ptp: ocp: Add sysfs attribute utc_tai_offset

IRIG and DCF output time in UTC, but the timecard operates
on TAI internally.  Add an attribute node which allows adding
an offset to these modes before output.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 2b3d428..2c3af3c 100644 (file)
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c
@@ -230,8 +230,9 @@ struct ptp_ocp {
        int                     gnss_port;
        int                     mac_port;       /* miniature atomic clock */
        u8                      serial[6];
-       int                     flash_start;
        bool                    has_serial;
+       int                     flash_start;
+       u32                     utc_tai_offset;
 };
 
 struct ocp_resource {
@@ -742,6 +743,23 @@ ptp_ocp_init_clock(struct ptp_ocp *bp)
 }
 
 static void
+ptp_ocp_utc_distribute(struct ptp_ocp *bp, u32 val)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&bp->lock, flags);
+
+       bp->utc_tai_offset = val;
+
+       if (bp->irig_out)
+               iowrite32(val, &bp->irig_out->adj_sec);
+       if (bp->dcf_out)
+               iowrite32(val, &bp->dcf_out->adj_sec);
+
+       spin_unlock_irqrestore(&bp->lock, flags);
+}
+
+static void
 ptp_ocp_tod_info(struct ptp_ocp *bp)
 {
        static const char * const proto_name[] = {
@@ -1677,6 +1695,34 @@ gnss_sync_show(struct device *dev, struct device_attribute *attr, char *buf)
 static DEVICE_ATTR_RO(gnss_sync);
 
 static ssize_t
+utc_tai_offset_show(struct device *dev,
+                   struct device_attribute *attr, char *buf)
+{
+       struct ptp_ocp *bp = dev_get_drvdata(dev);
+
+       return sysfs_emit(buf, "%d\n", bp->utc_tai_offset);
+}
+
+static ssize_t
+utc_tai_offset_store(struct device *dev,
+                    struct device_attribute *attr,
+                    const char *buf, size_t count)
+{
+       struct ptp_ocp *bp = dev_get_drvdata(dev);
+       int err;
+       u32 val;
+
+       err = kstrtou32(buf, 0, &val);
+       if (err)
+               return err;
+
+       ptp_ocp_utc_distribute(bp, val);
+
+       return count;
+}
+static DEVICE_ATTR_RW(utc_tai_offset);
+
+static ssize_t
 irig_b_mode_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
        struct ptp_ocp *bp = dev_get_drvdata(dev);
@@ -1769,6 +1815,7 @@ static struct attribute *timecard_attrs[] = {
        &dev_attr_available_sma_inputs.attr,
        &dev_attr_available_sma_outputs.attr,
        &dev_attr_irig_b_mode.attr,
+       &dev_attr_utc_tai_offset.attr,
        NULL,
 };
 ATTRIBUTE_GROUPS(timecard);