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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright (C) 2010-2011 Canonical Ltd <[email protected]>
- * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <[email protected]>
- *
- * 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
- 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
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