+static int __maybe_unused rk3399_gmac_set_parent(struct clk *clk, struct clk *parent)
+{
+ struct rk3399_clk_priv *priv = dev_get_priv(clk->dev);
+ const char *clock_output_name;
+ int ret;
+
+ /*
+ * If the requested parent is in the same clock-controller and
+ * the id is SCLK_MAC ("clk_gmac"), switch to the internal clock.
+ */
+ if ((parent->dev == clk->dev) && (parent->id == SCLK_MAC)) {
+ debug("%s: switching RGMII to SCLK_MAC\n", __func__);
+ rk_clrreg(&priv->cru->clksel_con[19], BIT(4));
+ return 0;
+ }
+
+ /*
+ * Otherwise, we need to check the clock-output-names of the
+ * requested parent to see if the requested id is "clkin_gmac".
+ */
+ ret = dev_read_string_index(parent->dev, "clock-output-names",
+ parent->id, &clock_output_name);
+ if (ret < 0)
+ return -ENODATA;
+
+ /* If this is "clkin_gmac", switch to the external clock input */
+ if (!strcmp(clock_output_name, "clkin_gmac")) {
+ debug("%s: switching RGMII to CLKIN\n", __func__);
+ rk_setreg(&priv->cru->clksel_con[19], BIT(4));
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int __maybe_unused rk3399_clk_set_parent(struct clk *clk, struct clk *parent)
+{
+ switch (clk->id) {
+ case SCLK_RMII_SRC:
+ return rk3399_gmac_set_parent(clk, parent);
+ }
+
+ debug("%s: unsupported clk %ld\n", __func__, clk->id);
+ return -ENOENT;
+}
+