On Mon, May 16, 2016 at 05:20:32PM +1200, Joshua Scott wrote:
> The ADT7470 supports a variety of PWM frequencies. This patch allows the
> frequency to be configured and viewed through sysfs.
>
> The valid options are:
> -> 11.0 Hz
> -> 14.7 Hz
> -> 22.1 Hz
> -> 29.4 Hz
> -> 35.3 Hz
> -> 44.1 Hz
> -> 58.8 Hz
> -> 88.2 Hz
> -> 1.4 kHz
> -> 22.5 kHz
>
Please use a standard attribute name (pwm1_freq), and the standard ABI
(frequency in Hz, no units). Sure, that means rounding for the lower
frequencies, but that is better than a non-standard ABI for which user
space applications would have to be modified and that would leave the user
guessing how exactly to provide an acceptable frequency.
Also, I strongly suggest to not expect the user to know acceptable
frequencies, but to select the closest supported frequency.
Other drivers use find_closest() or find_closest_descending(), and
the same should be possible here.
Thanks,
Guenter
> Signed-off-by: Joshua Scott <joshua.scott@xxxxxxxxxxxxxxxxxxx>
> ---
> Documentation/hwmon/adt7470 | 17 +++++
> drivers/hwmon/adt7470.c | 150 ++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 167 insertions(+)
>
> diff --git a/Documentation/hwmon/adt7470 b/Documentation/hwmon/adt7470
> index 8ce4aa0..f8a58f0 100644
> --- a/Documentation/hwmon/adt7470
> +++ b/Documentation/hwmon/adt7470
> @@ -65,6 +65,23 @@ from 0 (off) to 255 (full speed). Fan speed will be set to maximum when the
> temperature sensor associated with the PWM control exceeds
> pwm#_auto_point2_temp.
>
> +The driver also allows control of the PWM frequency:
> +
> +* pwm_freq
> +
> +The following frequencies are valid:
> +
> +* 11.0 Hz
> +* 14.7 Hz
> +* 22.1 Hz
> +* 29.4 Hz
> +* 35.3 Hz
> +* 44.1 Hz
> +* 58.8 Hz
> +* 88.2 Hz
> +* 1.4 kHz
> +* 22.5 kHz
> +
> Notes
> -----
>
> diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
> index f5da39a..e5f0d6e 100644
> --- a/drivers/hwmon/adt7470.c
> +++ b/drivers/hwmon/adt7470.c
> @@ -83,6 +83,7 @@ static const unsigned short normal_i2c[] = { 0x2C, 0x2E, 0x2F, I2C_CLIENT_END };
> #define ADT7470_REG_PWM_MIN_MAX_ADDR 0x6D
> #define ADT7470_REG_PWM_TEMP_MIN_BASE_ADDR 0x6E
> #define ADT7470_REG_PWM_TEMP_MIN_MAX_ADDR 0x71
> +#define ADT7470_REG_CFG_2 0x74
> #define ADT7470_REG_ACOUSTICS12 0x75
> #define ADT7470_REG_ACOUSTICS34 0x76
> #define ADT7470_REG_DEVICE 0x3D
> @@ -142,6 +143,32 @@ static const unsigned short normal_i2c[] = { 0x2C, 0x2E, 0x2F, I2C_CLIENT_END };
> #define FAN_PERIOD_INVALID 65535
> #define FAN_DATA_VALID(x) ((x) && (x) != FAN_PERIOD_INVALID)
>
> +/* The datasheet includes a table of available pwm frequencies
> + * controlled by values in config registers 1 and 2.
> + */
> +#define ADT7470_CFG_LF 0x40
> +#define ADT7470_FREQ_BITS 0x70
> +#define ADT7470_CFG_LF_11_0_HZ 0x00
> +#define ADT7470_CFG_LF_14_7_HZ 0x10
> +#define ADT7470_CFG_LF_22_1_HZ 0x20
> +#define ADT7470_CFG_LF_29_4_HZ 0x30
> +#define ADT7470_CFG_LF_35_3_HZ 0x40
> +#define ADT7470_CFG_LF_44_1_HZ 0x50
> +#define ADT7470_CFG_LF_58_8_HZ 0x60
> +#define ADT7470_CFG_LF_88_2_HZ 0x70
> +#define ADT7470_CFG_HF_1_4_KHZ 0x00
> +#define ADT7470_CFG_HF_22_5_KHZ 0x10
> +#define ADT7470_11_0_HZ_STR "11.0 Hz"
> +#define ADT7470_14_7_HZ_STR "14.7 Hz"
> +#define ADT7470_22_1_HZ_STR "22.1 Hz"
> +#define ADT7470_29_4_HZ_STR "29.4 Hz"
> +#define ADT7470_35_3_HZ_STR "35.3 Hz"
> +#define ADT7470_44_1_HZ_STR "44.1 Hz"
> +#define ADT7470_58_8_HZ_STR "58.8 Hz"
> +#define ADT7470_88_2_HZ_STR "88.2 Hz"
> +#define ADT7470_1_4_KHZ_STR "1.4 kHz"
> +#define ADT7470_22_5_KHZ_STR "22.5 kHz"
> +
> struct adt7470_data {
> struct i2c_client *client;
> struct mutex lock;
> @@ -688,6 +715,126 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr,
> return count;
> }
>
> +static ssize_t show_pwm_freq(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct adt7470_data *data = adt7470_update_device(dev);
> + unsigned char cfg_reg_1;
> + unsigned char cfg_reg_2;
> + char *freq = "invalid";
> +
> + mutex_lock(&data->lock);
> + cfg_reg_1 = i2c_smbus_read_byte_data(data->client, ADT7470_REG_CFG);
> + cfg_reg_2 = i2c_smbus_read_byte_data(data->client, ADT7470_REG_CFG_2);
> + mutex_unlock(&data->lock);
> +
> + if (cfg_reg_1 & ADT7470_CFG_LF)
> + switch (cfg_reg_2 & ADT7470_FREQ_BITS) {
> + case ADT7470_CFG_LF_11_0_HZ:
> + freq = ADT7470_11_0_HZ_STR;
> + break;
> + case ADT7470_CFG_LF_14_7_HZ:
> + freq = ADT7470_14_7_HZ_STR;
> + break;
> + case ADT7470_CFG_LF_22_1_HZ:
> + freq = ADT7470_22_1_HZ_STR;
> + break;
> + case ADT7470_CFG_LF_29_4_HZ:
> + freq = ADT7470_29_4_HZ_STR;
> + break;
> + case ADT7470_CFG_LF_35_3_HZ:
> + freq = ADT7470_35_3_HZ_STR;
> + break;
> + case ADT7470_CFG_LF_44_1_HZ:
> + freq = ADT7470_44_1_HZ_STR;
> + break;
> + case ADT7470_CFG_LF_58_8_HZ:
> + freq = ADT7470_58_8_HZ_STR;
> + break;
> + case ADT7470_CFG_LF_88_2_HZ:
> + freq = ADT7470_88_2_HZ_STR;
> + break;
> + }
> + else
> + switch (cfg_reg_2 & ADT7470_FREQ_BITS) {
> + case ADT7470_CFG_HF_1_4_KHZ:
> + freq = ADT7470_1_4_KHZ_STR;
> + break;
> + default:
> + freq = ADT7470_22_5_KHZ_STR;
> + break;
> + }
> + return scnprintf(buf, PAGE_SIZE, "%s\n", freq);
> +}
> +
> +static ssize_t set_pwm_freq(struct device *dev,
> + struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + struct adt7470_data *data = dev_get_drvdata(dev);
> + struct i2c_client *client = data->client;
> + int low_freq = ADT7470_CFG_LF;
> + int freq_bits;
> + unsigned char val;
> +
> + if (!strncmp(ADT7470_11_0_HZ_STR, buf, strlen(ADT7470_11_0_HZ_STR)))
> + freq_bits = ADT7470_CFG_LF_11_0_HZ;
> +
> + else if (!strncmp(ADT7470_14_7_HZ_STR, buf,
> + strlen(ADT7470_14_7_HZ_STR)))
> + freq_bits = ADT7470_CFG_LF_14_7_HZ;
> +
> + else if (!strncmp(ADT7470_22_1_HZ_STR, buf,
> + strlen(ADT7470_22_1_HZ_STR)))
> + freq_bits = ADT7470_CFG_LF_22_1_HZ;
> +
> + else if (!strncmp(ADT7470_29_4_HZ_STR, buf,
> + strlen(ADT7470_29_4_HZ_STR)))
> + freq_bits = ADT7470_CFG_LF_29_4_HZ;
> +
> + else if (!strncmp(ADT7470_35_3_HZ_STR, buf,
> + strlen(ADT7470_35_3_HZ_STR)))
> + freq_bits = ADT7470_CFG_LF_35_3_HZ;
> +
> + else if (!strncmp(ADT7470_44_1_HZ_STR, buf,
> + strlen(ADT7470_44_1_HZ_STR)))
> + freq_bits = ADT7470_CFG_LF_44_1_HZ;
> +
> + else if (!strncmp(ADT7470_58_8_HZ_STR, buf,
> + strlen(ADT7470_58_8_HZ_STR)))
> + freq_bits = ADT7470_CFG_LF_58_8_HZ;
> +
> + else if (!strncmp(ADT7470_88_2_HZ_STR, buf,
> + strlen(ADT7470_88_2_HZ_STR)))
> + freq_bits = ADT7470_CFG_LF_88_2_HZ;
> +
> + else if (!strncmp(ADT7470_1_4_KHZ_STR, buf,
> + strlen(ADT7470_1_4_KHZ_STR))) {
> + freq_bits = ADT7470_CFG_HF_1_4_KHZ;
> + low_freq = 0;
> +
> + } else if (!strncmp(ADT7470_22_5_KHZ_STR, buf,
> + strlen(ADT7470_22_5_KHZ_STR))) {
> + freq_bits = ADT7470_CFG_HF_22_5_KHZ;
> + low_freq = 0;
> +
> + } else
> + return -EINVAL;
> +
> + mutex_lock(&data->lock);
> + /* Configuration Register 1 */
> + val = i2c_smbus_read_byte_data(client, ADT7470_REG_CFG);
> + i2c_smbus_write_byte_data(client, ADT7470_REG_CFG,
> + (val & ~ADT7470_CFG_LF) | low_freq);
> + /* Configuration Register 2 */
> + val = i2c_smbus_read_byte_data(client, ADT7470_REG_CFG_2);
> + i2c_smbus_write_byte_data(client, ADT7470_REG_CFG_2,
> + (val & ~ADT7470_FREQ_BITS) | freq_bits);
> + mutex_unlock(&data->lock);
> +
> + return count;
> +}
> +
> static ssize_t show_pwm_max(struct device *dev,
> struct device_attribute *devattr,
> char *buf)
> @@ -1038,6 +1185,8 @@ static SENSOR_DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 1);
> static SENSOR_DEVICE_ATTR(pwm3, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 2);
> static SENSOR_DEVICE_ATTR(pwm4, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 3);
>
> +static DEVICE_ATTR(pwm_freq, S_IWUSR | S_IRUGO, show_pwm_freq, set_pwm_freq);
> +
> static SENSOR_DEVICE_ATTR(pwm1_auto_point1_pwm, S_IWUSR | S_IRUGO,
> show_pwm_min, set_pwm_min, 0);
> static SENSOR_DEVICE_ATTR(pwm2_auto_point1_pwm, S_IWUSR | S_IRUGO,
> @@ -1096,6 +1245,7 @@ static struct attribute *adt7470_attrs[] = {
> &dev_attr_alarm_mask.attr,
> &dev_attr_num_temp_sensors.attr,
> &dev_attr_auto_update_interval.attr,
> + &dev_attr_pwm_freq.attr,
> &sensor_dev_attr_temp1_max.dev_attr.attr,
> &sensor_dev_attr_temp2_max.dev_attr.attr,
> &sensor_dev_attr_temp3_max.dev_attr.attr,
> --
> 2.8.1
>
--
To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
