[PATCH] Update the rtc-rs5c372 driver

 Bugfixes:
  - Handle RTCs which are configured to use 12-hour mode.
  - Never report bogus/un-initialized times.
  - Displaying "raw trim" requires not masking it first!
  - Fix the sysfs and procfs display of crystal and trim data.

 Features:
  - Handle other RTCs in this family, notably rv5c386/rv5c387.
  - Declare the other registers.
  - Provide alarm get/set functionality.
  - Handle AIE and UIE; but no IRQ handling yet.

 Cleanup:
  - Shrink object by not including needless sysfs or procfs support
  - We don't need no steenkin' forward declarations.  (Except one.)

Until the I2C framework merges "new style" driver support, matching
the driver model better, using rv5c chips or alarm IRQs requires a
separate board-specific patch.  (And an IRQ handler, handing off labor
through a work_struct...)

This uses the "method 3" register reads, but notes that it's done
to work around an evident i2c adapter driver bug.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 467 insertions, 68 deletions

diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
index 1460f6b769f2..e7851e3739ab 100644
--- a/drivers/rtc/rtc-rs5c372.c
+++ b/drivers/rtc/rtc-rs5c372.c
@@ -1,5 +1,5 @@
 /*
- * An I2C driver for the Ricoh RS5C372 RTC
+ * An I2C driver for Ricoh RS5C372 and RV5C38[67] RTCs
  *
  * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
  * Copyright (C) 2006 Tower Technologies
@@ -13,7 +13,7 @@
 #include <linux/rtc.h>
 #include <linux/bcd.h>
 
-#define DRV_VERSION "0.3"
+#define DRV_VERSION "0.4"
 
 /* Addresses to scan */
 static unsigned short normal_i2c[] = { /* 0x32,*/ I2C_CLIENT_END };
@@ -21,6 +21,13 @@ static unsigned short normal_i2c[] = { /* 0x32,*/ I2C_CLIENT_END };
 /* Insmod parameters */
 I2C_CLIENT_INSMOD;
 
+
+/*
+ * Ricoh has a family of I2C based RTCs, which differ only slightly from
+ * each other.  Differences center on pinout (e.g. how many interrupts,
+ * output clock, etc) and how the control registers are used.  The '372
+ * is significant only because that's the one this driver first supported.
+ */
 #define RS5C372_REG_SECS        0
 #define RS5C372_REG_MINS        1
 #define RS5C372_REG_HOURS       2
@@ -29,59 +36,142 @@ I2C_CLIENT_INSMOD;
 #define RS5C372_REG_MONTH       5
 #define RS5C372_REG_YEAR        6
 #define RS5C372_REG_TRIM        7
+#       define RS5C372_TRIM_XSL         0x80
+#       define RS5C372_TRIM_MASK        0x7F
+
+#define RS5C_REG_ALARM_A_MIN    8                       /* or ALARM_W */
+#define RS5C_REG_ALARM_A_HOURS  9
+#define RS5C_REG_ALARM_A_WDAY   10
+
+#define RS5C_REG_ALARM_B_MIN    11                      /* or ALARM_D */
+#define RS5C_REG_ALARM_B_HOURS  12
+#define RS5C_REG_ALARM_B_WDAY   13                      /* (ALARM_B only) */
+
+#define RS5C_REG_CTRL1          14
+#       define RS5C_CTRL1_AALE          (1 << 7)        /* or WALE */
+#       define RS5C_CTRL1_BALE          (1 << 6)        /* or DALE */
+#       define RV5C387_CTRL1_24         (1 << 5)
+#       define RS5C372A_CTRL1_SL1       (1 << 5)
+#       define RS5C_CTRL1_CT_MASK       (7 << 0)
+#       define RS5C_CTRL1_CT0           (0 << 0)        /* no periodic irq */
+#       define RS5C_CTRL1_CT4           (4 << 0)        /* 1 Hz level irq */
+#define RS5C_REG_CTRL2          15
+#       define RS5C372_CTRL2_24         (1 << 5)
+#       define RS5C_CTRL2_XSTP          (1 << 4)
+#       define RS5C_CTRL2_CTFG          (1 << 2)
+#       define RS5C_CTRL2_AAFG          (1 << 1)        /* or WAFG */
+#       define RS5C_CTRL2_BAFG          (1 << 0)        /* or DAFG */
+
+
+/* to read (style 1) or write registers starting at R */
+#define RS5C_ADDR(R)            (((R) << 4) | 0)
+
+
+enum rtc_type {
+        rtc_undef = 0,
+        rtc_rs5c372a,
+        rtc_rs5c372b,
+        rtc_rv5c386,
+        rtc_rv5c387a,
+};
 
-#define RS5C372_TRIM_XSL        0x80
-#define RS5C372_TRIM_MASK       0x7F
+/* REVISIT:  this assumes that:
+ *  - we're in the 21st century, so it's safe to ignore the century
+ *    bit for rv5c38[67] (REG_MONTH bit 7);
+ *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
+ */
+struct rs5c372 {
+        struct i2c_client       *client;
+        struct rtc_device       *rtc;
+        enum rtc_type           type;
+        unsigned                time24:1;
+        unsigned                has_irq:1;
+        char                    buf[17];
+        char                    *regs;
+
+        /* on conversion to a "new style" i2c driver, this vanishes */
+        struct i2c_client       dev;
+};
 
-#define RS5C372_REG_BASE        0
+static int rs5c_get_regs(struct rs5c372 *rs5c)
+{
+        struct i2c_client       *client = rs5c->client;
+        struct i2c_msg          msgs[] = {
+                { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
+        };
+
+        /* This implements the third reading method from the datasheet, using
+         * an internal address that's reset after each transaction (by STOP)
+         * to 0x0f ... so we read extra registers, and skip the first one.
+         *
+         * The first method doesn't work with the iop3xx adapter driver, on at
+         * least 80219 chips; this works around that bug.
+         */
+        if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
+                pr_debug("%s: can't read registers\n", rs5c->rtc->name);
+                return -EIO;
+        }
 
-static int rs5c372_attach(struct i2c_adapter *adapter);
-static int rs5c372_detach(struct i2c_client *client);
-static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind);
+        dev_dbg(&client->dev,
+                "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
+                "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
+                rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
+                rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
+                rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
+                rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
 
-struct rs5c372 {
-        u8 reg_addr;
-        u8 regs[17];
-        struct i2c_msg msg[1];
-        struct i2c_client client;
-        struct rtc_device *rtc;
-};
+        return 0;
+}
 
-static struct i2c_driver rs5c372_driver = {
-        .driver         = {
-                .name   = "rs5c372",
-        },
-        .attach_adapter = &rs5c372_attach,
-        .detach_client  = &rs5c372_detach,
-};
+static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
+{
+        unsigned        hour;
 
-static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
+        if (rs5c->time24)
+                return BCD2BIN(reg & 0x3f);
+
+        hour = BCD2BIN(reg & 0x1f);
+        if (hour == 12)
+                hour = 0;
+        if (reg & 0x20)
+                hour += 12;
+        return hour;
+}
+
+static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
 {
+        if (rs5c->time24)
+                return BIN2BCD(hour);
+
+        if (hour > 12)
+                return 0x20 | BIN2BCD(hour - 12);
+        if (hour == 12)
+                return 0x20 | BIN2BCD(12);
+        if (hour == 0)
+                return BIN2BCD(12);
+        return BIN2BCD(hour);
+}
 
-        struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
-        u8 *buf = &(rs5c372->regs[1]);
+static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
+{
+        struct rs5c372  *rs5c = i2c_get_clientdata(client);
+        int             status = rs5c_get_regs(rs5c);
 
-        /* this implements the 3rd reading method, according
-         * to the datasheet. rs5c372 defaults to internal
-         * address 0xF, so 0x0 is in regs[1]
-         */
+        if (status < 0)
+                return status;
 
-        if ((i2c_transfer(client->adapter, rs5c372->msg, 1)) != 1) {
-                dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
-                return -EIO;
-        }
+        tm->tm_sec = BCD2BIN(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
+        tm->tm_min = BCD2BIN(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
+        tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
 
-        tm->tm_sec = BCD2BIN(buf[RS5C372_REG_SECS] & 0x7f);
-        tm->tm_min = BCD2BIN(buf[RS5C372_REG_MINS] & 0x7f);
-        tm->tm_hour = BCD2BIN(buf[RS5C372_REG_HOURS] & 0x3f);
-        tm->tm_wday = BCD2BIN(buf[RS5C372_REG_WDAY] & 0x07);
-        tm->tm_mday = BCD2BIN(buf[RS5C372_REG_DAY] & 0x3f);
+        tm->tm_wday = BCD2BIN(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
+        tm->tm_mday = BCD2BIN(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
 
         /* tm->tm_mon is zero-based */
-        tm->tm_mon = BCD2BIN(buf[RS5C372_REG_MONTH] & 0x1f) - 1;
+        tm->tm_mon = BCD2BIN(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
 
         /* year is 1900 + tm->tm_year */
-        tm->tm_year = BCD2BIN(buf[RS5C372_REG_YEAR]) + 100;
+        tm->tm_year = BCD2BIN(rs5c->regs[RS5C372_REG_YEAR]) + 100;
 
         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
                 "mday=%d, mon=%d, year=%d, wday=%d\n",
@@ -89,22 +179,25 @@ static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
                 tm->tm_sec, tm->tm_min, tm->tm_hour,
                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 
-        return 0;
+        /* rtc might need initialization */
+        return rtc_valid_tm(tm);
 }
 
 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
-        unsigned char buf[8] = { RS5C372_REG_BASE };
+        struct rs5c372  *rs5c = i2c_get_clientdata(client);
+        unsigned char   buf[8];
 
-        dev_dbg(&client->dev,
-                "%s: secs=%d, mins=%d, hours=%d "
+        dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
                 "mday=%d, mon=%d, year=%d, wday=%d\n",
-                __FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour,
+                __FUNCTION__,
+                tm->tm_sec, tm->tm_min, tm->tm_hour,
                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 
+        buf[0] = RS5C_ADDR(RS5C372_REG_SECS);
         buf[1] = BIN2BCD(tm->tm_sec);
         buf[2] = BIN2BCD(tm->tm_min);
-        buf[3] = BIN2BCD(tm->tm_hour);
+        buf[3] = rs5c_hr2reg(rs5c, tm->tm_hour);
         buf[4] = BIN2BCD(tm->tm_wday);
         buf[5] = BIN2BCD(tm->tm_mday);
         buf[6] = BIN2BCD(tm->tm_mon + 1);
@@ -118,21 +211,43 @@ static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
         return 0;
 }
 
+#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
+#define NEED_TRIM
+#endif
+
+#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
+#define NEED_TRIM
+#endif
+
+#ifdef  NEED_TRIM
 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 {
         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
-        u8 tmp = rs5c372->regs[RS5C372_REG_TRIM + 1];
+        u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 
         if (osc)
                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
 
         if (trim) {
-                *trim = tmp & RS5C372_TRIM_MASK;
-                dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, *trim);
+                dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, tmp);
+                tmp &= RS5C372_TRIM_MASK;
+                if (tmp & 0x3e) {
+                        int t = tmp & 0x3f;
+
+                        if (tmp & 0x40)
+                                t = (~t | (s8)0xc0) + 1;
+                        else
+                                t = t - 1;
+
+                        tmp = t * 2;
+                } else
+                        tmp = 0;
+                *trim = tmp;
         }
 
         return 0;
 }
+#endif
 
 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
@@ -144,25 +259,190 @@ static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
         return rs5c372_set_datetime(to_i2c_client(dev), tm);
 }
 
+#if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
+
+static int
+rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+        struct i2c_client       *client = to_i2c_client(dev);
+        struct rs5c372          *rs5c = i2c_get_clientdata(client);
+        unsigned char           buf[2];
+        int                     status;
+
+        buf[1] = rs5c->regs[RS5C_REG_CTRL1];
+        switch (cmd) {
+        case RTC_UIE_OFF:
+        case RTC_UIE_ON:
+                /* some 327a modes use a different IRQ pin for 1Hz irqs */
+                if (rs5c->type == rtc_rs5c372a
+                                && (buf[1] & RS5C372A_CTRL1_SL1))
+                        return -ENOIOCTLCMD;
+        case RTC_AIE_OFF:
+        case RTC_AIE_ON:
+                /* these irq management calls only make sense for chips
+                 * which are wired up to an IRQ.
+                 */
+                if (!rs5c->has_irq)
+                        return -ENOIOCTLCMD;
+                break;
+        default:
+                return -ENOIOCTLCMD;
+        }
+
+        status = rs5c_get_regs(rs5c);
+        if (status < 0)
+                return status;
+
+        buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
+        switch (cmd) {
+        case RTC_AIE_OFF:       /* alarm off */
+                buf[1] &= ~RS5C_CTRL1_AALE;
+                break;
+        case RTC_AIE_ON:        /* alarm on */
+                buf[1] |= RS5C_CTRL1_AALE;
+                break;
+        case RTC_UIE_OFF:       /* update off */
+                buf[1] &= ~RS5C_CTRL1_CT_MASK;
+                break;
+        case RTC_UIE_ON:        /* update on */
+                buf[1] &= ~RS5C_CTRL1_CT_MASK;
+                buf[1] |= RS5C_CTRL1_CT4;
+                break;
+        }
+        if ((i2c_master_send(client, buf, 2)) != 2) {
+                printk(KERN_WARNING "%s: can't update alarm\n",
+                        rs5c->rtc->name);
+                status = -EIO;
+        } else
+                rs5c->regs[RS5C_REG_CTRL1] = buf[1];
+        return status;
+}
+
+#else
+#define rs5c_rtc_ioctl  NULL
+#endif
+
+
+/* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
+ * which only exposes a polled programming interface; and since
+ * these calls map directly to those EFI requests; we don't demand
+ * we have an IRQ for this chip when we go through this API.
+ *
+ * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
+ * though, managed through RTC_AIE_{ON,OFF} requests.
+ */
+
+static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+        struct i2c_client       *client = to_i2c_client(dev);
+        struct rs5c372          *rs5c = i2c_get_clientdata(client);
+        int                     status;
+
+        status = rs5c_get_regs(rs5c);
+        if (status < 0)
+                return status;
+
+        /* report alarm time */
+        t->time.tm_sec = 0;
+        t->time.tm_min = BCD2BIN(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
+        t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
+        t->time.tm_mday = -1;
+        t->time.tm_mon = -1;
+        t->time.tm_year = -1;
+        t->time.tm_wday = -1;
+        t->time.tm_yday = -1;
+        t->time.tm_isdst = -1;
+
+        /* ... and status */
+        t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
+        t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
+
+        return 0;
+}
+
+static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+        struct i2c_client       *client = to_i2c_client(dev);
+        struct rs5c372          *rs5c = i2c_get_clientdata(client);
+        int                     status;
+        unsigned char           buf[4];
+
+        /* only handle up to 24 hours in the future, like RTC_ALM_SET */
+        if (t->time.tm_mday != -1
+                        || t->time.tm_mon != -1
+                        || t->time.tm_year != -1)
+                return -EINVAL;
+
+        /* REVISIT: round up tm_sec */
+
+        /* if needed, disable irq (clears pending status) */
+        status = rs5c_get_regs(rs5c);
+        if (status < 0)
+                return status;
+        if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
+                buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
+                buf[1] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
+                if (i2c_master_send(client, buf, 2) != 2) {
+                        pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
+                        return -EIO;
+                }
+                rs5c->regs[RS5C_REG_CTRL1] = buf[1];
+        }
+
+        /* set alarm */
+        buf[0] = RS5C_ADDR(RS5C_REG_ALARM_A_MIN);
+        buf[1] = BIN2BCD(t->time.tm_min);
+        buf[2] = rs5c_hr2reg(rs5c, t->time.tm_hour);
+        buf[3] = 0x7f;  /* any/all days */
+        if ((i2c_master_send(client, buf, 4)) != 4) {
+                pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
+                return -EIO;
+        }
+
+        /* ... and maybe enable its irq */
+        if (t->enabled) {
+                buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
+                buf[1] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
+                if ((i2c_master_send(client, buf, 2)) != 2)
+                        printk(KERN_WARNING "%s: can't enable alarm\n",
+                                rs5c->rtc->name);
+                rs5c->regs[RS5C_REG_CTRL1] = buf[1];
+        }
+
+        return 0;
+}
+
+#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
+
 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 {
         int err, osc, trim;
 
         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
         if (err == 0) {
-                seq_printf(seq, "%d.%03d KHz\n", osc / 1000, osc % 1000);
-                seq_printf(seq, "trim\t: %d\n", trim);
+                seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
+                                osc / 1000, osc % 1000);
+                seq_printf(seq, "trim\t\t: %d\n", trim);
         }
 
         return 0;
 }
 
+#else
+#define rs5c372_rtc_proc        NULL
+#endif
+
 static const struct rtc_class_ops rs5c372_rtc_ops = {
         .proc           = rs5c372_rtc_proc,
+        .ioctl          = rs5c_rtc_ioctl,
         .read_time      = rs5c372_rtc_read_time,
         .set_time       = rs5c372_rtc_set_time,
+        .read_alarm     = rs5c_read_alarm,
+        .set_alarm      = rs5c_set_alarm,
 };
 
+#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
+
 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
                                 struct device_attribute *attr, char *buf)
 {
@@ -172,7 +452,7 @@ static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
         if (err)
                 return err;
 
-        return sprintf(buf, "0x%2x\n", trim);
+        return sprintf(buf, "%d\n", trim);
 }
 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 
@@ -189,16 +469,35 @@ static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
 }
 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 
-static int rs5c372_attach(struct i2c_adapter *adapter)
+static int rs5c_sysfs_register(struct device *dev)
 {
-        return i2c_probe(adapter, &addr_data, rs5c372_probe);
+        int err;
+
+        err = device_create_file(dev, &dev_attr_trim);
+        if (err)
+                return err;
+        err = device_create_file(dev, &dev_attr_osc);
+        if (err)
+                device_remove_file(dev, &dev_attr_trim);
+
+        return err;
+}
+
+#else
+static int rs5c_sysfs_register(struct device *dev)
+{
+        return 0;
 }
+#endif  /* SYSFS */
+
+static struct i2c_driver rs5c372_driver;
 
 static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind)
 {
         int err = 0;
         struct i2c_client *client;
         struct rs5c372 *rs5c372;
+        struct rtc_time tm;
 
         dev_dbg(adapter->class_dev.dev, "%s\n", __FUNCTION__);
 
@@ -211,7 +510,15 @@ static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind)
                 err = -ENOMEM;
                 goto exit;
         }
-        client = &rs5c372->client;
+
+        /* we read registers 0x0f then 0x00-0x0f; skip the first one */
+        rs5c372->regs=&rs5c372->buf[1];
+
+        /* On conversion to a "new style" i2c driver, we'll be handed
+         * the i2c_client (we won't create it)
+         */
+        client = &rs5c372->dev;
+        rs5c372->client = client;
 
         /* I2C client */
         client->addr = address;
@@ -222,16 +529,99 @@ static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind)
 
         i2c_set_clientdata(client, rs5c372);
 
-        rs5c372->msg[0].addr = address;
-        rs5c372->msg[0].flags = I2C_M_RD;
-        rs5c372->msg[0].len = sizeof(rs5c372->regs);
-        rs5c372->msg[0].buf = rs5c372->regs;
-
         /* Inform the i2c layer */
         if ((err = i2c_attach_client(client)))
                 goto exit_kfree;
 
-        dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
+        err = rs5c_get_regs(rs5c372);
+        if (err < 0)
+                goto exit_detach;
+
+        /* For "new style" drivers, irq is in i2c_client and chip type
+         * info comes from i2c_client.dev.platform_data.  Meanwhile:
+         *
+         * STICK BOARD-SPECIFIC SETUP CODE RIGHT HERE
+         */
+        if (rs5c372->type == rtc_undef) {
+                rs5c372->type = rtc_rs5c372b;
+                dev_warn(&client->dev, "assuming rs5c372b\n");
+        }
+
+        /* clock may be set for am/pm or 24 hr time */
+        switch (rs5c372->type) {
+        case rtc_rs5c372a:
+        case rtc_rs5c372b:
+                /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
+                 * so does periodic irq, except some 327a modes.
+                 */
+                if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
+                        rs5c372->time24 = 1;
+                break;
+        case rtc_rv5c386:
+        case rtc_rv5c387a:
+                if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
+                        rs5c372->time24 = 1;
+                /* alarm uses ALARM_W; and nINTRB for alarm and periodic
+                 * irq, on both 386 and 387
+                 */
+                break;
+        default:
+                dev_err(&client->dev, "unknown RTC type\n");
+                goto exit_detach;
+        }
+
+        /* if the oscillator lost power and no other software (like
+         * the bootloader) set it up, do it here.
+         */
+        if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP) {
+                unsigned char buf[3];
+
+                rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
+
+                buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
+                buf[1] = rs5c372->regs[RS5C_REG_CTRL1];
+                buf[2] = rs5c372->regs[RS5C_REG_CTRL2];
+
+                /* use 24hr mode */
+                switch (rs5c372->type) {
+                case rtc_rs5c372a:
+                case rtc_rs5c372b:
+                        buf[2] |= RS5C372_CTRL2_24;
+                        rs5c372->time24 = 1;
+                        break;
+                case rtc_rv5c386:
+                case rtc_rv5c387a:
+                        buf[1] |= RV5C387_CTRL1_24;
+                        rs5c372->time24 = 1;
+                        break;
+                default:
+                        /* impossible */
+                        break;
+                }
+
+                if ((i2c_master_send(client, buf, 3)) != 3) {
+                        dev_err(&client->dev, "setup error\n");
+                        goto exit_detach;
+                }
+                rs5c372->regs[RS5C_REG_CTRL1] = buf[1];
+                rs5c372->regs[RS5C_REG_CTRL2] = buf[2];
+        }
+
+        if (rs5c372_get_datetime(client, &tm) < 0)
+                dev_warn(&client->dev, "clock needs to be set\n");
+
+        dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
+                        ({ char *s; switch (rs5c372->type) {
+                        case rtc_rs5c372a:      s = "rs5c372a"; break;
+                        case rtc_rs5c372b:      s = "rs5c372b"; break;
+                        case rtc_rv5c386:       s = "rv5c386"; break;
+                        case rtc_rv5c387a:      s = "rv5c387a"; break;
+                        default:                s = "chip"; break;
+                        }; s;}),
+                        rs5c372->time24 ? "24hr" : "am/pm"
+                        );
+
+        /* FIXME when client->irq exists, use it to register alarm irq */
 
         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
@@ -241,18 +631,12 @@ static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind)
                 goto exit_detach;
         }
 
-        err = device_create_file(&client->dev, &dev_attr_trim);
+        err = rs5c_sysfs_register(&client->dev);
         if (err)
                 goto exit_devreg;
-        err = device_create_file(&client->dev, &dev_attr_osc);
-        if (err)
-                goto exit_trim;
 
         return 0;
 
-exit_trim:
-        device_remove_file(&client->dev, &dev_attr_trim);
-
 exit_devreg:
         rtc_device_unregister(rs5c372->rtc);
 
@@ -266,6 +650,11 @@ exit:
         return err;
 }
 
+static int rs5c372_attach(struct i2c_adapter *adapter)
+{
+        return i2c_probe(adapter, &addr_data, rs5c372_probe);
+}
+
 static int rs5c372_detach(struct i2c_client *client)
 {
         int err;
@@ -274,6 +663,8 @@ static int rs5c372_detach(struct i2c_client *client)
         if (rs5c372->rtc)
                 rtc_device_unregister(rs5c372->rtc);
 
+        /* REVISIT properly destroy the sysfs files ... */
+
         if ((err = i2c_detach_client(client)))
                 return err;
 
@@ -281,6 +672,14 @@ static int rs5c372_detach(struct i2c_client *client)
         return 0;
 }
 
+static struct i2c_driver rs5c372_driver = {
+        .driver         = {
+                .name   = "rtc-rs5c372",
+        },
+        .attach_adapter = &rs5c372_attach,
+        .detach_client  = &rs5c372_detach,
+};
+
 static __init int rs5c372_init(void)
 {
         return i2c_add_driver(&rs5c372_driver);