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PM / devfreq: exynos-bus: Convert to use dev_pm_opp_set_rate()
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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]>
Acked-by: Chanwoo Choi <[email protected]>
Signed-off-by: MyungJoo Ham <[email protected]>
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@myungjoo
Kamil Konieczny authored and myungjoo committed Aug 25, 2019
1 parent 2c2b20e commit 4294a77
Showing 1 changed file with 24 additions and 106 deletions.
130 changes: 24 additions & 106 deletions drivers/devfreq/exynos-bus.c
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Original file line number Diff line number Diff line change
Expand Up @@ -22,7 +22,6 @@
#include <linux/slab.h>

#define DEFAULT_SATURATION_RATIO 40
#define DEFAULT_VOLTAGE_TOLERANCE 2

struct exynos_bus {
struct device *dev;
Expand All @@ -34,9 +33,8 @@ 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;
};

Expand Down Expand Up @@ -90,62 +88,29 @@ 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;
Expand Down Expand Up @@ -193,54 +158,10 @@ 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)
Expand All @@ -255,21 +176,19 @@ 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.
Expand Down Expand Up @@ -310,14 +229,11 @@ 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;
}
Expand Down Expand Up @@ -468,7 +384,7 @@ 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 */
Expand Down Expand Up @@ -508,8 +424,10 @@ 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;
}
Expand Down

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