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authorChris Packham <chris.packham@alliedtelesis.co.nz>2020-02-27 09:46:42 +0100
committerGuenter Roeck <linux@roeck-us.net>2020-03-09 04:35:48 +0100
commit86da28eed4fbc64dfdc386337f6cbac36c9c1ed2 (patch)
treed456e32a696fda4bc1862664779e677072bb10ad /drivers/hwmon
parenthwmon: (adt7475) Add attenuator bypass support (diff)
downloadlinux-86da28eed4fbc64dfdc386337f6cbac36c9c1ed2.tar.xz
linux-86da28eed4fbc64dfdc386337f6cbac36c9c1ed2.zip
hwmon: (adt7475) Add support for inverting pwm output
Add a "adi,pwm-active-state" device-tree property to allow hardware designs to use inverted logic on the PWM output. Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> [groeck: dev_err -> dev_warn] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/adt7475.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 79e50e6aa94e..054080443b47 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -1509,6 +1509,36 @@ static int load_attenuators(const struct i2c_client *client, int chip,
return 0;
}
+static int adt7475_set_pwm_polarity(struct i2c_client *client)
+{
+ u32 states[ADT7475_PWM_COUNT];
+ int ret, i;
+ u8 val;
+
+ ret = of_property_read_u32_array(client->dev.of_node,
+ "adi,pwm-active-state", states,
+ ARRAY_SIZE(states));
+ if (ret)
+ return ret;
+
+ for (i = 0; i < ADT7475_PWM_COUNT; i++) {
+ ret = adt7475_read(PWM_CONFIG_REG(i));
+ if (ret < 0)
+ return ret;
+ val = ret;
+ if (states[i])
+ val &= ~BIT(4);
+ else
+ val |= BIT(4);
+
+ ret = i2c_smbus_write_byte_data(client, PWM_CONFIG_REG(i), val);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
static int adt7475_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -1617,6 +1647,10 @@ static int adt7475_probe(struct i2c_client *client,
for (i = 0; i < ADT7475_PWM_COUNT; i++)
adt7475_read_pwm(client, i);
+ ret = adt7475_set_pwm_polarity(client);
+ if (ret && ret != -EINVAL)
+ dev_warn(&client->dev, "Error configuring pwm polarity\n");
+
/* Start monitoring */
switch (chip) {
case adt7475: