[Patch v2] cpufreq: tegra194: remove opp table in exit hook

[Sumit Gupta <sumitg@nvidia.com>]

Add exit hook and remove OPP table when the device gets unregistered.
This will fix the error messages when the CPU FREQ driver module is
removed and then re-inserted. It also fixes these messages while
onlining the first CPU from a policy whose all CPU's were previously
offlined.

 debugfs: File 'cpu5' in directory 'opp' already present!
 debugfs: File 'cpu6' in directory 'opp' already present!
 debugfs: File 'cpu7' in directory 'opp' already present!

Fixes: f41e1442ac5b ("cpufreq: tegra194: add OPP support and set bandwidth")
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
---

v1[1] -> v2:
- updated commit description.

[1] https://lore.kernel.org/lkml/20230809153455.29056-1-sumitg@nvidia.com/

 drivers/cpufreq/tegra194-cpufreq.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/cpufreq/tegra194-cpufreq.c b/drivers/cpufreq/tegra194-cpufreq.c
index c90b30469165..66a9c23544db 100644
--- a/drivers/cpufreq/tegra194-cpufreq.c
+++ b/drivers/cpufreq/tegra194-cpufreq.c
@@ -454,6 +454,8 @@ static int tegra_cpufreq_init_cpufreq_table(struct cpufreq_policy *policy,
 		if (ret < 0)
 			return ret;
 
+		dev_pm_opp_put(opp);
+
 		freq_table[j].driver_data = pos->driver_data;
 		freq_table[j].frequency = pos->frequency;
 		j++;
@@ -508,6 +510,16 @@ static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
 	return 0;
 }
 
+static int tegra194_cpufreq_exit(struct cpufreq_policy *policy)
+{
+	struct device *cpu_dev = get_cpu_device(policy->cpu);
+
+	dev_pm_opp_remove_all_dynamic(cpu_dev);
+	dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
+
+	return 0;
+}
+
 static int tegra194_cpufreq_set_target(struct cpufreq_policy *policy,
 				       unsigned int index)
 {
@@ -535,6 +547,7 @@ static struct cpufreq_driver tegra194_cpufreq_driver = {
 	.target_index = tegra194_cpufreq_set_target,
 	.get = tegra194_get_speed,
 	.init = tegra194_cpufreq_init,
+	.exit = tegra194_cpufreq_exit,
 	.attr = cpufreq_generic_attr,
 };
 
-- 
2.17.1