[PATCH v3] hwmon: (pmbus/mp2975) Fix IRQ masking

[Naresh Solanki <naresh.solanki@9elements.com>]

From: Patrick Rudolph <patrick.rudolph@9elements.com>

The MP2971/MP2973 use a custom 16bit register format for
SMBALERT_MASK which doesn't follow the PMBUS specification.

Map the PMBUS defined bits used by the common code onto the custom
format used by MPS and since the SMBALERT_MASK is currently never read
by common code only implement the mapping for write transactions.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>

---

Changes in V3:
1. Avoid precedence issues in Macro
2. Optimise macro.

Changes in V2:
1. Add/Update comment
2. Update SWAP define to include both variable.
3. Add defines for each bits of SMBALERT mask.
---
 drivers/hwmon/pmbus/mp2975.c | 77 ++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/drivers/hwmon/pmbus/mp2975.c b/drivers/hwmon/pmbus/mp2975.c
index e5fa10b3b8bc..953c02a2aeb5 100644
--- a/drivers/hwmon/pmbus/mp2975.c
+++ b/drivers/hwmon/pmbus/mp2975.c
@@ -392,6 +392,82 @@ static int mp2973_read_word_data(struct i2c_client *client, int page,
 	return ret;
 }
 
+static int mp2973_write_word_data(struct i2c_client *client, int page,
+				  int reg, u16 word)
+{
+	u8 target, mask;
+	int ret;
+
+	if (reg != PMBUS_SMBALERT_MASK)
+		return -ENODATA;
+
+	/*
+	 * Vendor-specific SMBALERT_MASK register with 16 maskable bits.
+	 */
+	ret = pmbus_read_word_data(client, 0, 0, PMBUS_SMBALERT_MASK);
+	if (ret < 0)
+		return ret;
+
+	target = word & 0xff;
+	mask = word >> 8;
+
+/*
+ * Set/Clear 'bit' in 'ret' based on condition followed by define for each bit in SMBALERT_MASK.
+ * Also bit 2 & 15 are reserved.
+ */
+#define SWAP(val, mask, cond, bit) (((mask) & (cond)) ? ((val) & ~BIT(bit)) : ((val) | BIT(bit)))
+
+#define MP2973_TEMP_OT		0
+#define MP2973_VIN_UVLO		1
+#define MP2973_VIN_OVP		3
+#define MP2973_MTP_FAULT	4
+#define MP2973_OTHER_COMM	5
+#define MP2973_MTP_BLK_TRIG	6
+#define MP2973_PACKET_ERROR	7
+#define MP2973_INVALID_DATA	8
+#define MP2973_INVALID_COMMAND	9
+#define MP2973_IOUT_OC_LV	10
+#define MP2973_IOUT_OC		11
+#define MP2973_VOUT_MAX_MIN_WARNING 12
+#define MP2973_VOLTAGE_UV	13
+#define MP2973_VOLTAGE_OV	14
+
+	switch (target) {
+	case PMBUS_STATUS_CML:
+		ret = SWAP(ret, mask, PB_CML_FAULT_INVALID_DATA, MP2973_INVALID_DATA);
+		ret = SWAP(ret, mask, PB_CML_FAULT_INVALID_COMMAND,  MP2973_INVALID_COMMAND);
+		ret = SWAP(ret, mask, PB_CML_FAULT_OTHER_COMM, MP2973_OTHER_COMM);
+		ret = SWAP(ret, mask, PB_CML_FAULT_PACKET_ERROR, MP2973_PACKET_ERROR);
+		break;
+	case PMBUS_STATUS_VOUT:
+		ret = SWAP(ret, mask, PB_VOLTAGE_UV_FAULT, MP2973_VOLTAGE_UV);
+		ret = SWAP(ret, mask, PB_VOLTAGE_OV_FAULT, MP2973_VOLTAGE_OV);
+		break;
+	case PMBUS_STATUS_IOUT:
+		ret = SWAP(ret, mask, PB_IOUT_OC_FAULT, MP2973_IOUT_OC);
+		ret = SWAP(ret, mask, PB_IOUT_OC_LV_FAULT, MP2973_IOUT_OC_LV);
+		break;
+	case PMBUS_STATUS_TEMPERATURE:
+		ret = SWAP(ret, mask, PB_TEMP_OT_FAULT, MP2973_TEMP_OT);
+		break;
+	/*
+	 * Map remaining bits to MFR specific to let the PMBUS core mask
+	 * those bits by default.
+	 */
+	case PMBUS_STATUS_MFR_SPECIFIC:
+		ret = SWAP(ret, mask, BIT(1), MP2973_VIN_UVLO);
+		ret = SWAP(ret, mask, BIT(3), MP2973_VIN_OVP);
+		ret = SWAP(ret, mask, BIT(4), MP2973_MTP_FAULT);
+		ret = SWAP(ret, mask, BIT(6), MP2973_MTP_BLK_TRIG);
+		break;
+	default:
+		return 0;
+	}
+#undef SWAP
+
+	return pmbus_write_word_data(client, 0, PMBUS_SMBALERT_MASK, ret);
+}
+
 static int mp2975_read_word_data(struct i2c_client *client, int page,
 				 int phase, int reg)
 {
@@ -907,6 +983,7 @@ static struct pmbus_driver_info mp2973_info = {
 		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT |
 		PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT,
 	.read_word_data = mp2973_read_word_data,
+	.write_word_data = mp2973_write_word_data,
 #if IS_ENABLED(CONFIG_SENSORS_MP2975_REGULATOR)
 	.num_regulators = 1,
 	.reg_desc = mp2975_reg_desc,

base-commit: 8debe3c1295ef36958dae77487eed9cf6584c008
-- 
2.42.0