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11#include <linux/module.h>
12#include <linux/kernel.h>
13#include <linux/cpufreq.h>
14#include <linux/delay.h>
15#include <linux/slab.h>
16#include <linux/platform_device.h>
17#include <linux/clk.h>
18#include <mach/id.h>
19
20static struct cpufreq_frequency_table *freq_table;
21static struct clk *armss_clk;
22
23static struct freq_attr *db8500_cpufreq_attr[] = {
24 &cpufreq_freq_attr_scaling_available_freqs,
25 NULL,
26};
27
28static int db8500_cpufreq_verify_speed(struct cpufreq_policy *policy)
29{
30 return cpufreq_frequency_table_verify(policy, freq_table);
31}
32
33static int db8500_cpufreq_target(struct cpufreq_policy *policy,
34 unsigned int target_freq,
35 unsigned int relation)
36{
37 struct cpufreq_freqs freqs;
38 unsigned int idx;
39
40
41 if (target_freq < policy->cpuinfo.min_freq)
42 target_freq = policy->cpuinfo.min_freq;
43 if (target_freq > policy->cpuinfo.max_freq)
44 target_freq = policy->cpuinfo.max_freq;
45
46
47 if (cpufreq_frequency_table_target
48 (policy, freq_table, target_freq, relation, &idx)) {
49 return -EINVAL;
50 }
51
52 freqs.old = policy->cur;
53 freqs.new = freq_table[idx].frequency;
54
55 if (freqs.old == freqs.new)
56 return 0;
57
58
59 for_each_cpu(freqs.cpu, policy->cpus)
60 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
61
62
63 if (clk_set_rate(armss_clk, freq_table[idx].frequency * 1000)) {
64 pr_err("db8500-cpufreq: Failed to update armss clk\n");
65 return -EINVAL;
66 }
67
68
69 for_each_cpu(freqs.cpu, policy->cpus)
70 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
71
72 return 0;
73}
74
75static unsigned int db8500_cpufreq_getspeed(unsigned int cpu)
76{
77 int i = 0;
78 unsigned long freq = clk_get_rate(armss_clk) / 1000;
79
80 while (freq_table[i].frequency != CPUFREQ_TABLE_END) {
81 if (freq <= freq_table[i].frequency)
82 return freq_table[i].frequency;
83 i++;
84 }
85
86
87 pr_err("db8500-cpufreq: Failed to find cpufreq speed\n");
88 return 0;
89}
90
91static int __cpuinit db8500_cpufreq_init(struct cpufreq_policy *policy)
92{
93 int i = 0;
94 int res;
95
96 armss_clk = clk_get(NULL, "armss");
97 if (IS_ERR(armss_clk)) {
98 pr_err("db8500-cpufreq : Failed to get armss clk\n");
99 return PTR_ERR(armss_clk);
100 }
101
102 pr_info("db8500-cpufreq : Available frequencies:\n");
103 while (freq_table[i].frequency != CPUFREQ_TABLE_END) {
104 pr_info(" %d Mhz\n", freq_table[i].frequency/1000);
105 i++;
106 }
107
108
109 res = cpufreq_frequency_table_cpuinfo(policy, freq_table);
110 if (!res)
111 cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
112 else {
113 pr_err("db8500-cpufreq : Failed to read policy table\n");
114 clk_put(armss_clk);
115 return res;
116 }
117
118 policy->min = policy->cpuinfo.min_freq;
119 policy->max = policy->cpuinfo.max_freq;
120 policy->cur = db8500_cpufreq_getspeed(policy->cpu);
121 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
122
123
124
125
126
127
128 policy->cpuinfo.transition_latency = 20 * 1000;
129
130
131 cpumask_copy(policy->cpus, cpu_present_mask);
132
133 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
134
135 return 0;
136}
137
138static struct cpufreq_driver db8500_cpufreq_driver = {
139 .flags = CPUFREQ_STICKY,
140 .verify = db8500_cpufreq_verify_speed,
141 .target = db8500_cpufreq_target,
142 .get = db8500_cpufreq_getspeed,
143 .init = db8500_cpufreq_init,
144 .name = "DB8500",
145 .attr = db8500_cpufreq_attr,
146};
147
148static int db8500_cpufreq_probe(struct platform_device *pdev)
149{
150 freq_table = dev_get_platdata(&pdev->dev);
151
152 if (!freq_table) {
153 pr_err("db8500-cpufreq: Failed to fetch cpufreq table\n");
154 return -ENODEV;
155 }
156
157 return cpufreq_register_driver(&db8500_cpufreq_driver);
158}
159
160static struct platform_driver db8500_cpufreq_plat_driver = {
161 .driver = {
162 .name = "cpufreq-u8500",
163 .owner = THIS_MODULE,
164 },
165 .probe = db8500_cpufreq_probe,
166};
167
168static int __init db8500_cpufreq_register(void)
169{
170 if (!cpu_is_u8500_family())
171 return -ENODEV;
172
173 pr_info("cpufreq for DB8500 started\n");
174 return platform_driver_register(&db8500_cpufreq_plat_driver);
175}
176device_initcall(db8500_cpufreq_register);
177
178MODULE_LICENSE("GPL v2");
179MODULE_DESCRIPTION("cpufreq driver for DB8500");
180
