Re: [PATCH v4 3/3] hwmon: (adt7475) add high frequency support

From: Guenter Roeck
Date: Mon May 15 2017 - 09:26:27 EST


On 05/14/2017 06:30 PM, Chris Packham wrote:
Systems using 4-wire fans usually require high frequency (22.5kHz)
output on the pwm. Add 22500 as a valid option in the pwmfreq_table. In
high frequency mode the low-order bit are ignored so they can safely be
set to 0.

Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>

Applied to hwmon-next.

Thanks,
Guenter

---
Changes in v3:
- New
Changes in v4:
- Fix pwmfreq_table array indexing

drivers/hwmon/adt7475.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 3056076fae27..1baa213a60bd 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -934,7 +934,7 @@ static ssize_t set_pwmctrl(struct device *dev, struct device_attribute *attr,

/* List of frequencies for the PWM */
static const int pwmfreq_table[] = {
- 11, 14, 22, 29, 35, 44, 58, 88
+ 11, 14, 22, 29, 35, 44, 58, 88, 22500
};

static ssize_t show_pwmfreq(struct device *dev, struct device_attribute *attr,
@@ -942,9 +942,10 @@ static ssize_t show_pwmfreq(struct device *dev, struct device_attribute *attr,
{
struct adt7475_data *data = adt7475_update_device(dev);
struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+ int i = clamp_val(data->range[sattr->index] & 0xf, 0,
+ ARRAY_SIZE(pwmfreq_table) - 1);

- return sprintf(buf, "%d\n",
- pwmfreq_table[data->range[sattr->index] & 7]);
+ return sprintf(buf, "%d\n", pwmfreq_table[i]);
}

static ssize_t set_pwmfreq(struct device *dev, struct device_attribute *attr,
@@ -965,7 +966,7 @@ static ssize_t set_pwmfreq(struct device *dev, struct device_attribute *attr,

data->range[sattr->index] =
adt7475_read(TEMP_TRANGE_REG(sattr->index));
- data->range[sattr->index] &= ~7;
+ data->range[sattr->index] &= ~0xf;
data->range[sattr->index] |= out;

i2c_smbus_write_byte_data(client, TEMP_TRANGE_REG(sattr->index),