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SubjectRe: [PATCH v1 3/3] PM / AVS: rockchip-cpu-avs: add driver handling Rockchip cpu avs
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在 2016/8/17 1:24, Heiko Stübner 写道:
> Hi Finley,
>
> Am Dienstag, 16. August 2016, 10:38:59 schrieb Finlye Xiao:
>> From: Finley Xiao <finley.xiao@rock-chips.com>
>>
>> This patch supports adjusting opp's voltage according to leakage
>>
>> Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
> we of course talked about this before and it generally looks good, I just
> found a bunch of smaller issues below.
>
>
>> ---
>> .../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
> the binding should generally be a separate patch, so that Rob and other
> devicetree-maintainers can spot them better, so name it something like
> dt-bindings: add binding document for Rockchip cpu avs
> or similar.
>
>
>> @@ -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>.
> vol -> volt ?
>
>> + min-leakage: minimum leakage in mA.
>> + max-leakage: maximum leakage in mA.
>> + vol: voltage in microvolt.
> vol -> volt?
>
> maybe also make that
> volt: voltage offset in mV to apply to the opp table entries
>
>
>> +
>> +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
> as the kbuild-robot found out, you'll need as well a
> depends on CPU_FREQ
>
> also, I don't know if this also applies to the rk3288 and before (arm32), but
> if so and with your generic depends on ARCH_ROCKCHIP, you'd also need a
> depends on ARM_CPU_TOPOLOGY if ARM
>
> as the topology-stuff is not always active on arm32.
>
>
>> + 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
> copy'n'pasted from somewhere? Should probably not be here
>
>
>> +#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;
> you have the leakage_volt_table nicely in the rockchip_cpu_avs struct, so that
> looks like something forgotten?
>
>
>> +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;
> hmm, I don't trust that INVALID_VALUE to much - as it blocks the 255 value
> from the efuse. Can you tell what is the value range for the leakage in the
> efuse? Especially, as the range in your conversion-table is reaching 300, 255
> does look like it might be a valid value on some chip.

According to the internal document, the cpu leakage ranges from 0 to 254,
0xff is considered to be an invalid value on Rockchip SoCs.
I will modify the conversion-table.

>
> So I'd suggest to convert "leakage" and the function return type to an int.
> That way you can easily keep the full value range and also put the actual
> errors (as negative values) into it so that callers can act accordingly.
>
>
>> +
>> + 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;
> looks strange. If the cluster cannot be determined, shouldn't this just return
> the error and not work with possible wrong assumptions?
>
>
>> + 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;
> why not directly "return table[j].volt"? No need to assign and then return.
>
>
>> +}
>> +
>> +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;
> same as above
>
>
>> + 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@rock-chips.com>");
>> +MODULE_LICENSE("GPL v2");
>
>
>

--
Finley


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