cpufreq: merge arm_big_little and vexpress-spc
authorSudeep Holla <sudeep.holla@arm.com>
Mon, 21 Oct 2019 10:20:34 +0000 (11:20 +0100)
committerViresh Kumar <viresh.kumar@linaro.org>
Mon, 21 Oct 2019 10:53:58 +0000 (16:23 +0530)
arm_big_little cpufreq driver was designed as a generic big little
driver that could be used by any platform and make use of bL switcher.
Over years alternate solutions have been designed and merged to deal
with bL/HMP systems like EAS.

Also since no other driver made use of generic arm_big_little cpufreq
driver except Vexpress SPC, we can merge them together as vexpress-spc
driver used only on Vexpress TC2(CA15_CA7) platform.

Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
MAINTAINERS
drivers/cpufreq/Kconfig.arm
drivers/cpufreq/Makefile
drivers/cpufreq/arm_big_little.c [deleted file]
drivers/cpufreq/arm_big_little.h [deleted file]
drivers/cpufreq/vexpress-spc-cpufreq.c

index 296de2b51c832ecc1869a77624c964ce398a5236..07f5d8dc30277d8d9089d2257736a7cf85f0a4f2 100644 (file)
@@ -4273,14 +4273,13 @@ F:      include/linux/cpufreq.h
 F:     include/linux/sched/cpufreq.h
 F:     tools/testing/selftests/cpufreq/
 
-CPU FREQUENCY DRIVERS - ARM BIG LITTLE
+CPU FREQUENCY DRIVERS - VEXPRESS SPC ARM BIG LITTLE
 M:     Viresh Kumar <viresh.kumar@linaro.org>
 M:     Sudeep Holla <sudeep.holla@arm.com>
 L:     linux-pm@vger.kernel.org
 W:     http://www.arm.com/products/processors/technologies/biglittleprocessing.php
 S:     Maintained
-F:     drivers/cpufreq/arm_big_little.h
-F:     drivers/cpufreq/arm_big_little.c
+F:     drivers/cpufreq/vexpress-spc-cpufreq.c
 
 CPU POWER MONITORING SUBSYSTEM
 M:     Thomas Renninger <trenn@suse.com>
index a905796f7f856516ea6299b5ff83b098e2f0e015..3858d86cf409c7cf33ad436f9f0cc5a1dfdf6f53 100644 (file)
@@ -49,14 +49,6 @@ config ARM_ARMADA_8K_CPUFREQ
 
          If in doubt, say N.
 
-# big LITTLE core layer and glue drivers
-config ARM_BIG_LITTLE_CPUFREQ
-       tristate "Generic ARM big LITTLE CPUfreq driver"
-       depends on ARM_CPU_TOPOLOGY && HAVE_CLK
-       select PM_OPP
-       help
-         This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.
-
 config ARM_SCPI_CPUFREQ
        tristate "SCPI based CPUfreq driver"
        depends on ARM_SCPI_PROTOCOL && COMMON_CLK_SCPI
@@ -69,7 +61,9 @@ config ARM_SCPI_CPUFREQ
 
 config ARM_VEXPRESS_SPC_CPUFREQ
        tristate "Versatile Express SPC based CPUfreq driver"
-       depends on ARM_BIG_LITTLE_CPUFREQ && ARCH_VEXPRESS_SPC
+       depends on ARM_CPU_TOPOLOGY && HAVE_CLK
+       depends on ARCH_VEXPRESS_SPC
+       select PM_OPP
        help
          This add the CPUfreq driver support for Versatile Express
          big.LITTLE platforms using SPC for power management.
index 9a9f5ccd13d981ed5ad1a69d58b9509d00c0184a..f6670c4abbb0305cf5844c4a94307685ae44d660 100644 (file)
@@ -47,8 +47,6 @@ obj-$(CONFIG_X86_SFI_CPUFREQ)         += sfi-cpufreq.o
 
 ##################################################################################
 # ARM SoC drivers
-obj-$(CONFIG_ARM_BIG_LITTLE_CPUFREQ)   += arm_big_little.o
-
 obj-$(CONFIG_ARM_ARMADA_37XX_CPUFREQ)  += armada-37xx-cpufreq.o
 obj-$(CONFIG_ARM_ARMADA_8K_CPUFREQ)    += armada-8k-cpufreq.o
 obj-$(CONFIG_ARM_BRCMSTB_AVS_CPUFREQ)  += brcmstb-avs-cpufreq.o
diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c
deleted file mode 100644 (file)
index 7fe52fc..0000000
+++ /dev/null
@@ -1,658 +0,0 @@
-/*
- * ARM big.LITTLE Platforms CPUFreq support
- *
- * Copyright (C) 2013 ARM Ltd.
- * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
- *
- * Copyright (C) 2013 Linaro.
- * Viresh Kumar <viresh.kumar@linaro.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/clk.h>
-#include <linux/cpu.h>
-#include <linux/cpufreq.h>
-#include <linux/cpumask.h>
-#include <linux/cpu_cooling.h>
-#include <linux/export.h>
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/of_platform.h>
-#include <linux/pm_opp.h>
-#include <linux/slab.h>
-#include <linux/topology.h>
-#include <linux/types.h>
-
-#include "arm_big_little.h"
-
-/* Currently we support only two clusters */
-#define A15_CLUSTER    0
-#define A7_CLUSTER     1
-#define MAX_CLUSTERS   2
-
-#ifdef CONFIG_BL_SWITCHER
-#include <asm/bL_switcher.h>
-static bool bL_switching_enabled;
-#define is_bL_switching_enabled()      bL_switching_enabled
-#define set_switching_enabled(x)       (bL_switching_enabled = (x))
-#else
-#define is_bL_switching_enabled()      false
-#define set_switching_enabled(x)       do { } while (0)
-#define bL_switch_request(...)         do { } while (0)
-#define bL_switcher_put_enabled()      do { } while (0)
-#define bL_switcher_get_enabled()      do { } while (0)
-#endif
-
-#define ACTUAL_FREQ(cluster, freq)  ((cluster == A7_CLUSTER) ? freq << 1 : freq)
-#define VIRT_FREQ(cluster, freq)    ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
-
-static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
-static const struct cpufreq_arm_bL_ops *arm_bL_ops;
-static struct clk *clk[MAX_CLUSTERS];
-static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
-static atomic_t cluster_usage[MAX_CLUSTERS + 1];
-
-static unsigned int clk_big_min;       /* (Big) clock frequencies */
-static unsigned int clk_little_max;    /* Maximum clock frequency (Little) */
-
-static DEFINE_PER_CPU(unsigned int, physical_cluster);
-static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
-
-static struct mutex cluster_lock[MAX_CLUSTERS];
-
-static inline int raw_cpu_to_cluster(int cpu)
-{
-       return topology_physical_package_id(cpu);
-}
-
-static inline int cpu_to_cluster(int cpu)
-{
-       return is_bL_switching_enabled() ?
-               MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
-}
-
-static unsigned int find_cluster_maxfreq(int cluster)
-{
-       int j;
-       u32 max_freq = 0, cpu_freq;
-
-       for_each_online_cpu(j) {
-               cpu_freq = per_cpu(cpu_last_req_freq, j);
-
-               if ((cluster == per_cpu(physical_cluster, j)) &&
-                               (max_freq < cpu_freq))
-                       max_freq = cpu_freq;
-       }
-
-       pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
-                       max_freq);
-
-       return max_freq;
-}
-
-static unsigned int clk_get_cpu_rate(unsigned int cpu)
-{
-       u32 cur_cluster = per_cpu(physical_cluster, cpu);
-       u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
-
-       /* For switcher we use virtual A7 clock rates */
-       if (is_bL_switching_enabled())
-               rate = VIRT_FREQ(cur_cluster, rate);
-
-       pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
-                       cur_cluster, rate);
-
-       return rate;
-}
-
-static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
-{
-       if (is_bL_switching_enabled()) {
-               pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
-                                       cpu));
-
-               return per_cpu(cpu_last_req_freq, cpu);
-       } else {
-               return clk_get_cpu_rate(cpu);
-       }
-}
-
-static unsigned int
-bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
-{
-       u32 new_rate, prev_rate;
-       int ret;
-       bool bLs = is_bL_switching_enabled();
-
-       mutex_lock(&cluster_lock[new_cluster]);
-
-       if (bLs) {
-               prev_rate = per_cpu(cpu_last_req_freq, cpu);
-               per_cpu(cpu_last_req_freq, cpu) = rate;
-               per_cpu(physical_cluster, cpu) = new_cluster;
-
-               new_rate = find_cluster_maxfreq(new_cluster);
-               new_rate = ACTUAL_FREQ(new_cluster, new_rate);
-       } else {
-               new_rate = rate;
-       }
-
-       pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
-                       __func__, cpu, old_cluster, new_cluster, new_rate);
-
-       ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
-       if (!ret) {
-               /*
-                * FIXME: clk_set_rate hasn't returned an error here however it
-                * may be that clk_change_rate failed due to hardware or
-                * firmware issues and wasn't able to report that due to the
-                * current design of the clk core layer. To work around this
-                * problem we will read back the clock rate and check it is
-                * correct. This needs to be removed once clk core is fixed.
-                */
-               if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
-                       ret = -EIO;
-       }
-
-       if (WARN_ON(ret)) {
-               pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
-                               new_cluster);
-               if (bLs) {
-                       per_cpu(cpu_last_req_freq, cpu) = prev_rate;
-                       per_cpu(physical_cluster, cpu) = old_cluster;
-               }
-
-               mutex_unlock(&cluster_lock[new_cluster]);
-
-               return ret;
-       }
-
-       mutex_unlock(&cluster_lock[new_cluster]);
-
-       /* Recalc freq for old cluster when switching clusters */
-       if (old_cluster != new_cluster) {
-               pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
-                               __func__, cpu, old_cluster, new_cluster);
-
-               /* Switch cluster */
-               bL_switch_request(cpu, new_cluster);
-
-               mutex_lock(&cluster_lock[old_cluster]);
-
-               /* Set freq of old cluster if there are cpus left on it */
-               new_rate = find_cluster_maxfreq(old_cluster);
-               new_rate = ACTUAL_FREQ(old_cluster, new_rate);
-
-               if (new_rate) {
-                       pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
-                                       __func__, old_cluster, new_rate);
-
-                       if (clk_set_rate(clk[old_cluster], new_rate * 1000))
-                               pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
-                                               __func__, ret, old_cluster);
-               }
-               mutex_unlock(&cluster_lock[old_cluster]);
-       }
-
-       return 0;
-}
-
-/* Set clock frequency */
-static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
-               unsigned int index)
-{
-       u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
-       unsigned int freqs_new;
-       int ret;
-
-       cur_cluster = cpu_to_cluster(cpu);
-       new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
-
-       freqs_new = freq_table[cur_cluster][index].frequency;
-
-       if (is_bL_switching_enabled()) {
-               if ((actual_cluster == A15_CLUSTER) &&
-                               (freqs_new < clk_big_min)) {
-                       new_cluster = A7_CLUSTER;
-               } else if ((actual_cluster == A7_CLUSTER) &&
-                               (freqs_new > clk_little_max)) {
-                       new_cluster = A15_CLUSTER;
-               }
-       }
-
-       ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
-
-       if (!ret) {
-               arch_set_freq_scale(policy->related_cpus, freqs_new,
-                                   policy->cpuinfo.max_freq);
-       }
-
-       return ret;
-}
-
-static inline u32 get_table_count(struct cpufreq_frequency_table *table)
-{
-       int count;
-
-       for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
-               ;
-
-       return count;
-}
-
-/* get the minimum frequency in the cpufreq_frequency_table */
-static inline u32 get_table_min(struct cpufreq_frequency_table *table)
-{
-       struct cpufreq_frequency_table *pos;
-       uint32_t min_freq = ~0;
-       cpufreq_for_each_entry(pos, table)
-               if (pos->frequency < min_freq)
-                       min_freq = pos->frequency;
-       return min_freq;
-}
-
-/* get the maximum frequency in the cpufreq_frequency_table */
-static inline u32 get_table_max(struct cpufreq_frequency_table *table)
-{
-       struct cpufreq_frequency_table *pos;
-       uint32_t max_freq = 0;
-       cpufreq_for_each_entry(pos, table)
-               if (pos->frequency > max_freq)
-                       max_freq = pos->frequency;
-       return max_freq;
-}
-
-static int merge_cluster_tables(void)
-{
-       int i, j, k = 0, count = 1;
-       struct cpufreq_frequency_table *table;
-
-       for (i = 0; i < MAX_CLUSTERS; i++)
-               count += get_table_count(freq_table[i]);
-
-       table = kcalloc(count, sizeof(*table), GFP_KERNEL);
-       if (!table)
-               return -ENOMEM;
-
-       freq_table[MAX_CLUSTERS] = table;
-
-       /* Add in reverse order to get freqs in increasing order */
-       for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
-               for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
-                               j++) {
-                       table[k].frequency = VIRT_FREQ(i,
-                                       freq_table[i][j].frequency);
-                       pr_debug("%s: index: %d, freq: %d\n", __func__, k,
-                                       table[k].frequency);
-                       k++;
-               }
-       }
-
-       table[k].driver_data = k;
-       table[k].frequency = CPUFREQ_TABLE_END;
-
-       pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
-
-       return 0;
-}
-
-static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
-                                           const struct cpumask *cpumask)
-{
-       u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
-
-       if (!freq_table[cluster])
-               return;
-
-       clk_put(clk[cluster]);
-       dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
-       if (arm_bL_ops->free_opp_table)
-               arm_bL_ops->free_opp_table(cpumask);
-       dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
-}
-
-static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
-                                          const struct cpumask *cpumask)
-{
-       u32 cluster = cpu_to_cluster(cpu_dev->id);
-       int i;
-
-       if (atomic_dec_return(&cluster_usage[cluster]))
-               return;
-
-       if (cluster < MAX_CLUSTERS)
-               return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
-
-       for_each_present_cpu(i) {
-               struct device *cdev = get_cpu_device(i);
-               if (!cdev) {
-                       pr_err("%s: failed to get cpu%d device\n", __func__, i);
-                       return;
-               }
-
-               _put_cluster_clk_and_freq_table(cdev, cpumask);
-       }
-
-       /* free virtual table */
-       kfree(freq_table[cluster]);
-}
-
-static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
-                                          const struct cpumask *cpumask)
-{
-       u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
-       int ret;
-
-       if (freq_table[cluster])
-               return 0;
-
-       ret = arm_bL_ops->init_opp_table(cpumask);
-       if (ret) {
-               dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
-                               __func__, cpu_dev->id, ret);
-               goto out;
-       }
-
-       ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
-       if (ret) {
-               dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
-                               __func__, cpu_dev->id, ret);
-               goto free_opp_table;
-       }
-
-       clk[cluster] = clk_get(cpu_dev, NULL);
-       if (!IS_ERR(clk[cluster])) {
-               dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
-                               __func__, clk[cluster], freq_table[cluster],
-                               cluster);
-               return 0;
-       }
-
-       dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
-                       __func__, cpu_dev->id, cluster);
-       ret = PTR_ERR(clk[cluster]);
-       dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
-
-free_opp_table:
-       if (arm_bL_ops->free_opp_table)
-               arm_bL_ops->free_opp_table(cpumask);
-out:
-       dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
-                       cluster);
-       return ret;
-}
-
-static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
-                                         const struct cpumask *cpumask)
-{
-       u32 cluster = cpu_to_cluster(cpu_dev->id);
-       int i, ret;
-
-       if (atomic_inc_return(&cluster_usage[cluster]) != 1)
-               return 0;
-
-       if (cluster < MAX_CLUSTERS) {
-               ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
-               if (ret)
-                       atomic_dec(&cluster_usage[cluster]);
-               return ret;
-       }
-
-       /*
-        * Get data for all clusters and fill virtual cluster with a merge of
-        * both
-        */
-       for_each_present_cpu(i) {
-               struct device *cdev = get_cpu_device(i);
-               if (!cdev) {
-                       pr_err("%s: failed to get cpu%d device\n", __func__, i);
-                       return -ENODEV;
-               }
-
-               ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
-               if (ret)
-                       goto put_clusters;
-       }
-
-       ret = merge_cluster_tables();
-       if (ret)
-               goto put_clusters;
-
-       /* Assuming 2 cluster, set clk_big_min and clk_little_max */
-       clk_big_min = get_table_min(freq_table[0]);
-       clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
-
-       pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
-                       __func__, cluster, clk_big_min, clk_little_max);
-
-       return 0;
-
-put_clusters:
-       for_each_present_cpu(i) {
-               struct device *cdev = get_cpu_device(i);
-               if (!cdev) {
-                       pr_err("%s: failed to get cpu%d device\n", __func__, i);
-                       return -ENODEV;
-               }
-
-               _put_cluster_clk_and_freq_table(cdev, cpumask);
-       }
-
-       atomic_dec(&cluster_usage[cluster]);
-
-       return ret;
-}
-
-/* Per-CPU initialization */
-static int bL_cpufreq_init(struct cpufreq_policy *policy)
-{
-       u32 cur_cluster = cpu_to_cluster(policy->cpu);
-       struct device *cpu_dev;
-       int ret;
-
-       cpu_dev = get_cpu_device(policy->cpu);
-       if (!cpu_dev) {
-               pr_err("%s: failed to get cpu%d device\n", __func__,
-                               policy->cpu);
-               return -ENODEV;
-       }
-
-       if (cur_cluster < MAX_CLUSTERS) {
-               int cpu;
-
-               cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
-
-               for_each_cpu(cpu, policy->cpus)
-                       per_cpu(physical_cluster, cpu) = cur_cluster;
-       } else {
-               /* Assumption: during init, we are always running on A15 */
-               per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
-       }
-
-       ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
-       if (ret)
-               return ret;
-
-       policy->freq_table = freq_table[cur_cluster];
-       policy->cpuinfo.transition_latency =
-                               arm_bL_ops->get_transition_latency(cpu_dev);
-
-       dev_pm_opp_of_register_em(policy->cpus);
-
-       if (is_bL_switching_enabled())
-               per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
-
-       dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
-       return 0;
-}
-
-static int bL_cpufreq_exit(struct cpufreq_policy *policy)
-{
-       struct device *cpu_dev;
-       int cur_cluster = cpu_to_cluster(policy->cpu);
-
-       if (cur_cluster < MAX_CLUSTERS) {
-               cpufreq_cooling_unregister(cdev[cur_cluster]);
-               cdev[cur_cluster] = NULL;
-       }
-
-       cpu_dev = get_cpu_device(policy->cpu);
-       if (!cpu_dev) {
-               pr_err("%s: failed to get cpu%d device\n", __func__,
-                               policy->cpu);
-               return -ENODEV;
-       }
-
-       put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
-       dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
-
-       return 0;
-}
-
-static void bL_cpufreq_ready(struct cpufreq_policy *policy)
-{
-       int cur_cluster = cpu_to_cluster(policy->cpu);
-
-       /* Do not register a cpu_cooling device if we are in IKS mode */
-       if (cur_cluster >= MAX_CLUSTERS)
-               return;
-
-       cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
-}
-
-static struct cpufreq_driver bL_cpufreq_driver = {
-       .name                   = "arm-big-little",
-       .flags                  = CPUFREQ_STICKY |
-                                       CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
-                                       CPUFREQ_NEED_INITIAL_FREQ_CHECK,
-       .verify                 = cpufreq_generic_frequency_table_verify,
-       .target_index           = bL_cpufreq_set_target,
-       .get                    = bL_cpufreq_get_rate,
-       .init                   = bL_cpufreq_init,
-       .exit                   = bL_cpufreq_exit,
-       .ready                  = bL_cpufreq_ready,
-       .attr                   = cpufreq_generic_attr,
-};
-
-#ifdef CONFIG_BL_SWITCHER
-static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
-                                       unsigned long action, void *_arg)
-{
-       pr_debug("%s: action: %ld\n", __func__, action);
-
-       switch (action) {
-       case BL_NOTIFY_PRE_ENABLE:
-       case BL_NOTIFY_PRE_DISABLE:
-               cpufreq_unregister_driver(&bL_cpufreq_driver);
-               break;
-
-       case BL_NOTIFY_POST_ENABLE:
-               set_switching_enabled(true);
-               cpufreq_register_driver(&bL_cpufreq_driver);
-               break;
-
-       case BL_NOTIFY_POST_DISABLE:
-               set_switching_enabled(false);
-               cpufreq_register_driver(&bL_cpufreq_driver);
-               break;
-
-       default:
-               return NOTIFY_DONE;
-       }
-
-       return NOTIFY_OK;
-}
-
-static struct notifier_block bL_switcher_notifier = {
-       .notifier_call = bL_cpufreq_switcher_notifier,
-};
-
-static int __bLs_register_notifier(void)
-{
-       return bL_switcher_register_notifier(&bL_switcher_notifier);
-}
-
-static int __bLs_unregister_notifier(void)
-{
-       return bL_switcher_unregister_notifier(&bL_switcher_notifier);
-}
-#else
-static int __bLs_register_notifier(void) { return 0; }
-static int __bLs_unregister_notifier(void) { return 0; }
-#endif
-
-int bL_cpufreq_register(const struct cpufreq_arm_bL_ops *ops)
-{
-       int ret, i;
-
-       if (arm_bL_ops) {
-               pr_debug("%s: Already registered: %s, exiting\n", __func__,
-                               arm_bL_ops->name);
-               return -EBUSY;
-       }
-
-       if (!ops || !strlen(ops->name) || !ops->init_opp_table ||
-           !ops->get_transition_latency) {
-               pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
-               return -ENODEV;
-       }
-
-       arm_bL_ops = ops;
-
-       set_switching_enabled(bL_switcher_get_enabled());
-
-       for (i = 0; i < MAX_CLUSTERS; i++)
-               mutex_init(&cluster_lock[i]);
-
-       ret = cpufreq_register_driver(&bL_cpufreq_driver);
-       if (ret) {
-               pr_info("%s: Failed registering platform driver: %s, err: %d\n",
-                               __func__, ops->name, ret);
-               arm_bL_ops = NULL;
-       } else {
-               ret = __bLs_register_notifier();
-               if (ret) {
-                       cpufreq_unregister_driver(&bL_cpufreq_driver);
-                       arm_bL_ops = NULL;
-               } else {
-                       pr_info("%s: Registered platform driver: %s\n",
-                                       __func__, ops->name);
-               }
-       }
-
-       bL_switcher_put_enabled();
-       return ret;
-}
-EXPORT_SYMBOL_GPL(bL_cpufreq_register);
-
-void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops)
-{
-       if (arm_bL_ops != ops) {
-               pr_err("%s: Registered with: %s, can't unregister, exiting\n",
-                               __func__, arm_bL_ops->name);
-               return;
-       }
-
-       bL_switcher_get_enabled();
-       __bLs_unregister_notifier();
-       cpufreq_unregister_driver(&bL_cpufreq_driver);
-       bL_switcher_put_enabled();
-       pr_info("%s: Un-registered platform driver: %s\n", __func__,
-                       arm_bL_ops->name);
-       arm_bL_ops = NULL;
-}
-EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
-
-MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
-MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/cpufreq/arm_big_little.h b/drivers/cpufreq/arm_big_little.h
deleted file mode 100644 (file)
index 88a176e..0000000
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * ARM big.LITTLE platform's CPUFreq header file
- *
- * Copyright (C) 2013 ARM Ltd.
- * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
- *
- * Copyright (C) 2013 Linaro.
- * Viresh Kumar <viresh.kumar@linaro.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-#ifndef CPUFREQ_ARM_BIG_LITTLE_H
-#define CPUFREQ_ARM_BIG_LITTLE_H
-
-#include <linux/cpufreq.h>
-#include <linux/device.h>
-#include <linux/types.h>
-
-struct cpufreq_arm_bL_ops {
-       char name[CPUFREQ_NAME_LEN];
-
-       /*
-        * This must set opp table for cpu_dev in a similar way as done by
-        * dev_pm_opp_of_add_table().
-        */
-       int (*init_opp_table)(const struct cpumask *cpumask);
-
-       /* Optional */
-       int (*get_transition_latency)(struct device *cpu_dev);
-       void (*free_opp_table)(const struct cpumask *cpumask);
-};
-
-int bL_cpufreq_register(const struct cpufreq_arm_bL_ops *ops);
-void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops);
-
-#endif /* CPUFREQ_ARM_BIG_LITTLE_H */
index 53237289e6060a52f66b3f2a47ba72428eb6feab..622dc42e42b1027d4cec8688ebda0bb7c626096e 100644 (file)
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Versatile Express SPC CPUFreq Interface driver
  *
- * It provides necessary ops to arm_big_little cpufreq driver.
+ * Copyright (C) 2013 - 2019 ARM Ltd.
+ * Sudeep Holla <sudeep.holla@arm.com>
  *
- * Copyright (C) 2013 ARM Ltd.
- * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * Copyright (C) 2013 Linaro.
+ * Viresh Kumar <viresh.kumar@linaro.org>
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/clk.h>
 #include <linux/cpu.h>
 #include <linux/cpufreq.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_cooling.h>
+#include <linux/device.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include <linux/topology.h>
 #include <linux/types.h>
 
-#include "arm_big_little.h"
+struct cpufreq_arm_bL_ops {
+       char name[CPUFREQ_NAME_LEN];
+
+       /*
+        * This must set opp table for cpu_dev in a similar way as done by
+        * dev_pm_opp_of_add_table().
+        */
+       int (*init_opp_table)(const struct cpumask *cpumask);
+
+       /* Optional */
+       int (*get_transition_latency)(struct device *cpu_dev);
+       void (*free_opp_table)(const struct cpumask *cpumask);
+};
+
+/* Currently we support only two clusters */
+#define A15_CLUSTER    0
+#define A7_CLUSTER     1
+#define MAX_CLUSTERS   2
+
+#ifdef CONFIG_BL_SWITCHER
+#include <asm/bL_switcher.h>
+static bool bL_switching_enabled;
+#define is_bL_switching_enabled()      bL_switching_enabled
+#define set_switching_enabled(x)       (bL_switching_enabled = (x))
+#else
+#define is_bL_switching_enabled()      false
+#define set_switching_enabled(x)       do { } while (0)
+#define bL_switch_request(...)         do { } while (0)
+#define bL_switcher_put_enabled()      do { } while (0)
+#define bL_switcher_get_enabled()      do { } while (0)
+#endif
+
+#define ACTUAL_FREQ(cluster, freq)  ((cluster == A7_CLUSTER) ? freq << 1 : freq)
+#define VIRT_FREQ(cluster, freq)    ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
+
+static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
+static const struct cpufreq_arm_bL_ops *arm_bL_ops;
+static struct clk *clk[MAX_CLUSTERS];
+static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
+static atomic_t cluster_usage[MAX_CLUSTERS + 1];
+
+static unsigned int clk_big_min;       /* (Big) clock frequencies */
+static unsigned int clk_little_max;    /* Maximum clock frequency (Little) */
+
+static DEFINE_PER_CPU(unsigned int, physical_cluster);
+static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
+
+static struct mutex cluster_lock[MAX_CLUSTERS];
+
+static inline int raw_cpu_to_cluster(int cpu)
+{
+       return topology_physical_package_id(cpu);
+}
+
+static inline int cpu_to_cluster(int cpu)
+{
+       return is_bL_switching_enabled() ?
+               MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
+}
+
+static unsigned int find_cluster_maxfreq(int cluster)
+{
+       int j;
+       u32 max_freq = 0, cpu_freq;
+
+       for_each_online_cpu(j) {
+               cpu_freq = per_cpu(cpu_last_req_freq, j);
+
+               if ((cluster == per_cpu(physical_cluster, j)) &&
+                               (max_freq < cpu_freq))
+                       max_freq = cpu_freq;
+       }
+
+       pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
+                       max_freq);
+
+       return max_freq;
+}
+
+static unsigned int clk_get_cpu_rate(unsigned int cpu)
+{
+       u32 cur_cluster = per_cpu(physical_cluster, cpu);
+       u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
+
+       /* For switcher we use virtual A7 clock rates */
+       if (is_bL_switching_enabled())
+               rate = VIRT_FREQ(cur_cluster, rate);
+
+       pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
+                       cur_cluster, rate);
+
+       return rate;
+}
+
+static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
+{
+       if (is_bL_switching_enabled()) {
+               pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
+                                       cpu));
+
+               return per_cpu(cpu_last_req_freq, cpu);
+       } else {
+               return clk_get_cpu_rate(cpu);
+       }
+}
+
+static unsigned int
+bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
+{
+       u32 new_rate, prev_rate;
+       int ret;
+       bool bLs = is_bL_switching_enabled();
+
+       mutex_lock(&cluster_lock[new_cluster]);
+
+       if (bLs) {
+               prev_rate = per_cpu(cpu_last_req_freq, cpu);
+               per_cpu(cpu_last_req_freq, cpu) = rate;
+               per_cpu(physical_cluster, cpu) = new_cluster;
+
+               new_rate = find_cluster_maxfreq(new_cluster);
+               new_rate = ACTUAL_FREQ(new_cluster, new_rate);
+       } else {
+               new_rate = rate;
+       }
+
+       pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
+                       __func__, cpu, old_cluster, new_cluster, new_rate);
+
+       ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
+       if (!ret) {
+               /*
+                * FIXME: clk_set_rate hasn't returned an error here however it
+                * may be that clk_change_rate failed due to hardware or
+                * firmware issues and wasn't able to report that due to the
+                * current design of the clk core layer. To work around this
+                * problem we will read back the clock rate and check it is
+                * correct. This needs to be removed once clk core is fixed.
+                */
+               if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
+                       ret = -EIO;
+       }
+
+       if (WARN_ON(ret)) {
+               pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
+                               new_cluster);
+               if (bLs) {
+                       per_cpu(cpu_last_req_freq, cpu) = prev_rate;
+                       per_cpu(physical_cluster, cpu) = old_cluster;
+               }
+
+               mutex_unlock(&cluster_lock[new_cluster]);
+
+               return ret;
+       }
+
+       mutex_unlock(&cluster_lock[new_cluster]);
+
+       /* Recalc freq for old cluster when switching clusters */
+       if (old_cluster != new_cluster) {
+               pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
+                               __func__, cpu, old_cluster, new_cluster);
+
+               /* Switch cluster */
+               bL_switch_request(cpu, new_cluster);
+
+               mutex_lock(&cluster_lock[old_cluster]);
+
+               /* Set freq of old cluster if there are cpus left on it */
+               new_rate = find_cluster_maxfreq(old_cluster);
+               new_rate = ACTUAL_FREQ(old_cluster, new_rate);
+
+               if (new_rate) {
+                       pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
+                                       __func__, old_cluster, new_rate);
+
+                       if (clk_set_rate(clk[old_cluster], new_rate * 1000))
+                               pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
+                                               __func__, ret, old_cluster);
+               }
+               mutex_unlock(&cluster_lock[old_cluster]);
+       }
+
+       return 0;
+}
+
+/* Set clock frequency */
+static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
+               unsigned int index)
+{
+       u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
+       unsigned int freqs_new;
+       int ret;
+
+       cur_cluster = cpu_to_cluster(cpu);
+       new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
+
+       freqs_new = freq_table[cur_cluster][index].frequency;
+
+       if (is_bL_switching_enabled()) {
+               if ((actual_cluster == A15_CLUSTER) &&
+                               (freqs_new < clk_big_min)) {
+                       new_cluster = A7_CLUSTER;
+               } else if ((actual_cluster == A7_CLUSTER) &&
+                               (freqs_new > clk_little_max)) {
+                       new_cluster = A15_CLUSTER;
+               }
+       }
+
+       ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
+
+       if (!ret) {
+               arch_set_freq_scale(policy->related_cpus, freqs_new,
+                                   policy->cpuinfo.max_freq);
+       }
+
+       return ret;
+}
+
+static inline u32 get_table_count(struct cpufreq_frequency_table *table)
+{
+       int count;
+
+       for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
+               ;
+
+       return count;
+}
+
+/* get the minimum frequency in the cpufreq_frequency_table */
+static inline u32 get_table_min(struct cpufreq_frequency_table *table)
+{
+       struct cpufreq_frequency_table *pos;
+       uint32_t min_freq = ~0;
+       cpufreq_for_each_entry(pos, table)
+               if (pos->frequency < min_freq)
+                       min_freq = pos->frequency;
+       return min_freq;
+}
+
+/* get the maximum frequency in the cpufreq_frequency_table */
+static inline u32 get_table_max(struct cpufreq_frequency_table *table)
+{
+       struct cpufreq_frequency_table *pos;
+       uint32_t max_freq = 0;
+       cpufreq_for_each_entry(pos, table)
+               if (pos->frequency > max_freq)
+                       max_freq = pos->frequency;
+       return max_freq;
+}
+
+static int merge_cluster_tables(void)
+{
+       int i, j, k = 0, count = 1;
+       struct cpufreq_frequency_table *table;
+
+       for (i = 0; i < MAX_CLUSTERS; i++)
+               count += get_table_count(freq_table[i]);
+
+       table = kcalloc(count, sizeof(*table), GFP_KERNEL);
+       if (!table)
+               return -ENOMEM;
+
+       freq_table[MAX_CLUSTERS] = table;
+
+       /* Add in reverse order to get freqs in increasing order */
+       for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
+               for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
+                               j++) {
+                       table[k].frequency = VIRT_FREQ(i,
+                                       freq_table[i][j].frequency);
+                       pr_debug("%s: index: %d, freq: %d\n", __func__, k,
+                                       table[k].frequency);
+                       k++;
+               }
+       }
+
+       table[k].driver_data = k;
+       table[k].frequency = CPUFREQ_TABLE_END;
+
+       pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
+
+       return 0;
+}
+
+static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
+                                           const struct cpumask *cpumask)
+{
+       u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
+
+       if (!freq_table[cluster])
+               return;
+
+       clk_put(clk[cluster]);
+       dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
+       if (arm_bL_ops->free_opp_table)
+               arm_bL_ops->free_opp_table(cpumask);
+       dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
+}
+
+static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
+                                          const struct cpumask *cpumask)
+{
+       u32 cluster = cpu_to_cluster(cpu_dev->id);
+       int i;
+
+       if (atomic_dec_return(&cluster_usage[cluster]))
+               return;
+
+       if (cluster < MAX_CLUSTERS)
+               return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
+
+       for_each_present_cpu(i) {
+               struct device *cdev = get_cpu_device(i);
+               if (!cdev) {
+                       pr_err("%s: failed to get cpu%d device\n", __func__, i);
+                       return;
+               }
+
+               _put_cluster_clk_and_freq_table(cdev, cpumask);
+       }
+
+       /* free virtual table */
+       kfree(freq_table[cluster]);
+}
+
+static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
+                                          const struct cpumask *cpumask)
+{
+       u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
+       int ret;
+
+       if (freq_table[cluster])
+               return 0;
+
+       ret = arm_bL_ops->init_opp_table(cpumask);
+       if (ret) {
+               dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
+                               __func__, cpu_dev->id, ret);
+               goto out;
+       }
+
+       ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
+       if (ret) {
+               dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
+                               __func__, cpu_dev->id, ret);
+               goto free_opp_table;
+       }
+
+       clk[cluster] = clk_get(cpu_dev, NULL);
+       if (!IS_ERR(clk[cluster])) {
+               dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
+                               __func__, clk[cluster], freq_table[cluster],
+                               cluster);
+               return 0;
+       }
+
+       dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
+                       __func__, cpu_dev->id, cluster);
+       ret = PTR_ERR(clk[cluster]);
+       dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
+
+free_opp_table:
+       if (arm_bL_ops->free_opp_table)
+               arm_bL_ops->free_opp_table(cpumask);
+out:
+       dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
+                       cluster);
+       return ret;
+}
+
+static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
+                                         const struct cpumask *cpumask)
+{
+       u32 cluster = cpu_to_cluster(cpu_dev->id);
+       int i, ret;
+
+       if (atomic_inc_return(&cluster_usage[cluster]) != 1)
+               return 0;
+
+       if (cluster < MAX_CLUSTERS) {
+               ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
+               if (ret)
+                       atomic_dec(&cluster_usage[cluster]);
+               return ret;
+       }
+
+       /*
+        * Get data for all clusters and fill virtual cluster with a merge of
+        * both
+        */
+       for_each_present_cpu(i) {
+               struct device *cdev = get_cpu_device(i);
+               if (!cdev) {
+                       pr_err("%s: failed to get cpu%d device\n", __func__, i);
+                       return -ENODEV;
+               }
+
+               ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
+               if (ret)
+                       goto put_clusters;
+       }
+
+       ret = merge_cluster_tables();
+       if (ret)
+               goto put_clusters;
+
+       /* Assuming 2 cluster, set clk_big_min and clk_little_max */
+       clk_big_min = get_table_min(freq_table[0]);
+       clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
+
+       pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
+                       __func__, cluster, clk_big_min, clk_little_max);
+
+       return 0;
+
+put_clusters:
+       for_each_present_cpu(i) {
+               struct device *cdev = get_cpu_device(i);
+               if (!cdev) {
+                       pr_err("%s: failed to get cpu%d device\n", __func__, i);
+                       return -ENODEV;
+               }
+
+               _put_cluster_clk_and_freq_table(cdev, cpumask);
+       }
+
+       atomic_dec(&cluster_usage[cluster]);
+
+       return ret;
+}
+
+/* Per-CPU initialization */
+static int bL_cpufreq_init(struct cpufreq_policy *policy)
+{
+       u32 cur_cluster = cpu_to_cluster(policy->cpu);
+       struct device *cpu_dev;
+       int ret;
+
+       cpu_dev = get_cpu_device(policy->cpu);
+       if (!cpu_dev) {
+               pr_err("%s: failed to get cpu%d device\n", __func__,
+                               policy->cpu);
+               return -ENODEV;
+       }
+
+       if (cur_cluster < MAX_CLUSTERS) {
+               int cpu;
+
+               cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
+
+               for_each_cpu(cpu, policy->cpus)
+                       per_cpu(physical_cluster, cpu) = cur_cluster;
+       } else {
+               /* Assumption: during init, we are always running on A15 */
+               per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
+       }
+
+       ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
+       if (ret)
+               return ret;
+
+       policy->freq_table = freq_table[cur_cluster];
+       policy->cpuinfo.transition_latency =
+                               arm_bL_ops->get_transition_latency(cpu_dev);
+
+       dev_pm_opp_of_register_em(policy->cpus);
+
+       if (is_bL_switching_enabled())
+               per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
+
+       dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
+       return 0;
+}
+
+static int bL_cpufreq_exit(struct cpufreq_policy *policy)
+{
+       struct device *cpu_dev;
+       int cur_cluster = cpu_to_cluster(policy->cpu);
+
+       if (cur_cluster < MAX_CLUSTERS) {
+               cpufreq_cooling_unregister(cdev[cur_cluster]);
+               cdev[cur_cluster] = NULL;
+       }
+
+       cpu_dev = get_cpu_device(policy->cpu);
+       if (!cpu_dev) {
+               pr_err("%s: failed to get cpu%d device\n", __func__,
+                               policy->cpu);
+               return -ENODEV;
+       }
+
+       put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
+       dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
+
+       return 0;
+}
+
+static void bL_cpufreq_ready(struct cpufreq_policy *policy)
+{
+       int cur_cluster = cpu_to_cluster(policy->cpu);
+
+       /* Do not register a cpu_cooling device if we are in IKS mode */
+       if (cur_cluster >= MAX_CLUSTERS)
+               return;
+
+       cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
+}
+
+static struct cpufreq_driver bL_cpufreq_driver = {
+       .name                   = "arm-big-little",
+       .flags                  = CPUFREQ_STICKY |
+                                       CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
+                                       CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+       .verify                 = cpufreq_generic_frequency_table_verify,
+       .target_index           = bL_cpufreq_set_target,
+       .get                    = bL_cpufreq_get_rate,
+       .init                   = bL_cpufreq_init,
+       .exit                   = bL_cpufreq_exit,
+       .ready                  = bL_cpufreq_ready,
+       .attr                   = cpufreq_generic_attr,
+};
+
+#ifdef CONFIG_BL_SWITCHER
+static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
+                                       unsigned long action, void *_arg)
+{
+       pr_debug("%s: action: %ld\n", __func__, action);
+
+       switch (action) {
+       case BL_NOTIFY_PRE_ENABLE:
+       case BL_NOTIFY_PRE_DISABLE:
+               cpufreq_unregister_driver(&bL_cpufreq_driver);
+               break;
+
+       case BL_NOTIFY_POST_ENABLE:
+               set_switching_enabled(true);
+               cpufreq_register_driver(&bL_cpufreq_driver);
+               break;
+
+       case BL_NOTIFY_POST_DISABLE:
+               set_switching_enabled(false);
+               cpufreq_register_driver(&bL_cpufreq_driver);
+               break;
+
+       default:
+               return NOTIFY_DONE;
+       }
+
+       return NOTIFY_OK;
+}
+
+static struct notifier_block bL_switcher_notifier = {
+       .notifier_call = bL_cpufreq_switcher_notifier,
+};
+
+static int __bLs_register_notifier(void)
+{
+       return bL_switcher_register_notifier(&bL_switcher_notifier);
+}
+
+static int __bLs_unregister_notifier(void)
+{
+       return bL_switcher_unregister_notifier(&bL_switcher_notifier);
+}
+#else
+static int __bLs_register_notifier(void) { return 0; }
+static int __bLs_unregister_notifier(void) { return 0; }
+#endif
+
+int bL_cpufreq_register(const struct cpufreq_arm_bL_ops *ops)
+{
+       int ret, i;
+
+       if (arm_bL_ops) {
+               pr_debug("%s: Already registered: %s, exiting\n", __func__,
+                               arm_bL_ops->name);
+               return -EBUSY;
+       }
+
+       if (!ops || !strlen(ops->name) || !ops->init_opp_table ||
+           !ops->get_transition_latency) {
+               pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
+               return -ENODEV;
+       }
+
+       arm_bL_ops = ops;
+
+       set_switching_enabled(bL_switcher_get_enabled());
+
+       for (i = 0; i < MAX_CLUSTERS; i++)
+               mutex_init(&cluster_lock[i]);
+
+       ret = cpufreq_register_driver(&bL_cpufreq_driver);
+       if (ret) {
+               pr_info("%s: Failed registering platform driver: %s, err: %d\n",
+                               __func__, ops->name, ret);
+               arm_bL_ops = NULL;
+       } else {
+               ret = __bLs_register_notifier();
+               if (ret) {
+                       cpufreq_unregister_driver(&bL_cpufreq_driver);
+                       arm_bL_ops = NULL;
+               } else {
+                       pr_info("%s: Registered platform driver: %s\n",
+                                       __func__, ops->name);
+               }
+       }
+
+       bL_switcher_put_enabled();
+       return ret;
+}
+
+void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops)
+{
+       if (arm_bL_ops != ops) {
+               pr_err("%s: Registered with: %s, can't unregister, exiting\n",
+                               __func__, arm_bL_ops->name);
+               return;
+       }
+
+       bL_switcher_get_enabled();
+       __bLs_unregister_notifier();
+       cpufreq_unregister_driver(&bL_cpufreq_driver);
+       bL_switcher_put_enabled();
+       pr_info("%s: Un-registered platform driver: %s\n", __func__,
+                       arm_bL_ops->name);
+       arm_bL_ops = NULL;
+}
 
 static int ve_spc_init_opp_table(const struct cpumask *cpumask)
 {
@@ -68,4 +697,7 @@ static struct platform_driver ve_spc_cpufreq_platdrv = {
 };
 module_platform_driver(ve_spc_cpufreq_platdrv);
 
-MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("Vexpress SPC ARM big LITTLE cpufreq driver");
+MODULE_LICENSE("GPL v2");