diff options
Diffstat (limited to 'drivers/clk/at91/clk-smd.c')
-rw-r--r-- | drivers/clk/at91/clk-smd.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-smd.c b/drivers/clk/at91/clk-smd.c new file mode 100644 index 000000000000..144d47ecfe63 --- /dev/null +++ b/drivers/clk/at91/clk-smd.c | |||
@@ -0,0 +1,171 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> | ||
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 as published by | ||
6 | * the Free Software Foundation; either version 2 of the License, or | ||
7 | * (at your option) any later version. | ||
8 | * | ||
9 | */ | ||
10 | |||
11 | #include <linux/clk-provider.h> | ||
12 | #include <linux/clkdev.h> | ||
13 | #include <linux/clk/at91_pmc.h> | ||
14 | #include <linux/of.h> | ||
15 | #include <linux/of_address.h> | ||
16 | #include <linux/io.h> | ||
17 | |||
18 | #include "pmc.h" | ||
19 | |||
20 | #define SMD_SOURCE_MAX 2 | ||
21 | |||
22 | #define SMD_DIV_SHIFT 8 | ||
23 | #define SMD_MAX_DIV 0xf | ||
24 | |||
25 | struct at91sam9x5_clk_smd { | ||
26 | struct clk_hw hw; | ||
27 | struct at91_pmc *pmc; | ||
28 | }; | ||
29 | |||
30 | #define to_at91sam9x5_clk_smd(hw) \ | ||
31 | container_of(hw, struct at91sam9x5_clk_smd, hw) | ||
32 | |||
33 | static unsigned long at91sam9x5_clk_smd_recalc_rate(struct clk_hw *hw, | ||
34 | unsigned long parent_rate) | ||
35 | { | ||
36 | u32 tmp; | ||
37 | u8 smddiv; | ||
38 | struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw); | ||
39 | struct at91_pmc *pmc = smd->pmc; | ||
40 | |||
41 | tmp = pmc_read(pmc, AT91_PMC_SMD); | ||
42 | smddiv = (tmp & AT91_PMC_SMD_DIV) >> SMD_DIV_SHIFT; | ||
43 | return parent_rate / (smddiv + 1); | ||
44 | } | ||
45 | |||
46 | static long at91sam9x5_clk_smd_round_rate(struct clk_hw *hw, unsigned long rate, | ||
47 | unsigned long *parent_rate) | ||
48 | { | ||
49 | unsigned long div; | ||
50 | unsigned long bestrate; | ||
51 | unsigned long tmp; | ||
52 | |||
53 | if (rate >= *parent_rate) | ||
54 | return *parent_rate; | ||
55 | |||
56 | div = *parent_rate / rate; | ||
57 | if (div > SMD_MAX_DIV) | ||
58 | return *parent_rate / (SMD_MAX_DIV + 1); | ||
59 | |||
60 | bestrate = *parent_rate / div; | ||
61 | tmp = *parent_rate / (div + 1); | ||
62 | if (bestrate - rate > rate - tmp) | ||
63 | bestrate = tmp; | ||
64 | |||
65 | return bestrate; | ||
66 | } | ||
67 | |||
68 | static int at91sam9x5_clk_smd_set_parent(struct clk_hw *hw, u8 index) | ||
69 | { | ||
70 | u32 tmp; | ||
71 | struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw); | ||
72 | struct at91_pmc *pmc = smd->pmc; | ||
73 | |||
74 | if (index > 1) | ||
75 | return -EINVAL; | ||
76 | tmp = pmc_read(pmc, AT91_PMC_SMD) & ~AT91_PMC_SMDS; | ||
77 | if (index) | ||
78 | tmp |= AT91_PMC_SMDS; | ||
79 | pmc_write(pmc, AT91_PMC_SMD, tmp); | ||
80 | return 0; | ||
81 | } | ||
82 | |||
83 | static u8 at91sam9x5_clk_smd_get_parent(struct clk_hw *hw) | ||
84 | { | ||
85 | struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw); | ||
86 | struct at91_pmc *pmc = smd->pmc; | ||
87 | |||
88 | return pmc_read(pmc, AT91_PMC_SMD) & AT91_PMC_SMDS; | ||
89 | } | ||
90 | |||
91 | static int at91sam9x5_clk_smd_set_rate(struct clk_hw *hw, unsigned long rate, | ||
92 | unsigned long parent_rate) | ||
93 | { | ||
94 | u32 tmp; | ||
95 | struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw); | ||
96 | struct at91_pmc *pmc = smd->pmc; | ||
97 | unsigned long div = parent_rate / rate; | ||
98 | |||
99 | if (parent_rate % rate || div < 1 || div > (SMD_MAX_DIV + 1)) | ||
100 | return -EINVAL; | ||
101 | tmp = pmc_read(pmc, AT91_PMC_SMD) & ~AT91_PMC_SMD_DIV; | ||
102 | tmp |= (div - 1) << SMD_DIV_SHIFT; | ||
103 | pmc_write(pmc, AT91_PMC_SMD, tmp); | ||
104 | |||
105 | return 0; | ||
106 | } | ||
107 | |||
108 | static const struct clk_ops at91sam9x5_smd_ops = { | ||
109 | .recalc_rate = at91sam9x5_clk_smd_recalc_rate, | ||
110 | .round_rate = at91sam9x5_clk_smd_round_rate, | ||
111 | .get_parent = at91sam9x5_clk_smd_get_parent, | ||
112 | .set_parent = at91sam9x5_clk_smd_set_parent, | ||
113 | .set_rate = at91sam9x5_clk_smd_set_rate, | ||
114 | }; | ||
115 | |||
116 | static struct clk * __init | ||
117 | at91sam9x5_clk_register_smd(struct at91_pmc *pmc, const char *name, | ||
118 | const char **parent_names, u8 num_parents) | ||
119 | { | ||
120 | struct at91sam9x5_clk_smd *smd; | ||
121 | struct clk *clk = NULL; | ||
122 | struct clk_init_data init; | ||
123 | |||
124 | smd = kzalloc(sizeof(*smd), GFP_KERNEL); | ||
125 | if (!smd) | ||
126 | return ERR_PTR(-ENOMEM); | ||
127 | |||
128 | init.name = name; | ||
129 | init.ops = &at91sam9x5_smd_ops; | ||
130 | init.parent_names = parent_names; | ||
131 | init.num_parents = num_parents; | ||
132 | init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; | ||
133 | |||
134 | smd->hw.init = &init; | ||
135 | smd->pmc = pmc; | ||
136 | |||
137 | clk = clk_register(NULL, &smd->hw); | ||
138 | if (IS_ERR(clk)) | ||
139 | kfree(smd); | ||
140 | |||
141 | return clk; | ||
142 | } | ||
143 | |||
144 | void __init of_at91sam9x5_clk_smd_setup(struct device_node *np, | ||
145 | struct at91_pmc *pmc) | ||
146 | { | ||
147 | struct clk *clk; | ||
148 | int i; | ||
149 | int num_parents; | ||
150 | const char *parent_names[SMD_SOURCE_MAX]; | ||
151 | const char *name = np->name; | ||
152 | |||
153 | num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells"); | ||
154 | if (num_parents <= 0 || num_parents > SMD_SOURCE_MAX) | ||
155 | return; | ||
156 | |||
157 | for (i = 0; i < num_parents; i++) { | ||
158 | parent_names[i] = of_clk_get_parent_name(np, i); | ||
159 | if (!parent_names[i]) | ||
160 | return; | ||
161 | } | ||
162 | |||
163 | of_property_read_string(np, "clock-output-names", &name); | ||
164 | |||
165 | clk = at91sam9x5_clk_register_smd(pmc, name, parent_names, | ||
166 | num_parents); | ||
167 | if (IS_ERR(clk)) | ||
168 | return; | ||
169 | |||
170 | of_clk_add_provider(np, of_clk_src_simple_get, clk); | ||
171 | } | ||