3 files changed, 135 insertions, 0 deletions

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 642fd49793b0..1582c1c016b0 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -199,6 +199,16 @@ config ARM_SA1100_CPUFREQ
 config ARM_SA1110_CPUFREQ
         bool
 
+config ARM_SCPI_CPUFREQ
+        tristate "SCPI based CPUfreq driver"
+        depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL
+        help
+          This adds the CPUfreq driver support for ARM big.LITTLE platforms
+          using SCPI protocol for CPU power management.
+
+          This driver uses SCPI Message Protocol driver to interact with the
+          firmware providing the CPU DVFS functionality.
+
 config ARM_SPEAR_CPUFREQ
         bool "SPEAr CPUFreq support"
         depends on PLAT_SPEAR
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index d11309c487d0..c0af1a1281c8 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -71,6 +71,7 @@ obj-$(CONFIG_ARM_S3C64XX_CPUFREQ)	+= s3c64xx-cpufreq.o
 obj-$(CONFIG_ARM_S5PV210_CPUFREQ)       += s5pv210-cpufreq.o
 obj-$(CONFIG_ARM_SA1100_CPUFREQ)        += sa1100-cpufreq.o
 obj-$(CONFIG_ARM_SA1110_CPUFREQ)        += sa1110-cpufreq.o
+obj-$(CONFIG_ARM_SCPI_CPUFREQ)          += scpi-cpufreq.o
 obj-$(CONFIG_ARM_SPEAR_CPUFREQ)         += spear-cpufreq.o
 obj-$(CONFIG_ARM_TEGRA20_CPUFREQ)       += tegra20-cpufreq.o
 obj-$(CONFIG_ARM_TEGRA124_CPUFREQ)      += tegra124-cpufreq.o
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
new file mode 100644
index 000000000000..2c3b16fd3a01
--- /dev/null
+++ b/drivers/cpufreq/scpi-cpufreq.c
@@ -0,0 +1,124 @@
+/*
+ * System Control and Power Interface (SCPI) based CPUFreq Interface driver
+ *
+ * It provides necessary ops to arm_big_little cpufreq driver.
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Sudeep Holla <sudeep.holla@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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cpufreq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/scpi_protocol.h>
+#include <linux/types.h>
+
+#include "arm_big_little.h"
+
+static struct scpi_ops *scpi_ops;
+
+static struct scpi_dvfs_info *scpi_get_dvfs_info(struct device *cpu_dev)
+{
+        u8 domain = topology_physical_package_id(cpu_dev->id);
+
+        if (domain < 0)
+                return ERR_PTR(-EINVAL);
+        return scpi_ops->dvfs_get_info(domain);
+}
+
+static int scpi_opp_table_ops(struct device *cpu_dev, bool remove)
+{
+        int idx, ret = 0;
+        struct scpi_opp *opp;
+        struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev);
+
+        if (IS_ERR(info))
+                return PTR_ERR(info);
+
+        if (!info->opps)
+                return -EIO;
+
+        for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
+                if (remove)
+                        dev_pm_opp_remove(cpu_dev, opp->freq);
+                else
+                        ret = dev_pm_opp_add(cpu_dev, opp->freq,
+                                             opp->m_volt * 1000);
+                if (ret) {
+                        dev_warn(cpu_dev, "failed to add opp %uHz %umV\n",
+                                 opp->freq, opp->m_volt);
+                        while (idx-- > 0)
+                                dev_pm_opp_remove(cpu_dev, (--opp)->freq);
+                        return ret;
+                }
+        }
+        return ret;
+}
+
+static int scpi_get_transition_latency(struct device *cpu_dev)
+{
+        struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev);
+
+        if (IS_ERR(info))
+                return PTR_ERR(info);
+        return info->latency;
+}
+
+static int scpi_init_opp_table(struct device *cpu_dev)
+{
+        return scpi_opp_table_ops(cpu_dev, false);
+}
+
+static void scpi_free_opp_table(struct device *cpu_dev)
+{
+        scpi_opp_table_ops(cpu_dev, true);
+}
+
+static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = {
+        .name   = "scpi",
+        .get_transition_latency = scpi_get_transition_latency,
+        .init_opp_table = scpi_init_opp_table,
+        .free_opp_table = scpi_free_opp_table,
+};
+
+static int scpi_cpufreq_probe(struct platform_device *pdev)
+{
+        scpi_ops = get_scpi_ops();
+        if (!scpi_ops)
+                return -EIO;
+
+        return bL_cpufreq_register(&scpi_cpufreq_ops);
+}
+
+static int scpi_cpufreq_remove(struct platform_device *pdev)
+{
+        bL_cpufreq_unregister(&scpi_cpufreq_ops);
+        scpi_ops = NULL;
+        return 0;
+}
+
+static struct platform_driver scpi_cpufreq_platdrv = {
+        .driver = {
+                .name   = "scpi-cpufreq",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = scpi_cpufreq_probe,
+        .remove         = scpi_cpufreq_remove,
+};
+module_platform_driver(scpi_cpufreq_platdrv);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCPI CPUFreq interface driver");
+MODULE_LICENSE("GPL v2");