[PATCH v1 3/3] PM / AVS: rockchip-cpu-avs: add driver handling Rockchip cpu avs
Finlye Xiao
finley.xiao at rock-chips.com
Mon Aug 15 19:38:59 PDT 2016
From: Finley Xiao <finley.xiao at rock-chips.com>
This patch supports adjusting opp's voltage according to leakage
Signed-off-by: Finley Xiao <finley.xiao at rock-chips.com>
---
.../devicetree/bindings/power/rockchip-cpu-avs.txt | 37 +++
drivers/power/avs/Kconfig | 8 +
drivers/power/avs/Makefile | 1 +
drivers/power/avs/rockchip-cpu-avs.c | 314 +++++++++++++++++++++
4 files changed, 360 insertions(+)
create mode 100644 Documentation/devicetree/bindings/power/rockchip-cpu-avs.txt
create mode 100644 drivers/power/avs/rockchip-cpu-avs.c
diff --git a/Documentation/devicetree/bindings/power/rockchip-cpu-avs.txt b/Documentation/devicetree/bindings/power/rockchip-cpu-avs.txt
new file mode 100644
index 0000000..90f6b08
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/rockchip-cpu-avs.txt
@@ -0,0 +1,37 @@
+Rockchip cpu avs device tree bindings
+-------------------------------------
+
+Under the same frequency, the operating voltage tends to decrease with
+increasing leakage. so it is necessary to adjust opp's voltage according
+to leakage for power.
+
+
+Required properties:
+- compatible: Should be one of the following.
+ - "rockchip,rk3399-cpu-avs" - for RK3399 SoCs.
+- leakage-volt-<name>: Named leakage-volt property. At runtime, the
+ platform can find a cpu's cluster_id according to it's cpu_id and match
+ leakage-volt-<name> property. The property is an array of 3-tuples
+ items, and each item consists of leakage and voltage like
+ <min-leakage-mA max-leakage-mA vol-uV>.
+ min-leakage: minimum leakage in mA.
+ max-leakage: maximum leakage in mA.
+ vol: voltage in microvolt.
+
+Example:
+
+ cpu_avs: cpu-avs {
+ compatible = "rockchip,rk3399-cpu-avs";
+ leakage-volt-cluster0 = <
+ /* mA mA uV*/
+ 0 100 0
+ 101 200 (-25000)
+ 201 300 (-50000)
+ >;
+ leakage-volt-cluster1 = <
+ /* mA mA uV*/
+ 0 100 0
+ 101 200 (-25000)
+ 201 300 (-50000)
+ >;
+ };
diff --git a/drivers/power/avs/Kconfig b/drivers/power/avs/Kconfig
index a67eeac..c8f2d09 100644
--- a/drivers/power/avs/Kconfig
+++ b/drivers/power/avs/Kconfig
@@ -18,3 +18,11 @@ config ROCKCHIP_IODOMAIN
Say y here to enable support io domains on Rockchip SoCs. It is
necessary for the io domain setting of the SoC to match the
voltage supplied by the regulators.
+
+config ROCKCHIP_CPU_AVS
+ bool "Rockchip CPU AVS support"
+ depends on POWER_AVS && ARCH_ROCKCHIP && OF
+ help
+ Say y here to enable support CPU AVS on Rockchip SoCs.
+ The cpu's operating voltage is adapted depending on leakage
+ or pvtm.
diff --git a/drivers/power/avs/Makefile b/drivers/power/avs/Makefile
index ba4c7bc..11ce242 100644
--- a/drivers/power/avs/Makefile
+++ b/drivers/power/avs/Makefile
@@ -1,2 +1,3 @@
obj-$(CONFIG_POWER_AVS_OMAP) += smartreflex.o
obj-$(CONFIG_ROCKCHIP_IODOMAIN) += rockchip-io-domain.o
+obj-$(CONFIG_ROCKCHIP_CPU_AVS) += rockchip-cpu-avs.o
diff --git a/drivers/power/avs/rockchip-cpu-avs.c b/drivers/power/avs/rockchip-cpu-avs.c
new file mode 100644
index 0000000..8266c02
--- /dev/null
+++ b/drivers/power/avs/rockchip-cpu-avs.c
@@ -0,0 +1,314 @@
+/*
+ * Rockchip CPU AVS support.
+ *
+ * Copyright (c) 2016 ROCKCHIP, Co. Ltd.
+ *
+ * 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.
+ */
+
+#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>
+#include "../../base/power/opp/opp.h"
+
+#define MAX_NAME_LEN 22
+#define LEAKAGE_TABLE_END ~1
+#define INVALID_VALUE 0xff
+
+struct leakage_volt_table {
+ int min;
+ int max;
+ int volt;
+};
+
+struct leakage_volt_table *leakage_volt_table;
+
+struct rockchip_cpu_avs {
+ struct leakage_volt_table **volt_table;
+ struct notifier_block cpufreq_notify;
+};
+
+#define notifier_to_avs(_n) container_of(_n, struct rockchip_cpu_avs, \
+ cpufreq_notify)
+
+static unsigned char rockchip_fetch_leakage(struct device *dev)
+{
+ struct nvmem_cell *cell;
+ unsigned char *buf;
+ size_t len;
+ unsigned char leakage = INVALID_VALUE;
+
+ cell = nvmem_cell_get(dev, "cpu_leakage");
+ if (IS_ERR(cell)) {
+ pr_err("failed to get cpu_leakage cell\n");
+ return INVALID_VALUE;
+ }
+
+ buf = (unsigned char *)nvmem_cell_read(cell, &len);
+
+ nvmem_cell_put(cell);
+
+ if (IS_ERR(buf)) {
+ pr_err("failed to read nvmem cell\n");
+ return INVALID_VALUE;
+ }
+ leakage = buf[0];
+ kfree(buf);
+
+ return leakage;
+}
+
+static int rockchip_fetch_leakage_volt_table(
+ struct device_node *np,
+ struct leakage_volt_table **table,
+ const char *name)
+{
+ struct leakage_volt_table *volt_table = NULL;
+ const struct property *prop;
+ int count, i;
+
+ prop = of_find_property(np, name, NULL);
+ if (!prop) {
+ pr_err("failed to find prop %s\n", name);
+ return -EINVAL;
+ }
+ if (!prop->value) {
+ pr_err("%s value is NULL\n", name);
+ return -ENODATA;
+ }
+
+ count = of_property_count_u32_elems(np, name);
+ if (count < 0) {
+ pr_err("Invalid %s property (%d)\n", name, count);
+ return -EINVAL;
+ }
+ if (count % 3) {
+ pr_err("Invalid number of elements in %s property (%d)\n",
+ name, count);
+ return -EINVAL;
+ }
+
+ volt_table = kzalloc(sizeof(*table) * (count / 3 + 1), GFP_KERNEL);
+ if (!volt_table)
+ return -ENOMEM;
+
+ if (volt_table) {
+ for (i = 0; i < count / 3; i++) {
+ of_property_read_s32_index(np, name, 3 * i,
+ &volt_table[i].min);
+ of_property_read_s32_index(np, name, 3 * i + 1,
+ &volt_table[i].max);
+ of_property_read_s32_index(np, name, 3 * i + 2,
+ &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_parse_leakage_volt(unsigned char leakage,
+ unsigned int cpu,
+ struct rockchip_cpu_avs *avs)
+{
+ struct leakage_volt_table *table;
+ unsigned int i, j, id;
+ int volt;
+
+ id = topology_physical_package_id(cpu);
+ if (id < 0)
+ id = 0;
+
+ table = avs->volt_table[id];
+ if (!table)
+ return 0;
+
+ for (i = 0; table[i].volt != LEAKAGE_TABLE_END; i++) {
+ if (leakage >= table[i].min)
+ j = i;
+ }
+
+ volt = table[j].volt;
+
+ return volt;
+}
+
+static void rockchip_adjust_opp_table(struct device *dev,
+ struct cpufreq_frequency_table *table,
+ int volt)
+{
+ struct opp_table *opp_table;
+ struct cpufreq_frequency_table *pos;
+ struct dev_pm_opp *opp;
+ int ret;
+
+ rcu_read_lock();
+
+ opp_table = _find_opp_table(dev);
+ if (IS_ERR(opp_table)) {
+ pr_err("failed to find OPP table\n");
+ rcu_read_unlock();
+ return;
+ }
+
+ cpufreq_for_each_valid_entry(pos, table) {
+ opp = dev_pm_opp_find_freq_exact(dev, pos->frequency * 1000,
+ true);
+ if (IS_ERR(opp)) {
+ pr_err("failed to find OPP for freq %d (%d)\n",
+ pos->frequency, ret);
+ continue;
+ }
+ opp->u_volt += volt;
+ opp->u_volt_min += volt;
+ opp->u_volt_max += volt;
+ }
+
+ rcu_read_unlock();
+}
+
+static void rockchip_adjust_volt_by_leakage(
+ struct device *dev,
+ struct cpufreq_frequency_table *table,
+ unsigned int cpu,
+ struct rockchip_cpu_avs *avs)
+{
+ unsigned char leakage;
+ int volt;
+
+ /* fetch leakage from efuse */
+ leakage = rockchip_fetch_leakage(dev);
+ if (leakage == INVALID_VALUE) {
+ pr_err("cpu%d leakage invalid\n", cpu);
+ return;
+ }
+
+ /* fetch adjust volt from table */
+ volt = rockchip_parse_leakage_volt(leakage, cpu, avs);
+ if (volt)
+ rockchip_adjust_opp_table(dev, table, volt);
+
+ pr_debug("cpu%d, leakage=%d, adjust_volt=%d\n", cpu, leakage, 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 device *dev;
+
+ struct cpufreq_frequency_table *table;
+
+ if (event != CPUFREQ_START)
+ goto out;
+
+ dev = get_cpu_device(policy->cpu);
+ if (!dev) {
+ pr_err("cpu%d Failed to get device\n", policy->cpu);
+ goto out;
+ }
+
+ table = cpufreq_frequency_get_table(policy->cpu);
+ if (!table) {
+ pr_err("cpu%d CPUFreq table not found\n", policy->cpu);
+ goto out;
+ }
+
+ rockchip_adjust_volt_by_leakage(dev, table, policy->cpu, avs);
+
+out:
+
+ return NOTIFY_OK;
+}
+
+static const struct of_device_id rockchip_cpu_avs_match[] = {
+ {
+ .compatible = "rockchip,rk3399-cpu-avs",
+ },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, rockchip_cpu_avs_match);
+
+static int rockchip_cpu_avs_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct rockchip_cpu_avs *avs;
+ char name[MAX_NAME_LEN];
+ int i, ret, cpu, id;
+ int last_id = -1;
+ int cluster_num = 0;
+
+ avs = devm_kzalloc(&pdev->dev, sizeof(struct rockchip_cpu_avs),
+ GFP_KERNEL);
+ if (!avs)
+ return -ENOMEM;
+
+ avs->cpufreq_notify.notifier_call = rockchip_cpu_avs_notifier;
+
+ for_each_online_cpu(cpu) {
+ id = topology_physical_package_id(cpu);
+ if (id < 0)
+ id = 0;
+ if (id != last_id) {
+ last_id = id;
+ cluster_num++;
+ }
+ }
+
+ avs->volt_table = devm_kzalloc(&pdev->dev,
+ sizeof(struct leakage_volt_table) * cluster_num, GFP_KERNEL);
+ if (!avs->volt_table)
+ return -ENOMEM;
+
+ for (i = 0; i < cluster_num; i++) {
+ snprintf(name, MAX_NAME_LEN, "leakage-volt-cluster%d", i);
+ ret = rockchip_fetch_leakage_volt_table(np, &avs->volt_table[i],
+ name);
+ if (ret)
+ continue;
+ }
+
+ return cpufreq_register_notifier(&avs->cpufreq_notify,
+ CPUFREQ_POLICY_NOTIFIER);
+}
+
+static struct platform_driver rockchip_cpu_avs_driver = {
+ .probe = rockchip_cpu_avs_probe,
+ .driver = {
+ .name = "rockchip-cpu-avs",
+ .of_match_table = rockchip_cpu_avs_match,
+ .suppress_bind_attrs = true,
+ },
+};
+
+static int __init rockchip_cpu_avs_module_init(void)
+{
+ return platform_driver_probe(&rockchip_cpu_avs_driver,
+ rockchip_cpu_avs_probe);
+}
+
+subsys_initcall(rockchip_cpu_avs_module_init);
+
+MODULE_DESCRIPTION("Rockchip CPU AVS driver");
+MODULE_AUTHOR("Finley Xiao <finley.xiao at rock-chips.com>");
+MODULE_LICENSE("GPL v2");
--
1.9.1
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