--- /dev/null
+/*
+ * 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 *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)) {
+ u8 date2[7];
+
+ 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");
projects / karo-tx-linux.git / commitdiff