2 * pmi backend for the cbe_cpufreq driver
4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
6 * Author: Christian Krafft <krafft@de.ibm.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 #include <linux/kernel.h>
24 #include <linux/types.h>
25 #include <linux/timer.h>
26 #include <asm/of_platform.h>
27 #include <asm/processor.h>
30 #include <asm/cell-regs.h>
36 #include "cbe_cpufreq.h"
38 static u8 pmi_slow_mode_limit
[MAX_CBE
];
40 bool cbe_cpufreq_has_pmi
= false;
41 EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi
);
44 * hardware specific functions
47 int cbe_cpufreq_set_pmode_pmi(int cpu
, unsigned int pmode
)
50 pmi_message_t pmi_msg
;
54 pmi_msg
.type
= PMI_TYPE_FREQ_CHANGE
;
55 pmi_msg
.data1
= cbe_cpu_to_node(cpu
);
56 pmi_msg
.data2
= pmode
;
61 pmi_send_message(pmi_msg
);
64 time
= jiffies
- time
;
65 time
= jiffies_to_msecs(time
);
66 pr_debug("had to wait %lu ms for a transition using " \
70 pr_debug("PMI returned slow mode %d\n", ret
);
74 EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi
);
77 static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg
)
81 BUG_ON(pmi_msg
.type
!= PMI_TYPE_FREQ_CHANGE
);
84 slow_mode
= pmi_msg
.data2
;
86 pmi_slow_mode_limit
[node
] = slow_mode
;
88 pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node
, slow_mode
);
91 static int pmi_notifier(struct notifier_block
*nb
,
92 unsigned long event
, void *data
)
94 struct cpufreq_policy
*policy
= data
;
95 struct cpufreq_frequency_table
*cbe_freqs
;
98 cbe_freqs
= cpufreq_frequency_get_table(policy
->cpu
);
99 node
= cbe_cpu_to_node(policy
->cpu
);
101 pr_debug("got notified, event=%lu, node=%u\n", event
, node
);
103 if (pmi_slow_mode_limit
[node
] != 0) {
104 pr_debug("limiting node %d to slow mode %d\n",
105 node
, pmi_slow_mode_limit
[node
]);
107 cpufreq_verify_within_limits(policy
, 0,
109 cbe_freqs
[pmi_slow_mode_limit
[node
]].frequency
);
115 static struct notifier_block pmi_notifier_block
= {
116 .notifier_call
= pmi_notifier
,
119 static struct pmi_handler cbe_pmi_handler
= {
120 .type
= PMI_TYPE_FREQ_CHANGE
,
121 .handle_pmi_message
= cbe_cpufreq_handle_pmi
,
126 static int __init
cbe_cpufreq_pmi_init(void)
128 cbe_cpufreq_has_pmi
= pmi_register_handler(&cbe_pmi_handler
) == 0;
130 if (!cbe_cpufreq_has_pmi
)
133 cpufreq_register_notifier(&pmi_notifier_block
, CPUFREQ_POLICY_NOTIFIER
);
138 static void __exit
cbe_cpufreq_pmi_exit(void)
140 cpufreq_unregister_notifier(&pmi_notifier_block
, CPUFREQ_POLICY_NOTIFIER
);
141 pmi_unregister_handler(&cbe_pmi_handler
);
144 module_init(cbe_cpufreq_pmi_init
);
145 module_exit(cbe_cpufreq_pmi_exit
);
147 MODULE_LICENSE("GPL");
148 MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");