hwmon: (pmbus/adm1275) Fix power sampling support

Not every chip supported by this driver supports setting the number
of samples for power averaging. Also, the power monitoring register
is not always a 16-bit register, and the configuration bits used for
voltage sampling are different depending on the register width.
Some conditional code is needed to fix the problem.

On top of all that, the compiler complains about problems with
FIELD_GET and FIELD_PREP macros if the file is built with W=1.
Avoid using those macros to silence the warning.

Cc: Krzysztof Adamski <[e-mail]>
Cc: Alexander Sverdlin <[e-mail]>
Reviewed-by: Krzysztof Adamski <[e-mail]>
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/pmbus/adm1275.c

···
 #define ADM1075_VAUX_OV_WARN		BIT(7)
 #define ADM1075_VAUX_UV_WARN		BIT(6)
 
-#define ADM1275_PWR_AVG_MASK		GENMASK(13, 11)
-#define ADM1275_VI_AVG_MASK		GENMASK(10, 8)
-#define ADM1275_SAMPLES_AVG_MAX	128
+#define ADM1275_VI_AVG_SHIFT		0
+#define ADM1275_VI_AVG_MASK		GENMASK(ADM1275_VI_AVG_SHIFT + 2, \
+						ADM1275_VI_AVG_SHIFT)
+#define ADM1275_SAMPLES_AVG_MAX		128
+
+#define ADM1278_PWR_AVG_SHIFT		11
+#define ADM1278_PWR_AVG_MASK		GENMASK(ADM1278_PWR_AVG_SHIFT + 2, \
+						ADM1278_PWR_AVG_SHIFT)
+#define ADM1278_VI_AVG_SHIFT		8
+#define ADM1278_VI_AVG_MASK		GENMASK(ADM1278_VI_AVG_SHIFT + 2, \
+						ADM1278_VI_AVG_SHIFT)
 
 struct adm1275_data {
 	int id;
···
 	bool have_pin_min;
 	bool have_pin_max;
 	bool have_temp_max;
+	bool have_power_sampling;
 	struct pmbus_driver_info info;
 };
 
···
 	[18] = { 7658, 0, -3 },		/* power, 21V, irange200 */
 };
 
-static inline int adm1275_read_pmon_config(struct i2c_client *client, u16 mask)
+static int adm1275_read_pmon_config(const struct adm1275_data *data,
+				    struct i2c_client *client, bool is_power)
 {
-	int ret;
+	int shift, ret;
+	u16 mask;
 
-	ret = i2c_smbus_read_word_data(client, ADM1275_PMON_CONFIG);
+	/*
+	 * The PMON configuration register is a 16-bit register only on chips
+	 * supporting power average sampling. On other chips it is an 8-bit
+	 * register.
+	 */
+	if (data->have_power_sampling) {
+		ret = i2c_smbus_read_word_data(client, ADM1275_PMON_CONFIG);
+		mask = is_power ? ADM1278_PWR_AVG_MASK : ADM1278_VI_AVG_MASK;
+		shift = is_power ? ADM1278_PWR_AVG_SHIFT : ADM1278_VI_AVG_SHIFT;
+	} else {
+		ret = i2c_smbus_read_byte_data(client, ADM1275_PMON_CONFIG);
+		mask = ADM1275_VI_AVG_MASK;
+		shift = ADM1275_VI_AVG_SHIFT;
+	}
 	if (ret < 0)
 		return ret;
 
-	return FIELD_GET(mask, (u16)ret);
+	return (ret & mask) >> shift;
 }
 
-static inline int adm1275_write_pmon_config(struct i2c_client *client, u16 mask,
-					    u16 word)
+static int adm1275_write_pmon_config(const struct adm1275_data *data,
+				     struct i2c_client *client,
+				     bool is_power, u16 word)
 {
-	int ret;
+	int shift, ret;
+	u16 mask;
 
-	ret = i2c_smbus_read_word_data(client, ADM1275_PMON_CONFIG);
+	if (data->have_power_sampling) {
+		ret = i2c_smbus_read_word_data(client, ADM1275_PMON_CONFIG);
+		mask = is_power ? ADM1278_PWR_AVG_MASK : ADM1278_VI_AVG_MASK;
+		shift = is_power ? ADM1278_PWR_AVG_SHIFT : ADM1278_VI_AVG_SHIFT;
+	} else {
+		ret = i2c_smbus_read_byte_data(client, ADM1275_PMON_CONFIG);
+		mask = ADM1275_VI_AVG_MASK;
+		shift = ADM1275_VI_AVG_SHIFT;
+	}
 	if (ret < 0)
 		return ret;
 
-	word = FIELD_PREP(mask, word) | (ret & ~mask);
-	ret = i2c_smbus_write_word_data(client, ADM1275_PMON_CONFIG, word);
+	word = (ret & ~mask) | ((word << shift) & mask);
+	if (data->have_power_sampling)
+		ret = i2c_smbus_write_word_data(client, ADM1275_PMON_CONFIG,
+						word);
+	else
+		ret = i2c_smbus_write_byte_data(client, ADM1275_PMON_CONFIG,
+						word);
 
 	return ret;
 }
···
 			return -ENXIO;
 		break;
 	case PMBUS_VIRT_POWER_SAMPLES:
-		ret = adm1275_read_pmon_config(client, ADM1275_PWR_AVG_MASK);
+		if (!data->have_power_sampling)
+			return -ENXIO;
+		ret = adm1275_read_pmon_config(data, client, true);
 		if (ret < 0)
 			break;
 		ret = BIT(ret);
 		break;
 	case PMBUS_VIRT_IN_SAMPLES:
 	case PMBUS_VIRT_CURR_SAMPLES:
-		ret = adm1275_read_pmon_config(client, ADM1275_VI_AVG_MASK);
+		ret = adm1275_read_pmon_config(data, client, false);
 		if (ret < 0)
 			break;
 		ret = BIT(ret);
···
 		ret = pmbus_write_word_data(client, 0, ADM1278_PEAK_TEMP, 0);
 		break;
 	case PMBUS_VIRT_POWER_SAMPLES:
+		if (!data->have_power_sampling)
+			return -ENXIO;
 		word = clamp_val(word, 1, ADM1275_SAMPLES_AVG_MAX);
-		ret = adm1275_write_pmon_config(client, ADM1275_PWR_AVG_MASK,
+		ret = adm1275_write_pmon_config(data, client, true,
 						ilog2(word));
 		break;
 	case PMBUS_VIRT_IN_SAMPLES:
 	case PMBUS_VIRT_CURR_SAMPLES:
 		word = clamp_val(word, 1, ADM1275_SAMPLES_AVG_MAX);
-		ret = adm1275_write_pmon_config(client, ADM1275_VI_AVG_MASK,
+		ret = adm1275_write_pmon_config(data, client, false,
 						ilog2(word));
 		break;
 	default:
···
 		data->have_vout = true;
 		data->have_pin_max = true;
 		data->have_temp_max = true;
+		data->have_power_sampling = true;
 
 		coefficients = adm1272_coefficients;
 		vindex = (config & ADM1275_VRANGE) ? 1 : 0;
···
 		data->have_vout = true;
 		data->have_pin_max = true;
 		data->have_temp_max = true;
+		data->have_power_sampling = true;
 
 		coefficients = adm1278_coefficients;
 		vindex = 0;
···
 		data->have_pin_min = true;
 		data->have_pin_max = true;
 		data->have_mfr_vaux_status = true;
+		data->have_power_sampling = true;
 
 		coefficients = adm1293_coefficients;