| /* |
| * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com> |
| * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * 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 |
| */ |
| |
| 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) |
| { |
| return to_clk_fixed_rate(hw)->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); |
| |
| /** |
| * clk_hw_register_fixed_rate_with_accuracy - register fixed-rate clock with |
| * the clock framework |
| * @dev: device that is registering this clock |
| * @name: name of this clock |
| * @parent_name: name of clock's parent |
| * @flags: framework-specific flags |
| * @fixed_rate: non-adjustable clock rate |
| * @fixed_accuracy: non-adjustable clock rate |
| */ |
| struct clk_hw *clk_hw_register_fixed_rate_with_accuracy(struct device *dev, |
| const char *name, const char *parent_name, unsigned long flags, |
| unsigned long fixed_rate, unsigned long fixed_accuracy) |
| { |
| struct clk_fixed_rate *fixed; |
| struct clk_hw *hw; |
| struct clk_init_data init; |
| int ret; |
| |
| /* allocate fixed-rate clock */ |
| fixed = kzalloc(sizeof(*fixed), GFP_KERNEL); |
| if (!fixed) |
| return ERR_PTR(-ENOMEM); |
| |
| init.name = name; |
| init.ops = &clk_fixed_rate_ops; |
| init.flags = flags | CLK_IS_BASIC; |
| init.parent_names = (parent_name ? &parent_name: NULL); |
| init.num_parents = (parent_name ? 1 : 0); |
| |
| /* struct clk_fixed_rate assignments */ |
| fixed->fixed_rate = fixed_rate; |
| fixed->fixed_accuracy = fixed_accuracy; |
| fixed->hw.init = &init; |
| |
| /* register the clock */ |
| hw = &fixed->hw; |
| ret = clk_hw_register(dev, hw); |
| if (ret) { |
| kfree(fixed); |
| hw = ERR_PTR(ret); |
| } |
| |
| return hw; |
| } |
| EXPORT_SYMBOL_GPL(clk_hw_register_fixed_rate_with_accuracy); |
| |
| struct clk *clk_register_fixed_rate_with_accuracy(struct device *dev, |
| const char *name, const char *parent_name, unsigned long flags, |
| unsigned long fixed_rate, unsigned long fixed_accuracy) |
| { |
| struct clk_hw *hw; |
| |
| hw = clk_hw_register_fixed_rate_with_accuracy(dev, name, parent_name, |
| flags, fixed_rate, fixed_accuracy); |
| if (IS_ERR(hw)) |
| return ERR_CAST(hw); |
| return hw->clk; |
| } |
| EXPORT_SYMBOL_GPL(clk_register_fixed_rate_with_accuracy); |
| |
| /** |
| * clk_hw_register_fixed_rate - register fixed-rate clock with the clock |
| * framework |
| * @dev: device that is registering this clock |
| * @name: name of this clock |
| * @parent_name: name of clock's parent |
| * @flags: framework-specific flags |
| * @fixed_rate: non-adjustable clock rate |
| */ |
| struct clk_hw *clk_hw_register_fixed_rate(struct device *dev, const char *name, |
| const char *parent_name, unsigned long flags, |
| unsigned long fixed_rate) |
| { |
| return clk_hw_register_fixed_rate_with_accuracy(dev, name, parent_name, |
| flags, fixed_rate, 0); |
| } |
| 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) |
| { |
| return clk_register_fixed_rate_with_accuracy(dev, name, parent_name, |
| flags, fixed_rate, 0); |
| } |
| 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 *_of_fixed_clk_setup(struct device_node *node) |
| { |
| struct clk *clk; |
| 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); |
| |
| clk = clk_register_fixed_rate_with_accuracy(NULL, clk_name, NULL, |
| 0, rate, accuracy); |
| if (IS_ERR(clk)) |
| return clk; |
| |
| ret = of_clk_add_provider(node, of_clk_src_simple_get, clk); |
| if (ret) { |
| clk_unregister(clk); |
| return ERR_PTR(ret); |
| } |
| |
| return clk; |
| } |
| |
| /** |
| * of_fixed_clk_setup() - Setup function for simple fixed rate clock |
| */ |
| void of_fixed_clk_setup(struct device_node *node) |
| { |
| _of_fixed_clk_setup(node); |
| } |
| EXPORT_SYMBOL_GPL(of_fixed_clk_setup); |
| CLK_OF_DECLARE(fixed_clk, "fixed-clock", of_fixed_clk_setup); |
| |
| static int of_fixed_clk_remove(struct platform_device *pdev) |
| { |
| struct clk *clk = platform_get_drvdata(pdev); |
| |
| clk_unregister_fixed_rate(clk); |
| |
| return 0; |
| } |
| |
| static int of_fixed_clk_probe(struct platform_device *pdev) |
| { |
| struct clk *clk; |
| |
| /* |
| * This function is not executed when of_fixed_clk_setup |
| * succeeded. |
| */ |
| clk = _of_fixed_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_clk_ids[] = { |
| { .compatible = "fixed-clock" }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, of_fixed_clk_ids); |
| |
| 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 |