Re: [PATCH v6 2/3] OPP: Add support for bandwidth OPP tables
From: Viresh Kumar
Date: Wed Jan 08 2020 - 05:53:58 EST
On 06-12-19, 16:24, Saravana Kannan wrote:
> Not all devices quantify their performance points in terms of frequency.
> Devices like interconnects quantify their performance points in terms of
> bandwidth. We need a way to represent these bandwidth levels in OPP. So,
> add support for parsing bandwidth OPPs from DT.
>
> Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
> ---
> drivers/opp/core.c | 15 +++++++++--
> drivers/opp/of.c | 63 ++++++++++++++++++++++++++++++++--------------
> drivers/opp/opp.h | 5 ++++
> 3 files changed, 62 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index be7a7d332332..c79bbfac7289 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -1282,11 +1282,21 @@ static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
> return true;
> }
>
> +int opp_compare_key(struct dev_pm_opp *opp1, struct dev_pm_opp *opp2)
> +{
> + if (opp1->rate != opp2->rate)
> + return opp1->rate < opp2->rate ? -1 : 1;
> + if (opp1->peak_bw != opp2->peak_bw)
> + return opp1->peak_bw < opp2->peak_bw ? -1 : 1;
Please also add level here.
> + return 0;
> +}
> +
> static int _opp_is_duplicate(struct device *dev, struct dev_pm_opp *new_opp,
> struct opp_table *opp_table,
> struct list_head **head)
> {
> struct dev_pm_opp *opp;
> + int opp_cmp;
>
> /*
> * Insert new OPP in order of increasing frequency and discard if
> @@ -1297,12 +1307,13 @@ static int _opp_is_duplicate(struct device *dev, struct dev_pm_opp *new_opp,
> * loop.
> */
> list_for_each_entry(opp, &opp_table->opp_list, node) {
> - if (new_opp->rate > opp->rate) {
> + opp_cmp = opp_compare_key(new_opp, opp);
> + if (opp_cmp > 0) {
> *head = &opp->node;
> continue;
> }
>
> - if (new_opp->rate < opp->rate)
> + if (opp_cmp < 0)
> return 0;
>
> /* Duplicate OPPs */
> diff --git a/drivers/opp/of.c b/drivers/opp/of.c
> index 1cbb58240b80..b565da5a2b1f 100644
> --- a/drivers/opp/of.c
> +++ b/drivers/opp/of.c
> @@ -521,6 +521,44 @@ void dev_pm_opp_of_remove_table(struct device *dev)
> }
> EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
>
> +static int _read_opp_key(struct dev_pm_opp *new_opp, struct device_node *np,
> + bool *rate_not_available)
> +{
> + int ret;
> + u64 rate;
> + u32 bw;
> +
> + ret = of_property_read_u64(np, "opp-hz", &rate);
> + if (!ret) {
> + /*
> + * Rate is defined as an unsigned long in clk API, and so
> + * casting explicitly to its type. Must be fixed once rate is 64
> + * bit guaranteed in clk API.
> + */
> + new_opp->rate = (unsigned long)rate;
> + goto out;
> + }
> +
> + ret = of_property_read_u32(np, "opp-peak-kBps", &bw);
> + if (!ret) {
> + new_opp->peak_bw = bw;
> +
> + if (!of_property_read_u32(np, "opp-avg-kBps", &bw))
> + new_opp->avg_bw = bw;
Maybe
of_property_read_u32(np, "opp-avg-kBps", &new_opp->avg_bw);
and same for opp-peak-kbps as well.
> + }
> +
> +out:
> + *rate_not_available = !!ret;
> + /*
> + * If ret is 0 at this point, we have already found a key. If we
> + * haven't found a key yet, then ret already has an error value. In
> + * either case, we don't need to update ret.
> + */
> + of_property_read_u32(np, "opp-level", &new_opp->level);
Yes, it wasn't done earlier but we should do it now. Check level as
well and treat it as any other key.
I think add a preparatory patch first which does all the cleanup
before bandwidth thing is added.
> +
> + return ret;
> +}
> +
> /**
> * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
> * @opp_table: OPP table
> @@ -558,26 +596,12 @@ static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
> if (!new_opp)
> return ERR_PTR(-ENOMEM);
>
> - ret = of_property_read_u64(np, "opp-hz", &rate);
> - if (ret < 0) {
> - /* "opp-hz" is optional for devices like power domains. */
> - if (!opp_table->is_genpd) {
> - dev_err(dev, "%s: opp-hz not found\n", __func__);
> - goto free_opp;
> - }
> -
> - rate_not_available = true;
> - } else {
> - /*
> - * Rate is defined as an unsigned long in clk API, and so
> - * casting explicitly to its type. Must be fixed once rate is 64
> - * bit guaranteed in clk API.
> - */
> - new_opp->rate = (unsigned long)rate;
> + ret = _read_opp_key(new_opp, np, &rate_not_available);
> + if (ret) {
> + dev_err(dev, "%s: opp key field not found\n", __func__);
> + goto free_opp;
> }
>
> - of_property_read_u32(np, "opp-level", &new_opp->level);
> -
> /* Check if the OPP supports hardware's hierarchy of versions or not */
> if (!_opp_is_supported(dev, opp_table, np)) {
> dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
> @@ -616,7 +640,8 @@ static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
> if (of_property_read_bool(np, "opp-suspend")) {
> if (opp_table->suspend_opp) {
> /* Pick the OPP with higher rate as suspend OPP */
> - if (new_opp->rate > opp_table->suspend_opp->rate) {
> + if (opp_compare_key(new_opp,
> + opp_table->suspend_opp) > 1) {
Maybe leave this place as is as we never want to compare anything else
but rate.
> opp_table->suspend_opp->suspend = false;
> new_opp->suspend = true;
> opp_table->suspend_opp = new_opp;
> diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
> index 01a500e2c40a..0def3154d07b 100644
> --- a/drivers/opp/opp.h
> +++ b/drivers/opp/opp.h
> @@ -57,6 +57,8 @@ extern struct list_head opp_tables;
> * @suspend: true if suspend OPP
> * @pstate: Device's power domain's performance state.
> * @rate: Frequency in hertz
> + * @peak_bw: Peak bandwidth in kilobytes per second
> + * @avg_bw: Average bandwidth in kilobytes per second
> * @level: Performance level
> * @supplies: Power supplies voltage/current values
> * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
> @@ -78,6 +80,8 @@ struct dev_pm_opp {
> bool suspend;
> unsigned int pstate;
> unsigned long rate;
> + unsigned int peak_bw;
> + unsigned int avg_bw;
> unsigned int level;
>
> struct dev_pm_opp_supply *supplies;
> @@ -213,6 +217,7 @@ struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_
> void _dev_pm_opp_find_and_remove_table(struct device *dev);
> struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table);
> void _opp_free(struct dev_pm_opp *opp);
> +int opp_compare_key(struct dev_pm_opp *opp1, struct dev_pm_opp *opp2);
make it _opp_compare_key() instead.
> int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table, bool rate_not_available);
> int _opp_add_v1(struct opp_table *opp_table, struct device *dev, unsigned long freq, long u_volt, bool dynamic);
> void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, int last_cpu);
> --
> 2.24.0.393.g34dc348eaf-goog
--
viresh