File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/clk/sunxi/clk-a10-hosc.c b/drivers/clk/sunxi/clk-a10-hosc.c
new file mode 100644
index 0000000..0481d5d
--- /dev/null
+++ b/drivers/clk/sunxi/clk-a10-hosc.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2013 Emilio López
+ *
+ * Emilio López <emilio@elopez.com.ar>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#define SUNXI_OSC24M_GATE	0
+
+static DEFINE_SPINLOCK(hosc_lock);
+
+static void __init sun4i_osc_clk_setup(struct device_node *node)
+{
+	struct clk *clk;
+	struct clk_fixed_rate *fixed;
+	struct clk_gate *gate;
+	const char *clk_name = node->name;
+	u32 rate;
+
+	if (of_property_read_u32(node, "clock-frequency", &rate))
+		return;
+
+	/* allocate fixed-rate and gate clock structs */
+	fixed = kzalloc(sizeof(struct clk_fixed_rate), GFP_KERNEL);
+	if (!fixed)
+		return;
+	gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL);
+	if (!gate)
+		goto err_free_fixed;
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	/* set up gate and fixed rate properties */
+	gate->reg = of_iomap(node, 0);
+	gate->bit_idx = SUNXI_OSC24M_GATE;
+	gate->lock = &hosc_lock;
+	fixed->fixed_rate = rate;
+
+	clk = clk_register_composite(NULL, clk_name,
+			NULL, 0,
+			NULL, NULL,
+			&fixed->hw, &clk_fixed_rate_ops,
+			&gate->hw, &clk_gate_ops,
+			CLK_IS_ROOT);
+
+	if (IS_ERR(clk))
+		goto err_free_gate;
+
+	of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	clk_register_clkdev(clk, clk_name, NULL);
+
+	return;
+
+err_free_gate:
+	kfree(gate);
+err_free_fixed:
+	kfree(fixed);
+}
+CLK_OF_DECLARE(sun4i_osc, "allwinner,sun4i-a10-osc-clk", sun4i_osc_clk_setup);