--- /dev/null
+/*
+ * An I2C driver for the PCF85063 RTC
+ * Copyright 2014 Rose Technology
+ *
+ * Author: Søren Andersen <san@rosetechnology.dk>
+ * Maintainers: http://www.nslu2-linux.org/
+ *
+ * based on the other drivers in this same directory.
+ *
+ * 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/i2c.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+#include <linux/module.h>
+
+#define DRV_VERSION "0.0.1"
+
+#define PCF85063_REG_CTRL1 0x00 /* status */
+#define PCF85063_REG_CTRL2 0x01
+
+#define PCF85063_REG_SC 0x04 /* datetime */
+#define PCF85063_REG_MN 0x05
+#define PCF85063_REG_HR 0x06
+#define PCF85063_REG_DM 0x07
+#define PCF85063_REG_DW 0x08
+#define PCF85063_REG_MO 0x09
+#define PCF85063_REG_YR 0x0A
+
+#define PCF85063_MO_C 0x80 /* century */
+
+static struct i2c_driver pcf85063_driver;
+
+struct pcf85063 {
+ struct rtc_device *rtc;
+ int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
+ int voltage_low; /* indicates if a low_voltage was detected */
+};
+
+/*
+ * In the routines that deal directly with the pcf85063 hardware, we use
+ * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
+ */
+static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)
+{
+ struct pcf85063 *pcf85063 = i2c_get_clientdata(client);
+ unsigned char buf[13] = { PCF85063_REG_CTRL1 };
+ struct i2c_msg msgs[] = {
+ {/* setup read ptr */
+ .addr = client->addr,
+ .len = 1,
+ .buf = buf
+ },
+ {/* read status + date */
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = 13,
+ .buf = buf
+ },
+ };
+
+ /* read registers */
+ if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
+ dev_err(&client->dev, "%s: read error\n", __func__);
+ return -EIO;
+ }
+
+ tm->tm_sec = bcd2bin(buf[PCF85063_REG_SC] & 0x7F);
+ tm->tm_min = bcd2bin(buf[PCF85063_REG_MN] & 0x7F);
+ tm->tm_hour = bcd2bin(buf[PCF85063_REG_HR] & 0x3F); /* rtc hr 0-23 */
+ tm->tm_mday = bcd2bin(buf[PCF85063_REG_DM] & 0x3F);
+ tm->tm_wday = buf[PCF85063_REG_DW] & 0x07;
+ tm->tm_mon = bcd2bin(buf[PCF85063_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
+ tm->tm_year = bcd2bin(buf[PCF85063_REG_YR]);
+ if (tm->tm_year < 70)
+ tm->tm_year += 100; /* assume we are in 1970...2069 */
+ /* detect the polarity heuristically. see note above. */
+ pcf85063->c_polarity = (buf[PCF85063_REG_MO] & PCF85063_MO_C) ?
+ (tm->tm_year >= 100) : (tm->tm_year < 100);
+
+ /* the clock can give out invalid datetime, but we cannot return
+ * -EINVAL otherwise hwclock will refuse to set the time on bootup.
+ */
+ if (rtc_valid_tm(tm) < 0)
+ dev_err(&client->dev, "retrieved date/time is not valid.\n");
+
+ return 0;
+}
+
+static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)
+{
+ int i = 0, err = 0;
+ unsigned char buf[11];
+
+ /* Control & status */
+ buf[PCF85063_REG_CTRL1] = 0;
+ buf[PCF85063_REG_CTRL2] = 5;
+
+ /* hours, minutes and seconds */
+ buf[PCF85063_REG_SC] = bin2bcd(tm->tm_sec) & 0x7F;
+
+ buf[PCF85063_REG_MN] = bin2bcd(tm->tm_min);
+ buf[PCF85063_REG_HR] = bin2bcd(tm->tm_hour);
+
+ /* Day of month, 1 - 31 */
+ buf[PCF85063_REG_DM] = bin2bcd(tm->tm_mday);
+
+ /* Day, 0 - 6 */
+ buf[PCF85063_REG_DW] = tm->tm_wday & 0x07;
+
+ /* month, 1 - 12 */
+ buf[PCF85063_REG_MO] = bin2bcd(tm->tm_mon + 1);
+
+ /* year and century */
+ buf[PCF85063_REG_YR] = bin2bcd(tm->tm_year % 100);
+
+ /* write register's data */
+ for (i = 0; i < sizeof(buf); i++) {
+ unsigned char data[2] = { i, buf[i] };
+
+ err = i2c_master_send(client, data, sizeof(data));
+ if (err != sizeof(data)) {
+ dev_err(&client->dev, "%s: err=%d addr=%02x, data=%02x\n",
+ __func__, err, data[0], data[1]);
+ return -EIO;
+ }
+ }
+
+ return 0;
+}
+
+static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ return pcf85063_get_datetime(to_i2c_client(dev), tm);
+}
+
+static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ return pcf85063_set_datetime(to_i2c_client(dev), tm);
+}
+
+static const struct rtc_class_ops pcf85063_rtc_ops = {
+ .read_time = pcf85063_rtc_read_time,
+ .set_time = pcf85063_rtc_set_time
+};
+
+static int pcf85063_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct pcf85063 *pcf85063;
+
+ dev_dbg(&client->dev, "%s\n", __func__);
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+ return -ENODEV;
+
+ pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063),
+ GFP_KERNEL);
+ if (!pcf85063)
+ return -ENOMEM;
+
+ dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
+
+ i2c_set_clientdata(client, pcf85063);
+
+ pcf85063->rtc = devm_rtc_device_register(&client->dev,
+ pcf85063_driver.driver.name,
+ &pcf85063_rtc_ops, THIS_MODULE);
+
+ return PTR_ERR_OR_ZERO(pcf85063->rtc);
+}
+
+static const struct i2c_device_id pcf85063_id[] = {
+ { "pcf85063", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, pcf85063_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id pcf85063_of_match[] = {
+ { .compatible = "nxp,pcf85063" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, pcf85063_of_match);
+#endif
+
+static struct i2c_driver pcf85063_driver = {
+ .driver = {
+ .name = "rtc-pcf85063",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(pcf85063_of_match),
+ },
+ .probe = pcf85063_probe,
+ .id_table = pcf85063_id,
+};
+
+module_i2c_driver(pcf85063_driver);
+
+MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>");
+MODULE_DESCRIPTION("PCF85063 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
Code Review / kvmfornfv.git / blobdiff