1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/clk/clk-fixed-rate.c b/drivers/clk/clk-fixed-rate.c
new file mode 100644
index 000000000..62e994d18
--- /dev/null
+++ b/drivers/clk/clk-fixed-rate.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
+ * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
+ *
+ * Fixed rate clock implementation
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+/*
+ * DOC: basic fixed-rate clock that cannot gate
+ *
+ * Traits of this clock:
+ * prepare - clk_(un)prepare only ensures parents are prepared
+ * enable - clk_enable only ensures parents are enabled
+ * rate - rate is always a fixed value.  No clk_set_rate support
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+#define to_clk_fixed_rate(_hw) container_of(_hw, struct clk_fixed_rate, hw)
+
+static unsigned long clk_fixed_rate_recalc_rate(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	return to_clk_fixed_rate(hw)->fixed_rate;
+}
+
+static unsigned long clk_fixed_rate_recalc_accuracy(struct clk_hw *hw,
+		unsigned long parent_accuracy)
+{
+	struct clk_fixed_rate *fixed = to_clk_fixed_rate(hw);
+
+	if (fixed->flags & CLK_FIXED_RATE_PARENT_ACCURACY)
+		return parent_accuracy;
+
+	return fixed->fixed_accuracy;
+}
+
+const struct clk_ops clk_fixed_rate_ops = {
+	.recalc_rate = clk_fixed_rate_recalc_rate,
+	.recalc_accuracy = clk_fixed_rate_recalc_accuracy,
+};
+EXPORT_SYMBOL_GPL(clk_fixed_rate_ops);
+
+static void devm_clk_hw_register_fixed_rate_release(struct device *dev, void *res)
+{
+	struct clk_fixed_rate *fix = res;
+
+	/*
+	 * We can not use clk_hw_unregister_fixed_rate, since it will kfree()
+	 * the hw, resulting in double free. Just unregister the hw and let
+	 * devres code kfree() it.
+	 */
+	clk_hw_unregister(&fix->hw);
+}
+
+struct clk_hw *__clk_hw_register_fixed_rate(struct device *dev,
+		struct device_node *np, const char *name,
+		const char *parent_name, const struct clk_hw *parent_hw,
+		const struct clk_parent_data *parent_data, unsigned long flags,
+		unsigned long fixed_rate, unsigned long fixed_accuracy,
+		unsigned long clk_fixed_flags, bool devm)
+{
+	struct clk_fixed_rate *fixed;
+	struct clk_hw *hw;
+	struct clk_init_data init = {};
+	int ret = -EINVAL;
+
+	/* allocate fixed-rate clock */
+	if (devm)
+		fixed = devres_alloc(devm_clk_hw_register_fixed_rate_release,
+				     sizeof(*fixed), GFP_KERNEL);
+	else
+		fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
+	if (!fixed)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &clk_fixed_rate_ops;
+	init.flags = flags;
+	init.parent_names = parent_name ? &parent_name : NULL;
+	init.parent_hws = parent_hw ? &parent_hw : NULL;
+	init.parent_data = parent_data;
+	if (parent_name || parent_hw || parent_data)
+		init.num_parents = 1;
+	else
+		init.num_parents = 0;
+
+	/* struct clk_fixed_rate assignments */
+	fixed->flags = clk_fixed_flags;
+	fixed->fixed_rate = fixed_rate;
+	fixed->fixed_accuracy = fixed_accuracy;
+	fixed->hw.init = &init;
+
+	/* register the clock */
+	hw = &fixed->hw;
+	if (dev || !np)
+		ret = clk_hw_register(dev, hw);
+	else if (np)
+		ret = of_clk_hw_register(np, hw);
+	if (ret) {
+		if (devm)
+			devres_free(fixed);
+		else
+			kfree(fixed);
+		hw = ERR_PTR(ret);
+	} else if (devm)
+		devres_add(dev, fixed);
+
+	return hw;
+}
+EXPORT_SYMBOL_GPL(__clk_hw_register_fixed_rate);
+
+struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
+		const char *parent_name, unsigned long flags,
+		unsigned long fixed_rate)
+{
+	struct clk_hw *hw;
+
+	hw = clk_hw_register_fixed_rate_with_accuracy(dev, name, parent_name,
+						      flags, fixed_rate, 0);
+	if (IS_ERR(hw))
+		return ERR_CAST(hw);
+	return hw->clk;
+}
+EXPORT_SYMBOL_GPL(clk_register_fixed_rate);
+
+void clk_unregister_fixed_rate(struct clk *clk)
+{
+	struct clk_hw *hw;
+
+	hw = __clk_get_hw(clk);
+	if (!hw)
+		return;
+
+	clk_unregister(clk);
+	kfree(to_clk_fixed_rate(hw));
+}
+EXPORT_SYMBOL_GPL(clk_unregister_fixed_rate);
+
+void clk_hw_unregister_fixed_rate(struct clk_hw *hw)
+{
+	struct clk_fixed_rate *fixed;
+
+	fixed = to_clk_fixed_rate(hw);
+
+	clk_hw_unregister(hw);
+	kfree(fixed);
+}
+EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_rate);
+
+#ifdef CONFIG_OF
+static struct clk_hw *_of_fixed_clk_setup(struct device_node *node)
+{
+	struct clk_hw *hw;
+	const char *clk_name = node->name;
+	u32 rate;
+	u32 accuracy = 0;
+	int ret;
+
+	if (of_property_read_u32(node, "clock-frequency", &rate))
+		return ERR_PTR(-EIO);
+
+	of_property_read_u32(node, "clock-accuracy", &accuracy);
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	hw = clk_hw_register_fixed_rate_with_accuracy(NULL, clk_name, NULL,
+						    0, rate, accuracy);
+	if (IS_ERR(hw))
+		return hw;
+
+	ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
+	if (ret) {
+		clk_hw_unregister_fixed_rate(hw);
+		return ERR_PTR(ret);
+	}
+
+	return hw;
+}
+
+/**
+ * of_fixed_clk_setup() - Setup function for simple fixed rate clock
+ * @node:	device node for the clock
+ */
+void __init of_fixed_clk_setup(struct device_node *node)
+{
+	_of_fixed_clk_setup(node);
+}
+CLK_OF_DECLARE(fixed_clk, "fixed-clock", of_fixed_clk_setup);
+
+static int of_fixed_clk_remove(struct platform_device *pdev)
+{
+	struct clk_hw *hw = platform_get_drvdata(pdev);
+
+	of_clk_del_provider(pdev->dev.of_node);
+	clk_hw_unregister_fixed_rate(hw);
+
+	return 0;
+}
+
+static int of_fixed_clk_probe(struct platform_device *pdev)
+{
+	struct clk_hw *hw;
+
+	/*
+	 * This function is not executed when of_fixed_clk_setup
+	 * succeeded.
+	 */
+	hw = _of_fixed_clk_setup(pdev->dev.of_node);
+	if (IS_ERR(hw))
+		return PTR_ERR(hw);
+
+	platform_set_drvdata(pdev, hw);
+
+	return 0;
+}
+
+static const struct of_device_id of_fixed_clk_ids[] = {
+	{ .compatible = "fixed-clock" },
+	{ }
+};
+
+static struct platform_driver of_fixed_clk_driver = {
+	.driver = {
+		.name = "of_fixed_clk",
+		.of_match_table = of_fixed_clk_ids,
+	},
+	.probe = of_fixed_clk_probe,
+	.remove = of_fixed_clk_remove,
+};
+builtin_platform_driver(of_fixed_clk_driver);
+#endif