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035e111f JN |
1 | #include <linux/init.h> |
2 | #include <linux/module.h> | |
3 | #include <linux/cpufreq.h> | |
4 | #include <hwregs/reg_map.h> | |
556dcee7 JN |
5 | #include <arch/hwregs/reg_rdwr.h> |
6 | #include <arch/hwregs/config_defs.h> | |
7 | #include <arch/hwregs/bif_core_defs.h> | |
035e111f JN |
8 | |
9 | static int | |
10 | cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val, | |
11 | void *data); | |
12 | ||
13 | static struct notifier_block cris_sdram_freq_notifier_block = { | |
14 | .notifier_call = cris_sdram_freq_notifier | |
15 | }; | |
16 | ||
17 | static struct cpufreq_frequency_table cris_freq_table[] = { | |
18 | {0x01, 6000}, | |
19 | {0x02, 200000}, | |
20 | {0, CPUFREQ_TABLE_END}, | |
21 | }; | |
22 | ||
23 | static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu) | |
24 | { | |
25 | reg_config_rw_clk_ctrl clk_ctrl; | |
26 | clk_ctrl = REG_RD(config, regi_config, rw_clk_ctrl); | |
27 | return clk_ctrl.pll ? 200000 : 6000; | |
28 | } | |
29 | ||
30 | static void cris_freq_set_cpu_state(unsigned int state) | |
31 | { | |
32 | int i; | |
33 | struct cpufreq_freqs freqs; | |
34 | reg_config_rw_clk_ctrl clk_ctrl; | |
35 | clk_ctrl = REG_RD(config, regi_config, rw_clk_ctrl); | |
36 | ||
37 | for_each_possible_cpu(i) { | |
38 | freqs.old = cris_freq_get_cpu_frequency(i); | |
39 | freqs.new = cris_freq_table[state].frequency; | |
40 | freqs.cpu = i; | |
41 | } | |
42 | ||
43 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
44 | ||
45 | local_irq_disable(); | |
46 | ||
47 | /* Even though we may be SMP they will share the same clock | |
48 | * so all settings are made on CPU0. */ | |
49 | if (cris_freq_table[state].frequency == 200000) | |
50 | clk_ctrl.pll = 1; | |
51 | else | |
52 | clk_ctrl.pll = 0; | |
53 | REG_WR(config, regi_config, rw_clk_ctrl, clk_ctrl); | |
54 | ||
55 | local_irq_enable(); | |
56 | ||
57 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
58 | }; | |
59 | ||
60 | static int cris_freq_verify(struct cpufreq_policy *policy) | |
61 | { | |
62 | return cpufreq_frequency_table_verify(policy, &cris_freq_table[0]); | |
63 | } | |
64 | ||
65 | static int cris_freq_target(struct cpufreq_policy *policy, | |
66 | unsigned int target_freq, unsigned int relation) | |
67 | { | |
68 | unsigned int newstate = 0; | |
69 | ||
70 | if (cpufreq_frequency_table_target | |
71 | (policy, cris_freq_table, target_freq, relation, &newstate)) | |
72 | return -EINVAL; | |
73 | ||
74 | cris_freq_set_cpu_state(newstate); | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | static int cris_freq_cpu_init(struct cpufreq_policy *policy) | |
80 | { | |
81 | int result; | |
82 | ||
83 | /* cpuinfo and default policy values */ | |
035e111f JN |
84 | policy->cpuinfo.transition_latency = 1000000; /* 1ms */ |
85 | policy->cur = cris_freq_get_cpu_frequency(0); | |
86 | ||
87 | result = cpufreq_frequency_table_cpuinfo(policy, cris_freq_table); | |
88 | if (result) | |
89 | return (result); | |
90 | ||
91 | cpufreq_frequency_table_get_attr(cris_freq_table, policy->cpu); | |
92 | ||
93 | return 0; | |
94 | } | |
95 | ||
96 | static int cris_freq_cpu_exit(struct cpufreq_policy *policy) | |
97 | { | |
98 | cpufreq_frequency_table_put_attr(policy->cpu); | |
99 | return 0; | |
100 | } | |
101 | ||
102 | static struct freq_attr *cris_freq_attr[] = { | |
103 | &cpufreq_freq_attr_scaling_available_freqs, | |
104 | NULL, | |
105 | }; | |
106 | ||
107 | static struct cpufreq_driver cris_freq_driver = { | |
108 | .get = cris_freq_get_cpu_frequency, | |
109 | .verify = cris_freq_verify, | |
110 | .target = cris_freq_target, | |
111 | .init = cris_freq_cpu_init, | |
112 | .exit = cris_freq_cpu_exit, | |
113 | .name = "cris_freq", | |
114 | .owner = THIS_MODULE, | |
115 | .attr = cris_freq_attr, | |
116 | }; | |
117 | ||
118 | static int __init cris_freq_init(void) | |
119 | { | |
120 | int ret; | |
121 | ret = cpufreq_register_driver(&cris_freq_driver); | |
122 | cpufreq_register_notifier(&cris_sdram_freq_notifier_block, | |
123 | CPUFREQ_TRANSITION_NOTIFIER); | |
124 | return ret; | |
125 | } | |
126 | ||
127 | static int | |
128 | cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val, | |
129 | void *data) | |
130 | { | |
131 | int i; | |
132 | struct cpufreq_freqs *freqs = data; | |
133 | if (val == CPUFREQ_PRECHANGE) { | |
134 | reg_bif_core_rw_sdram_timing timing = | |
135 | REG_RD(bif_core, regi_bif_core, rw_sdram_timing); | |
136 | timing.cpd = (freqs->new == 200000 ? 0 : 1); | |
137 | ||
138 | if (freqs->new == 200000) | |
139 | for (i = 0; i < 50000; i++) ; | |
140 | REG_WR(bif_core, regi_bif_core, rw_sdram_timing, timing); | |
141 | } | |
142 | return 0; | |
143 | } | |
144 | ||
145 | module_init(cris_freq_init); |