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Diffstat (limited to 'drivers/cpufreq/scpi-cpufreq.c')
-rw-r--r--drivers/cpufreq/scpi-cpufreq.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
new file mode 100644
index 000000000..de5e89b2e
--- /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)
+{
+ int 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");