hwmon: (pmbus/xdpe12284) Add callback for vout limits conversion

Provide read_word_data() callback for overvoltage and undervoltage
output readouts conversion. These registers are presented in
'slinear11' format, while default conversion for 'vout' class for the
devices is 'vid'. It is resulted in wrong conversion in pmbus_reg2data()
for in{3-4}_lcrit and in{3-4}_crit attributes.
)
Fixes: aaafb7c8 ("hwmon: (pmbus) Add support for Infineon Multi-phase xdpe122 family controllers")
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Link: https://lore.kernel.org/r/20200224225202.19576-1-vadimp@mellanox.com
[gropeck: Adjusted to mainline PMBus API]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/pmbus/xdpe12284.c

@@ -18,6 +18,59 @@
 #define XDPE122_AMD_625MV		0x10 /* AMD mode 6.25mV */
 #define XDPE122_PAGE_NUM		2
 
+static int xdpe122_read_word_data(struct i2c_client *client, int page, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	long val;
+	s16 exponent;
+	s32 mantissa;
+	int ret;
+
+	switch (reg) {
+	case PMBUS_VOUT_OV_FAULT_LIMIT:
+	case PMBUS_VOUT_UV_FAULT_LIMIT:
+		ret = pmbus_read_word_data(client, page, reg);
+		if (ret < 0)
+			return ret;
+
+		/* Convert register value to LINEAR11 data. */
+		exponent = ((s16)ret) >> 11;
+		mantissa = ((s16)((ret & GENMASK(10, 0)) << 5)) >> 5;
+		val = mantissa * 1000L;
+		if (exponent >= 0)
+			val <<= exponent;
+		else
+			val >>= -exponent;
+
+		/* Convert data to VID register. */
+		switch (info->vrm_version[page]) {
+		case vr13:
+			if (val >= 500)
+				return 1 + DIV_ROUND_CLOSEST(val - 500, 10);
+			return 0;
+		case vr12:
+			if (val >= 250)
+				return 1 + DIV_ROUND_CLOSEST(val - 250, 5);
+			return 0;
+		case imvp9:
+			if (val >= 200)
+				return 1 + DIV_ROUND_CLOSEST(val - 200, 10);
+			return 0;
+		case amd625mv:
+			if (val >= 200 && val <= 1550)
+				return DIV_ROUND_CLOSEST((1550 - val) * 100,
+							 625);
+			return 0;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -ENODATA;
+	}
+
+	return 0;
+}
+
 static int xdpe122_identify(struct i2c_client *client,
 			    struct pmbus_driver_info *info)
 {
@@ -70,6 +123,7 @@ static struct pmbus_driver_info xdpe122_info = {
 		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
 		PMBUS_HAVE_POUT | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT,
 	.identify = xdpe122_identify,
+	.read_word_data = xdpe122_read_word_data,
 };
 
 static int xdpe122_probe(struct i2c_client *client,