hwmon: (adm1275) Add support for ADM1278

ADM1278 is mostly compatible to other chips of the same series.
Besides the usual difference in coefficients, it supports
a temperature sensor, and it can measure both input and output
voltage at the same time.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Documentation/hwmon/adm1275

@@ -14,6 +14,10 @@ Supported chips:
     Prefix: 'adm1276'
     Addresses scanned: -
     Datasheet: www.analog.com/static/imported-files/data_sheets/ADM1276.pdf
+  * Analog Devices ADM1278
+    Prefix: 'adm1278'
+    Addresses scanned: -
+    Datasheet: www.analog.com/static/imported-files/data_sheets/ADM1278.pdf
   * Analog Devices ADM1293/ADM1294
     Prefix: 'adm1293', 'adm1294'
     Addresses scanned: -
@@ -26,12 +30,14 @@ Description
 -----------
 
 This driver supports hardware monitoring for Analog Devices ADM1075, ADM1275,
-ADM1276, ADM1293, and ADM1294 Hot-Swap Controller and Digital Power Monitors.
+ADM1276, ADM1278, ADM1293, and ADM1294 Hot-Swap Controller and Digital
+Power Monitors.
 
-ADM1075, ADM1275, ADM1276, ADM1293, and ADM1294 are hot-swap controllers that
-allow a circuit board to be removed from or inserted into a live backplane.
-They also feature current and voltage readback via an integrated 12
-bit analog-to-digital converter (ADC), accessed using a PMBus interface.
+ADM1075, ADM1275, ADM1276, ADM1278, ADM1293, and ADM1294 are hot-swap
+controllers that allow a circuit board to be removed from or inserted into
+a live backplane. They also feature current and voltage readback via an
+integrated 12 bit analog-to-digital converter (ADC), accessed using a
+PMBus interface.
 
 The driver is a client driver to the core PMBus driver. Please see
 Documentation/hwmon/pmbus for details on PMBus client drivers.
@@ -96,3 +102,14 @@ power1_reset_history	Write any value to reset history.
 
 			Power attributes are supported on ADM1075, ADM1276,
 			ADM1293, and ADM1294.
+
+temp1_input		Chip temperature.
+			Temperature attributes are only available on ADM1278.
+temp1_max		Maximum chip temperature.
+temp1_max_alarm		Temperature alarm.
+temp1_crit		Critical chip temperature.
+temp1_crit_alarm	Critical temperature high alarm.
+temp1_highest		Highest observed temperature.
+temp1_reset_history	Write any value to reset history.
+
+			Temperature attributes are supported on ADM1278.

drivers/hwmon/pmbus/Kconfig

@@ -31,8 +31,8 @@ config SENSORS_ADM1275
 	default n
 	help
 	  If you say yes here you get hardware monitoring support for Analog
-	  Devices ADM1075, ADM1275, ADM1276, ADM1293, and ADM1294 Hot-Swap
-	  Controller and Digital Power Monitors.
+	  Devices ADM1075, ADM1275, ADM1276, ADM1278, ADM1293, and ADM1294
+	  Hot-Swap Controller and Digital Power Monitors.
 
 	  This driver can also be built as a module. If so, the module will
 	  be called adm1275.

drivers/hwmon/pmbus/adm1275.c

@@ -24,7 +24,7 @@
 #include <linux/bitops.h>
 #include "pmbus.h"
 
-enum chips { adm1075, adm1275, adm1276, adm1293, adm1294 };
+enum chips { adm1075, adm1275, adm1276, adm1278, adm1293, adm1294 };
 
 #define ADM1275_MFR_STATUS_IOUT_WARN2	BIT(0)
 #define ADM1293_MFR_STATUS_VAUX_UV_WARN	BIT(5)
@@ -41,6 +41,10 @@ enum chips { adm1075, adm1275, adm1276, adm1293, adm1294 };
 #define ADM1075_IRANGE_25		BIT(3)
 #define ADM1075_IRANGE_MASK		(BIT(3) | BIT(4))
 
+#define ADM1278_TEMP1_EN		BIT(3)
+#define ADM1278_VIN_EN			BIT(2)
+#define ADM1278_VOUT_EN			BIT(1)
+
 #define ADM1293_IRANGE_25		0
 #define ADM1293_IRANGE_50		BIT(6)
 #define ADM1293_IRANGE_100		BIT(7)
@@ -54,6 +58,7 @@ enum chips { adm1075, adm1275, adm1276, adm1293, adm1294 };
 
 #define ADM1293_VAUX_EN			BIT(1)
 
+#define ADM1278_PEAK_TEMP		0xd7
 #define ADM1275_IOUT_WARN2_LIMIT	0xd7
 #define ADM1275_DEVICE_CONFIG		0xd8
 
@@ -80,6 +85,7 @@ struct adm1275_data {
 	bool have_iout_min;
 	bool have_pin_min;
 	bool have_pin_max;
+	bool have_temp_max;
 	struct pmbus_driver_info info;
 };
 
@@ -113,6 +119,13 @@ static const struct coefficients adm1276_coefficients[] = {
 	[4] = { 2115, 0, -1 },		/* power, vrange not set */
 };
 
+static const struct coefficients adm1278_coefficients[] = {
+	[0] = { 19599, 0, -2 },		/* voltage */
+	[1] = { 800, 20475, -1 },	/* current */
+	[2] = { 6123, 0, -2 },		/* power */
+	[3] = { 42, 31880, -1 },	/* temperature */
+};
+
 static const struct coefficients adm1293_coefficients[] = {
 	[0] = { 3333, -1, 0 },		/* voltage, vrange 1.2V */
 	[1] = { 5552, -5, -1 },		/* voltage, vrange 7.4V */
@@ -196,6 +209,11 @@ static int adm1275_read_word_data(struct i2c_client *client, int page, int reg)
 			return -ENXIO;
 		ret = pmbus_read_word_data(client, 0, ADM1276_PEAK_PIN);
 		break;
+	case PMBUS_VIRT_READ_TEMP_MAX:
+		if (!data->have_temp_max)
+			return -ENXIO;
+		ret = pmbus_read_word_data(client, 0, ADM1278_PEAK_TEMP);
+		break;
 	case PMBUS_VIRT_RESET_IOUT_HISTORY:
 	case PMBUS_VIRT_RESET_VOUT_HISTORY:
 	case PMBUS_VIRT_RESET_VIN_HISTORY:
@@ -204,6 +222,10 @@ static int adm1275_read_word_data(struct i2c_client *client, int page, int reg)
 		if (!data->have_pin_max)
 			return -ENXIO;
 		break;
+	case PMBUS_VIRT_RESET_TEMP_HISTORY:
+		if (!data->have_temp_max)
+			return -ENXIO;
+		break;
 	default:
 		ret = -ENODATA;
 		break;
@@ -245,6 +267,9 @@ static int adm1275_write_word_data(struct i2c_client *client, int page, int reg,
 			ret = pmbus_write_word_data(client, 0,
 						    ADM1293_PIN_MIN, 0);
 		break;
+	case PMBUS_VIRT_RESET_TEMP_HISTORY:
+		ret = pmbus_write_word_data(client, 0, ADM1278_PEAK_TEMP, 0);
+		break;
 	default:
 		ret = -ENODATA;
 		break;
@@ -312,6 +337,7 @@ static const struct i2c_device_id adm1275_id[] = {
 	{ "adm1075", adm1075 },
 	{ "adm1275", adm1275 },
 	{ "adm1276", adm1276 },
+	{ "adm1278", adm1278 },
 	{ "adm1293", adm1293 },
 	{ "adm1294", adm1294 },
 	{ }
@@ -329,6 +355,7 @@ static int adm1275_probe(struct i2c_client *client,
 	const struct i2c_device_id *mid;
 	const struct coefficients *coefficients;
 	int vindex = -1, voindex = -1, cindex = -1, pindex = -1;
+	int tindex = -1;
 
 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_READ_BYTE_DATA
@@ -386,6 +413,7 @@ static int adm1275_probe(struct i2c_client *client,
 	info->format[PSC_VOLTAGE_OUT] = direct;
 	info->format[PSC_CURRENT_OUT] = direct;
 	info->format[PSC_POWER] = direct;
+	info->format[PSC_TEMPERATURE] = direct;
 	info->func[0] = PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
 
 	info->read_word_data = adm1275_read_word_data;
@@ -460,6 +488,27 @@ static int adm1275_probe(struct i2c_client *client,
 			info->func[0] |=
 			  PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT;
 		break;
+	case adm1278:
+		data->have_vout = true;
+		data->have_pin_max = true;
+		data->have_temp_max = true;
+
+		coefficients = adm1278_coefficients;
+		vindex = 0;
+		cindex = 1;
+		pindex = 2;
+		tindex = 3;
+
+		info->func[0] |= PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT;
+		if (config & ADM1278_TEMP1_EN)
+			info->func[0] |=
+				PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
+		if (config & ADM1278_VIN_EN)
+			info->func[0] |= PMBUS_HAVE_VIN;
+		if (config & ADM1278_VOUT_EN)
+			info->func[0] |=
+				PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT;
+		break;
 	case adm1293:
 	case adm1294:
 		data->have_iout_min = true;
@@ -537,6 +586,11 @@ static int adm1275_probe(struct i2c_client *client,
 		info->b[PSC_POWER] = coefficients[pindex].b;
 		info->R[PSC_POWER] = coefficients[pindex].R;
 	}
+	if (tindex >= 0) {
+		info->m[PSC_TEMPERATURE] = coefficients[tindex].m;
+		info->b[PSC_TEMPERATURE] = coefficients[tindex].b;
+		info->R[PSC_TEMPERATURE] = coefficients[tindex].R;
+	}
 
 	return pmbus_do_probe(client, id, info);
 }