1 files changed, 204 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
new file mode 100644
index 000000000000..6a12bf62c504
--- /dev/null
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -0,0 +1,204 @@
+/*
+ * 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);