pmbus (max31785): Add support for devicetree configuration

OpenBMC-Staging-Count: 18
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Tested-by: George Keishing <gkeishin@in.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>

drivers/hwmon/pmbus/max31785.c

@@ -12,14 +12,24 @@
 
 enum max31785_regs {
 	MFR_REVISION		= 0x9b,
+	MFR_FAULT_RESPONSE	= 0xd9,
+	MFR_TEMP_SENSOR_CONFIG	= 0xf0,
 	MFR_FAN_CONFIG		= 0xf1,
+	MFR_FAN_FAULT_LIMIT	= 0xf5,
 };
 
 #define MAX31785			0x3030
 #define MAX31785A			0x3040
 #define MAX31785B			0x3061
 
 #define MFR_FAN_CONFIG_DUAL_TACH	BIT(12)
+#define MFR_FAN_CONFIG_TSFO		BIT(9)
+#define MFR_FAN_CONFIG_TACHO		BIT(8)
+#define MFR_FAN_CONFIG_HEALTH		BIT(4)
+#define MFR_FAN_CONFIG_ROTOR_HI_LO	BIT(3)
+#define MFR_FAN_CONFIG_ROTOR		BIT(2)
+
+#define MFR_FAULT_RESPONSE_MONITOR	BIT(0)
 
 #define MAX31785_NR_PAGES		23
 #define MAX31785_NR_FAN_PAGES		6
@@ -236,6 +246,271 @@ static int max31785_write_word_data(struct i2c_client *client, int page,
 	return -ENODATA;
 }
 
+/*
+ * Returns negative error codes if an unrecoverable problem is detected, 0 if a
+ * recoverable problem is detected, or a positive value on success.
+ */
+static int max31785_of_fan_config(struct i2c_client *client,
+				  struct pmbus_driver_info *info,
+				  struct device_node *child)
+{
+	int mfr_cfg = 0, mfr_fault_resp = 0, pb_cfg;
+	struct device *dev = &client->dev;
+	char *lock_polarity = NULL;
+	const char *sval;
+	u32 page;
+	u32 uval;
+	int ret;
+
+	if (!of_device_is_compatible(child, "pmbus-fan"))
+		return 0;
+
+	ret = of_property_read_u32(child, "reg", &page);
+	if (ret < 0) {
+		dev_err(&client->dev, "Missing valid reg property\n");
+		return ret;
+	}
+
+	if (!(info->func[page] & PMBUS_HAVE_FAN12)) {
+		dev_err(dev, "Page %d does not have fan capabilities\n", page);
+		return -ENXIO;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
+	if (ret < 0)
+		return ret;
+
+	pb_cfg = i2c_smbus_read_byte_data(client, PMBUS_FAN_CONFIG_12);
+	if (pb_cfg < 0)
+		return pb_cfg;
+
+	if (of_property_read_bool(child->parent, "use-stored-presence")) {
+		if (!(pb_cfg & PB_FAN_1_INSTALLED))
+			dev_info(dev, "Fan %d is configured but not installed\n",
+				 page);
+	} else {
+		pb_cfg |= PB_FAN_1_INSTALLED;
+	}
+
+	ret = of_property_read_string(child, "maxim,fan-rotor-input", &sval);
+	if (ret < 0) {
+		dev_err(dev, "Missing valid maxim,fan-rotor-input property for fan %d\n",
+				page);
+		return ret;
+	}
+
+	if (strcmp("tach", sval) && strcmp("lock", sval)) {
+		dev_err(dev, "maxim,fan-rotor-input has invalid value for fan %d: %s\n",
+				page, sval);
+		return -EINVAL;
+	} else if (!strcmp("lock", sval)) {
+		mfr_cfg |= MFR_FAN_CONFIG_ROTOR;
+
+		ret = i2c_smbus_write_word_data(client, MFR_FAN_FAULT_LIMIT, 1);
+		if (ret < 0)
+			return ret;
+
+		ret = of_property_read_string(child, "maxim,fan-lock-polarity",
+					      &sval);
+		if (ret < 0) {
+			dev_err(dev, "Missing valid maxim,fan-lock-polarity property for fan %d\n",
+					page);
+			return ret;
+		}
+
+		if (strcmp("low", sval) && strcmp("high", sval)) {
+			dev_err(dev, "maxim,fan-lock-polarity has invalid value for fan %d: %s\n",
+					page, lock_polarity);
+			return -EINVAL;
+		} else if (!strcmp("high", sval))
+			mfr_cfg |= MFR_FAN_CONFIG_ROTOR_HI_LO;
+	}
+
+	if (!of_property_read_string(child, "fan-mode", &sval)) {
+		if (!strcmp("rpm", sval))
+			pb_cfg |= PB_FAN_1_RPM;
+		else if (!strcmp("pwm", sval))
+			pb_cfg &= ~PB_FAN_1_RPM;
+		else {
+			dev_err(dev, "fan-mode has invalid value for fan %d: %s\n",
+					page, sval);
+			return -EINVAL;
+		}
+	}
+
+	ret = of_property_read_u32(child, "tach-pulses", &uval);
+	if (ret < 0) {
+		pb_cfg &= ~PB_FAN_1_PULSE_MASK;
+	} else if (uval && (uval - 1) < 4) {
+		pb_cfg = ((pb_cfg & ~PB_FAN_1_PULSE_MASK) | ((uval - 1) << 4));
+	} else {
+		dev_err(dev, "tach-pulses has invalid value for fan %d: %u\n",
+				page, uval);
+		return -EINVAL;
+	}
+
+	if (of_property_read_bool(child, "maxim,fan-health"))
+		mfr_cfg |= MFR_FAN_CONFIG_HEALTH;
+
+	if (of_property_read_bool(child, "maxim,fan-no-watchdog") ||
+		of_property_read_bool(child, "maxim,tmp-no-fault-ramp"))
+		mfr_cfg |= MFR_FAN_CONFIG_TSFO;
+
+	if (of_property_read_bool(child, "maxim,fan-dual-tach"))
+		mfr_cfg |= MFR_FAN_CONFIG_DUAL_TACH;
+
+	if (of_property_read_bool(child, "maxim,fan-no-fault-ramp"))
+		mfr_cfg |= MFR_FAN_CONFIG_TACHO;
+
+	if (!of_property_read_u32(child, "maxim,fan-startup", &uval)) {
+		uval /= 2;
+		if (uval < 5) {
+			mfr_cfg |= uval;
+		} else {
+			dev_err(dev, "maxim,fan-startup has invalid value for fan %d: %u\n",
+					page, uval);
+			return -EINVAL;
+		}
+	}
+
+	if (!of_property_read_u32(child, "maxim,fan-ramp", &uval)) {
+		if (uval < 8) {
+			mfr_cfg |= uval << 5;
+		} else {
+			dev_err(dev, "maxim,fan-ramp has invalid value for fan %d: %u\n",
+					page, uval);
+			return -EINVAL;
+		}
+	}
+
+	if (!of_property_read_u32(child, "maxim,tmp-hysteresis", &uval)) {
+		uval /= 2;
+		uval -= 1;
+		if (uval < 4) {
+			mfr_cfg |= uval << 10;
+		} else {
+			dev_err(dev, "maxim,tmp-hysteresis has invalid value for fan %d, %u\n",
+					page, uval);
+			return -EINVAL;
+		}
+	}
+
+	if (!of_property_read_u32(child, "maxim,fan-pwm-freq", &uval)) {
+		u16 val;
+
+		if (uval == 30) {
+			val = 0;
+		} else if (uval == 50) {
+			val = 1;
+		} else if (uval == 100) {
+			val = 2;
+		} else if (uval == 150) {
+			val = 3;
+		} else if (uval == 25000) {
+			val = 7;
+		} else {
+			dev_err(dev, "maxim,fan-pwm-freq has invalid value for fan %d: %u\n",
+					page, uval);
+			return -EINVAL;
+		}
+
+		mfr_cfg |= val << 13;
+	}
+
+	if (of_property_read_bool(child, "maxim,fan-fault-pin-mon"))
+		mfr_fault_resp |= MFR_FAULT_RESPONSE_MONITOR;
+
+	ret = i2c_smbus_write_byte_data(client, PMBUS_FAN_CONFIG_12,
+					pb_cfg & ~PB_FAN_1_INSTALLED);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_word_data(client, MFR_FAN_CONFIG, mfr_cfg);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, MFR_FAULT_RESPONSE,
+					mfr_fault_resp);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, PMBUS_FAN_CONFIG_12, pb_cfg);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Fans are on pages 0 - 5. If the page property of a fan node is
+	 * greater than 5 we will have errored in checks above out above.
+	 * Therefore we don't need to cope with values up to 31, and the int
+	 * return type is enough.
+	 *
+	 * The bit mask return value is used to populate a bitfield of fans
+	 * who are both configured in the devicetree _and_ reported as
+	 * installed by the hardware. Any fans that are not configured in the
+	 * devicetree but are reported as installed by the hardware will have
+	 * their hardware configuration updated to unset the installed bit.
+	 */
+	return BIT(page);
+}
+
+static int max31785_of_tmp_config(struct i2c_client *client,
+				  struct pmbus_driver_info *info,
+				  struct device_node *child)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np;
+	u16 mfr_tmp_cfg = 0;
+	u32 page;
+	u32 uval;
+	int ret;
+	int i;
+
+	if (!of_device_is_compatible(child, "pmbus-temperature"))
+		return 0;
+
+	ret = of_property_read_u32(child, "reg", &page);
+	if (ret < 0) {
+		dev_err(&client->dev, "Missing valid reg property\n");
+		return ret;
+	}
+
+	if (!(info->func[page] & PMBUS_HAVE_TEMP)) {
+		dev_err(dev, "Page %d does not have temp capabilities\n", page);
+		return -ENXIO;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
+	if (ret < 0)
+		return ret;
+
+	if (!of_property_read_u32(child, "maxim,tmp-offset", &uval)) {
+		if (uval < 32)
+			mfr_tmp_cfg |= uval << 10;
+	}
+
+	i = 0;
+	while ((np = of_parse_phandle(child, "maxim,tmp-fans", i))) {
+		if (of_property_read_u32(np, "reg", &uval)) {
+			dev_err(&client->dev, "Failed to read fan reg property for phandle index %d\n",
+					i);
+		} else {
+			if (uval < 6)
+				mfr_tmp_cfg |= BIT(uval);
+			else
+				dev_warn(&client->dev, "Invalid fan page: %d\n",
+						uval);
+		}
+		i++;
+	}
+
+	ret = i2c_smbus_write_word_data(client, MFR_TEMP_SENSOR_CONFIG,
+					mfr_tmp_cfg);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
 #define MAX31785_FAN_FUNCS \
 	(PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12 | PMBUS_HAVE_PWM12)
 
@@ -328,9 +603,12 @@ static int max31785_configure_dual_tach(struct i2c_client *client,
 static int max31785_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
+	struct device_node *child;
 	struct pmbus_driver_info *info;
 	bool dual_tach = false;
 	int ret;
+	u32 fans;
+	int i;
 
 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_BYTE_DATA |
@@ -362,6 +640,46 @@ static int max31785_probe(struct i2c_client *client)
 		return -ENODEV;
 	}
 
+	fans = 0;
+	for_each_child_of_node(dev->of_node, child) {
+		ret = max31785_of_fan_config(client, info, child);
+		if (ret < 0) {
+			of_node_put(child);
+			return ret;
+		}
+
+		if (ret)
+			fans |= ret;
+
+		ret = max31785_of_tmp_config(client, info, child);
+		if (ret < 0) {
+			of_node_put(child);
+			return ret;
+		}
+	}
+
+	for (i = 0; i < MAX31785_NR_PAGES; i++) {
+		bool have_fan = !!(info->func[i] & PMBUS_HAVE_FAN12);
+		bool fan_configured = !!(fans & BIT(i));
+
+		if (!have_fan || fan_configured)
+			continue;
+
+		ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
+		if (ret < 0)
+			return ret;
+
+		ret = i2c_smbus_read_byte_data(client, PMBUS_FAN_CONFIG_12);
+		if (ret < 0)
+			return ret;
+
+		ret &= ~PB_FAN_1_INSTALLED;
+		ret = i2c_smbus_write_word_data(client, PMBUS_FAN_CONFIG_12,
+						ret);
+		if (ret < 0)
+			return ret;
+	}
+
 	if (dual_tach) {
 		ret = max31785_configure_dual_tach(client, info);
 		if (ret < 0)