diff mbox series

[v7,3/3] hwmon: (adt7475) Add support for configuring initial PWM state

Message ID 20240722221737.3407958-4-chris.packham@alliedtelesis.co.nz (mailing list archive)
State Accepted
Headers show
Series hwmon: (adt7475) duty cycle configuration | expand

Commit Message

Chris Packham July 22, 2024, 10:17 p.m. UTC
By default the PWM duty cycle in hardware is 100%. On some systems this
can cause unwanted fan noise. Add the ability to specify the fan
connections and initial state of the PWMs via device properties.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---

Notes:
    Changes in v7:
    - Use plain / for freq_hz since this can't overflow. Use div_u64 to
      avoid overflow when calculating duty.
    Changes in v6:
    - Use do_div() instead of plain /
    - Use a helper function to avoid repetition between the of and non-of
      code paths.
    Changes in v5:
    - Deal with PWM frequency and duty cycle being specified in nanoseconds
    Changes in v4:
    - Support DT and ACPI fwnodes
    - Put PWM into manual mode
    Changes in v3:
    - Use the pwm provider/consumer bindings
    Changes in v2:
    - Use correct device property string for frequency
    - Allow -EINVAL and only warn on error
    - Use a frequency of 0 to indicate that the hardware should be left as-is

 drivers/hwmon/adt7475.c | 131 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)

Comments

Guenter Roeck July 25, 2024, 2:09 p.m. UTC | #1
On Tue, Jul 23, 2024 at 10:17:37AM +1200, Chris Packham wrote:
> By default the PWM duty cycle in hardware is 100%. On some systems this
> can cause unwanted fan noise. Add the ability to specify the fan
> connections and initial state of the PWMs via device properties.
> 
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>

CHECK: Blank lines aren't necessary before a close brace '}'
#207: FILE: drivers/hwmon/adt7475.c:1734:
+
+}

Never mind, applied after fixing the above.

Thanks,
Guenter
Chris Packham July 25, 2024, 9:02 p.m. UTC | #2
On 26/07/24 02:09, Guenter Roeck wrote:
> On Tue, Jul 23, 2024 at 10:17:37AM +1200, Chris Packham wrote:
>> By default the PWM duty cycle in hardware is 100%. On some systems this
>> can cause unwanted fan noise. Add the ability to specify the fan
>> connections and initial state of the PWMs via device properties.
>>
>> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> CHECK: Blank lines aren't necessary before a close brace '}'
> #207: FILE: drivers/hwmon/adt7475.c:1734:
> +
> +}
>
> Never mind, applied after fixing the above.

Hmm, odd checkpatch.pl doesn't complain for me

$ ./scripts/checkpatch.pl 
patches/adt-init-duty/v7/v7-0003-hwmon-adt7475-Add-support-for-configuring-initial.patch 

total: 0 errors, 0 warnings, 149 lines checked

patches/adt-init-duty/v7/v7-0003-hwmon-adt7475-Add-support-for-configuring-initial.patch 
has no obvious style problems and is ready for submission.

>
> Thanks,
> Guenter
Guenter Roeck July 25, 2024, 10:01 p.m. UTC | #3
On 7/25/24 14:02, Chris Packham wrote:
> 
> On 26/07/24 02:09, Guenter Roeck wrote:
>> On Tue, Jul 23, 2024 at 10:17:37AM +1200, Chris Packham wrote:
>>> By default the PWM duty cycle in hardware is 100%. On some systems this
>>> can cause unwanted fan noise. Add the ability to specify the fan
>>> connections and initial state of the PWMs via device properties.
>>>
>>> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
>> CHECK: Blank lines aren't necessary before a close brace '}'
>> #207: FILE: drivers/hwmon/adt7475.c:1734:
>> +
>> +}
>>
>> Never mind, applied after fixing the above.
> 
> Hmm, odd checkpatch.pl doesn't complain for me
> 

This is a CHECK message. You did not use --strict.

Guenter

> $ ./scripts/checkpatch.pl
> patches/adt-init-duty/v7/v7-0003-hwmon-adt7475-Add-support-for-configuring-initial.patch
> 
> total: 0 errors, 0 warnings, 149 lines checked
> 
> patches/adt-init-duty/v7/v7-0003-hwmon-adt7475-Add-support-for-configuring-initial.patch
> has no obvious style problems and is ready for submission.
> 
>>
>> Thanks,
>> Guenter
diff mbox series

Patch

diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 4224ffb30483..2037a4b57031 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -21,6 +21,8 @@ 
 #include <linux/of.h>
 #include <linux/util_macros.h>
 
+#include <dt-bindings/pwm/pwm.h>
+
 /* Indexes for the sysfs hooks */
 
 #define INPUT		0
@@ -1662,6 +1664,131 @@  static int adt7475_set_pwm_polarity(struct i2c_client *client)
 	return 0;
 }
 
+struct adt7475_pwm_config {
+	int index;
+	int freq;
+	int flags;
+	int duty;
+};
+
+static int _adt7475_pwm_properties_parse_args(u32 args[4], struct adt7475_pwm_config *cfg)
+{
+	int freq_hz;
+	int duty;
+
+	if (args[1] == 0)
+		return -EINVAL;
+
+	freq_hz = 1000000000UL / args[1];
+	if (args[3] >= args[1])
+		duty = 255;
+	else
+		duty = div_u64(255ULL * args[3], args[1]);
+
+	cfg->index = args[0];
+	cfg->freq = find_closest(freq_hz, pwmfreq_table, ARRAY_SIZE(pwmfreq_table));
+	cfg->flags = args[2];
+	cfg->duty = duty;
+
+	return 0;
+}
+
+static int adt7475_pwm_properties_parse_reference_args(struct fwnode_handle *fwnode,
+						       struct adt7475_pwm_config *cfg)
+{
+	int ret, i;
+	struct fwnode_reference_args rargs = {};
+	u32 args[4] = {};
+
+	ret = fwnode_property_get_reference_args(fwnode, "pwms", "#pwm-cells", 0, 0, &rargs);
+	if (ret)
+		return ret;
+
+	if (rargs.nargs != 4) {
+		fwnode_handle_put(rargs.fwnode);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < 4; i++)
+		args[i] = rargs.args[i];
+
+	ret = _adt7475_pwm_properties_parse_args(args, cfg);
+
+	fwnode_handle_put(rargs.fwnode);
+
+	return ret;
+}
+
+static int adt7475_pwm_properties_parse_args(struct fwnode_handle *fwnode,
+					     struct adt7475_pwm_config *cfg)
+{
+	int ret;
+	u32 args[4] = {};
+
+	ret = fwnode_property_read_u32_array(fwnode, "pwms", args, ARRAY_SIZE(args));
+	if (ret)
+		return ret;
+
+	return _adt7475_pwm_properties_parse_args(args, cfg);
+
+}
+
+static int adt7475_fan_pwm_config(struct i2c_client *client)
+{
+	struct adt7475_data *data = i2c_get_clientdata(client);
+	struct fwnode_handle *child;
+	struct adt7475_pwm_config cfg = {};
+	int ret;
+
+	device_for_each_child_node(&client->dev, child) {
+		if (!fwnode_property_present(child, "pwms"))
+			continue;
+
+		if (is_of_node(child))
+			ret = adt7475_pwm_properties_parse_reference_args(child, &cfg);
+		else
+			ret = adt7475_pwm_properties_parse_args(child, &cfg);
+
+		if (cfg.index >= ADT7475_PWM_COUNT)
+			return -EINVAL;
+
+		ret = adt7475_read(PWM_CONFIG_REG(cfg.index));
+		if (ret < 0)
+			return ret;
+		data->pwm[CONTROL][cfg.index] = ret;
+		if (cfg.flags & PWM_POLARITY_INVERTED)
+			data->pwm[CONTROL][cfg.index] |= BIT(4);
+		else
+			data->pwm[CONTROL][cfg.index] &= ~BIT(4);
+
+		/* Force to manual mode so PWM values take effect */
+		data->pwm[CONTROL][cfg.index] &= ~0xE0;
+		data->pwm[CONTROL][cfg.index] |= 0x07 << 5;
+
+		ret = i2c_smbus_write_byte_data(client, PWM_CONFIG_REG(cfg.index),
+						data->pwm[CONTROL][cfg.index]);
+		if (ret)
+			return ret;
+
+		data->pwm[INPUT][cfg.index] = cfg.duty;
+		ret = i2c_smbus_write_byte_data(client, PWM_REG(cfg.index),
+						data->pwm[INPUT][cfg.index]);
+		if (ret)
+			return ret;
+
+		data->range[cfg.index] = adt7475_read(TEMP_TRANGE_REG(cfg.index));
+		data->range[cfg.index] &= ~0xf;
+		data->range[cfg.index] |= cfg.freq;
+
+		ret = i2c_smbus_write_byte_data(client, TEMP_TRANGE_REG(cfg.index),
+						data->range[cfg.index]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static int adt7475_probe(struct i2c_client *client)
 {
 	enum chips chip;
@@ -1778,6 +1905,10 @@  static int adt7475_probe(struct i2c_client *client)
 	if (ret && ret != -EINVAL)
 		dev_warn(&client->dev, "Error configuring pwm polarity\n");
 
+	ret = adt7475_fan_pwm_config(client);
+	if (ret)
+		dev_warn(&client->dev, "Error %d configuring fan/pwm\n", ret);
+
 	/* Start monitoring */
 	switch (chip) {
 	case adt7475: