The ADT7470 supports a variety of PWM frequencies. This patch allows the
frequency to be configured and viewed through the sysfs entry pwm1_freq.
Signed-off-by: Joshua Scott <joshua.scott@xxxxxxxxxxxxxxxxxxx>
---
Documentation/hwmon/adt7470 | 17 +++++
drivers/hwmon/adt7470.c | 149 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 166 insertions(+)
diff --git a/Documentation/hwmon/adt7470 b/Documentation/hwmon/adt7470
index 8ce4aa0..fe68e18 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:
+
+* pwm1_freq
+
+The PWM frequency is rounded to the nearest one of:
+
+* 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..f57026f 100644
--- a/drivers/hwmon/adt7470.c
+++ b/drivers/hwmon/adt7470.c
@@ -32,6 +32,7 @@
#include <linux/log2.h>
#include <linux/kthread.h>
#include <linux/slab.h>
+#include <linux/util_macros.h>
/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x2C, 0x2E, 0x2F, I2C_CLIENT_END };
@@ -83,6 +84,7 @@ 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 +144,22 @@ 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
+
struct adt7470_data {
struct i2c_client *client;
struct mutex lock;
@@ -688,6 +706,134 @@ 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;
+ int freq = -EINVAL;
+
+ 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 = 11;
+ break;
+ case ADT7470_CFG_LF_14_7_HZ:
+ freq = 15;
+ break;
+ case ADT7470_CFG_LF_22_1_HZ:
+ freq = 22;
+ break;
+ case ADT7470_CFG_LF_29_4_HZ:
+ freq = 29;
+ break;
+ case ADT7470_CFG_LF_35_3_HZ:
+ freq = 35;
+ break;
+ case ADT7470_CFG_LF_44_1_HZ:
+ freq = 44;
+ break;
+ case ADT7470_CFG_LF_58_8_HZ:
+ freq = 59;
+ break;
+ case ADT7470_CFG_LF_88_2_HZ:
+ freq = 88;
+ break;
+ }
+ else
+ switch (cfg_reg_2 & ADT7470_FREQ_BITS) {
+ case ADT7470_CFG_HF_1_4_KHZ:
+ freq = 1400;
+ break;
+ default:
+ freq = 22500;
+ break;
+ }
+ return scnprintf(buf, PAGE_SIZE, "%d\n", freq);
+}
+
+/* These are the valid PWM frequencies to the nearest Hz */
+static const int adt7470_freq_map[] = {
+ 11, 15, 22, 29, 35, 44, 59, 88, 1400, 22500
+};
+
+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;
+ long freq;
+ int freq_index;
+ int low_freq = ADT7470_CFG_LF;
+ int freq_bits;
+ unsigned char val;
+
+ if (kstrtol(buf, 10, &freq))
+ return -EINVAL;
+
+ /* Round the user value given to the closest available frequency */
+ freq_index = find_closest(freq, adt7470_freq_map,
+ ARRAY_SIZE(adt7470_freq_map));
+ freq = adt7470_freq_map[freq_index];
+
+ switch (freq) {
+ case 11:
+ freq_bits = ADT7470_CFG_LF_11_0_HZ;
+ break;
+ case 15:
+ freq_bits = ADT7470_CFG_LF_14_7_HZ;
+ break;
+ case 22:
+ freq_bits = ADT7470_CFG_LF_22_1_HZ;
+ break;
+ case 29:
+ freq_bits = ADT7470_CFG_LF_29_4_HZ;
+ break;
+ case 35:
+ freq_bits = ADT7470_CFG_LF_35_3_HZ;
+ break;
+ case 44:
+ freq_bits = ADT7470_CFG_LF_44_1_HZ;
+ break;
+ case 59:
+ freq_bits = ADT7470_CFG_LF_58_8_HZ;
+ break;
+ case 88:
+ freq_bits = ADT7470_CFG_LF_88_2_HZ;
+ break;
+ case 1400:
+ freq_bits = ADT7470_CFG_HF_1_4_KHZ;
+ low_freq = 0;
+ break;
+ case 22500:
+ freq_bits = ADT7470_CFG_HF_22_5_KHZ;
+ low_freq = 0;
+ break;
+ default:
+ 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 +1184,8 @@ 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(pwm1_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 +1244,7 @@ static struct attribute *adt7470_attrs[] = {
&dev_attr_alarm_mask.attr,
&dev_attr_num_temp_sensors.attr,
&dev_attr_auto_update_interval.attr,
+ &dev_attr_pwm1_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,
--
2.9.0
--
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