[RFC v2 02/11] OPP: Make dev_pm_opp_set_rate() with freq=0 as valid

Rajendra Nayak
2019-03-20T09:49:49Z

For devices with performance state, we use dev_pm_opp_set_rate()
to set the appropriate clk rate and the performance state.
We do need a way to *remove* the performance state vote when
we idle the device and turn the clocks off. Use dev_pm_opp_set_rate()
with freq=0 to achieve this.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
drivers/opp/core.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index bc9a7762dd4c..d6acc880676e 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -708,18 +708,24 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
struct clk *clk;
int ret;

- if (unlikely(!target_freq)) {
- dev_err(dev, "%s: Invalid target frequency %lu\n", __func__,
- target_freq);
- return -EINVAL;
- }
-
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
dev_err(dev, "%s: device opp doesn't exist\n", __func__);
return PTR_ERR(opp_table);
}

+ if (unlikely(!target_freq)) {
+ if (opp_table->required_opp_tables) {
+ /* drop the performance state vote */
+ dev_pm_genpd_set_performance_state(dev, 0);
+ return 0;
+ } else {
+ dev_err(dev, "%s: Invalid target frequency %lu\n", __func__,
+ target_freq);
+ return -EINVAL;
+ }
+ }
+
clk = opp_table->clk;
if (IS_ERR(clk)) {
dev_err(dev, "%s: No clock available for the device\n",