1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
new file mode 100644
index 000000000..037fe23bc
--- /dev/null
+++ b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * pmi backend for the cbe_cpufreq driver
+ *
+ * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
+ *
+ * Author: Christian Krafft <krafft@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/init.h>
+#include <linux/of_platform.h>
+#include <linux/pm_qos.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"
+
+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)
+{
+	struct cpufreq_policy *policy;
+	struct freq_qos_request *req;
+	u8 node, slow_mode;
+	int cpu, ret;
+
+	BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE);
+
+	node = pmi_msg.data1;
+	slow_mode = pmi_msg.data2;
+
+	cpu = cbe_node_to_cpu(node);
+
+	pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode);
+
+	policy = cpufreq_cpu_get(cpu);
+	if (!policy) {
+		pr_warn("cpufreq policy not found cpu%d\n", cpu);
+		return;
+	}
+
+	req = policy->driver_data;
+
+	ret = freq_qos_update_request(req,
+			policy->freq_table[slow_mode].frequency);
+	if (ret < 0)
+		pr_warn("Failed to update freq constraint: %d\n", ret);
+	else
+		pr_debug("limiting node %d to slow mode %d\n", node, slow_mode);
+
+	cpufreq_cpu_put(policy);
+}
+
+static struct pmi_handler cbe_pmi_handler = {
+	.type			= PMI_TYPE_FREQ_CHANGE,
+	.handle_pmi_message	= cbe_cpufreq_handle_pmi,
+};
+
+void cbe_cpufreq_pmi_policy_init(struct cpufreq_policy *policy)
+{
+	struct freq_qos_request *req;
+	int ret;
+
+	if (!cbe_cpufreq_has_pmi)
+		return;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return;
+
+	ret = freq_qos_add_request(&policy->constraints, req, FREQ_QOS_MAX,
+				   policy->freq_table[0].frequency);
+	if (ret < 0) {
+		pr_err("Failed to add freq constraint (%d)\n", ret);
+		kfree(req);
+		return;
+	}
+
+	policy->driver_data = req;
+}
+EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_init);
+
+void cbe_cpufreq_pmi_policy_exit(struct cpufreq_policy *policy)
+{
+	struct freq_qos_request *req = policy->driver_data;
+
+	if (cbe_cpufreq_has_pmi) {
+		freq_qos_remove_request(req);
+		kfree(req);
+	}
+}
+EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_policy_exit);
+
+void cbe_cpufreq_pmi_init(void)
+{
+	if (!pmi_register_handler(&cbe_pmi_handler))
+		cbe_cpufreq_has_pmi = true;
+}
+EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_init);
+
+void cbe_cpufreq_pmi_exit(void)
+{
+	pmi_unregister_handler(&cbe_pmi_handler);
+	cbe_cpufreq_has_pmi = false;
+}
+EXPORT_SYMBOL_GPL(cbe_cpufreq_pmi_exit);