Re: [PATCH v7 2/7] OPP: Add helpers for reading the binding properties

Matthias Kaehlcke
2020-04-24T17:30:56Z

Hi Georgi,

On Fri, Apr 24, 2020 at 06:53:59PM +0300, Georgi Djakov wrote:
> From: Saravana Kannan <saravanak@google.com>
>
> The opp-hz DT property is not mandatory and we may use another property
> as a key in the OPP table. Add helper functions to simplify the reading
> and comparing the keys.
>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
> ---
> v7:
> * Extracted just the helpers from patch v6, as Viresh advised to split it.
>
> v6: https://lore.kernel.org/r/20191207002424.201796-3-saravanak@google.com
>
> drivers/opp/core.c | 15 +++++++++++++--
> drivers/opp/of.c | 42 ++++++++++++++++++++++++++----------------
> drivers/opp/opp.h | 1 +
> 3 files changed, 40 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index ba43e6a3dc0a..c9c1bbe6ae27 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -1272,11 +1272,21 @@ 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->level != opp2->level)
> + return opp1->level < opp2->level ? -1 : 1;
> + 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
> @@ -1287,12 +1297,13 @@ 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 9cd8f0adacae..e33169c7e045 100644
> --- a/drivers/opp/of.c
> +++ b/drivers/opp/of.c
> @@ -521,6 +521,28 @@ 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)
> +{
> + u64 rate;
> + int ret;
> +
> + 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;
> + }

nit: curly braces are not needed

> + *rate_not_available = !!ret;
> +
> + of_property_read_u32(np, "opp-level", &new_opp->level);
> +
> + return ret;
> +}
> +
> /**
> * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
> * @opp_table: OPP table
> @@ -558,26 +580,14 @@ 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);
> + ret = _read_opp_key(new_opp, np, &rate_not_available);
> 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;
> - }
> + if (!opp_table->is_genpd)
> + dev_err(dev, "%s: opp key field not found\n", __func__);
>
> - 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;
> + 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);
> diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
> index d14e27102730..bcadb1e328a4 100644
> --- a/drivers/opp/opp.h
> +++ b/drivers/opp/opp.h
> @@ -211,6 +211,7 @@ 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);
> 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);

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>