Merge tag 'stable/for-linus-3.15-tag' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-microblaze.git] / drivers / cpufreq / cris-artpec3-cpufreq.c
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
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
30 static int cris_freq_target(struct cpufreq_policy *policy, unsigned int state)
31 {
32         reg_clkgen_rw_clk_ctrl clk_ctrl;
33         clk_ctrl = REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
34
35         local_irq_disable();
36
37         /* Even though we may be SMP they will share the same clock
38          * so all settings are made on CPU0. */
39         if (cris_freq_table[state].frequency == 200000)
40                 clk_ctrl.pll = 1;
41         else
42                 clk_ctrl.pll = 0;
43         REG_WR(clkgen, regi_clkgen, rw_clk_ctrl, clk_ctrl);
44
45         local_irq_enable();
46
47         return 0;
48 }
49
50 static int cris_freq_cpu_init(struct cpufreq_policy *policy)
51 {
52         return cpufreq_generic_init(policy, cris_freq_table, 1000000);
53 }
54
55 static struct cpufreq_driver cris_freq_driver = {
56         .get    = cris_freq_get_cpu_frequency,
57         .verify = cpufreq_generic_frequency_table_verify,
58         .target_index = cris_freq_target,
59         .init   = cris_freq_cpu_init,
60         .name   = "cris_freq",
61         .attr   = cpufreq_generic_attr,
62 };
63
64 static int __init cris_freq_init(void)
65 {
66         int ret;
67         ret = cpufreq_register_driver(&cris_freq_driver);
68         cpufreq_register_notifier(&cris_sdram_freq_notifier_block,
69                 CPUFREQ_TRANSITION_NOTIFIER);
70         return ret;
71 }
72
73 static int
74 cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val,
75         void *data)
76 {
77         int i;
78         struct cpufreq_freqs *freqs = data;
79         if (val == CPUFREQ_PRECHANGE) {
80                 reg_ddr2_rw_cfg cfg =
81                   REG_RD(ddr2, regi_ddr2_ctrl, rw_cfg);
82                 cfg.ref_interval = (freqs->new == 200000 ? 1560 : 46);
83
84                 if (freqs->new == 200000)
85                         for (i = 0; i < 50000; i++);
86                 REG_WR(bif_core, regi_bif_core, rw_sdram_timing, timing);
87         }
88         return 0;
89 }
90
91
92 module_init(cris_freq_init);