| Sascha Hauer | f0948f5 | 2012-05-03 15:36:14 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * Standard functionality for the common clock API. |
| 9 | */ |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/clk-provider.h> |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/err.h> |
| 14 | |
| 15 | /* |
| 16 | * DOC: basic fixed multiplier and divider clock that cannot gate |
| 17 | * |
| 18 | * Traits of this clock: |
| 19 | * prepare - clk_prepare only ensures that parents are prepared |
| 20 | * enable - clk_enable only ensures that parents are enabled |
| 21 | * rate - rate is fixed. clk->rate = parent->rate / div * mult |
| 22 | * parent - fixed parent. No clk_set_parent support |
| 23 | */ |
| 24 | |
| 25 | #define to_clk_fixed_factor(_hw) container_of(_hw, struct clk_fixed_factor, hw) |
| 26 | |
| 27 | static unsigned long clk_factor_recalc_rate(struct clk_hw *hw, |
| 28 | unsigned long parent_rate) |
| 29 | { |
| 30 | struct clk_fixed_factor *fix = to_clk_fixed_factor(hw); |
| 31 | |
| 32 | return parent_rate * fix->mult / fix->div; |
| 33 | } |
| 34 | |
| 35 | static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate, |
| 36 | unsigned long *prate) |
| 37 | { |
| 38 | struct clk_fixed_factor *fix = to_clk_fixed_factor(hw); |
| 39 | |
| 40 | if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) { |
| 41 | unsigned long best_parent; |
| 42 | |
| 43 | best_parent = (rate / fix->mult) * fix->div; |
| 44 | *prate = __clk_round_rate(__clk_get_parent(hw->clk), |
| 45 | best_parent); |
| 46 | } |
| 47 | |
| 48 | return (*prate / fix->div) * fix->mult; |
| 49 | } |
| 50 | |
| 51 | static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate, |
| 52 | unsigned long parent_rate) |
| 53 | { |
| 54 | return 0; |
| 55 | } |
| 56 | |
| 57 | struct clk_ops clk_fixed_factor_ops = { |
| 58 | .round_rate = clk_factor_round_rate, |
| 59 | .set_rate = clk_factor_set_rate, |
| 60 | .recalc_rate = clk_factor_recalc_rate, |
| 61 | }; |
| 62 | EXPORT_SYMBOL_GPL(clk_fixed_factor_ops); |
| 63 | |
| 64 | struct clk *clk_register_fixed_factor(struct device *dev, const char *name, |
| 65 | const char *parent_name, unsigned long flags, |
| 66 | unsigned int mult, unsigned int div) |
| 67 | { |
| 68 | struct clk_fixed_factor *fix; |
| 69 | struct clk_init_data init; |
| 70 | struct clk *clk; |
| 71 | |
| 72 | fix = kmalloc(sizeof(*fix), GFP_KERNEL); |
| 73 | if (!fix) { |
| 74 | pr_err("%s: could not allocate fixed factor clk\n", __func__); |
| 75 | return ERR_PTR(-ENOMEM); |
| 76 | } |
| 77 | |
| 78 | /* struct clk_fixed_factor assignments */ |
| 79 | fix->mult = mult; |
| 80 | fix->div = div; |
| 81 | fix->hw.init = &init; |
| 82 | |
| 83 | init.name = name; |
| 84 | init.ops = &clk_fixed_factor_ops; |
| Rajendra Nayak | f7d8caa | 2012-06-01 14:02:47 +0530 | [diff] [blame] | 85 | init.flags = flags | CLK_IS_BASIC; |
| Sascha Hauer | f0948f5 | 2012-05-03 15:36:14 +0530 | [diff] [blame] | 86 | init.parent_names = &parent_name; |
| 87 | init.num_parents = 1; |
| 88 | |
| 89 | clk = clk_register(dev, &fix->hw); |
| 90 | |
| 91 | if (IS_ERR(clk)) |
| 92 | kfree(fix); |
| 93 | |
| 94 | return clk; |
| 95 | } |