[PATCH v4 2/7] pwm: tegra: Avoid hard-coded max clock frequency

Mikko Perttunen
2026-03-31T02:12:39Z

From: Yi-Wei Wang <yiweiw@nvidia.com>

The clock driving the Tegra PWM IP can be sourced from different parent
clocks. Hence, let dev_pm_opp_set_rate() set the max clock rate based
upon the current parent clock that can be specified via device-tree.

After this, the Tegra194 SoC data becomes redundant, so get rid of it.

Signed-off-by: Yi-Wei Wang <yiweiw@nvidia.com>
Co-developed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
drivers/pwm/pwm-tegra.c | 16 +++-------------
1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c
index 172063b51d44..8a330169d531 100644
--- a/drivers/pwm/pwm-tegra.c
+++ b/drivers/pwm/pwm-tegra.c
@@ -59,9 +59,6 @@

struct tegra_pwm_soc {
unsigned int num_channels;
-
- /* Maximum IP frequency for given SoCs */
- unsigned long max_frequency;
};

struct tegra_pwm_chip {
@@ -303,7 +300,7 @@ static int tegra_pwm_probe(struct platform_device *pdev)
return ret;

/* Set maximum frequency of the IP */
- ret = dev_pm_opp_set_rate(&pdev->dev, pc->soc->max_frequency);
+ ret = dev_pm_opp_set_rate(&pdev->dev, ULONG_MAX);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to set max frequency: %d\n", ret);
goto put_pm;
@@ -318,7 +315,7 @@ static int tegra_pwm_probe(struct platform_device *pdev)

/* Set minimum limit of PWM period for the IP */
pc->min_period_ns =
- (NSEC_PER_SEC / (pc->soc->max_frequency >> PWM_DUTY_WIDTH)) + 1;
+ (NSEC_PER_SEC / (pc->clk_rate >> PWM_DUTY_WIDTH)) + 1;

pc->rst = devm_reset_control_get_exclusive(&pdev->dev, "pwm");
if (IS_ERR(pc->rst)) {
@@ -397,23 +394,16 @@ static int __maybe_unused tegra_pwm_runtime_resume(struct device *dev)

static const struct tegra_pwm_soc tegra20_pwm_soc = {
.num_channels = 4,
- .max_frequency = 48000000UL,
};

static const struct tegra_pwm_soc tegra186_pwm_soc = {
.num_channels = 1,
- .max_frequency = 102000000UL,
-};
-
-static const struct tegra_pwm_soc tegra194_pwm_soc = {
- .num_channels = 1,
- .max_frequency = 408000000UL,
};

static const struct of_device_id tegra_pwm_of_match[] = {
{ .compatible = "nvidia,tegra20-pwm", .data = &tegra20_pwm_soc },
{ .compatible = "nvidia,tegra186-pwm", .data = &tegra186_pwm_soc },
- { .compatible = "nvidia,tegra194-pwm", .data = &tegra194_pwm_soc },
+ { .compatible = "nvidia,tegra194-pwm", .data = &tegra186_pwm_soc },
{ }
};
MODULE_DEVICE_TABLE(of, tegra_pwm_of_match);

--
2.53.0