Re: [PATCH v2 1/6] soc: qcom: rpmpd: Add a powerdomain driver to model corners

[Rajendra Nayak <rnayak@codeaurora.org>]

On 05/30/2018 02:47 PM, Ulf Hansson wrote:
> On 25 May 2018 at 12:01, Rajendra Nayak <rnayak@codeaurora.org> wrote:
>> The powerdomains for corners just pass the performance state set by the
>> consumers to the RPM (Remote Power manager) which then takes care
>> of setting the appropriate voltage on the corresponding rails to
>> meet the performance needs.
>>
>> We add all powerdomain data needed on msm8996 here. This driver can easily
>> be extended by adding data for other qualcomm SoCs as well.
>>
>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
>> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>> ---
>>  .../devicetree/bindings/power/qcom,rpmpd.txt  |  55 ++++
> 
> Please split DT doc changes into separate patches, to simplify review.

yes, i will split it when I resend the series.

> 
>>  drivers/soc/qcom/Kconfig                      |   9 +
>>  drivers/soc/qcom/Makefile                     |   1 +
>>  drivers/soc/qcom/rpmpd.c                      | 299 ++++++++++++++++++
>>  4 files changed, 364 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/power/qcom,rpmpd.txt
>>  create mode 100644 drivers/soc/qcom/rpmpd.c
>>
> 
> [...]
> 
>> +++ b/drivers/soc/qcom/rpmpd.c
>> @@ -0,0 +1,299 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
>> + */
>> +
>> +#include <linux/err.h>
>> +#include <linux/export.h>
>> +#include <linux/init.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/pm_domain.h>
>> +#include <linux/mfd/qcom_rpm.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/soc/qcom/smd-rpm.h>
>> +
>> +#include <dt-bindings/mfd/qcom-rpm.h>
>> +
>> +#define domain_to_rpmpd(domain) container_of(domain, struct rpmpd, pd)
>> +
>> +/* Resource types */
>> +#define RPMPD_SMPA 0x61706d73
>> +#define RPMPD_LDOA 0x616f646c
>> +
>> +/* Operation Keys */
>> +#define KEY_CORNER             0x6e726f63 /* corn */
>> +#define KEY_ENABLE             0x6e657773 /* swen */
>> +#define KEY_FLOOR_CORNER       0x636676   /* vfc */
>> +
>> +#define DEFINE_RPMPD_CORN_SMPA(_platform, _name, _active, r_id)                \
>> +       static struct rpmpd _platform##_##_active;                      \
>> +       static struct rpmpd _platform##_##_name = {                     \
>> +               .pd = { .name = #_name, },                              \
>> +               .peer = &_platform##_##_active,                         \
>> +               .res_type = RPMPD_SMPA,                                 \
>> +               .res_id = r_id,                                         \
>> +               .key = KEY_CORNER,                                      \
>> +       };                                                              \
>> +       static struct rpmpd _platform##_##_active = {                   \
>> +               .pd = { .name = #_active, },                            \
>> +               .peer = &_platform##_##_name,                           \
>> +               .active_only = true,                                    \
>> +               .res_type = RPMPD_SMPA,                                 \
>> +               .res_id = r_id,                                         \
>> +               .key = KEY_CORNER,                                      \
>> +       }
>> +
>> +#define DEFINE_RPMPD_CORN_LDOA(_platform, _name, r_id)                 \
>> +       static struct rpmpd _platform##_##_name = {                     \
>> +               .pd = { .name = #_name, },                              \
>> +               .res_type = RPMPD_LDOA,                                 \
>> +               .res_id = r_id,                                         \
>> +               .key = KEY_CORNER,                                      \
>> +       }
>> +
>> +#define DEFINE_RPMPD_VFC(_platform, _name, r_id, r_type)               \
>> +       static struct rpmpd _platform##_##_name = {                     \
>> +               .pd = { .name = #_name, },                              \
>> +               .res_type = r_type,                                     \
>> +               .res_id = r_id,                                         \
>> +               .key = KEY_FLOOR_CORNER,                                \
>> +       }
>> +
>> +#define DEFINE_RPMPD_VFC_SMPA(_platform, _name, r_id)                  \
>> +       DEFINE_RPMPD_VFC(_platform, _name, r_id, RPMPD_SMPA)
>> +
>> +#define DEFINE_RPMPD_VFC_LDOA(_platform, _name, r_id)                  \
>> +       DEFINE_RPMPD_VFC(_platform, _name, r_id, RPMPD_LDOA)
>> +
>> +struct rpmpd_req {
>> +       __le32 key;
>> +       __le32 nbytes;
>> +       __le32 value;
>> +};
>> +
>> +struct rpmpd {
>> +       struct generic_pm_domain pd;
>> +       struct rpmpd *peer;
>> +       const bool active_only;
>> +       unsigned long corner;
>> +       bool enabled;
>> +       const char *res_name;
>> +       const int res_type;
>> +       const int res_id;
>> +       struct qcom_smd_rpm *rpm;
>> +       __le32 key;
>> +};
>> +
>> +struct rpmpd_desc {
>> +       struct rpmpd **rpmpds;
>> +       size_t num_pds;
>> +};
>> +
>> +static DEFINE_MUTEX(rpmpd_lock);
>> +
>> +/* msm8996 RPM powerdomains */
>> +DEFINE_RPMPD_CORN_SMPA(msm8996, vddcx, vddcx_ao, 1);
>> +DEFINE_RPMPD_CORN_SMPA(msm8996, vddmx, vddmx_ao, 2);
>> +DEFINE_RPMPD_CORN_LDOA(msm8996, vddsscx, 26);
>> +
>> +DEFINE_RPMPD_VFC_SMPA(msm8996, vddcx_vfc, 1);
>> +DEFINE_RPMPD_VFC_LDOA(msm8996, vddsscx_vfc, 26);
>> +
>> +static struct rpmpd *msm8996_rpmpds[] = {
>> +       [0] = &msm8996_vddcx,
>> +       [1] = &msm8996_vddcx_ao,
>> +       [2] = &msm8996_vddcx_vfc,
>> +       [3] = &msm8996_vddmx,
>> +       [4] = &msm8996_vddmx_ao,
>> +       [5] = &msm8996_vddsscx,
>> +       [6] = &msm8996_vddsscx_vfc,
>> +};
> 
> It's not my call, but honestly the above all macros makes the code
> less readable.

This is all static data per SoC. The macros will keep the new additions
needed for every new SoC to a minimal. Currently this supports only
msm8996.

> 
> Anyway, I think you should convert to allocate these structs
> dynamically from the heap (kzalloc/kcalloc), instead of statically as
> above.
> 
>> +
>> +static const struct rpmpd_desc msm8996_desc = {
>> +       .rpmpds = msm8996_rpmpds,
>> +       .num_pds = ARRAY_SIZE(msm8996_rpmpds),
>> +};
>> +
>> +static const struct of_device_id rpmpd_match_table[] = {
>> +       { .compatible = "qcom,msm8996-rpmpd", .data = &msm8996_desc },
>> +       { }
>> +};
>> +MODULE_DEVICE_TABLE(of, rpmpd_match_table);
> 
> [...]
> 
>> +static int rpmpd_aggregate_corner(struct rpmpd *pd)
>> +{
> 
> Isn't the aggregation of the performance states in genpd sufficient
> for your case?
> 
> I guess this is SoC specific and needed anyways, but then could you
> perhaps add a few comments about what goes on here?

Yes, this is SoC specific aggregation for active and sleep votes.
i will add comments to clarify this is different from the aggregation
done at the framework level.

> 
>> +       int ret;
>> +       struct rpmpd *peer = pd->peer;
>> +       unsigned long active_corner, sleep_corner;
>> +       unsigned long this_corner = 0, this_sleep_corner = 0;
>> +       unsigned long peer_corner = 0, peer_sleep_corner = 0;
>> +
>> +       to_active_sleep(pd, pd->corner, &this_corner, &this_sleep_corner);
>> +
>> +       if (peer && peer->enabled)
>> +               to_active_sleep(peer, peer->corner, &peer_corner,
>> +                               &peer_sleep_corner);
>> +
>> +       active_corner = max(this_corner, peer_corner);
>> +
>> +       ret = rpmpd_send_corner(pd, QCOM_RPM_ACTIVE_STATE, active_corner);
>> +       if (ret)
>> +               return ret;
>> +
>> +       sleep_corner = max(this_sleep_corner, peer_sleep_corner);
>> +
>> +       return rpmpd_send_corner(pd, QCOM_RPM_SLEEP_STATE, sleep_corner);
>> +}
> 
> [...]
> 
>> +static int rpmpd_probe(struct platform_device *pdev)
>> +{
>> +       int i;
>> +       size_t num;
>> +       struct genpd_onecell_data *data;
>> +       struct qcom_smd_rpm *rpm;
>> +       struct rpmpd **rpmpds;
>> +       const struct rpmpd_desc *desc;
>> +
>> +       rpm = dev_get_drvdata(pdev->dev.parent);
>> +       if (!rpm) {
>> +               dev_err(&pdev->dev, "Unable to retrieve handle to RPM\n");
>> +               return -ENODEV;
>> +       }
>> +
>> +       desc = of_device_get_match_data(&pdev->dev);
>> +       if (!desc)
>> +               return -EINVAL;
>> +
>> +       rpmpds = desc->rpmpds;
>> +       num = desc->num_pds;
>> +
>> +       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
>> +       if (!data)
>> +               return -ENOMEM;
>> +
>> +       data->domains = devm_kcalloc(&pdev->dev, num, sizeof(*data->domains),
>> +                                    GFP_KERNEL);
>> +       data->num_domains = num;
>> +
>> +       for (i = 0; i < num; i++) {
>> +               if (!rpmpds[i])
>> +                       continue;
>> +
>> +               rpmpds[i]->rpm = rpm;
>> +               rpmpds[i]->pd.power_off = rpmpd_power_off;
>> +               rpmpds[i]->pd.power_on = rpmpd_power_on;
>> +               pm_genpd_init(&rpmpds[i]->pd, NULL, true);
> 
> Question: Is there no hierarchical topology of the PM domains. No
> genpd subdomains?

The hierarchy if any is all handled by the remote core (RPM in this case).
For Linux its just a flat view.

> 
>> +
>> +               data->domains[i] = &rpmpds[i]->pd;
>> +       }
>> +
>> +       return of_genpd_add_provider_onecell(pdev->dev.of_node, data);
>> +}
>> +
>> +static int rpmpd_remove(struct platform_device *pdev)
>> +{
>> +       of_genpd_del_provider(pdev->dev.of_node);
>> +       return 0;
>> +}
>> +
>> +static struct platform_driver rpmpd_driver = {
>> +       .driver = {
>> +               .name = "qcom-rpmpd",
>> +               .of_match_table = rpmpd_match_table,
>> +       },
>> +       .probe = rpmpd_probe,
>> +       .remove = rpmpd_remove,
>> +};
>> +
>> +static int __init rpmpd_init(void)
>> +{
>> +       return platform_driver_register(&rpmpd_driver);
>> +}
>> +core_initcall(rpmpd_init);
>> +
>> +static void __exit rpmpd_exit(void)
>> +{
>> +       platform_driver_unregister(&rpmpd_driver);
>> +}
>> +module_exit(rpmpd_exit);
>> +
>> +MODULE_DESCRIPTION("Qualcomm RPM Power Domain Driver");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_ALIAS("platform:qcom-rpmpd");
>> --
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
>> of Code Aurora Forum, hosted by The Linux Foundation
>>
> 
> Besides the minor things above, this looks good to me.

thanks,
Rajendra


-- 
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