[PATCH v3 2/5] cpufreq: merge arm_big_little and vexpress-spc

From: Sudeep Holla
Date: Fri Oct 18 2019 - 06:38:33 EST


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@xxxxxxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
MAINTAINERS | 5 +-
drivers/cpufreq/Kconfig.arm | 12 +--
drivers/cpufreq/Makefile | 2 -
drivers/cpufreq/arm_big_little.h | 43 ----------
...rm_big_little.c => vexpress-spc-cpufreq.c} | 79 +++++++++++++++----
5 files changed, 67 insertions(+), 74 deletions(-)
delete mode 100644 drivers/cpufreq/arm_big_little.h
rename drivers/cpufreq/{arm_big_little.c => vexpress-spc-cpufreq.c} (90%)

diff --git a/MAINTAINERS b/MAINTAINERS
index a69e6db80c79..78a4adff7892 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4269,14 +4269,13 @@ 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@xxxxxxxxxx>
M: Sudeep Holla <sudeep.holla@xxxxxxx>
L: linux-pm@xxxxxxxxxxxxxxx
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@xxxxxxxx>
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index a905796f7f85..3858d86cf409 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -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.
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 9a9f5ccd13d9..f6670c4abbb0 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -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.h b/drivers/cpufreq/arm_big_little.h
deleted file mode 100644
index 88a176e466c8..000000000000
--- a/drivers/cpufreq/arm_big_little.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * ARM big.LITTLE platform's CPUFreq header file
- *
- * Copyright (C) 2013 ARM Ltd.
- * Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
- *
- * Copyright (C) 2013 Linaro.
- * Viresh Kumar <viresh.kumar@xxxxxxxxxx>
- *
- * 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 */
diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/vexpress-spc-cpufreq.c
similarity index 90%
rename from drivers/cpufreq/arm_big_little.c
rename to drivers/cpufreq/vexpress-spc-cpufreq.c
index 7fe52fcddcf1..622dc42e42b1 100644
--- a/drivers/cpufreq/arm_big_little.c
+++ b/drivers/cpufreq/vexpress-spc-cpufreq.c
@@ -1,20 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
/*
- * ARM big.LITTLE Platforms CPUFreq support
+ * Versatile Express SPC CPUFreq Interface driver
*
- * Copyright (C) 2013 ARM Ltd.
- * Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
+ * Copyright (C) 2013 - 2019 ARM Ltd.
+ * Sudeep Holla <sudeep.holla@xxxxxxx>
*
* Copyright (C) 2013 Linaro.
* Viresh Kumar <viresh.kumar@xxxxxxxxxx>
- *
- * 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
@@ -24,16 +16,29 @@
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/cpu_cooling.h>
-#include <linux/export.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
@@ -633,7 +638,6 @@ int bL_cpufreq_register(const struct cpufreq_arm_bL_ops *ops)
bL_switcher_put_enabled();
return ret;
}
-EXPORT_SYMBOL_GPL(bL_cpufreq_register);

void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops)
{
@@ -651,8 +655,49 @@ void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops)
arm_bL_ops->name);
arm_bL_ops = NULL;
}
-EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
+
+static int ve_spc_init_opp_table(const struct cpumask *cpumask)
+{
+ struct device *cpu_dev = get_cpu_device(cpumask_first(cpumask));
+ /*
+ * platform specific SPC code must initialise the opp table
+ * so just check if the OPP count is non-zero
+ */
+ return dev_pm_opp_get_opp_count(cpu_dev) <= 0;
+}
+
+static int ve_spc_get_transition_latency(struct device *cpu_dev)
+{
+ return 1000000; /* 1 ms */
+}
+
+static const struct cpufreq_arm_bL_ops ve_spc_cpufreq_ops = {
+ .name = "vexpress-spc",
+ .get_transition_latency = ve_spc_get_transition_latency,
+ .init_opp_table = ve_spc_init_opp_table,
+};
+
+static int ve_spc_cpufreq_probe(struct platform_device *pdev)
+{
+ return bL_cpufreq_register(&ve_spc_cpufreq_ops);
+}
+
+static int ve_spc_cpufreq_remove(struct platform_device *pdev)
+{
+ bL_cpufreq_unregister(&ve_spc_cpufreq_ops);
+ return 0;
+}
+
+static struct platform_driver ve_spc_cpufreq_platdrv = {
+ .driver = {
+ .name = "vexpress-spc-cpufreq",
+ },
+ .probe = ve_spc_cpufreq_probe,
+ .remove = ve_spc_cpufreq_remove,
+};
+module_platform_driver(ve_spc_cpufreq_platdrv);

MODULE_AUTHOR("Viresh Kumar <viresh.kumar@xxxxxxxxxx>");
-MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@xxxxxxx>");
+MODULE_DESCRIPTION("Vexpress SPC ARM big LITTLE cpufreq driver");
MODULE_LICENSE("GPL v2");
--
2.17.1