2019-08-07 13:40:10

by Kamil Konieczny

[permalink] [raw]
Subject: [PATCH v5 2/4] devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()

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). After applying changes both functions exynos_bus_passive_target()
and exynos_bus_target() have the same code, so remove
exynos_bus_passive_target(). In exynos_bus_probe() replace it with
exynos_bus_target.

Signed-off-by: Kamil Konieczny <[email protected]>
---
Changes:
v5:
- squashed last patch into this one, as suggested by Chanwoo Choi
v4:
- remove unrelated changes, add newline before comment

---
drivers/devfreq/exynos-bus.c | 130 +++++++----------------------------
1 file changed, 24 insertions(+), 106 deletions(-)

diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
index f34fa26f00d0..2aeb6cc07960 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;
};

@@ -93,62 +91,29 @@ static int exynos_bus_get_event(struct exynos_bus *bus,
}

/*
- * Must necessary function for devfreq simple-ondemand governor
+ * devfreq function for both simple-ondemand and passive governor
*/
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;
@@ -196,54 +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);
-}
-
-/*
- * Must necessary function for devfreq passive governor
- */
-static int exynos_bus_passive_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;
- int ret = 0;
-
- /* Get new opp-bus instance according to new bus clock */
- 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 = clk_set_rate(bus->clk, new_freq);
- if (ret < 0) {
- dev_err(dev, "failed to set the clock of bus\n");
- goto out;
+ if (bus->opp_table) {
+ dev_pm_opp_put_regulators(bus->opp_table);
+ bus->opp_table = NULL;
}
-
- *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;
}

static void exynos_bus_passive_exit(struct device *dev)
@@ -258,21 +179,19 @@ 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 +232,11 @@ 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;
}
@@ -471,7 +387,7 @@ static int exynos_bus_probe(struct platform_device *pdev)
goto out;
passive:
/* Initialize the struct profile and governor data for passive device */
- profile->target = exynos_bus_passive_target;
+ profile->target = exynos_bus_target;
profile->exit = exynos_bus_passive_exit;

/* Get the instance of parent devfreq device */
@@ -511,8 +427,10 @@ 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


2019-08-08 01:19:28

by Chanwoo Choi

[permalink] [raw]
Subject: Re: [PATCH v5 2/4] devfreq: exynos-bus: convert to use dev_pm_opp_set_rate()

Hi Kamil,

On 19. 8. 7. 오후 10:38, [email protected] wrote:
> 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). After applying changes both functions exynos_bus_passive_target()
> and exynos_bus_target() have the same code, so remove
> exynos_bus_passive_target(). In exynos_bus_probe() replace it with
> exynos_bus_target.
>
> Signed-off-by: Kamil Konieczny <[email protected]>
> ---
> Changes:
> v5:
> - squashed last patch into this one, as suggested by Chanwoo Choi
> v4:
> - remove unrelated changes, add newline before comment
>
> ---
> drivers/devfreq/exynos-bus.c | 130 +++++++----------------------------
> 1 file changed, 24 insertions(+), 106 deletions(-)
>
> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
> index f34fa26f00d0..2aeb6cc07960 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;
> };
>
> @@ -93,62 +91,29 @@ static int exynos_bus_get_event(struct exynos_bus *bus,
> }
>
> /*
> - * Must necessary function for devfreq simple-ondemand governor
> + * devfreq function for both simple-ondemand and passive governor
> */
> 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;
> @@ -196,54 +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);
> -}
> -
> -/*
> - * Must necessary function for devfreq passive governor
> - */
> -static int exynos_bus_passive_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;
> - int ret = 0;
> -
> - /* Get new opp-bus instance according to new bus clock */
> - 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 = clk_set_rate(bus->clk, new_freq);
> - if (ret < 0) {
> - dev_err(dev, "failed to set the clock of bus\n");
> - goto out;
> + if (bus->opp_table) {
> + dev_pm_opp_put_regulators(bus->opp_table);
> + bus->opp_table = NULL;
> }
> -
> - *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;
> }
>
> static void exynos_bus_passive_exit(struct device *dev)
> @@ -258,21 +179,19 @@ 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 +232,11 @@ 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;
> }
> @@ -471,7 +387,7 @@ static int exynos_bus_probe(struct platform_device *pdev)
> goto out;
> passive:
> /* Initialize the struct profile and governor data for passive device */
> - profile->target = exynos_bus_passive_target;
> + profile->target = exynos_bus_target;
> profile->exit = exynos_bus_passive_exit;
>
> /* Get the instance of parent devfreq device */
> @@ -511,8 +427,10 @@ 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;
> }
>

It looks good to me.
Acked-by: Chanwoo Choi <[email protected]>


--
Best Regards,
Chanwoo Choi
Samsung Electronics