rtc: Ramtron FM3130 RTC support
authorSergey Lapin <slapin@ossfans.org>
Thu, 12 Jun 2008 22:21:55 +0000 (15:21 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 13 Jun 2008 01:05:42 +0000 (18:05 -0700)
Ramtron FM3130 is a chip with two separate devices inside, RTC clock and
FRAM.  This driver provides only RTC functionality.

This chip is met in lots of custom boards with AT91SAMXXXX CPU I work
with, is cheap and in no way better or worse than any other RTC on market.
 While it is mostly met on much smaller devices, I think it is great to
have it supported in Linux.

Signed-off-by: Sergey Lapin <slapin@ossfans.org>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-fm3130.c [new file with mode: 0644]

index 60f8afc7a56ee643209b133e7eaa88042ff2e001..4949dc4859be662806b62eb60c487702648570eb 100644 (file)
@@ -256,6 +256,17 @@ config RTC_DRV_S35390A
          This driver can also be built as a module. If so the module
          will be called rtc-s35390a.
 
+config RTC_DRV_FM3130
+       tristate "Ramtron FM3130"
+       help
+         If you say Y here you will get support for the
+         Ramtron FM3130 RTC chips.
+         Ramtron FM3130 is a chip with two separate devices inside,
+         RTC clock and FRAM. This driver provides only RTC functionality.
+
+         This driver can also be built as a module. If so the module
+         will be called rtc-fm3130.
+
 endif # I2C
 
 comment "SPI RTC drivers"
index ebe871cf16c1c26395633b8bf364c4056b761de2..b6e14d51670b83556c688458c044c3433be8900f 100644 (file)
@@ -31,6 +31,7 @@ obj-$(CONFIG_RTC_DRV_DS1553)  += rtc-ds1553.o
 obj-$(CONFIG_RTC_DRV_DS1672)   += rtc-ds1672.o
 obj-$(CONFIG_RTC_DRV_DS1742)   += rtc-ds1742.o
 obj-$(CONFIG_RTC_DRV_EP93XX)   += rtc-ep93xx.o
+obj-$(CONFIG_RTC_DRV_FM3130)   += rtc-fm3130.o
 obj-$(CONFIG_RTC_DRV_ISL1208)  += rtc-isl1208.o
 obj-$(CONFIG_RTC_DRV_M41T80)   += rtc-m41t80.o
 obj-$(CONFIG_RTC_DRV_M48T59)   += rtc-m48t59.o
@@ -41,6 +42,7 @@ obj-$(CONFIG_RTC_DRV_OMAP)    += rtc-omap.o
 obj-$(CONFIG_RTC_DRV_PCF8563)  += rtc-pcf8563.o
 obj-$(CONFIG_RTC_DRV_PCF8583)  += rtc-pcf8583.o
 obj-$(CONFIG_RTC_DRV_PL031)    += rtc-pl031.o
+obj-$(CONFIG_RTC_DRV_PPC)      += rtc-ppc.o
 obj-$(CONFIG_RTC_DRV_R9701)    += rtc-r9701.o
 obj-$(CONFIG_RTC_DRV_RS5C313)  += rtc-rs5c313.o
 obj-$(CONFIG_RTC_DRV_RS5C348)  += rtc-rs5c348.o
@@ -54,4 +56,3 @@ obj-$(CONFIG_RTC_DRV_TEST)    += rtc-test.o
 obj-$(CONFIG_RTC_DRV_V3020)    += rtc-v3020.o
 obj-$(CONFIG_RTC_DRV_VR41XX)   += rtc-vr41xx.o
 obj-$(CONFIG_RTC_DRV_X1205)    += rtc-x1205.o
-obj-$(CONFIG_RTC_DRV_PPC)      += rtc-ppc.o
diff --git a/drivers/rtc/rtc-fm3130.c b/drivers/rtc/rtc-fm3130.c
new file mode 100644 (file)
index 0000000..11644c8
--- /dev/null
@@ -0,0 +1,501 @@
+/*
+ * rtc-fm3130.c - RTC driver for Ramtron FM3130 I2C chip.
+ *
+ *  Copyright (C) 2008 Sergey Lapin
+ *  Based on ds1307 driver by James Chapman and David Brownell
+ *
+ * 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/module.h>
+#include <linux/i2c.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+
+#define FM3130_RTC_CONTROL     (0x0)
+#define FM3130_CAL_CONTROL     (0x1)
+#define FM3130_RTC_SECONDS     (0x2)
+#define FM3130_RTC_MINUTES     (0x3)
+#define FM3130_RTC_HOURS       (0x4)
+#define FM3130_RTC_DAY         (0x5)
+#define FM3130_RTC_DATE                (0x6)
+#define FM3130_RTC_MONTHS      (0x7)
+#define FM3130_RTC_YEARS       (0x8)
+
+#define FM3130_ALARM_SECONDS   (0x9)
+#define FM3130_ALARM_MINUTES   (0xa)
+#define FM3130_ALARM_HOURS     (0xb)
+#define FM3130_ALARM_DATE      (0xc)
+#define FM3130_ALARM_MONTHS    (0xd)
+#define FM3130_ALARM_WP_CONTROL        (0xe)
+
+#define FM3130_CAL_CONTROL_BIT_nOSCEN (1 << 7) /* Osciallator enabled */
+#define FM3130_RTC_CONTROL_BIT_LB (1 << 7) /* Low battery */
+#define FM3130_RTC_CONTROL_BIT_AF (1 << 6) /* Alarm flag */
+#define FM3130_RTC_CONTROL_BIT_CF (1 << 5) /* Century overflow */
+#define FM3130_RTC_CONTROL_BIT_POR (1 << 4) /* Power on reset */
+#define FM3130_RTC_CONTROL_BIT_AEN (1 << 3) /* Alarm enable */
+#define FM3130_RTC_CONTROL_BIT_CAL (1 << 2) /* Calibration mode */
+#define FM3130_RTC_CONTROL_BIT_WRITE (1 << 1) /* W=1 -> write mode W=0 normal */
+#define FM3130_RTC_CONTROL_BIT_READ (1 << 0) /* R=1 -> read mode R=0 normal */
+
+#define FM3130_CLOCK_REGS 7
+#define FM3130_ALARM_REGS 5
+
+struct fm3130 {
+       u8                      reg_addr_time;
+       u8                      reg_addr_alarm;
+       u8                      regs[15];
+       struct i2c_msg          msg[4];
+       struct i2c_client       *client;
+       struct rtc_device       *rtc;
+       int                     data_valid;
+       int                     alarm;
+};
+static const struct i2c_device_id fm3130_id[] = {
+       { "fm3130-rtc", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, fm3130_id);
+
+#define FM3130_MODE_NORMAL             0
+#define FM3130_MODE_WRITE              1
+#define FM3130_MODE_READ               2
+
+static void fm3130_rtc_mode(struct device *dev, int mode)
+{
+       struct fm3130 *fm3130 = dev_get_drvdata(dev);
+
+       fm3130->regs[FM3130_RTC_CONTROL] =
+               i2c_smbus_read_byte_data(fm3130->client, FM3130_RTC_CONTROL);
+       switch (mode) {
+       case FM3130_MODE_NORMAL:
+               fm3130->regs[FM3130_RTC_CONTROL] &=
+                       ~(FM3130_RTC_CONTROL_BIT_WRITE |
+                       FM3130_RTC_CONTROL_BIT_READ);
+               break;
+       case FM3130_MODE_WRITE:
+               fm3130->regs[FM3130_RTC_CONTROL] |= FM3130_RTC_CONTROL_BIT_WRITE;
+               break;
+       case FM3130_MODE_READ:
+               fm3130->regs[FM3130_RTC_CONTROL] |= FM3130_RTC_CONTROL_BIT_READ;
+               break;
+       default:
+               dev_dbg(dev, "invalid mode %d\n", mode);
+               break;
+       }
+       /* Checking for alarm */
+       if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_AF) {
+               fm3130->alarm = 1;
+               fm3130->regs[FM3130_RTC_CONTROL] &= ~FM3130_RTC_CONTROL_BIT_AF;
+       }
+       i2c_smbus_write_byte_data(fm3130->client,
+                FM3130_RTC_CONTROL, fm3130->regs[FM3130_RTC_CONTROL]);
+}
+
+static int fm3130_get_time(struct device *dev, struct rtc_time *t)
+{
+       struct fm3130 *fm3130 = dev_get_drvdata(dev);
+       int             tmp;
+
+       if (!fm3130->data_valid) {
+               /* We have invalid data in RTC, probably due
+               to battery faults or other problems. Return EIO
+               for now, it will allow us to set data later insted
+               of error during probing which disables device */
+               return -EIO;
+       }
+       fm3130_rtc_mode(dev, FM3130_MODE_READ);
+
+       /* read the RTC date and time registers all at once */
+       tmp = i2c_transfer(to_i2c_adapter(fm3130->client->dev.parent),
+                       fm3130->msg, 2);
+       if (tmp != 2) {
+               dev_err(dev, "%s error %d\n", "read", tmp);
+               return -EIO;
+       }
+
+       fm3130_rtc_mode(dev, FM3130_MODE_NORMAL);
+
+       dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x %02x"
+                       "%02x %02x %02x %02x %02x %02x %02x\n",
+                       "read",
+                       fm3130->regs[0], fm3130->regs[1],
+                       fm3130->regs[2], fm3130->regs[3],
+                       fm3130->regs[4], fm3130->regs[5],
+                       fm3130->regs[6], fm3130->regs[7],
+                       fm3130->regs[8], fm3130->regs[9],
+                       fm3130->regs[0xa], fm3130->regs[0xb],
+                       fm3130->regs[0xc], fm3130->regs[0xd],
+                       fm3130->regs[0xe]);
+
+       t->tm_sec = BCD2BIN(fm3130->regs[FM3130_RTC_SECONDS] & 0x7f);
+       t->tm_min = BCD2BIN(fm3130->regs[FM3130_RTC_MINUTES] & 0x7f);
+       tmp = fm3130->regs[FM3130_RTC_HOURS] & 0x3f;
+       t->tm_hour = BCD2BIN(tmp);
+       t->tm_wday = BCD2BIN(fm3130->regs[FM3130_RTC_DAY] & 0x07) - 1;
+       t->tm_mday = BCD2BIN(fm3130->regs[FM3130_RTC_DATE] & 0x3f);
+       tmp = fm3130->regs[FM3130_RTC_MONTHS] & 0x1f;
+       t->tm_mon = BCD2BIN(tmp) - 1;
+
+       /* assume 20YY not 19YY, and ignore CF bit */
+       t->tm_year = BCD2BIN(fm3130->regs[FM3130_RTC_YEARS]) + 100;
+
+       dev_dbg(dev, "%s secs=%d, mins=%d, "
+               "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
+               "read", t->tm_sec, t->tm_min,
+               t->tm_hour, t->tm_mday,
+               t->tm_mon, t->tm_year, t->tm_wday);
+
+       /* initial clock setting can be undefined */
+       return rtc_valid_tm(t);
+}
+
+
+static int fm3130_set_time(struct device *dev, struct rtc_time *t)
+{
+       struct fm3130 *fm3130 = dev_get_drvdata(dev);
+       int             tmp, i;
+       u8              *buf = fm3130->regs;
+
+       dev_dbg(dev, "%s secs=%d, mins=%d, "
+               "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
+               "write", t->tm_sec, t->tm_min,
+               t->tm_hour, t->tm_mday,
+               t->tm_mon, t->tm_year, t->tm_wday);
+
+       /* first register addr */
+       buf[FM3130_RTC_SECONDS] = BIN2BCD(t->tm_sec);
+       buf[FM3130_RTC_MINUTES] = BIN2BCD(t->tm_min);
+       buf[FM3130_RTC_HOURS] = BIN2BCD(t->tm_hour);
+       buf[FM3130_RTC_DAY] = BIN2BCD(t->tm_wday + 1);
+       buf[FM3130_RTC_DATE] = BIN2BCD(t->tm_mday);
+       buf[FM3130_RTC_MONTHS] = BIN2BCD(t->tm_mon + 1);
+
+       /* assume 20YY not 19YY */
+       tmp = t->tm_year - 100;
+       buf[FM3130_RTC_YEARS] = BIN2BCD(tmp);
+
+       dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x"
+               "%02x %02x %02x %02x %02x %02x %02x %02x\n",
+               "write", buf[0], buf[1], buf[2], buf[3],
+               buf[4], buf[5], buf[6], buf[7],
+               buf[8], buf[9], buf[0xa], buf[0xb],
+               buf[0xc], buf[0xd], buf[0xe]);
+
+       fm3130_rtc_mode(dev, FM3130_MODE_WRITE);
+
+       /* Writing time registers, we don't support multibyte transfers */
+       for (i = 0; i < FM3130_CLOCK_REGS; i++) {
+               i2c_smbus_write_byte_data(fm3130->client,
+                                       FM3130_RTC_SECONDS + i,
+                                       fm3130->regs[FM3130_RTC_SECONDS + i]);
+       }
+
+       fm3130_rtc_mode(dev, FM3130_MODE_NORMAL);
+
+       /* We assume here that data are valid once written */
+       if (!fm3130->data_valid)
+               fm3130->data_valid = 1;
+       return 0;
+}
+
+static int fm3130_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct fm3130 *fm3130 = dev_get_drvdata(dev);
+       int tmp;
+       struct rtc_time *tm = &alrm->time;
+       /* read the RTC alarm registers all at once */
+       tmp = i2c_transfer(to_i2c_adapter(fm3130->client->dev.parent),
+                       &fm3130->msg[2], 2);
+       if (tmp != 2) {
+               dev_err(dev, "%s error %d\n", "read", tmp);
+               return -EIO;
+       }
+       dev_dbg(dev, "alarm read %02x %02x %02x %02x %02x\n",
+                       fm3130->regs[FM3130_ALARM_SECONDS],
+                       fm3130->regs[FM3130_ALARM_MINUTES],
+                       fm3130->regs[FM3130_ALARM_HOURS],
+                       fm3130->regs[FM3130_ALARM_DATE],
+                       fm3130->regs[FM3130_ALARM_MONTHS]);
+
+
+       tm->tm_sec      = BCD2BIN(fm3130->regs[FM3130_ALARM_SECONDS] & 0x7F);
+       tm->tm_min      = BCD2BIN(fm3130->regs[FM3130_ALARM_MINUTES] & 0x7F);
+       tm->tm_hour     = BCD2BIN(fm3130->regs[FM3130_ALARM_HOURS] & 0x3F);
+       tm->tm_mday     = BCD2BIN(fm3130->regs[FM3130_ALARM_DATE] & 0x3F);
+       tm->tm_mon      = BCD2BIN(fm3130->regs[FM3130_ALARM_MONTHS] & 0x1F);
+       if (tm->tm_mon > 0)
+               tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
+       dev_dbg(dev, "%s secs=%d, mins=%d, "
+               "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
+               "read alarm", tm->tm_sec, tm->tm_min,
+               tm->tm_hour, tm->tm_mday,
+               tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+       return 0;
+}
+
+static int fm3130_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct fm3130 *fm3130 = dev_get_drvdata(dev);
+       struct rtc_time *tm = &alrm->time;
+       int i;
+
+       dev_dbg(dev, "%s secs=%d, mins=%d, "
+               "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
+               "write alarm", tm->tm_sec, tm->tm_min,
+               tm->tm_hour, tm->tm_mday,
+               tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+       if (tm->tm_sec != -1)
+               fm3130->regs[FM3130_ALARM_SECONDS] =
+                       BIN2BCD(tm->tm_sec) | 0x80;
+
+       if (tm->tm_min != -1)
+               fm3130->regs[FM3130_ALARM_MINUTES] =
+                       BIN2BCD(tm->tm_min) | 0x80;
+
+       if (tm->tm_hour != -1)
+               fm3130->regs[FM3130_ALARM_HOURS] =
+                       BIN2BCD(tm->tm_hour) | 0x80;
+
+       if (tm->tm_mday != -1)
+               fm3130->regs[FM3130_ALARM_DATE] =
+                       BIN2BCD(tm->tm_mday) | 0x80;
+
+       if (tm->tm_mon != -1)
+               fm3130->regs[FM3130_ALARM_MONTHS] =
+                       BIN2BCD(tm->tm_mon + 1) | 0x80;
+
+       dev_dbg(dev, "alarm write %02x %02x %02x %02x %02x\n",
+                       fm3130->regs[FM3130_ALARM_SECONDS],
+                       fm3130->regs[FM3130_ALARM_MINUTES],
+                       fm3130->regs[FM3130_ALARM_HOURS],
+                       fm3130->regs[FM3130_ALARM_DATE],
+                       fm3130->regs[FM3130_ALARM_MONTHS]);
+       /* Writing time registers, we don't support multibyte transfers */
+       for (i = 0; i < FM3130_ALARM_REGS; i++) {
+               i2c_smbus_write_byte_data(fm3130->client,
+                                       FM3130_ALARM_SECONDS + i,
+                                       fm3130->regs[FM3130_ALARM_SECONDS + i]);
+       }
+       fm3130->regs[FM3130_RTC_CONTROL] =
+               i2c_smbus_read_byte_data(fm3130->client, FM3130_RTC_CONTROL);
+       /* Checking for alarm */
+       if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_AF) {
+               fm3130->alarm = 1;
+               fm3130->regs[FM3130_RTC_CONTROL] &= ~FM3130_RTC_CONTROL_BIT_AF;
+       }
+       if (alrm->enabled) {
+               i2c_smbus_write_byte_data(fm3130->client, FM3130_RTC_CONTROL,
+                       (fm3130->regs[FM3130_RTC_CONTROL] &
+                               ~(FM3130_RTC_CONTROL_BIT_CAL)) |
+                                       FM3130_RTC_CONTROL_BIT_AEN);
+       } else {
+               i2c_smbus_write_byte_data(fm3130->client, FM3130_RTC_CONTROL,
+                       fm3130->regs[FM3130_RTC_CONTROL] &
+                               ~(FM3130_RTC_CONTROL_BIT_AEN));
+       }
+       return 0;
+}
+
+static const struct rtc_class_ops fm3130_rtc_ops = {
+       .read_time      = fm3130_get_time,
+       .set_time       = fm3130_set_time,
+       .read_alarm     = fm3130_read_alarm,
+       .set_alarm      = fm3130_set_alarm,
+};
+
+static struct i2c_driver fm3130_driver;
+
+static int __devinit fm3130_probe(struct i2c_client *client,
+                                 const struct i2c_device_id *id)
+{
+       struct fm3130           *fm3130;
+       int                     err = -ENODEV;
+       int                     tmp;
+       struct i2c_adapter      *adapter = to_i2c_adapter(client->dev.parent);
+
+       if (!i2c_check_functionality(adapter,
+                       I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
+               return -EIO;
+
+       fm3130 = kzalloc(sizeof(struct fm3130), GFP_KERNEL);
+
+       if (!fm3130)
+               return -ENOMEM;
+
+       fm3130->client = client;
+       i2c_set_clientdata(client, fm3130);
+       fm3130->reg_addr_time = FM3130_RTC_SECONDS;
+       fm3130->reg_addr_alarm = FM3130_ALARM_SECONDS;
+
+       /* Messages to read time */
+       fm3130->msg[0].addr = client->addr;
+       fm3130->msg[0].flags = 0;
+       fm3130->msg[0].len = 1;
+       fm3130->msg[0].buf = &fm3130->reg_addr_time;
+
+       fm3130->msg[1].addr = client->addr;
+       fm3130->msg[1].flags = I2C_M_RD;
+       fm3130->msg[1].len = FM3130_CLOCK_REGS;
+       fm3130->msg[1].buf = &fm3130->regs[FM3130_RTC_SECONDS];
+
+       /* Messages to read alarm */
+       fm3130->msg[2].addr = client->addr;
+       fm3130->msg[2].flags = 0;
+       fm3130->msg[2].len = 1;
+       fm3130->msg[2].buf = &fm3130->reg_addr_alarm;
+
+       fm3130->msg[3].addr = client->addr;
+       fm3130->msg[3].flags = I2C_M_RD;
+       fm3130->msg[3].len = FM3130_ALARM_REGS;
+       fm3130->msg[3].buf = &fm3130->regs[FM3130_ALARM_SECONDS];
+
+       fm3130->data_valid = 0;
+
+       tmp = i2c_transfer(adapter, fm3130->msg, 4);
+       if (tmp != 4) {
+               pr_debug("read error %d\n", tmp);
+               err = -EIO;
+               goto exit_free;
+       }
+
+       fm3130->regs[FM3130_RTC_CONTROL] =
+               i2c_smbus_read_byte_data(client, FM3130_RTC_CONTROL);
+       fm3130->regs[FM3130_CAL_CONTROL] =
+               i2c_smbus_read_byte_data(client, FM3130_CAL_CONTROL);
+
+       /* Checking for alarm */
+       if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_AF) {
+               fm3130->alarm = 1;
+               fm3130->regs[FM3130_RTC_CONTROL] &= ~FM3130_RTC_CONTROL_BIT_AF;
+       }
+
+       /* Disabling calibration mode */
+       if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_CAL)
+               i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL,
+                       fm3130->regs[FM3130_RTC_CONTROL] &
+                               ~(FM3130_RTC_CONTROL_BIT_CAL));
+               dev_warn(&client->dev, "Disabling calibration mode!\n");
+
+       /* Disabling read and write modes */
+       if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_WRITE ||
+           fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_READ)
+               i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL,
+                       fm3130->regs[FM3130_RTC_CONTROL] &
+                               ~(FM3130_RTC_CONTROL_BIT_READ |
+                                       FM3130_RTC_CONTROL_BIT_WRITE));
+               dev_warn(&client->dev, "Disabling READ or WRITE mode!\n");
+
+       /* oscillator off?  turn it on, so clock can tick. */
+       if (fm3130->regs[FM3130_CAL_CONTROL] & FM3130_CAL_CONTROL_BIT_nOSCEN)
+               i2c_smbus_write_byte_data(client, FM3130_CAL_CONTROL,
+                       fm3130->regs[FM3130_CAL_CONTROL] &
+                               ~(FM3130_CAL_CONTROL_BIT_nOSCEN));
+
+       /* oscillator fault?  clear flag, and warn */
+       if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_LB)
+               dev_warn(&client->dev, "Low battery!\n");
+
+       /* oscillator fault?  clear flag, and warn */
+       if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_POR) {
+               i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL,
+                       fm3130->regs[FM3130_RTC_CONTROL] &
+                               ~FM3130_RTC_CONTROL_BIT_POR);
+               dev_warn(&client->dev, "SET TIME!\n");
+       }
+       /* ACS is controlled by alarm */
+       i2c_smbus_write_byte_data(client, FM3130_ALARM_WP_CONTROL, 0x80);
+
+       /* TODO */
+       /* TODO need to sanity check alarm */
+       tmp = fm3130->regs[FM3130_RTC_SECONDS];
+       tmp = BCD2BIN(tmp & 0x7f);
+       if (tmp > 60)
+               goto exit_bad;
+       tmp = BCD2BIN(fm3130->regs[FM3130_RTC_MINUTES] & 0x7f);
+       if (tmp > 60)
+               goto exit_bad;
+
+       tmp = BCD2BIN(fm3130->regs[FM3130_RTC_DATE] & 0x3f);
+       if (tmp == 0 || tmp > 31)
+               goto exit_bad;
+
+       tmp = BCD2BIN(fm3130->regs[FM3130_RTC_MONTHS] & 0x1f);
+       if (tmp == 0 || tmp > 12)
+               goto exit_bad;
+
+       tmp = fm3130->regs[FM3130_RTC_HOURS];
+
+       fm3130->data_valid = 1;
+
+exit_bad:
+       if (!fm3130->data_valid)
+               dev_dbg(&client->dev,
+                               "%s: %02x %02x %02x %02x %02x %02x %02x %02x"
+                               "%02x %02x %02x %02x %02x %02x %02x\n",
+                       "bogus registers",
+                       fm3130->regs[0], fm3130->regs[1],
+                       fm3130->regs[2], fm3130->regs[3],
+                       fm3130->regs[4], fm3130->regs[5],
+                       fm3130->regs[6], fm3130->regs[7],
+                       fm3130->regs[8], fm3130->regs[9],
+                       fm3130->regs[0xa], fm3130->regs[0xb],
+                       fm3130->regs[0xc], fm3130->regs[0xd],
+                       fm3130->regs[0xe]);
+
+       /* We won't bail out here because we just got invalid data.
+          Time setting from u-boot doesn't work anyway */
+       fm3130->rtc = rtc_device_register(client->name, &client->dev,
+                               &fm3130_rtc_ops, THIS_MODULE);
+       if (IS_ERR(fm3130->rtc)) {
+               err = PTR_ERR(fm3130->rtc);
+               dev_err(&client->dev,
+                       "unable to register the class device\n");
+               goto exit_free;
+       }
+       return 0;
+exit_free:
+       kfree(fm3130);
+       return err;
+}
+
+static int __devexit fm3130_remove(struct i2c_client *client)
+{
+       struct fm3130 *fm3130 = i2c_get_clientdata(client);
+
+       rtc_device_unregister(fm3130->rtc);
+       kfree(fm3130);
+       return 0;
+}
+
+static struct i2c_driver fm3130_driver = {
+       .driver = {
+               .name   = "rtc-fm3130",
+               .owner  = THIS_MODULE,
+       },
+       .probe          = fm3130_probe,
+       .remove         = __devexit_p(fm3130_remove),
+       .id_table       = fm3130_id,
+};
+
+static int __init fm3130_init(void)
+{
+       return i2c_add_driver(&fm3130_driver);
+}
+module_init(fm3130_init);
+
+static void __exit fm3130_exit(void)
+{
+       i2c_del_driver(&fm3130_driver);
+}
+module_exit(fm3130_exit);
+
+MODULE_DESCRIPTION("RTC driver for FM3130");
+MODULE_AUTHOR("Sergey Lapin <slapin@ossfans.org>");
+MODULE_LICENSE("GPL");
+