diff options
Diffstat (limited to 'drivers/cpufreq/cris-etraxfs-cpufreq.c')
-rw-r--r-- | drivers/cpufreq/cris-etraxfs-cpufreq.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/cpufreq/cris-etraxfs-cpufreq.c b/drivers/cpufreq/cris-etraxfs-cpufreq.c new file mode 100644 index 000000000000..12952235d5db --- /dev/null +++ b/drivers/cpufreq/cris-etraxfs-cpufreq.c | |||
@@ -0,0 +1,142 @@ | |||
1 | #include <linux/init.h> | ||
2 | #include <linux/module.h> | ||
3 | #include <linux/cpufreq.h> | ||
4 | #include <hwregs/reg_map.h> | ||
5 | #include <arch/hwregs/reg_rdwr.h> | ||
6 | #include <arch/hwregs/config_defs.h> | ||
7 | #include <arch/hwregs/bif_core_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_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(struct cpufreq_policy *policy, | ||
31 | unsigned int state) | ||
32 | { | ||
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 | freqs.old = cris_freq_get_cpu_frequency(policy->cpu); | ||
38 | freqs.new = cris_freq_table[state].frequency; | ||
39 | |||
40 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | ||
41 | |||
42 | local_irq_disable(); | ||
43 | |||
44 | /* Even though we may be SMP they will share the same clock | ||
45 | * so all settings are made on CPU0. */ | ||
46 | if (cris_freq_table[state].frequency == 200000) | ||
47 | clk_ctrl.pll = 1; | ||
48 | else | ||
49 | clk_ctrl.pll = 0; | ||
50 | REG_WR(config, regi_config, rw_clk_ctrl, clk_ctrl); | ||
51 | |||
52 | local_irq_enable(); | ||
53 | |||
54 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | ||
55 | }; | ||
56 | |||
57 | static int cris_freq_verify(struct cpufreq_policy *policy) | ||
58 | { | ||
59 | return cpufreq_frequency_table_verify(policy, &cris_freq_table[0]); | ||
60 | } | ||
61 | |||
62 | static int cris_freq_target(struct cpufreq_policy *policy, | ||
63 | unsigned int target_freq, unsigned int relation) | ||
64 | { | ||
65 | unsigned int newstate = 0; | ||
66 | |||
67 | if (cpufreq_frequency_table_target | ||
68 | (policy, cris_freq_table, target_freq, relation, &newstate)) | ||
69 | return -EINVAL; | ||
70 | |||
71 | cris_freq_set_cpu_state(policy, newstate); | ||
72 | |||
73 | return 0; | ||
74 | } | ||
75 | |||
76 | static int cris_freq_cpu_init(struct cpufreq_policy *policy) | ||
77 | { | ||
78 | int result; | ||
79 | |||
80 | /* cpuinfo and default policy values */ | ||
81 | policy->cpuinfo.transition_latency = 1000000; /* 1ms */ | ||
82 | policy->cur = cris_freq_get_cpu_frequency(0); | ||
83 | |||
84 | result = cpufreq_frequency_table_cpuinfo(policy, cris_freq_table); | ||
85 | if (result) | ||
86 | return (result); | ||
87 | |||
88 | cpufreq_frequency_table_get_attr(cris_freq_table, policy->cpu); | ||
89 | |||
90 | return 0; | ||
91 | } | ||
92 | |||
93 | static int cris_freq_cpu_exit(struct cpufreq_policy *policy) | ||
94 | { | ||
95 | cpufreq_frequency_table_put_attr(policy->cpu); | ||
96 | return 0; | ||
97 | } | ||
98 | |||
99 | static struct freq_attr *cris_freq_attr[] = { | ||
100 | &cpufreq_freq_attr_scaling_available_freqs, | ||
101 | NULL, | ||
102 | }; | ||
103 | |||
104 | static struct cpufreq_driver cris_freq_driver = { | ||
105 | .get = cris_freq_get_cpu_frequency, | ||
106 | .verify = cris_freq_verify, | ||
107 | .target = cris_freq_target, | ||
108 | .init = cris_freq_cpu_init, | ||
109 | .exit = cris_freq_cpu_exit, | ||
110 | .name = "cris_freq", | ||
111 | .owner = THIS_MODULE, | ||
112 | .attr = cris_freq_attr, | ||
113 | }; | ||
114 | |||
115 | static int __init cris_freq_init(void) | ||
116 | { | ||
117 | int ret; | ||
118 | ret = cpufreq_register_driver(&cris_freq_driver); | ||
119 | cpufreq_register_notifier(&cris_sdram_freq_notifier_block, | ||
120 | CPUFREQ_TRANSITION_NOTIFIER); | ||
121 | return ret; | ||
122 | } | ||
123 | |||
124 | static int | ||
125 | cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val, | ||
126 | void *data) | ||
127 | { | ||
128 | int i; | ||
129 | struct cpufreq_freqs *freqs = data; | ||
130 | if (val == CPUFREQ_PRECHANGE) { | ||
131 | reg_bif_core_rw_sdram_timing timing = | ||
132 | REG_RD(bif_core, regi_bif_core, rw_sdram_timing); | ||
133 | timing.cpd = (freqs->new == 200000 ? 0 : 1); | ||
134 | |||
135 | if (freqs->new == 200000) | ||
136 | for (i = 0; i < 50000; i++) ; | ||
137 | REG_WR(bif_core, regi_bif_core, rw_sdram_timing, timing); | ||
138 | } | ||
139 | return 0; | ||
140 | } | ||
141 | |||
142 | module_init(cris_freq_init); | ||