--- /dev/null
+/*
+ * Rockchip CPU AVS support.
+ *
+ * Copyright (c) 2016 Rockchip Electronics Co. Ltd.
+ * Author: Finley Xiao <finley.xiao@rock-chips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; 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/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/cpumask.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define MAX_CLUSTERS 2
+#define LEAKAGE_TABLE_END ~1
+#define INVALID_VALUE 0xff
+
+struct leakage_volt_table {
+ unsigned int min;
+ unsigned int max;
+ int volt;
+};
+
+struct cluster_info {
+ unsigned int id;
+ int offset_volt;
+ unsigned char leakage;
+ unsigned int min_freq;
+ unsigned int min_volt;
+ struct leakage_volt_table *table;
+};
+
+struct rockchip_cpu_avs {
+ unsigned int num_clusters;
+ struct cluster_info *cluster;
+ struct notifier_block cpufreq_notify;
+};
+
+#define notifier_to_avs(_n) container_of(_n, struct rockchip_cpu_avs, \
+ cpufreq_notify)
+
+static void rockchip_adjust_opp_table(struct device *cpu_dev,
+ struct cpufreq_frequency_table *table,
+ struct cluster_info *cluster)
+{
+ struct cpufreq_frequency_table *pos;
+ struct dev_pm_opp *opp;
+ unsigned long adjust_volt;
+
+ if (!cluster->offset_volt)
+ return;
+
+ cpufreq_for_each_valid_entry(pos, table) {
+ if (pos->frequency < cluster->min_freq)
+ continue;
+
+ rcu_read_lock();
+
+ opp = dev_pm_opp_find_freq_exact(cpu_dev, pos->frequency * 1000,
+ true);
+ if (IS_ERR(opp)) {
+ rcu_read_unlock();
+ continue;
+ }
+
+ adjust_volt = dev_pm_opp_get_voltage(opp) +
+ cluster->offset_volt;
+
+ rcu_read_unlock();
+
+ if (adjust_volt < cluster->min_volt)
+ continue;
+
+ dev_pm_opp_adjust_voltage(cpu_dev, pos->frequency * 1000,
+ adjust_volt);
+ }
+}
+
+static int rockchip_cpu_avs_notifier(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct rockchip_cpu_avs *avs = notifier_to_avs(nb);
+ struct cpufreq_policy *policy = data;
+ struct cluster_info *cluster;
+ struct device *cpu_dev;
+ int i, id, cpu = policy->cpu;
+
+ if (event != CPUFREQ_START)
+ goto out;
+
+ id = topology_physical_package_id(cpu);
+ if (id < 0 || id >= MAX_CLUSTERS) {
+ pr_err("cpu%d invalid cluster id\n", cpu);
+ goto out;
+ }
+
+ for (i = 0; i < avs->num_clusters; i++) {
+ if (avs->cluster[i].id == id)
+ break;
+ }
+ if (i == avs->num_clusters)
+ goto out;
+ else
+ cluster = &avs->cluster[i];
+
+ if (!policy->freq_table) {
+ pr_err("cpu%d freq table not found\n", cpu);
+ goto out;
+ }
+
+ cpu_dev = get_cpu_device(cpu);
+ if (!cpu_dev) {
+ pr_err("cpu%d failed to get device\n", cpu);
+ goto out;
+ }
+
+ rockchip_adjust_opp_table(cpu_dev, policy->freq_table, cluster);
+out:
+
+ return NOTIFY_OK;
+}
+
+static int rockchip_get_leakage_volt_table(struct device_node *np,
+ struct leakage_volt_table **table)
+{
+ struct leakage_volt_table *volt_table;
+ const struct property *prop;
+ int count, i;
+
+ prop = of_find_property(np, "leakage-adjust-volt", NULL);
+ if (!prop) {
+ pr_err("failed to find property leakage-adjust-volt\n");
+ return -EINVAL;
+ }
+ if (!prop->value) {
+ pr_err("property leakage-adjust-volt is NULL\n");
+ return -ENODATA;
+ }
+
+ count = of_property_count_u32_elems(np, "leakage-adjust-volt");
+ if (count < 0) {
+ pr_err("Invalid property (%d)\n", count);
+ return -EINVAL;
+ }
+ if (count % 3) {
+ pr_err("Invalid number of elements in property (%d)\n", count);
+ return -EINVAL;
+ }
+
+ volt_table = kzalloc(sizeof(*volt_table) * (count / 3 + 1), GFP_KERNEL);
+ if (!volt_table)
+ return -ENOMEM;
+
+ for (i = 0; i < count / 3; i++) {
+ of_property_read_u32_index(np, "leakage-adjust-volt", 3 * i,
+ &volt_table[i].min);
+ of_property_read_u32_index(np, "leakage-adjust-volt", 3 * i + 1,
+ &volt_table[i].max);
+ of_property_read_u32_index(np, "leakage-adjust-volt", 3 * i + 2,
+ (u32 *)&volt_table[i].volt);
+ }
+ volt_table[i].min = 0;
+ volt_table[i].max = 0;
+ volt_table[i].volt = LEAKAGE_TABLE_END;
+
+ *table = volt_table;
+
+ return 0;
+}
+
+static int rockchip_get_leakage(struct device_node *np, unsigned char *leakage)
+{
+ struct nvmem_cell *cell;
+ unsigned char *buf;
+ size_t len;
+
+ cell = of_nvmem_cell_get(np, "cpu_leakage");
+ if (IS_ERR(cell)) {
+ pr_err("avs failed to get cpu_leakage cell\n");
+ return PTR_ERR(cell);
+ }
+
+ buf = (unsigned char *)nvmem_cell_read(cell, &len);
+
+ nvmem_cell_put(cell);
+
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+
+ if (buf[0] == INVALID_VALUE)
+ return -EINVAL;
+
+ *leakage = buf[0];
+ kfree(buf);
+
+ return 0;
+}
+
+static int rockchip_get_offset_volt(unsigned char leakage,
+ struct leakage_volt_table *table, int *volt)
+{
+ int i, j = -1;
+
+ if (!table)
+ return -EINVAL;
+
+ for (i = 0; table[i].volt != LEAKAGE_TABLE_END; i++) {
+ if (leakage >= (unsigned char)table[i].min)
+ j = i;
+ }
+
+ if (j == -1)
+ *volt = 0;
+ else
+ *volt = table[j].volt;
+
+ return 0;
+}
+
+static int rockchip_of_parse_cpu_avs(struct device_node *np,
+ struct cluster_info *cluster)
+{
+ int ret;
+
+ ret = of_property_read_u32(np, "cluster-id", &cluster->id);
+ if (ret < 0) {
+ pr_err("prop cluster-id missing\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (cluster->id >= MAX_CLUSTERS) {
+ pr_err("prop cluster-id invalid\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = of_property_read_u32(np, "min-freq", &cluster->min_freq);
+ if (ret < 0) {
+ pr_err("prop min_freq missing\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = of_property_read_u32(np, "min-volt", &cluster->min_volt);
+ if (ret < 0) {
+ pr_err("prop min_volt missing\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = rockchip_get_leakage_volt_table(np, &cluster->table);
+ if (ret) {
+ pr_err("prop leakage-adjust-volt invalid\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = rockchip_get_leakage(np, &cluster->leakage);
+ if (ret) {
+ pr_err("get leakage invalid\n");
+ goto out;
+ }
+
+ ret = rockchip_get_offset_volt(cluster->leakage, cluster->table,
+ &cluster->offset_volt);
+ if (ret) {
+ pr_err("get offset volt err\n");
+ goto out;
+ }
+
+ pr_info("cluster%d leakage=%d adjust_volt=%d\n", cluster->id,
+ cluster->leakage, cluster->offset_volt);
+
+out:
+ return ret;
+}
+
+static int rockchip_cpu_avs_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np, *node;
+ struct rockchip_cpu_avs *avs;
+ int ret, num_clusters = 0, i = 0;
+
+ np = of_find_node_by_name(NULL, "cpu-avs");
+ if (!np) {
+ pr_info("unable to find cpu-avs\n");
+ return 0;
+ }
+
+ if (!of_device_is_available(np)) {
+ pr_info("cpu-avs disabled\n");
+ ret = 0;
+ goto err;
+ }
+
+ for_each_available_child_of_node(np, node)
+ num_clusters++;
+
+ if (!num_clusters) {
+ pr_info("cpu-avs child disabled\n");
+ ret = 0;
+ goto err;
+ }
+
+ avs = devm_kzalloc(dev, sizeof(*avs), GFP_KERNEL);
+ if (!avs) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ avs->cluster = devm_kzalloc(dev, sizeof(*avs->cluster) * num_clusters,
+ GFP_KERNEL);
+ if (!avs->cluster) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ avs->num_clusters = num_clusters;
+
+ for_each_available_child_of_node(np, node) {
+ ret = rockchip_of_parse_cpu_avs(node, &avs->cluster[i++]);
+ if (ret)
+ goto err;
+ }
+
+ of_node_put(np);
+
+ avs->cpufreq_notify.notifier_call = rockchip_cpu_avs_notifier;
+
+ return cpufreq_register_notifier(&avs->cpufreq_notify,
+ CPUFREQ_POLICY_NOTIFIER);
+
+err:
+ of_node_put(np);
+
+ return ret;
+}
+
+static struct platform_driver rockchip_cpu_avs_platdrv = {
+ .driver = {
+ .name = "rockchip-cpu-avs",
+ },
+ .probe = rockchip_cpu_avs_probe,
+};
+
+static int __init rockchip_cpu_avs_init(void)
+{
+ struct platform_device *pdev;
+ int ret;
+
+ ret = platform_driver_register(&rockchip_cpu_avs_platdrv);
+ if (ret)
+ return ret;
+
+ /*
+ * Since there's no place to hold device registration code and no
+ * device tree based way to match cpu-avs driver yet, both the driver
+ * and the device registration codes are put here to handle defer
+ * probing.
+ */
+ pdev = platform_device_register_simple("rockchip-cpu-avs", -1, NULL, 0);
+ if (IS_ERR(pdev)) {
+ pr_err("failed to register rockchip-cpu-avs platform device\n");
+ return PTR_ERR(pdev);
+ }
+
+ return 0;
+}
+
+module_init(rockchip_cpu_avs_init);
+
+MODULE_DESCRIPTION("Rockchip CPU AVS driver");
+MODULE_AUTHOR("Finley Xiao <finley.xiao@rock-chips.com>");
+MODULE_LICENSE("GPL v2");
projects / firefly-linux-kernel-4.4.55.git / commitdiff