Added support for reading DTS properties to set attenuators on
device probe. Only bypasses attenuators on the ADT7476 and ADT7490
(other chips do not support this).
Signed-off-by: Logan Shaw <logan.shaw@xxxxxxxxxxxxxxxxxxx>
---
---
drivers/hwmon/adt7475.c | 73 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 73 insertions(+)
diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 6c64d50c9aae..1e6ca1bc28ce 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -19,6 +19,7 @@
#include <linux/hwmon-vid.h>
#include <linux/err.h>
#include <linux/jiffies.h>
+#include <linux/of.h>
#include <linux/util_macros.h>
/* Indexes for the sysfs hooks */
@@ -1457,6 +1458,68 @@ static int adt7475_update_limits(struct i2c_client *client)
return 0;
}
+/**
+ * Reads individual voltage input bypass attenuator properties from the DTS,
+ * and if the property is present the corresponding bit is set in the
+ * register. Only the ADT7476 and ADT7490 support bypassing individual
+ * attenuators.
+ *
+ * Properties must be in the form of "bypass-attenuator-inx", where x is an
+ * integer from the set {0, 1, 3, 4} (can not bypass in2 attenuator).
+ *
+ * Returns a negative error code if there was an error writing to the register.
+ */
+static int load_individual_bypass_attenuators(const struct i2c_client *client,
+ u8 *config4)
+{
+ u8 config4_copy = *config4;
+
+ if (of_get_property(client->dev.of_node, "bypass-attenuator-in0", NULL))
+ config4_copy |= (1 << 4);
+
+ if (of_get_property(client->dev.of_node, "bypass-attenuator-in1", NULL))
+ config4_copy |= (1 << 5);
+
+ if (of_get_property(client->dev.of_node, "bypass-attenuator-in3", NULL))
+ config4_copy |= (1 << 6);
+
+ if (of_get_property(client->dev.of_node, "bypass-attenuator-in4", NULL))
+ config4_copy |= (1 << 7);
+
+ if (i2c_smbus_write_byte_data(client, REG_CONFIG4, config4_copy) < 0)
+ return -EREMOTEIO;
+
+ *config4 = config4_copy;
+
+ return 0;
+}
+
+/**
+ * Sets the bypass all attenuators bit, if the "bypass-attenuator-all"
+ * property exists in the DTS.
+ *
+ * Returns a negative error code if there was an error writing to the
+ * register.
+ */
+static int load_all_bypass_attenuator(const struct i2c_client *client,
+ u8 *config2)
+{
+ u8 config2_copy = *config2;
+
+ if (!of_get_property(client->dev.of_node,
+ "bypass-attenuator-all", NULL))
+ return 0;
+
+ config2_copy |= (1 << 5);
+
+ if (i2c_smbus_write_byte_data(client, REG_CONFIG2, config2_copy) < 0)
+ return -EREMOTEIO;
+
+ *config2 = config2_copy;
+
+ return 0;
+}
+
static int adt7475_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -1545,7 +1608,17 @@ static int adt7475_probe(struct i2c_client *client,
}
/* Voltage attenuators can be bypassed, globally or individually */
+ if (chip == adt7476 || chip == adt7490)
+ if (load_individual_bypass_attenuators(client,
+ &(data->config4)) < 0)
+ dev_warn(&client->dev,
+ "Error setting bypass attenuator bits\n");
+
config2 = adt7475_read(REG_CONFIG2);
+ if (chip == adt7476 || chip == adt7490)
+ if (load_all_bypass_attenuator(client, &config2) < 0)
+ dev_warn(&client->dev, "Error setting bypass all attenuator\n");
+
if (config2 & CONFIG2_ATTN) {
data->bypass_attn = (0x3 << 3) | 0x3;
} else {
--
2.23.0
