Re: [PATCH 2/2] hwmon: (pmbus): Add driver for BluTek BPA-RS600

On 16/03/21 4:43 pm, Guenter Roeck wrote:

On 3/15/21 7:35 PM, Chris Packham wrote:

quoted

The BPA-RS600 is a compact 600W AC to DC removable power supply module.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---

<snip>

quoted

+
+static int bpa_rs600_read_word_data(struct i2c_client *client, int page,
+		int phase, int reg)+{
+	int ret;
+
+	if (page > 0)
+		return -ENXIO;
+
+	switch (reg) {
+	case PMBUS_VIN_UV_FAULT_LIMIT:
+	case PMBUS_VIN_OV_FAULT_LIMIT:
+	case PMBUS_VOUT_UV_FAULT_LIMIT:
+	case PMBUS_VOUT_OV_FAULT_LIMIT:
+		ret = -ENXIO;

Is that needed ? Why not -ENODATA ?

Basically these commands get responses on the bus but they don't have 
valid data (nor are they documented in the datasheet). I'll add a 
comment to that effect.

If I'm reading things correctly -ENODATA is a signal to 
_pmbus_read_word_data use the "normal" read operation. So I need to 
return something other than that. I found another driver (mp2975.c) 
doing the same thing for what I assume are similar reasons so I went 
with -ENXIO.

quoted

+		break;

<snip>

+

quoted

+static const struct i2c_device_id bpa_rs600_id[] = {
+	{ "bpa_rs600", 0 },

Hmm, no, this has an underscore. Guess you'll have to use the trick from
iio_hwmon.c or similar to generate a valid name.

Oh, wait, this is a pmbus driver, and the pmbus core uses client->name.
Maybe we need to add an optional strreplace() to the pmbus core.

Looking into this now.