[PATCH v7 5/8] clk: qcom: gdsc: enable optional power domain support

Dmitry Baryshkov
2021-08-29T15:48:10Z

On sm8250 dispcc and videocc registers are powered up by the MMCX power
domain. Currently we use a regulator to enable this domain on demand,
however this has some consequences, as genpd code is not reentrant.

Make gdsc code also use pm_runtime calls to ensure that registers are
accessible during the gdsc_enable/gdsc_disable operations.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
drivers/clk/qcom/gdsc.c | 51 ++++++++++++++++++++++++++++++++++++++---
drivers/clk/qcom/gdsc.h | 2 ++
2 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
index 4ece326ea233..7e1dd8ccfa38 100644
--- a/drivers/clk/qcom/gdsc.c
+++ b/drivers/clk/qcom/gdsc.c
@@ -11,6 +11,7 @@
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/reset-controller.h>
@@ -50,6 +51,22 @@ enum gdsc_status {
GDSC_ON
};

+static int gdsc_pm_runtime_get(struct gdsc *sc)
+{
+ if (!sc->dev)
+ return 0;
+
+ return pm_runtime_resume_and_get(sc->dev);
+}
+
+static int gdsc_pm_runtime_put(struct gdsc *sc)
+{
+ if (!sc->dev)
+ return 0;
+
+ return pm_runtime_put_sync(sc->dev);
+}
+
/* Returns 1 if GDSC status is status, 0 if not, and < 0 on error */
static int gdsc_check_status(struct gdsc *sc, enum gdsc_status status)
{
@@ -232,9 +249,8 @@ static void gdsc_retain_ff_on(struct gdsc *sc)
regmap_update_bits(sc->regmap, sc->gdscr, mask, mask);
}

-static int gdsc_enable(struct generic_pm_domain *domain)
+static int _gdsc_enable(struct gdsc *sc)
{
- struct gdsc *sc = domain_to_gdsc(domain);
int ret;

if (sc->pwrsts == PWRSTS_ON)
@@ -290,11 +306,22 @@ static int gdsc_enable(struct generic_pm_domain *domain)
return 0;
}

-static int gdsc_disable(struct generic_pm_domain *domain)
+static int gdsc_enable(struct generic_pm_domain *domain)
{
struct gdsc *sc = domain_to_gdsc(domain);
int ret;

+ ret = gdsc_pm_runtime_get(sc);
+ if (ret)
+ return ret;
+
+ return _gdsc_enable(sc);
+}
+
+static int _gdsc_disable(struct gdsc *sc)
+{
+ int ret;
+
if (sc->pwrsts == PWRSTS_ON)
return gdsc_assert_reset(sc);

@@ -329,6 +356,18 @@ static int gdsc_disable(struct generic_pm_domain *domain)
return 0;
}

+static int gdsc_disable(struct generic_pm_domain *domain)
+{
+ struct gdsc *sc = domain_to_gdsc(domain);
+ int ret;
+
+ ret = _gdsc_disable(sc);
+
+ gdsc_pm_runtime_put(sc);
+
+ return ret;
+}
+
static int gdsc_init(struct gdsc *sc)
{
u32 mask, val;
@@ -443,6 +482,8 @@ int gdsc_register(struct gdsc_desc *desc,
for (i = 0; i < num; i++) {
if (!scs[i])
continue;
+ if (pm_runtime_enabled(dev))
+ scs[i]->dev = dev;
scs[i]->regmap = regmap;
scs[i]->rcdev = rcdev;
ret = gdsc_init(scs[i]);
@@ -457,6 +498,8 @@ int gdsc_register(struct gdsc_desc *desc,
continue;
if (scs[i]->parent)
pm_genpd_add_subdomain(scs[i]->parent, &scs[i]->pd);
+ else if (!IS_ERR_OR_NULL(dev->pm_domain))
+ pm_genpd_add_subdomain(pd_to_genpd(dev->pm_domain), &scs[i]->pd);
}

return of_genpd_add_provider_onecell(dev->of_node, data);
@@ -475,6 +518,8 @@ void gdsc_unregister(struct gdsc_desc *desc)
continue;
if (scs[i]->parent)
pm_genpd_remove_subdomain(scs[i]->parent, &scs[i]->pd);
+ else if (!IS_ERR_OR_NULL(dev->pm_domain))
+ pm_genpd_remove_subdomain(pd_to_genpd(dev->pm_domain), &scs[i]->pd);
}
of_genpd_del_provider(dev->of_node);
}
diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h
index 5bb396b344d1..702d47a87af6 100644
--- a/drivers/clk/qcom/gdsc.h
+++ b/drivers/clk/qcom/gdsc.h
@@ -25,6 +25,7 @@ struct reset_controller_dev;
* @resets: ids of resets associated with this gdsc
* @reset_count: number of @resets
* @rcdev: reset controller
+ * @dev: the device holding the GDSC, used for pm_runtime calls
*/
struct gdsc {
struct generic_pm_domain pd;
@@ -58,6 +59,7 @@ struct gdsc {

const char *supply;
struct regulator *rsupply;
+ struct device *dev;
};

struct gdsc_desc {
--
2.33.0