Re: [PATCH v4 2/5] devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()

[Chanwoo Choi <cwchoi00@gmail.com>]

Hi,

This patch has the same problem as I mentioned on v3.
We need to discuss it on v3[1]. Please check my reply.
[1] [PATCH v3 3/5] devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()

2019년 7월 25일 (목) 오후 11:46, <k.konieczny@partner.samsung.com>님이 작성:
>
> Reuse opp core code for setting bus clock and voltage. As a side
> effect this allow usage of coupled regulators feature (required
> for boards using Exynos5422/5800 SoCs) because dev_pm_opp_set_rate()
> uses regulator_set_voltage_triplet() for setting regulator voltage
> while the old code used regulator_set_voltage_tol() with fixed
> tolerance. This patch also removes no longer needed parsing of DT
> property "exynos,voltage-tolerance" (no Exynos devfreq DT node uses
> it).
>
> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
> ---
> Changes:
> v4:
> - remove unrelated changes, add newline before comment
>
> ---
>  drivers/devfreq/exynos-bus.c | 108 +++++++++--------------------------
>  1 file changed, 28 insertions(+), 80 deletions(-)
>
> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
> index f34fa26f00d0..ebb8f46312b6 100644
> --- a/drivers/devfreq/exynos-bus.c
> +++ b/drivers/devfreq/exynos-bus.c
> @@ -25,7 +25,6 @@
>  #include <linux/slab.h>
>
>  #define DEFAULT_SATURATION_RATIO       40
> -#define DEFAULT_VOLTAGE_TOLERANCE      2
>
>  struct exynos_bus {
>         struct device *dev;
> @@ -37,9 +36,8 @@ struct exynos_bus {
>
>         unsigned long curr_freq;
>
> -       struct regulator *regulator;
> +       struct opp_table *opp_table;
>         struct clk *clk;
> -       unsigned int voltage_tolerance;
>         unsigned int ratio;
>  };
>
> @@ -99,56 +97,23 @@ static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
>  {
>         struct exynos_bus *bus = dev_get_drvdata(dev);
>         struct dev_pm_opp *new_opp;
> -       unsigned long old_freq, new_freq, new_volt, tol;
>         int ret = 0;
>
> -       /* Get new opp-bus instance according to new bus clock */
> +       /* Get correct frequency for bus. */
>         new_opp = devfreq_recommended_opp(dev, freq, flags);
>         if (IS_ERR(new_opp)) {
>                 dev_err(dev, "failed to get recommended opp instance\n");
>                 return PTR_ERR(new_opp);
>         }
>
> -       new_freq = dev_pm_opp_get_freq(new_opp);
> -       new_volt = dev_pm_opp_get_voltage(new_opp);
>         dev_pm_opp_put(new_opp);
>
> -       old_freq = bus->curr_freq;
> -
> -       if (old_freq == new_freq)
> -               return 0;
> -       tol = new_volt * bus->voltage_tolerance / 100;
> -
>         /* Change voltage and frequency according to new OPP level */
>         mutex_lock(&bus->lock);
> +       ret = dev_pm_opp_set_rate(dev, *freq);
> +       if (!ret)
> +               bus->curr_freq = *freq;
>
> -       if (old_freq < new_freq) {
> -               ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
> -               if (ret < 0) {
> -                       dev_err(bus->dev, "failed to set voltage\n");
> -                       goto out;
> -               }
> -       }
> -
> -       ret = clk_set_rate(bus->clk, new_freq);
> -       if (ret < 0) {
> -               dev_err(dev, "failed to change clock of bus\n");
> -               clk_set_rate(bus->clk, old_freq);
> -               goto out;
> -       }
> -
> -       if (old_freq > new_freq) {
> -               ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
> -               if (ret < 0) {
> -                       dev_err(bus->dev, "failed to set voltage\n");
> -                       goto out;
> -               }
> -       }
> -       bus->curr_freq = new_freq;
> -
> -       dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
> -                       old_freq, new_freq, clk_get_rate(bus->clk));
> -out:
>         mutex_unlock(&bus->lock);
>
>         return ret;
> @@ -196,8 +161,10 @@ static void exynos_bus_exit(struct device *dev)
>
>         dev_pm_opp_of_remove_table(dev);
>         clk_disable_unprepare(bus->clk);
> -       if (bus->regulator)
> -               regulator_disable(bus->regulator);
> +       if (bus->opp_table) {
> +               dev_pm_opp_put_regulators(bus->opp_table);
> +               bus->opp_table = NULL;
> +       }
>  }
>
>  /*
> @@ -208,39 +175,23 @@ static int exynos_bus_passive_target(struct device *dev, unsigned long *freq,
>  {
>         struct exynos_bus *bus = dev_get_drvdata(dev);
>         struct dev_pm_opp *new_opp;
> -       unsigned long old_freq, new_freq;
> -       int ret = 0;
> +       int ret;
>
> -       /* Get new opp-bus instance according to new bus clock */
> +       /* Get correct frequency for bus. */
>         new_opp = devfreq_recommended_opp(dev, freq, flags);
>         if (IS_ERR(new_opp)) {
>                 dev_err(dev, "failed to get recommended opp instance\n");
>                 return PTR_ERR(new_opp);
>         }
>
> -       new_freq = dev_pm_opp_get_freq(new_opp);
>         dev_pm_opp_put(new_opp);
>
> -       old_freq = bus->curr_freq;
> -
> -       if (old_freq == new_freq)
> -               return 0;
> -
>         /* Change the frequency according to new OPP level */
>         mutex_lock(&bus->lock);
> +       ret = dev_pm_opp_set_rate(dev, *freq);
> +       if (!ret)
> +               bus->curr_freq = *freq;
>
> -       ret = clk_set_rate(bus->clk, new_freq);
> -       if (ret < 0) {
> -               dev_err(dev, "failed to set the clock of bus\n");
> -               goto out;
> -       }
> -
> -       *freq = new_freq;
> -       bus->curr_freq = new_freq;
> -
> -       dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
> -                       old_freq, new_freq, clk_get_rate(bus->clk));
> -out:
>         mutex_unlock(&bus->lock);
>
>         return ret;
> @@ -258,21 +209,19 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>                                         struct exynos_bus *bus)
>  {
>         struct device *dev = bus->dev;
> +       struct opp_table *opp_table;
> +       const char *vdd = "vdd";
>         int i, ret, count, size;
>
> -       /* Get the regulator to provide each bus with the power */
> -       bus->regulator = devm_regulator_get(dev, "vdd");
> -       if (IS_ERR(bus->regulator)) {
> -               dev_err(dev, "failed to get VDD regulator\n");
> -               return PTR_ERR(bus->regulator);
> -       }
> -
> -       ret = regulator_enable(bus->regulator);
> -       if (ret < 0) {
> -               dev_err(dev, "failed to enable VDD regulator\n");
> +       opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
> +       if (IS_ERR(opp_table)) {
> +               ret = PTR_ERR(opp_table);
> +               dev_err(dev, "failed to set regulators %d\n", ret);
>                 return ret;
>         }
>
> +       bus->opp_table = opp_table;
> +
>         /*
>          * Get the devfreq-event devices to get the current utilization of
>          * buses. This raw data will be used in devfreq ondemand governor.
> @@ -313,14 +262,11 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
>         if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
>                 bus->ratio = DEFAULT_SATURATION_RATIO;
>
> -       if (of_property_read_u32(np, "exynos,voltage-tolerance",
> -                                       &bus->voltage_tolerance))
> -               bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE;
> -
>         return 0;
>
>  err_regulator:
> -       regulator_disable(bus->regulator);
> +       dev_pm_opp_put_regulators(bus->opp_table);
> +       bus->opp_table = NULL;
>
>         return ret;
>  }
> @@ -511,8 +457,10 @@ static int exynos_bus_probe(struct platform_device *pdev)
>         dev_pm_opp_of_remove_table(dev);
>         clk_disable_unprepare(bus->clk);
>  err_reg:
> -       if (!passive)
> -               regulator_disable(bus->regulator);
> +       if (!passive) {
> +               dev_pm_opp_put_regulators(bus->opp_table);
> +               bus->opp_table = NULL;
> +       }
>
>         return ret;
>  }
> --
> 2.22.0
>


-- 
Best Regards,
Chanwoo Choi

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel