[PATCH v2 6/8] hwmon: (pmbus/mp2975) Add support for MP2971 and MP2973

[Naresh Solanki]

From: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>

Add support for MP2971 and MP2973, the successor of MP2975.

The major differences are:
 - On MP2973 and MP2971 the Vref cannot be read and thus most of
   the OVP/current calculations won't work.
 - MP2973 and MP2971 also support LINEAR format for VOUT
 - MP2973 and MP2971 do not support OVP2
 - On MP2973 and MP2971 most registers are in LINEAR format
 - The IMVP9_EN bit has a different position
 - Per phase current sense haven't been implemented.

As on MP2975 most of the FAULT_LIMIT and WARN_LIMIT registers
have been redefined and doesn't provide the functionality as
defined in PMBUS spec.

Tested on MP2973 and MP2971.

Signed-off-by: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>

---
Changes in V2:
- Remove cosmetic changes like continue to use mp2975 instead of
  changing it to mp297x.
- Do i2c write back only if needed.
---
 drivers/hwmon/pmbus/mp2975.c | 247 ++++++++++++++++++++++++++++++-----
 1 file changed, 214 insertions(+), 33 deletions(-)

diff --git a/drivers/hwmon/pmbus/mp2975.c b/drivers/hwmon/pmbus/mp2975.c
index a4453b9284fa..4d72ed18cc8c 100644
--- a/drivers/hwmon/pmbus/mp2975.c
+++ b/drivers/hwmon/pmbus/mp2975.c
@@ -35,6 +35,8 @@
 #define MP2975_MFR_OVP_TH_SET		0xe5
 #define MP2975_MFR_UVP_SET		0xe6
 
+#define MP2973_MFR_RESO_SET		0xc7
+
 #define MP2975_VOUT_FORMAT		BIT(15)
 #define MP2975_VID_STEP_SEL_R1		BIT(4)
 #define MP2975_IMVP9_EN_R1		BIT(13)
@@ -49,8 +51,32 @@
 #define MP2975_SENSE_AMPL_HALF		2
 #define MP2975_VIN_UV_LIMIT_UNIT	8
 
+#define MP2973_VOUT_FORMAT_R1		GENMASK(7, 6)
+#define MP2973_VOUT_FORMAT_R2		GENMASK(4, 3)
+#define MP2973_VOUT_FORMAT_DIRECT_R1	BIT(7)
+#define MP2973_VOUT_FORMAT_LINEAR_R1	BIT(6)
+#define MP2973_VOUT_FORMAT_DIRECT_R2	BIT(4)
+#define MP2973_VOUT_FORMAT_LINEAR_R2	BIT(3)
+
+#define MP2973_MFR_VR_MULTI_CONFIG_R1	0x0d
+#define MP2973_MFR_VR_MULTI_CONFIG_R2	0x1d
+#define MP2973_VID_STEP_SEL_R1		BIT(4)
+#define MP2973_IMVP9_EN_R1		BIT(14)
+#define MP2973_VID_STEP_SEL_R2		BIT(3)
+#define MP2973_IMVP9_EN_R2		BIT(13)
+
+#define MP2973_MFR_READ_IOUT_PK		0x90
+#define MP2973_MFR_READ_POUT_PK		0x91
+
 #define MP2975_MAX_PHASE_RAIL1	8
 #define MP2975_MAX_PHASE_RAIL2	4
+
+#define MP2973_MAX_PHASE_RAIL1	14
+#define MP2973_MAX_PHASE_RAIL2	6
+
+#define MP2971_MAX_PHASE_RAIL1	8
+#define MP2971_MAX_PHASE_RAIL2	3
+
 #define MP2975_PAGE_NUM		2
 
 #define MP2975_RAIL2_FUNC	(PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | \
@@ -58,11 +84,13 @@
 				 PMBUS_HAVE_POUT | PMBUS_PHASE_VIRTUAL)
 
 enum chips {
-	mp2975
+	mp2971, mp2973, mp2975
 };
 
 static const int mp2975_max_phases[][MP2975_PAGE_NUM] = {
 	[mp2975] = { MP2975_MAX_PHASE_RAIL1, MP2975_MAX_PHASE_RAIL2 },
+	[mp2973] = { MP2973_MAX_PHASE_RAIL1, MP2973_MAX_PHASE_RAIL2 },
+	[mp2971] = { MP2971_MAX_PHASE_RAIL1, MP2971_MAX_PHASE_RAIL2 },
 };
 
 struct mp2975_data {
@@ -79,6 +107,8 @@ struct mp2975_data {
 };
 
 static const struct i2c_device_id mp2975_id[] = {
+	{"mp2971", mp2971},
+	{"mp2973", mp2973},
 	{"mp2975", mp2975},
 	{}
 };
@@ -215,6 +245,76 @@ mp2975_read_phases(struct i2c_client *client, struct mp2975_data *data,
 	return ret;
 }
 
+static int mp2973_read_word_data(struct i2c_client *client, int page,
+				 int phase, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct mp2975_data *data = to_mp2975_data(info);
+	int ret;
+
+	switch (reg) {
+	case PMBUS_OT_FAULT_LIMIT:
+		ret = mp2975_read_word_helper(client, page, phase, reg,
+					      GENMASK(7, 0));
+		break;
+	case PMBUS_VIN_OV_FAULT_LIMIT:
+		ret = mp2975_read_word_helper(client, page, phase, reg,
+					      GENMASK(7, 0));
+		if (ret < 0)
+			return ret;
+
+		ret = DIV_ROUND_CLOSEST(ret, MP2975_VIN_UV_LIMIT_UNIT);
+		break;
+	case PMBUS_VOUT_OV_FAULT_LIMIT:
+		/*
+		 * MP2971 and mp2973 only supports tracking (ovp1) mode.
+		 */
+		ret = mp2975_read_word_helper(client, page, phase,
+					      MP2975_MFR_OVP_TH_SET,
+					      GENMASK(2, 0));
+		if (ret < 0)
+			return ret;
+
+		ret = data->vout_max[page] + 50 * (ret + 1);
+		break;
+	case PMBUS_VOUT_UV_FAULT_LIMIT:
+		ret = mp2975_read_word_helper(client, page, phase, reg,
+					      GENMASK(8, 0));
+		if (ret < 0)
+			return ret;
+		ret = mp2975_vid2direct(info->vrm_version[page], ret);
+		break;
+	case PMBUS_VIRT_READ_POUT_MAX:
+		ret = pmbus_read_word_data(client, page, phase,
+					   MP2973_MFR_READ_POUT_PK);
+		break;
+	case PMBUS_VIRT_READ_IOUT_MAX:
+		ret = pmbus_read_word_data(client, page, phase,
+					   MP2973_MFR_READ_IOUT_PK);
+		break;
+	case PMBUS_UT_WARN_LIMIT:
+	case PMBUS_UT_FAULT_LIMIT:
+	case PMBUS_VIN_UV_WARN_LIMIT:
+	case PMBUS_VIN_UV_FAULT_LIMIT:
+	case PMBUS_VOUT_UV_WARN_LIMIT:
+	case PMBUS_VOUT_OV_WARN_LIMIT:
+	case PMBUS_VIN_OV_WARN_LIMIT:
+	case PMBUS_IIN_OC_FAULT_LIMIT:
+	case PMBUS_IOUT_OC_LV_FAULT_LIMIT:
+	case PMBUS_IOUT_OC_WARN_LIMIT:
+	case PMBUS_IOUT_OC_FAULT_LIMIT:
+	case PMBUS_IOUT_UC_FAULT_LIMIT:
+	case PMBUS_POUT_OP_FAULT_LIMIT:
+	case PMBUS_POUT_OP_WARN_LIMIT:
+	case PMBUS_PIN_OP_WARN_LIMIT:
+		return -ENXIO;
+	default:
+		return -ENODATA;
+	}
+
+	return ret;
+}
+
 static int mp2975_read_word_data(struct i2c_client *client, int page,
 				 int phase, int reg)
 {
@@ -434,6 +534,35 @@ mp2975_identify_rails_vid(struct i2c_client *client, struct mp2975_data *data,
 					  MP2975_MFR_VR_MULTI_CONFIG_R2, 1,
 					  MP2975_IMVP9_EN_R2,
 					  MP2975_VID_STEP_SEL_R2);
+
+	return ret;
+}
+
+static int
+mp2973_identify_rails_vid(struct i2c_client *client, struct mp2975_data *data,
+			  struct pmbus_driver_info *info)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
+	if (ret < 0)
+		return ret;
+
+	/* Identify VID mode for rail 1. */
+	ret = mp2975_identify_vid(client, data, info,
+				  MP2973_MFR_VR_MULTI_CONFIG_R1, 0,
+				  MP2973_IMVP9_EN_R1, MP2973_VID_STEP_SEL_R1);
+
+	if (ret < 0)
+		return ret;
+
+	/* Identify VID mode for rail 2, if connected. */
+	if (info->phases[1])
+		ret = mp2975_identify_vid(client, data, info,
+					  MP2973_MFR_VR_MULTI_CONFIG_R2, 1,
+					  MP2973_IMVP9_EN_R2,
+					  MP2973_VID_STEP_SEL_R2);
+
 	return ret;
 }
 
@@ -551,15 +680,32 @@ static int
 mp2975_set_vout_format(struct i2c_client *client,
 		       struct mp2975_data *data, int page)
 {
-	int ret;
+	int ret, i;
 
-	ret = i2c_smbus_read_word_data(client, MP2975_MFR_DC_LOOP_CTRL);
-	if (ret < 0)
-		return ret;
 	/* Enable DIRECT VOUT format 1mV/LSB */
-	if (ret & MP2975_VOUT_FORMAT) {
-		ret &= ~MP2975_VOUT_FORMAT;
-		ret = i2c_smbus_write_word_data(client, MP2975_MFR_DC_LOOP_CTRL, ret);
+	if (data->chip_id == mp2975) {
+		ret = i2c_smbus_read_word_data(client, MP2975_MFR_DC_LOOP_CTRL);
+		if (ret < 0)
+			return ret;
+		if (ret & MP2975_VOUT_FORMAT) {
+			ret &= ~MP2975_VOUT_FORMAT;
+			ret = i2c_smbus_write_word_data(client, MP2975_MFR_DC_LOOP_CTRL, ret);
+		}
+	} else {
+		ret = i2c_smbus_read_word_data(client, MP2973_MFR_RESO_SET);
+		if (ret < 0)
+			return ret;
+		i = ret;
+
+		if (page == 0) {
+			i &= ~MP2973_VOUT_FORMAT_R1;
+			i |= MP2973_VOUT_FORMAT_DIRECT_R1;
+		} else {
+			i &= ~MP2973_VOUT_FORMAT_R2;
+			i |= MP2973_VOUT_FORMAT_DIRECT_R2;
+		}
+		if (i != ret)
+			ret = i2c_smbus_write_word_data(client, MP2973_MFR_RESO_SET, i);
 	}
 	return ret;
 }
@@ -607,10 +753,10 @@ mp2975_vout_per_rail_config_get(struct i2c_client *client,
 	for (i = 0; i < data->info.pages; i++) {
 		ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
 		if (ret < 0)
-			return ret;
+			continue;
 
-		/* Obtain voltage reference offsets. */
-		ret = mp2975_vref_offset_get(client, data, i);
+		/* Set VOUT format for READ_VOUT command : direct. */
+		ret = mp2975_set_vout_format(client, data, i);
 		if (ret < 0)
 			return ret;
 
@@ -619,8 +765,12 @@ mp2975_vout_per_rail_config_get(struct i2c_client *client,
 		if (ret < 0)
 			return ret;
 
-		/* Set VOUT format for READ_VOUT command : direct. */
-		ret = mp2975_set_vout_format(client, data, i);
+		/* Skip if reading Vref is unsupported */
+		if (data->chip_id != mp2975)
+			continue;
+
+		/* Obtain voltage reference offsets. */
+		ret = mp2975_vref_offset_get(client, data, i);
 		if (ret < 0)
 			return ret;
 
@@ -658,6 +808,23 @@ static struct pmbus_driver_info mp2975_info = {
 	.read_word_data = mp2975_read_word_data,
 };
 
+static struct pmbus_driver_info mp2973_info = {
+	.pages = 1,
+	.format[PSC_VOLTAGE_IN] = linear,
+	.format[PSC_VOLTAGE_OUT] = direct,
+	.format[PSC_TEMPERATURE] = linear,
+	.format[PSC_CURRENT_IN] = linear,
+	.format[PSC_CURRENT_OUT] = linear,
+	.format[PSC_POWER] = linear,
+	.m[PSC_VOLTAGE_OUT] = 1,
+	.R[PSC_VOLTAGE_OUT] = 3,
+	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT |
+		PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT,
+	.read_word_data = mp2973_read_word_data,
+};
+
 static int mp2975_probe(struct i2c_client *client)
 {
 	struct pmbus_driver_info *info;
@@ -677,6 +844,11 @@ static int mp2975_probe(struct i2c_client *client)
 	memcpy(data->max_phases, mp2975_max_phases[data->chip_id],
 	       sizeof(data->max_phases));
 
+	if (data->chip_id == mp2975)
+		memcpy(&data->info, &mp2975_info, sizeof(*info));
+	else
+		memcpy(&data->info, &mp2973_info, sizeof(*info));
+
 	info = &data->info;
 
 	/* Identify multiphase configuration for rail 2. */
@@ -691,30 +863,37 @@ static int mp2975_probe(struct i2c_client *client)
 		data->info.func[1] = MP2975_RAIL2_FUNC;
 	}
 
-	/* Identify multiphase configuration. */
-	ret = mp2975_identify_multiphase(client, data, info);
-	if (ret)
-		return ret;
+	if (data->chip_id == mp2975) {
+		/* Identify multiphase configuration. */
+		ret = mp2975_identify_multiphase(client, data, info);
+		if (ret)
+			return ret;
 
-	/* Identify VID setting per rail. */
-	ret = mp2975_identify_rails_vid(client, data, info);
-	if (ret < 0)
-		return ret;
+		/* Identify VID setting per rail. */
+		ret = mp2975_identify_rails_vid(client, data, info);
+		if (ret < 0)
+			return ret;
 
-	/* Obtain current sense gain of power stage. */
-	ret = mp2975_current_sense_gain_get(client, data);
-	if (ret)
-		return ret;
+		/* Obtain current sense gain of power stage. */
+		ret = mp2975_current_sense_gain_get(client, data);
+		if (ret)
+			return ret;
 
-	/* Obtain voltage reference values. */
-	ret = mp2975_vref_get(client, data, info);
-	if (ret)
-		return ret;
+		/* Obtain voltage reference values. */
+		ret = mp2975_vref_get(client, data, info);
+		if (ret)
+			return ret;
 
-	/* Obtain vout over-voltage scales. */
-	ret = mp2975_vout_ov_scale_get(client, data, info);
-	if (ret < 0)
-		return ret;
+		/* Obtain vout over-voltage scales. */
+		ret = mp2975_vout_ov_scale_get(client, data, info);
+		if (ret < 0)
+			return ret;
+	} else {
+		/* Identify VID setting per rail. */
+		ret = mp2973_identify_rails_vid(client, data, info);
+		if (ret < 0)
+			return ret;
+	}
 
 	/* Obtain offsets, maximum and format for vout. */
 	ret = mp2975_vout_per_rail_config_get(client, data, info);
@@ -725,6 +904,8 @@ static int mp2975_probe(struct i2c_client *client)
 }
 
 static const struct of_device_id __maybe_unused mp2975_of_match[] = {
+	{.compatible = "mps,mp2971", .data = (void *)mp2971},
+	{.compatible = "mps,mp2973", .data = (void *)mp2973},
 	{.compatible = "mps,mp2975", .data = (void *)mp2975},
 	{}
 };
-- 
2.41.0