diff options
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/Makefile | 2 | ||||
-rw-r--r-- | drivers/clk/clk-fixed-factor.c | 95 |
2 files changed, 96 insertions, 1 deletions
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 1f736bc11c4b..24aa7144811b 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile | |||
@@ -1,4 +1,4 @@ | |||
1 | 1 | ||
2 | obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o | 2 | obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o |
3 | obj-$(CONFIG_COMMON_CLK) += clk.o clk-fixed-rate.o clk-gate.o \ | 3 | obj-$(CONFIG_COMMON_CLK) += clk.o clk-fixed-rate.o clk-gate.o \ |
4 | clk-mux.o clk-divider.o | 4 | clk-mux.o clk-divider.o clk-fixed-factor.o |
diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c new file mode 100644 index 000000000000..c8c003e217ad --- /dev/null +++ b/drivers/clk/clk-fixed-factor.c | |||
@@ -0,0 +1,95 @@ | |||
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; | ||
85 | init.flags = flags; | ||
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 | } | ||