1 #include <linux/init.h>
2 #include <linux/module.h>
3 #include <linux/cpufreq.h>
4 #include <hwregs/reg_map.h>
5 #include <hwregs/reg_rdwr.h>
6 #include <hwregs/clkgen_defs.h>
7 #include <hwregs/ddr2_defs.h>
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
cris_freq_get_cpu_frequency(unsigned int cpu)23 static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu)
24 {
25 reg_clkgen_rw_clk_ctrl clk_ctrl;
26 clk_ctrl = REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
27 return clk_ctrl.pll ? 200000 : 6000;
28 }
29
cris_freq_set_cpu_state(unsigned int state)30 static void cris_freq_set_cpu_state(unsigned int state)
31 {
32 int i = 0;
33 struct cpufreq_freqs freqs;
34 reg_clkgen_rw_clk_ctrl clk_ctrl;
35 clk_ctrl = REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
36
37 #ifdef CONFIG_SMP
38 for_each_present_cpu(i)
39 #endif
40 {
41 freqs.old = cris_freq_get_cpu_frequency(i);
42 freqs.new = cris_freq_table[state].frequency;
43 freqs.cpu = i;
44 }
45
46 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
47
48 local_irq_disable();
49
50 /* Even though we may be SMP they will share the same clock
51 * so all settings are made on CPU0. */
52 if (cris_freq_table[state].frequency == 200000)
53 clk_ctrl.pll = 1;
54 else
55 clk_ctrl.pll = 0;
56 REG_WR(clkgen, regi_clkgen, rw_clk_ctrl, clk_ctrl);
57
58 local_irq_enable();
59
60 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
61 };
62
cris_freq_verify(struct cpufreq_policy * policy)63 static int cris_freq_verify(struct cpufreq_policy *policy)
64 {
65 return cpufreq_frequency_table_verify(policy, &cris_freq_table[0]);
66 }
67
cris_freq_target(struct cpufreq_policy * policy,unsigned int target_freq,unsigned int relation)68 static int cris_freq_target(struct cpufreq_policy *policy,
69 unsigned int target_freq,
70 unsigned int relation)
71 {
72 unsigned int newstate = 0;
73
74 if (cpufreq_frequency_table_target(policy, cris_freq_table,
75 target_freq, relation, &newstate))
76 return -EINVAL;
77
78 cris_freq_set_cpu_state(newstate);
79
80 return 0;
81 }
82
cris_freq_cpu_init(struct cpufreq_policy * policy)83 static int cris_freq_cpu_init(struct cpufreq_policy *policy)
84 {
85 int result;
86
87 /* cpuinfo and default policy values */
88 policy->cpuinfo.transition_latency = 1000000; /* 1ms */
89 policy->cur = cris_freq_get_cpu_frequency(0);
90
91 result = cpufreq_frequency_table_cpuinfo(policy, cris_freq_table);
92 if (result)
93 return (result);
94
95 cpufreq_frequency_table_get_attr(cris_freq_table, policy->cpu);
96
97 return 0;
98 }
99
100
cris_freq_cpu_exit(struct cpufreq_policy * policy)101 static int cris_freq_cpu_exit(struct cpufreq_policy *policy)
102 {
103 cpufreq_frequency_table_put_attr(policy->cpu);
104 return 0;
105 }
106
107
108 static struct freq_attr *cris_freq_attr[] = {
109 &cpufreq_freq_attr_scaling_available_freqs,
110 NULL,
111 };
112
113 static struct cpufreq_driver cris_freq_driver = {
114 .get = cris_freq_get_cpu_frequency,
115 .verify = cris_freq_verify,
116 .target = cris_freq_target,
117 .init = cris_freq_cpu_init,
118 .exit = cris_freq_cpu_exit,
119 .name = "cris_freq",
120 .owner = THIS_MODULE,
121 .attr = cris_freq_attr,
122 };
123
cris_freq_init(void)124 static int __init cris_freq_init(void)
125 {
126 int ret;
127 ret = cpufreq_register_driver(&cris_freq_driver);
128 cpufreq_register_notifier(&cris_sdram_freq_notifier_block,
129 CPUFREQ_TRANSITION_NOTIFIER);
130 return ret;
131 }
132
133 static int
cris_sdram_freq_notifier(struct notifier_block * nb,unsigned long val,void * data)134 cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val,
135 void *data)
136 {
137 int i;
138 struct cpufreq_freqs *freqs = data;
139 if (val == CPUFREQ_PRECHANGE) {
140 reg_ddr2_rw_cfg cfg =
141 REG_RD(ddr2, regi_ddr2_ctrl, rw_cfg);
142 cfg.ref_interval = (freqs->new == 200000 ? 1560 : 46);
143
144 if (freqs->new == 200000)
145 for (i = 0; i < 50000; i++);
146 REG_WR(bif_core, regi_bif_core, rw_sdram_timing, timing);
147 }
148 return 0;
149 }
150
151
152 module_init(cris_freq_init);
153