From: Peter Korsgaard <peter@korsgaard.com>
To: linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org,
Guenter Roeck <linux@roeck-us.net>
Cc: Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Peter Korsgaard <peter@korsgaard.com>
Subject: [PATCH v2 2/2] hwmon: (pwm-fan): support default-pwm property to set default PWM value
Date: Wed, 24 Apr 2024 22:24:48 +0200 [thread overview]
Message-ID: <20240424202448.19033-2-peter@korsgaard.com> (raw)
In-Reply-To: <20240424202448.19033-1-peter@korsgaard.com>
For some use cases defaulting the PWM to full fan speed is not ideal
(noise, power consumption, ..), so support an optional default-pwm
property (0..255) to override the default PWM value.
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
---
Changes since v1:
- Rename property to default-pwm
- Drop u32 cast
drivers/hwmon/pwm-fan.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index b67bc9e833c0..a2a309f8e3ee 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -482,6 +482,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
const struct hwmon_channel_info **channels;
u32 *fan_channel_config;
int channel_count = 1; /* We always have a PWM channel. */
+ u32 default_pwm = MAX_PWM;
int i;
ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
@@ -527,11 +528,17 @@ static int pwm_fan_probe(struct platform_device *pdev)
ctx->enable_mode = pwm_disable_reg_enable;
+ of_property_read_u32(dev->of_node, "default-pwm", &default_pwm);
+ if (default_pwm > MAX_PWM) {
+ dev_err(dev, "Invalid default-pwm: %u > %d\n", default_pwm, MAX_PWM);
+ return -EINVAL;
+ }
+
/*
- * Set duty cycle to maximum allowed and enable PWM output as well as
+ * Set duty cycle to default and enable PWM output as well as
* the regulator. In case of error nothing is changed
*/
- ret = set_pwm(ctx, MAX_PWM);
+ ret = set_pwm(ctx, default_pwm);
if (ret) {
dev_err(dev, "Failed to configure PWM: %d\n", ret);
return ret;
--
2.39.2
next prev parent reply other threads:[~2024-04-24 20:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-24 20:24 [PATCH v2 1/2] dt-bindings: hwmon: pwm-fan: Document default-pwm property Peter Korsgaard
2024-04-24 20:24 ` Peter Korsgaard [this message]
2024-04-25 16:18 ` Rob Herring
2024-04-25 20:21 ` Peter Korsgaard
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