diff options
Diffstat (limited to 'drivers/cpufreq/ppc_cbe_cpufreq_pmi.c')
| -rw-r--r-- | drivers/cpufreq/ppc_cbe_cpufreq_pmi.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c new file mode 100644 index 000000000000..d29e8da396a0 --- /dev/null +++ b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c @@ -0,0 +1,156 @@ +/* + * pmi backend for the cbe_cpufreq driver + * + * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007 + * + * Author: Christian Krafft <krafft@de.ibm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/timer.h> +#include <linux/module.h> +#include <linux/of_platform.h> + +#include <asm/processor.h> +#include <asm/prom.h> +#include <asm/pmi.h> +#include <asm/cell-regs.h> + +#ifdef DEBUG +#include <asm/time.h> +#endif + +#include "ppc_cbe_cpufreq.h" + +static u8 pmi_slow_mode_limit[MAX_CBE]; + +bool cbe_cpufreq_has_pmi = false; +EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi); + +/* + * hardware specific functions + */ + +int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode) +{ + int ret; + pmi_message_t pmi_msg; +#ifdef DEBUG + long time; +#endif + pmi_msg.type = PMI_TYPE_FREQ_CHANGE; + pmi_msg.data1 = cbe_cpu_to_node(cpu); + pmi_msg.data2 = pmode; + +#ifdef DEBUG + time = jiffies; +#endif + pmi_send_message(pmi_msg); + +#ifdef DEBUG + time = jiffies - time; + time = jiffies_to_msecs(time); + pr_debug("had to wait %lu ms for a transition using " \ + "PMI\n", time); +#endif + ret = pmi_msg.data2; + pr_debug("PMI returned slow mode %d\n", ret); + + return ret; +} +EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi); + + +static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg) +{ + u8 node, slow_mode; + + BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE); + + node = pmi_msg.data1; + slow_mode = pmi_msg.data2; + + pmi_slow_mode_limit[node] = slow_mode; + + pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode); +} + +static int pmi_notifier(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct cpufreq_policy *policy = data; + struct cpufreq_frequency_table *cbe_freqs; + u8 node; + + /* Should this really be called for CPUFREQ_ADJUST, CPUFREQ_INCOMPATIBLE + * and CPUFREQ_NOTIFY policy events?) + */ + if (event == CPUFREQ_START) + return 0; + + cbe_freqs = cpufreq_frequency_get_table(policy->cpu); + node = cbe_cpu_to_node(policy->cpu); + + pr_debug("got notified, event=%lu, node=%u\n", event, node); + + if (pmi_slow_mode_limit[node] != 0) { + pr_debug("limiting node %d to slow mode %d\n", + node, pmi_slow_mode_limit[node]); + + cpufreq_verify_within_limits(policy, 0, + + cbe_freqs[pmi_slow_mode_limit[node]].frequency); + } + + return 0; +} + +static struct notifier_block pmi_notifier_block = { + .notifier_call = pmi_notifier, +}; + +static struct pmi_handler cbe_pmi_handler = { + .type = PMI_TYPE_FREQ_CHANGE, + .handle_pmi_message = cbe_cpufreq_handle_pmi, +}; + + + +static int __init cbe_cpufreq_pmi_init(void) +{ + cbe_cpufreq_has_pmi = pmi_register_handler(&cbe_pmi_handler) == 0; + + if (!cbe_cpufreq_has_pmi) + return -ENODEV; + + cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER); + + return 0; +} + +static void __exit cbe_cpufreq_pmi_exit(void) +{ + cpufreq_unregister_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER); + pmi_unregister_handler(&cbe_pmi_handler); +} + +module_init(cbe_cpufreq_pmi_init); +module_exit(cbe_cpufreq_pmi_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>"); |