cpts: specify the input clock frequency via DT

This patch adds a way to configure the CPTS input clock scaling factors
via the device tree.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index f165791..c04627c 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -854,6 +854,20 @@
 	}
 	data->cpts_active_slave = prop;
 
+	if (of_property_read_u32(node, "cpts_clock_mult", &prop)) {
+		pr_err("Missing cpts_clock_mult property in the DT.\n");
+		ret = -EINVAL;
+		goto error_ret;
+	}
+	data->cpts_clock_mult = prop;
+
+	if (of_property_read_u32(node, "cpts_clock_shift", &prop)) {
+		pr_err("Missing cpts_clock_shift property in the DT.\n");
+		ret = -EINVAL;
+		goto error_ret;
+	}
+	data->cpts_clock_shift = prop;
+
 	data->slave_data = kzalloc(sizeof(struct cpsw_slave_data) *
 				   data->slaves, GFP_KERNEL);
 	if (!data->slave_data) {