EIO; + + flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + if (flags < 0) + return flags; + + alrm->time.tm_sec = 0; + alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f); + alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f); + alrm->time.tm_wday = -1; + alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f); + alrm->time.tm_mon = -1; + alrm->time.tm_year = -1; + + alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE); + alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled; + + return 0; +} + +static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct rv8803_data *rv8803 = dev_get_drvdata(dev); + u8 alarmvals[3]; + u8 ctrl[2]; + int ret, err; + unsigned long irqflags; + + /* The alarm has no seconds, round up to nearest minute */ + if (alrm->time.tm_sec) { + time64_t alarm_time = rtc_tm_to_time64(&alrm->time); + + alarm_time += 60 - alrm->time.tm_sec; + rtc_time64_to_tm(alarm_time, &alrm->time); + } + + spin_lock_irqsave(&rv8803->flags_lock, irqflags); + + ret = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl); + if (ret != 2) { + spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + return ret < 0 ? ret : -EIO; + } + + alarmvals[0] = bin2bcd(alrm->time.tm_min); + alarmvals[1] = bin2bcd(alrm->time.tm_hour); + alarmvals[2] = bin2bcd(alrm->time.tm_mday); + + if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) { + rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE); + err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL, + rv8803->ctrl); + if (err) { + spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + return err; + } + } + + ctrl[1] &= ~RV8803_FLAG_AF; + err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]); + spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + if (err) + return err; + + err = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_ALARM_MIN, + 3, alarmvals); + if (err) + return err; + + if (alrm->enabled) { + if (rv8803->rtc->uie_rtctimer.enabled) + rv8803->ctrl |= RV8803_CTRL_UIE; + if (rv8803->rtc->aie_timer.enabled) + rv8803->ctrl |= RV8803_CTRL_AIE; + + err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL, + rv8803->ctrl); + if (err) + return err; + } + + return 0; +} + +static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct i2c_client *client = to_i2c_client(dev); + struct rv8803_data *rv8803 = dev_get_drvdata(dev); + int ctrl, flags, err; + unsigned long irqflags; + + ctrl = rv8803->ctrl; + + if (enabled) { + if (rv8803->rtc->uie_rtctimer.enabled) + ctrl |= RV8803_CTRL_UIE; + if (rv8803->rtc->aie_timer.enabled) + ctrl |= RV8803_CTRL_AIE; + } else { + if (!rv8803->rtc->uie_rtctimer.enabled) + ctrl &= ~RV8803_CTRL_UIE; + if (!rv8803->rtc->aie_timer.enabled) + ctrl &= ~RV8803_CTRL_AIE; + } + + spin_lock_irqsave(&rv8803->flags_lock, irqflags); + flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + if (flags < 0) { + spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + return flags; + } + flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF); + err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags); + spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + if (err) + return err; + + if (ctrl != rv8803->ctrl) { + rv8803->ctrl = ctrl; + err = i2c_smbus_write_byte_data(client, RV8803_CTRL, + rv8803->ctrl); + if (err) + return err; + } + + return 0; +} + +static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) +{ + struct i2c_client *client = to_i2c_client(dev); + struct rv8803_data *rv8803 = dev_get_drvdata(dev); + int flags, ret = 0; + unsigned long irqflags; + + switch (cmd) { + case RTC_VL_READ: + flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + if (flags < 0) + return flags; + + if (flags & RV8803_FLAG_V1F) + dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); + + if (flags & RV8803_FLAG_V2F) + dev_warn(&client->dev, "Voltage low, data loss detected.\n"); + + flags &= RV8803_FLAG_V1F | RV8803_FLAG_V2F; + + if (copy_to_user((void __user *)arg, &flags, sizeof(int))) + return -EFAULT; + + return 0; + + case RTC_VL_CLR: + spin_lock_irqsave(&rv8803->flags_lock, irqflags); + flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + if (flags < 0) { + spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + return flags; + } + + flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F); + ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags); + spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + if (ret < 0) + return ret; + + return 0; + + default: + return -ENOIOCTLCMD; + } +} + +static ssize_t rv8803_nvram_write(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct device *dev = kobj_to_dev(kobj); + struct i2c_client *client = to_i2c_client(dev); + int ret; + + ret = i2c_smbus_write_byte_data(client, RV8803_RAM, buf[0]); + if (ret < 0) + return ret; + + return 1; +} + +static ssize_t rv8803_nvram_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct device *dev = kobj_to_dev(kobj); + struct i2c_client *client = to_i2c_client(dev); + int ret; + + ret = i2c_smbus_read_byte_data(client, RV8803_RAM); + if (ret < 0) + return ret; + + buf[0] = ret; + + return 1; +} + +static struct bin_attribute rv8803_nvram_attr = { + .attr = { + .name = "nvram", + .mode = S_IRUGO | S_IWUSR, + }, + .size = 1, + .read = rv8803_nvram_read, + .write = rv8803_nvram_write, +}; + +static struct rtc_class_ops rv8803_rtc_ops = { + .read_time = rv8803_get_time, + .set_time = rv8803_set_time, + .ioctl = rv8803_ioctl, +}; + +static int rv8803_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); + struct rv8803_data *rv8803; + int err, flags; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_I2C_BLOCK)) { + dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n"); + return -EIO; + } + + rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data), + GFP_KERNEL); + if (!rv8803) + return -ENOMEM; + + rv8803->client = client; + i2c_set_clientdata(client, rv8803); + + flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + if (flags < 0) + return flags; + + if (flags & RV8803_FLAG_V1F) + dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); + + if (flags & RV8803_FLAG_V2F) + dev_warn(&client->dev, "Voltage low, data loss detected.\n"); + + if (flags & RV8803_FLAG_AF) + dev_warn(&client->dev, "An alarm maybe have been missed.\n"); + + if (client->irq > 0) { + err = devm_request_threaded_irq(&client->dev, client->irq, + NULL, rv8803_handle_irq, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + "rv8803", client); + if (err) { + dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); + client->irq = 0; + } else { + rv8803_rtc_ops.read_alarm = rv8803_get_alarm; + rv8803_rtc_ops.set_alarm = rv8803_set_alarm; + rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable; + } + } + + rv8803->rtc = devm_rtc_device_register(&client->dev, client->name, + &rv8803_rtc_ops, THIS_MODULE); + if (IS_ERR(rv8803->rtc)) { + dev_err(&client->dev, "unable to register the class device\n"); + return PTR_ERR(rv8803->rtc); + } + + err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT, + RV8803_EXT_WADA); + if (err) + return err; + + err = device_create_bin_file(&client->dev, &rv8803_nvram_attr); + if (err) + return err; + + rv8803->rtc->max_user_freq = 1; + + return 0; +} + +static int rv8803_remove(struct i2c_client *client) +{ + device_remove_bin_file(&client->dev, &rv8803_nvram_attr); + + return 0; +} + +static const struct i2c_device_id rv8803_id[] = { + { "rv8803", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, rv8803_id); + +static struct i2c_driver rv8803_driver = { + .driver = { + .name = "rtc-rv8803", + }, + .probe = rv8803_probe, + .remove = rv8803_remove, + .id_table = rv8803_id, +}; +module_i2c_driver(rv8803_driver); + +MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>"); +MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver"); +MODULE_LICENSE("GPL v2"); |