1 files changed, 342 insertions, 0 deletions
diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
new file mode 100644
index 000000000..f734e3473
--- /dev/null
+++ b/drivers/clk/clk-fixed-factor.c
@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
+ */
+#include <linux/module.h>
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+/*
+ * DOC: basic fixed multiplier and divider clock that cannot gate
+ *
+ * Traits of this clock:
+ * prepare - clk_prepare only ensures that parents are prepared
+ * enable - clk_enable only ensures that parents are enabled
+ * rate - rate is fixed.  clk->rate = parent->rate / div * mult
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+static unsigned long clk_factor_recalc_rate(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
+	unsigned long long int rate;
+
+	rate = (unsigned long long int)parent_rate * fix->mult;
+	do_div(rate, fix->div);
+	return (unsigned long)rate;
+}
+
+static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long *prate)
+{
+	struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
+
+	if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
+		unsigned long best_parent;
+
+		best_parent = (rate / fix->mult) * fix->div;
+		*prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
+	}
+
+	return (*prate / fix->div) * fix->mult;
+}
+
+static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long parent_rate)
+{
+	/*
+	 * We must report success but we can do so unconditionally because
+	 * clk_factor_round_rate returns values that ensure this call is a
+	 * nop.
+	 */
+
+	return 0;
+}
+
+const struct clk_ops clk_fixed_factor_ops = {
+	.round_rate = clk_factor_round_rate,
+	.set_rate = clk_factor_set_rate,
+	.recalc_rate = clk_factor_recalc_rate,
+};
+EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
+
+static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res)
+{
+	struct clk_fixed_factor *fix = res;
+
+	/*
+	 * We can not use clk_hw_unregister_fixed_factor, 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);
+}
+
+static struct clk_hw *
+__clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
+		const char *name, const char *parent_name,
+		const struct clk_hw *parent_hw, int index,
+		unsigned long flags, unsigned int mult, unsigned int div,
+		bool devm)
+{
+	struct clk_fixed_factor *fix;
+	struct clk_init_data init = { };
+	struct clk_parent_data pdata = { .index = index };
+	struct clk_hw *hw;
+	int ret;
+
+	/* You can't use devm without a dev */
+	if (devm && !dev)
+		return ERR_PTR(-EINVAL);
+
+	if (devm)
+		fix = devres_alloc(devm_clk_hw_register_fixed_factor_release,
+				sizeof(*fix), GFP_KERNEL);
+	else
+		fix = kmalloc(sizeof(*fix), GFP_KERNEL);
+	if (!fix)
+		return ERR_PTR(-ENOMEM);
+
+	/* struct clk_fixed_factor assignments */
+	fix->mult = mult;
+	fix->div = div;
+	fix->hw.init = &init;
+
+	init.name = name;
+	init.ops = &clk_fixed_factor_ops;
+	init.flags = flags;
+	if (parent_name)
+		init.parent_names = &parent_name;
+	else if (parent_hw)
+		init.parent_hws = &parent_hw;
+	else
+		init.parent_data = &pdata;
+	init.num_parents = 1;
+
+	hw = &fix->hw;
+	if (dev)
+		ret = clk_hw_register(dev, hw);
+	else
+		ret = of_clk_hw_register(np, hw);
+	if (ret) {
+		if (devm)
+			devres_free(fix);
+		else
+			kfree(fix);
+		hw = ERR_PTR(ret);
+	} else if (devm)
+		devres_add(dev, fix);
+
+	return hw;
+}
+
+/**
+ * devm_clk_hw_register_fixed_factor_index - Register a fixed factor clock with
+ * parent from DT index
+ * @dev: device that is registering this clock
+ * @name: name of this clock
+ * @index: index of phandle in @dev 'clocks' property
+ * @flags: fixed factor flags
+ * @mult: multiplier
+ * @div: divider
+ *
+ * Return: Pointer to fixed factor clk_hw structure that was registered or
+ * an error pointer.
+ */
+struct clk_hw *devm_clk_hw_register_fixed_factor_index(struct device *dev,
+		const char *name, unsigned int index, unsigned long flags,
+		unsigned int mult, unsigned int div)
+{
+	return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, index,
+					      flags, mult, div, true);
+}
+EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_index);
+
+/**
+ * devm_clk_hw_register_fixed_factor_parent_hw - Register a fixed factor clock with
+ * pointer to parent clock
+ * @dev: device that is registering this clock
+ * @name: name of this clock
+ * @parent_hw: pointer to parent clk
+ * @flags: fixed factor flags
+ * @mult: multiplier
+ * @div: divider
+ *
+ * Return: Pointer to fixed factor clk_hw structure that was registered or
+ * an error pointer.
+ */
+struct clk_hw *devm_clk_hw_register_fixed_factor_parent_hw(struct device *dev,
+		const char *name, const struct clk_hw *parent_hw,
+		unsigned long flags, unsigned int mult, unsigned int div)
+{
+	return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw,
+					      -1, flags, mult, div, true);
+}
+EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_parent_hw);
+
+struct clk_hw *clk_hw_register_fixed_factor_parent_hw(struct device *dev,
+		const char *name, const struct clk_hw *parent_hw,
+		unsigned long flags, unsigned int mult, unsigned int div)
+{
+	return __clk_hw_register_fixed_factor(dev, NULL, name, NULL,
+					      parent_hw, -1, flags, mult, div,
+					      false);
+}
+EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_parent_hw);
+
+struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
+		const char *name, const char *parent_name, unsigned long flags,
+		unsigned int mult, unsigned int div)
+{
+	return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL, -1,
+					      flags, mult, div, false);
+}
+EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
+
+struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
+		const char *parent_name, unsigned long flags,
+		unsigned int mult, unsigned int div)
+{
+	struct clk_hw *hw;
+
+	hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult,
+					  div);
+	if (IS_ERR(hw))
+		return ERR_CAST(hw);
+	return hw->clk;
+}
+EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
+
+void clk_unregister_fixed_factor(struct clk *clk)
+{
+	struct clk_hw *hw;
+
+	hw = __clk_get_hw(clk);
+	if (!hw)
+		return;
+
+	clk_unregister(clk);
+	kfree(to_clk_fixed_factor(hw));
+}
+EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
+
+void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
+{
+	struct clk_fixed_factor *fix;
+
+	fix = to_clk_fixed_factor(hw);
+
+	clk_hw_unregister(hw);
+	kfree(fix);
+}
+EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
+
+struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
+		const char *name, const char *parent_name, unsigned long flags,
+		unsigned int mult, unsigned int div)
+{
+	return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL, -1,
+			flags, mult, div, true);
+}
+EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);
+
+#ifdef CONFIG_OF
+static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
+{
+	struct clk_hw *hw;
+	const char *clk_name = node->name;
+	u32 div, mult;
+	int ret;
+
+	if (of_property_read_u32(node, "clock-div", &div)) {
+		pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n",
+			__func__, node);
+		return ERR_PTR(-EIO);
+	}
+
+	if (of_property_read_u32(node, "clock-mult", &mult)) {
+		pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n",
+			__func__, node);
+		return ERR_PTR(-EIO);
+	}
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, NULL, 0,
+					    0, mult, div, false);
+	if (IS_ERR(hw)) {
+		/*
+		 * Clear OF_POPULATED flag so that clock registration can be
+		 * attempted again from probe function.
+		 */
+		of_node_clear_flag(node, OF_POPULATED);
+		return ERR_CAST(hw);
+	}
+
+	ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
+	if (ret) {
+		clk_hw_unregister_fixed_factor(hw);
+		return ERR_PTR(ret);
+	}
+
+	return hw;
+}
+
+/**
+ * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
+ * @node:	device node for the clock
+ */
+void __init of_fixed_factor_clk_setup(struct device_node *node)
+{
+	_of_fixed_factor_clk_setup(node);
+}
+CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
+		of_fixed_factor_clk_setup);
+
+static int of_fixed_factor_clk_remove(struct platform_device *pdev)
+{
+	struct clk_hw *clk = platform_get_drvdata(pdev);
+
+	of_clk_del_provider(pdev->dev.of_node);
+	clk_hw_unregister_fixed_factor(clk);
+
+	return 0;
+}
+
+static int of_fixed_factor_clk_probe(struct platform_device *pdev)
+{
+	struct clk_hw *clk;
+
+	/*
+	 * This function is not executed when of_fixed_factor_clk_setup
+	 * succeeded.
+	 */
+	clk = _of_fixed_factor_clk_setup(pdev->dev.of_node);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	platform_set_drvdata(pdev, clk);
+
+	return 0;
+}
+
+static const struct of_device_id of_fixed_factor_clk_ids[] = {
+	{ .compatible = "fixed-factor-clock" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
+
+static struct platform_driver of_fixed_factor_clk_driver = {
+	.driver = {
+		.name = "of_fixed_factor_clk",
+		.of_match_table = of_fixed_factor_clk_ids,
+	},
+	.probe = of_fixed_factor_clk_probe,
+	.remove = of_fixed_factor_clk_remove,
+};
+builtin_platform_driver(of_fixed_factor_clk_driver);
+#endif