[PATCH 4/5] soc/tegra: pmc: Implement acquire/release for resets

From: Thierry Reding
Date: Thu Feb 21 2019 - 10:26:09 EST


From: Thierry Reding <treding@xxxxxxxxxx>

By implementing the acquire/release protocol, the resets can be shared
with other drivers that also adhere to this protocol. This will be used
for example by the SOR driver to put hardware into a known good state,
irrespective of whether or not the power domain can be reset.

Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
drivers/soc/tegra/pmc.c | 39 +++++++++++++++++++++++++++++++++------
1 file changed, 33 insertions(+), 6 deletions(-)

diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index 0df258518693..0c5f79528e5f 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -656,10 +656,15 @@ static int tegra_genpd_power_on(struct generic_pm_domain *domain)
int err;

err = tegra_powergate_power_up(pg, true);
- if (err)
+ if (err) {
dev_err(dev, "failed to turn on PM domain %s: %d\n",
pg->genpd.name, err);
+ goto out;
+ }

+ reset_control_release(pg->reset);
+
+out:
return err;
}

@@ -669,10 +674,18 @@ static int tegra_genpd_power_off(struct generic_pm_domain *domain)
struct device *dev = pg->pmc->dev;
int err;

+ err = reset_control_acquire(pg->reset);
+ if (err < 0) {
+ pr_err("failed to acquire resets: %d\n", err);
+ return err;
+ }
+
err = tegra_powergate_power_down(pg);
- if (err)
+ if (err) {
dev_err(dev, "failed to turn off PM domain %s: %d\n",
pg->genpd.name, err);
+ reset_control_release(pg->reset);
+ }

return err;
}
@@ -937,20 +950,34 @@ static int tegra_powergate_of_get_resets(struct tegra_powergate *pg,
struct device *dev = pg->pmc->dev;
int err;

- pg->reset = of_reset_control_array_get_exclusive(np);
+ pg->reset = of_reset_control_array_get_exclusive_released(np);
if (IS_ERR(pg->reset)) {
err = PTR_ERR(pg->reset);
dev_err(dev, "failed to get device resets: %d\n", err);
return err;
}

- if (off)
+ err = reset_control_acquire(pg->reset);
+ if (err < 0) {
+ pr_err("failed to acquire resets: %d\n", err);
+ goto out;
+ }
+
+ if (off) {
err = reset_control_assert(pg->reset);
- else
+ } else {
err = reset_control_deassert(pg->reset);
+ if (err < 0)
+ goto out;

- if (err)
+ reset_control_release(pg->reset);
+ }
+
+out:
+ if (err) {
+ reset_control_release(pg->reset);
reset_control_put(pg->reset);
+ }

return err;
}
--
2.20.1