clk: bulk: add of_clk_bulk_get()

'clock-names' property is optional in DT, so of_clk_bulk_get() is
introduced here to handle this for DT users without 'clock-names'
specified. Later clk_bulk_get_all() will be implemented on top of
it and this API will be kept private until someone proves they need
it because they don't have a struct device pointer.

Cc: Stephen Boyd <[e-mail]>
Cc: Michael Turquette <[e-mail]>
Cc: Russell King <[e-mail]>
Reported-by: Shawn Guo <[e-mail]>
Tested-by: Thor Thayer <[e-mail]>
Signed-off-by: Dong Aisheng <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/clk-bulk.c

···
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/export.h>
+#include <linux/of.h>
+
+static int __must_check of_clk_bulk_get(struct device_node *np, int num_clks,
+					struct clk_bulk_data *clks)
+{
+	int ret;
+	int i;
+
+	for (i = 0; i < num_clks; i++)
+		clks[i].clk = NULL;
+
+	for (i = 0; i < num_clks; i++) {
+		clks[i].clk = of_clk_get(np, i);
+		if (IS_ERR(clks[i].clk)) {
+			ret = PTR_ERR(clks[i].clk);
+			pr_err("%pOF: Failed to get clk index: %d ret: %d\n",
+			       np, i, ret);
+			clks[i].clk = NULL;
+			goto err;
+		}
+	}
+
+	return 0;
+
+err:
+	clk_bulk_put(i, clks);
+
+	return ret;
+}
 
 void clk_bulk_put(int num_clks, struct clk_bulk_data *clks)
 {