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authorViresh Kumar <viresh.kumar@linaro.org>2013-03-25 11:20:23 +0530
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-04-10 13:19:26 +0200
commit6eb1c377423572374518f5be93214d139d113090 (patch)
tree3e6163aead961442d07b7f5ad62e58d3e189560c /drivers
parent764295ae675bb252de3637e36a6602a9aed7de6b (diff)
downloadlinux-6eb1c377423572374518f5be93214d139d113090.tar.bz2
cpufreq: powerpc/platforms/cell: move cpufreq driver to drivers/cpufreq
This patch moves cpufreq driver of powerpc platforms/cell to drivers/cpufreq. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/cpufreq/Kconfig.powerpc18
-rw-r--r--drivers/cpufreq/Makefile3
-rw-r--r--drivers/cpufreq/ppc_cbe_cpufreq.c209
-rw-r--r--drivers/cpufreq/ppc_cbe_cpufreq.h24
-rw-r--r--drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c115
-rw-r--r--drivers/cpufreq/ppc_cbe_cpufreq_pmi.c156
6 files changed, 525 insertions, 0 deletions
diff --git a/drivers/cpufreq/Kconfig.powerpc b/drivers/cpufreq/Kconfig.powerpc
index e76992f79683..9c926ca0d718 100644
--- a/drivers/cpufreq/Kconfig.powerpc
+++ b/drivers/cpufreq/Kconfig.powerpc
@@ -1,3 +1,21 @@
+config CPU_FREQ_CBE
+ tristate "CBE frequency scaling"
+ depends on CBE_RAS && PPC_CELL
+ default m
+ help
+ This adds the cpufreq driver for Cell BE processors.
+ For details, take a look at <file:Documentation/cpu-freq/>.
+ If you don't have such processor, say N
+
+config CPU_FREQ_CBE_PMI
+ bool "CBE frequency scaling using PMI interface"
+ depends on CPU_FREQ_CBE
+ default n
+ help
+ Select this, if you want to use the PMI interface to switch
+ frequencies. Using PMI, the processor will not only be able to run at
+ lower speed, but also at lower core voltage.
+
config CPU_FREQ_MAPLE
bool "Support for Maple 970FX Evaluation Board"
depends on PPC_MAPLE
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 3a9ff23ff9d9..17417c7ee135 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -73,6 +73,9 @@ obj-$(CONFIG_ARCH_TEGRA) += tegra-cpufreq.o
##################################################################################
# PowerPC platform drivers
+obj-$(CONFIG_CPU_FREQ_CBE) += ppc-cbe-cpufreq.o
+ppc-cbe-cpufreq-y += ppc_cbe_cpufreq_pervasive.o ppc_cbe_cpufreq.o
+obj-$(CONFIG_CPU_FREQ_CBE_PMI) += ppc_cbe_cpufreq_pmi.o
obj-$(CONFIG_CPU_FREQ_MAPLE) += maple-cpufreq.o
##################################################################################
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq.c b/drivers/cpufreq/ppc_cbe_cpufreq.c
new file mode 100644
index 000000000000..e577a1dbbfcd
--- /dev/null
+++ b/drivers/cpufreq/ppc_cbe_cpufreq.c
@@ -0,0 +1,209 @@
+/*
+ * cpufreq driver for the cell processor
+ *
+ * (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/cpufreq.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+
+#include <asm/machdep.h>
+#include <asm/prom.h>
+#include <asm/cell-regs.h>
+
+#include "ppc_cbe_cpufreq.h"
+
+static DEFINE_MUTEX(cbe_switch_mutex);
+
+
+/* the CBE supports an 8 step frequency scaling */
+static struct cpufreq_frequency_table cbe_freqs[] = {
+ {1, 0},
+ {2, 0},
+ {3, 0},
+ {4, 0},
+ {5, 0},
+ {6, 0},
+ {8, 0},
+ {10, 0},
+ {0, CPUFREQ_TABLE_END},
+};
+
+/*
+ * hardware specific functions
+ */
+
+static int set_pmode(unsigned int cpu, unsigned int slow_mode)
+{
+ int rc;
+
+ if (cbe_cpufreq_has_pmi)
+ rc = cbe_cpufreq_set_pmode_pmi(cpu, slow_mode);
+ else
+ rc = cbe_cpufreq_set_pmode(cpu, slow_mode);
+
+ pr_debug("register contains slow mode %d\n", cbe_cpufreq_get_pmode(cpu));
+
+ return rc;
+}
+
+/*
+ * cpufreq functions
+ */
+
+static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+ const u32 *max_freqp;
+ u32 max_freq;
+ int i, cur_pmode;
+ struct device_node *cpu;
+
+ cpu = of_get_cpu_node(policy->cpu, NULL);
+
+ if (!cpu)
+ return -ENODEV;
+
+ pr_debug("init cpufreq on CPU %d\n", policy->cpu);
+
+ /*
+ * Let's check we can actually get to the CELL regs
+ */
+ if (!cbe_get_cpu_pmd_regs(policy->cpu) ||
+ !cbe_get_cpu_mic_tm_regs(policy->cpu)) {
+ pr_info("invalid CBE regs pointers for cpufreq\n");
+ return -EINVAL;
+ }
+
+ max_freqp = of_get_property(cpu, "clock-frequency", NULL);
+
+ of_node_put(cpu);
+
+ if (!max_freqp)
+ return -EINVAL;
+
+ /* we need the freq in kHz */
+ max_freq = *max_freqp / 1000;
+
+ pr_debug("max clock-frequency is at %u kHz\n", max_freq);
+ pr_debug("initializing frequency table\n");
+
+ /* initialize frequency table */
+ for (i=0; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
+ cbe_freqs[i].frequency = max_freq / cbe_freqs[i].index;
+ pr_debug("%d: %d\n", i, cbe_freqs[i].frequency);
+ }
+
+ /* if DEBUG is enabled set_pmode() measures the latency
+ * of a transition */
+ policy->cpuinfo.transition_latency = 25000;
+
+ cur_pmode = cbe_cpufreq_get_pmode(policy->cpu);
+ pr_debug("current pmode is at %d\n",cur_pmode);
+
+ policy->cur = cbe_freqs[cur_pmode].frequency;
+
+#ifdef CONFIG_SMP
+ cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
+#endif
+
+ cpufreq_frequency_table_get_attr(cbe_freqs, policy->cpu);
+
+ /* this ensures that policy->cpuinfo_min
+ * and policy->cpuinfo_max are set correctly */
+ return cpufreq_frequency_table_cpuinfo(policy, cbe_freqs);
+}
+
+static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ return 0;
+}
+
+static int cbe_cpufreq_verify(struct cpufreq_policy *policy)
+{
+ return cpufreq_frequency_table_verify(policy, cbe_freqs);
+}
+
+static int cbe_cpufreq_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ int rc;
+ struct cpufreq_freqs freqs;
+ unsigned int cbe_pmode_new;
+
+ cpufreq_frequency_table_target(policy,
+ cbe_freqs,
+ target_freq,
+ relation,
+ &cbe_pmode_new);
+
+ freqs.old = policy->cur;
+ freqs.new = cbe_freqs[cbe_pmode_new].frequency;
+
+ mutex_lock(&cbe_switch_mutex);
+ cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+
+ pr_debug("setting frequency for cpu %d to %d kHz, " \
+ "1/%d of max frequency\n",
+ policy->cpu,
+ cbe_freqs[cbe_pmode_new].frequency,
+ cbe_freqs[cbe_pmode_new].index);
+
+ rc = set_pmode(policy->cpu, cbe_pmode_new);
+
+ cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+ mutex_unlock(&cbe_switch_mutex);
+
+ return rc;
+}
+
+static struct cpufreq_driver cbe_cpufreq_driver = {
+ .verify = cbe_cpufreq_verify,
+ .target = cbe_cpufreq_target,
+ .init = cbe_cpufreq_cpu_init,
+ .exit = cbe_cpufreq_cpu_exit,
+ .name = "cbe-cpufreq",
+ .owner = THIS_MODULE,
+ .flags = CPUFREQ_CONST_LOOPS,
+};
+
+/*
+ * module init and destoy
+ */
+
+static int __init cbe_cpufreq_init(void)
+{
+ if (!machine_is(cell))
+ return -ENODEV;
+
+ return cpufreq_register_driver(&cbe_cpufreq_driver);
+}
+
+static void __exit cbe_cpufreq_exit(void)
+{
+ cpufreq_unregister_driver(&cbe_cpufreq_driver);
+}
+
+module_init(cbe_cpufreq_init);
+module_exit(cbe_cpufreq_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq.h b/drivers/cpufreq/ppc_cbe_cpufreq.h
new file mode 100644
index 000000000000..b4c00a5a6a59
--- /dev/null
+++ b/drivers/cpufreq/ppc_cbe_cpufreq.h
@@ -0,0 +1,24 @@
+/*
+ * ppc_cbe_cpufreq.h
+ *
+ * This file contains the definitions used by the cbe_cpufreq driver.
+ *
+ * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
+ *
+ * Author: Christian Krafft <krafft@de.ibm.com>
+ *
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/types.h>
+
+int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode);
+int cbe_cpufreq_get_pmode(int cpu);
+
+int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode);
+
+#if defined(CONFIG_CPU_FREQ_CBE_PMI) || defined(CONFIG_CPU_FREQ_CBE_PMI_MODULE)
+extern bool cbe_cpufreq_has_pmi;
+#else
+#define cbe_cpufreq_has_pmi (0)
+#endif
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c b/drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c
new file mode 100644
index 000000000000..84d2f2cf5ba7
--- /dev/null
+++ b/drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c
@@ -0,0 +1,115 @@
+/*
+ * pervasive backend for the cbe_cpufreq driver
+ *
+ * This driver makes use of the pervasive unit to
+ * engage the desired frequency.
+ *
+ * (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/io.h>
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <asm/machdep.h>
+#include <asm/hw_irq.h>
+#include <asm/cell-regs.h>
+
+#include "ppc_cbe_cpufreq.h"
+
+/* to write to MIC register */
+static u64 MIC_Slow_Fast_Timer_table[] = {
+ [0 ... 7] = 0x007fc00000000000ull,
+};
+
+/* more values for the MIC */
+static u64 MIC_Slow_Next_Timer_table[] = {
+ 0x0000240000000000ull,
+ 0x0000268000000000ull,
+ 0x000029C000000000ull,
+ 0x00002D0000000000ull,
+ 0x0000300000000000ull,
+ 0x0000334000000000ull,
+ 0x000039C000000000ull,
+ 0x00003FC000000000ull,
+};
+
+
+int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode)
+{
+ struct cbe_pmd_regs __iomem *pmd_regs;
+ struct cbe_mic_tm_regs __iomem *mic_tm_regs;
+ unsigned long flags;
+ u64 value;
+#ifdef DEBUG
+ long time;
+#endif
+
+ local_irq_save(flags);
+
+ mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
+ pmd_regs = cbe_get_cpu_pmd_regs(cpu);
+
+#ifdef DEBUG
+ time = jiffies;
+#endif
+
+ out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
+ out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);
+
+ out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
+ out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);
+
+ value = in_be64(&pmd_regs->pmcr);
+ /* set bits to zero */
+ value &= 0xFFFFFFFFFFFFFFF8ull;
+ /* set bits to next pmode */
+ value |= pmode;
+
+ out_be64(&pmd_regs->pmcr, value);
+
+#ifdef DEBUG
+ /* wait until new pmode appears in status register */
+ value = in_be64(&pmd_regs->pmsr) & 0x07;
+ while (value != pmode) {
+ cpu_relax();
+ value = in_be64(&pmd_regs->pmsr) & 0x07;
+ }
+
+ time = jiffies - time;
+ time = jiffies_to_msecs(time);
+ pr_debug("had to wait %lu ms for a transition using " \
+ "pervasive unit\n", time);
+#endif
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+
+int cbe_cpufreq_get_pmode(int cpu)
+{
+ int ret;
+ struct cbe_pmd_regs __iomem *pmd_regs;
+
+ pmd_regs = cbe_get_cpu_pmd_regs(cpu);
+ ret = in_be64(&pmd_regs->pmsr) & 0x07;
+
+ return ret;
+}
+
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>");