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14#undef DEBUG
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/module.h>
19#include <linux/types.h>
20#include <linux/errno.h>
21#include <linux/kernel.h>
22#include <linux/delay.h>
23#include <linux/sched.h>
24#include <linux/cpufreq.h>
25#include <linux/init.h>
26#include <linux/completion.h>
27#include <linux/mutex.h>
28#include <linux/time.h>
29#include <linux/of_device.h>
30
31#define DBG(fmt...) pr_debug(fmt)
32
33
34
35#define SCOM_PCR 0x0aa001
36
37#define PCR_HILO_SELECT 0x80000000U
38#define PCR_SPEED_FULL 0x00000000U
39#define PCR_SPEED_HALF 0x00020000U
40#define PCR_SPEED_QUARTER 0x00040000U
41#define PCR_SPEED_MASK 0x000e0000U
42#define PCR_SPEED_SHIFT 17
43#define PCR_FREQ_REQ_VALID 0x00010000U
44#define PCR_VOLT_REQ_VALID 0x00008000U
45#define PCR_TARGET_TIME_MASK 0x00006000U
46#define PCR_STATLAT_MASK 0x00001f00U
47#define PCR_SNOOPLAT_MASK 0x000000f0U
48#define PCR_SNOOPACC_MASK 0x0000000fU
49
50#define SCOM_PSR 0x408001
51
52#define PSR_CMD_RECEIVED 0x2000000000000000U
53#define PSR_CMD_COMPLETED 0x1000000000000000U
54#define PSR_CUR_SPEED_MASK 0x0300000000000000U
55#define PSR_CUR_SPEED_SHIFT (56)
56
57
58
59
60#define CPUFREQ_HIGH 0
61#define CPUFREQ_LOW 1
62
63static struct cpufreq_frequency_table maple_cpu_freqs[] = {
64 {0, CPUFREQ_HIGH, 0},
65 {0, CPUFREQ_LOW, 0},
66 {0, 0, CPUFREQ_TABLE_END},
67};
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69
70
71
72static int maple_pmode_cur;
73
74static const u32 *maple_pmode_data;
75static int maple_pmode_max;
76
77
78
79
80static int maple_scom_switch_freq(int speed_mode)
81{
82 unsigned long flags;
83 int to;
84
85 local_irq_save(flags);
86
87
88 scom970_write(SCOM_PCR, 0);
89
90 scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
91
92 scom970_write(SCOM_PCR, PCR_HILO_SELECT |
93 maple_pmode_data[speed_mode]);
94
95
96 for (to = 0; to < 10; to++) {
97 unsigned long psr = scom970_read(SCOM_PSR);
98
99 if ((psr & PSR_CMD_RECEIVED) == 0 &&
100 (((psr >> PSR_CUR_SPEED_SHIFT) ^
101 (maple_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
102 == 0)
103 break;
104 if (psr & PSR_CMD_COMPLETED)
105 break;
106 udelay(100);
107 }
108
109 local_irq_restore(flags);
110
111 maple_pmode_cur = speed_mode;
112 ppc_proc_freq = maple_cpu_freqs[speed_mode].frequency * 1000ul;
113
114 return 0;
115}
116
117static int maple_scom_query_freq(void)
118{
119 unsigned long psr = scom970_read(SCOM_PSR);
120 int i;
121
122 for (i = 0; i <= maple_pmode_max; i++)
123 if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
124 (maple_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
125 break;
126 return i;
127}
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130
131
132
133static int maple_cpufreq_target(struct cpufreq_policy *policy,
134 unsigned int index)
135{
136 return maple_scom_switch_freq(index);
137}
138
139static unsigned int maple_cpufreq_get_speed(unsigned int cpu)
140{
141 return maple_cpu_freqs[maple_pmode_cur].frequency;
142}
143
144static int maple_cpufreq_cpu_init(struct cpufreq_policy *policy)
145{
146 return cpufreq_generic_init(policy, maple_cpu_freqs, 12000);
147}
148
149static struct cpufreq_driver maple_cpufreq_driver = {
150 .name = "maple",
151 .flags = CPUFREQ_CONST_LOOPS,
152 .init = maple_cpufreq_cpu_init,
153 .verify = cpufreq_generic_frequency_table_verify,
154 .target_index = maple_cpufreq_target,
155 .get = maple_cpufreq_get_speed,
156 .attr = cpufreq_generic_attr,
157};
158
159static int __init maple_cpufreq_init(void)
160{
161 struct device_node *cpunode;
162 unsigned int psize;
163 unsigned long max_freq;
164 const u32 *valp;
165 u32 pvr_hi;
166 int rc = -ENODEV;
167
168
169
170
171
172 if (!of_machine_is_compatible("Momentum,Maple") &&
173 !of_machine_is_compatible("Momentum,Apache"))
174 return 0;
175
176
177 cpunode = of_cpu_device_node_get(0);
178 if (cpunode == NULL) {
179 pr_err("Can't find any CPU 0 node\n");
180 goto bail_noprops;
181 }
182
183
184
185 pvr_hi = PVR_VER(mfspr(SPRN_PVR));
186 if (pvr_hi != 0x3c && pvr_hi != 0x44) {
187 pr_err("Unsupported CPU version (%x)\n", pvr_hi);
188 goto bail_noprops;
189 }
190
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195
196
197 maple_pmode_data = of_get_property(cpunode, "power-mode-data", &psize);
198 if (!maple_pmode_data) {
199 DBG("No power-mode-data !\n");
200 goto bail_noprops;
201 }
202 maple_pmode_max = psize / sizeof(u32) - 1;
203
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209
210
211 valp = of_get_property(cpunode, "clock-frequency", NULL);
212 if (!valp)
213 return -ENODEV;
214 max_freq = (*valp)/1000;
215 maple_cpu_freqs[0].frequency = max_freq;
216 maple_cpu_freqs[1].frequency = max_freq/2;
217
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219
220
221
222 msleep(10);
223 maple_pmode_cur = -1;
224 maple_scom_switch_freq(maple_scom_query_freq());
225
226 pr_info("Registering Maple CPU frequency driver\n");
227 pr_info("Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
228 maple_cpu_freqs[1].frequency/1000,
229 maple_cpu_freqs[0].frequency/1000,
230 maple_cpu_freqs[maple_pmode_cur].frequency/1000);
231
232 rc = cpufreq_register_driver(&maple_cpufreq_driver);
233
234 of_node_put(cpunode);
235
236 return rc;
237
238bail_noprops:
239 of_node_put(cpunode);
240
241 return rc;
242}
243
244module_init(maple_cpufreq_init);
245
246
247MODULE_LICENSE("GPL");
248