hwmon: (pmbus/ibm-cffps) Add new manufacturer debugfs entries

Add support for a number of manufacturer-specific registers in the
debugfs entries, as well as support to read and write the
PMBUS_ON_OFF_CONFIG register through debugfs.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/1576788607-13567-2-git-send-email-eajames@linux.ibm.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/pmbus/ibm-cffps.c

@@ -20,7 +20,9 @@
 
 #define CFFPS_FRU_CMD				0x9A
 #define CFFPS_PN_CMD				0x9B
+#define CFFPS_HEADER_CMD			0x9C
 #define CFFPS_SN_CMD				0x9E
+#define CFFPS_MAX_POWER_OUT_CMD			0xA7
 #define CFFPS_CCIN_CMD				0xBD
 #define CFFPS_FW_CMD				0xFA
 #define CFFPS1_FW_NUM_BYTES			4
@@ -57,9 +59,12 @@ enum {
 	CFFPS_DEBUGFS_INPUT_HISTORY = 0,
 	CFFPS_DEBUGFS_FRU,
 	CFFPS_DEBUGFS_PN,
+	CFFPS_DEBUGFS_HEADER,
 	CFFPS_DEBUGFS_SN,
+	CFFPS_DEBUGFS_MAX_POWER_OUT,
 	CFFPS_DEBUGFS_CCIN,
 	CFFPS_DEBUGFS_FW,
+	CFFPS_DEBUGFS_ON_OFF_CONFIG,
 	CFFPS_DEBUGFS_NUM_ENTRIES
 };
 
@@ -136,15 +141,15 @@ static ssize_t ibm_cffps_read_input_history(struct ibm_cffps *psu,
 				       psu->input_history.byte_count);
 }
 
-static ssize_t ibm_cffps_debugfs_op(struct file *file, char __user *buf,
-				    size_t count, loff_t *ppos)
+static ssize_t ibm_cffps_debugfs_read(struct file *file, char __user *buf,
+				      size_t count, loff_t *ppos)
 {
 	u8 cmd;
 	int i, rc;
 	int *idxp = file->private_data;
 	int idx = *idxp;
 	struct ibm_cffps *psu = to_psu(idxp, idx);
-	char data[I2C_SMBUS_BLOCK_MAX] = { 0 };
+	char data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
 
 	pmbus_set_page(psu->client, 0);
 
@@ -157,9 +162,20 @@ static ssize_t ibm_cffps_debugfs_op(struct file *file, char __user *buf,
 	case CFFPS_DEBUGFS_PN:
 		cmd = CFFPS_PN_CMD;
 		break;
+	case CFFPS_DEBUGFS_HEADER:
+		cmd = CFFPS_HEADER_CMD;
+		break;
 	case CFFPS_DEBUGFS_SN:
 		cmd = CFFPS_SN_CMD;
 		break;
+	case CFFPS_DEBUGFS_MAX_POWER_OUT:
+		rc = i2c_smbus_read_word_swapped(psu->client,
+						 CFFPS_MAX_POWER_OUT_CMD);
+		if (rc < 0)
+			return rc;
+
+		rc = snprintf(data, I2C_SMBUS_BLOCK_MAX, "%d", rc);
+		goto done;
 	case CFFPS_DEBUGFS_CCIN:
 		rc = i2c_smbus_read_word_swapped(psu->client, CFFPS_CCIN_CMD);
 		if (rc < 0)
@@ -199,6 +215,14 @@ static ssize_t ibm_cffps_debugfs_op(struct file *file, char __user *buf,
 			return -EOPNOTSUPP;
 		}
 		goto done;
+	case CFFPS_DEBUGFS_ON_OFF_CONFIG:
+		rc = i2c_smbus_read_byte_data(psu->client,
+					      PMBUS_ON_OFF_CONFIG);
+		if (rc < 0)
+			return rc;
+
+		rc = snprintf(data, 3, "%02x", rc);
+		goto done;
 	default:
 		return -EINVAL;
 	}
@@ -214,9 +238,42 @@ static ssize_t ibm_cffps_debugfs_op(struct file *file, char __user *buf,
 	return simple_read_from_buffer(buf, count, ppos, data, rc);
 }
 
+static ssize_t ibm_cffps_debugfs_write(struct file *file,
+				       const char __user *buf, size_t count,
+				       loff_t *ppos)
+{
+	u8 data;
+	ssize_t rc;
+	int *idxp = file->private_data;
+	int idx = *idxp;
+	struct ibm_cffps *psu = to_psu(idxp, idx);
+
+	switch (idx) {
+	case CFFPS_DEBUGFS_ON_OFF_CONFIG:
+		pmbus_set_page(psu->client, 0);
+
+		rc = simple_write_to_buffer(&data, 1, ppos, buf, count);
+		if (rc < 0)
+			return rc;
+
+		rc = i2c_smbus_write_byte_data(psu->client,
+					       PMBUS_ON_OFF_CONFIG, data);
+		if (rc)
+			return rc;
+
+		rc = 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return rc;
+}
+
 static const struct file_operations ibm_cffps_fops = {
 	.llseek = noop_llseek,
-	.read = ibm_cffps_debugfs_op,
+	.read = ibm_cffps_debugfs_read,
+	.write = ibm_cffps_debugfs_write,
 	.open = simple_open,
 };
 
@@ -486,15 +543,24 @@ static int ibm_cffps_probe(struct i2c_client *client,
 	debugfs_create_file("part_number", 0444, ibm_cffps_dir,
 			    &psu->debugfs_entries[CFFPS_DEBUGFS_PN],
 			    &ibm_cffps_fops);
+	debugfs_create_file("header", 0444, ibm_cffps_dir,
+			    &psu->debugfs_entries[CFFPS_DEBUGFS_HEADER],
+			    &ibm_cffps_fops);
 	debugfs_create_file("serial_number", 0444, ibm_cffps_dir,
 			    &psu->debugfs_entries[CFFPS_DEBUGFS_SN],
 			    &ibm_cffps_fops);
+	debugfs_create_file("max_power_out", 0444, ibm_cffps_dir,
+			    &psu->debugfs_entries[CFFPS_DEBUGFS_MAX_POWER_OUT],
+			    &ibm_cffps_fops);
 	debugfs_create_file("ccin", 0444, ibm_cffps_dir,
 			    &psu->debugfs_entries[CFFPS_DEBUGFS_CCIN],
 			    &ibm_cffps_fops);
 	debugfs_create_file("fw_version", 0444, ibm_cffps_dir,
 			    &psu->debugfs_entries[CFFPS_DEBUGFS_FW],
 			    &ibm_cffps_fops);
+	debugfs_create_file("on_off_config", 0644, ibm_cffps_dir,
+			    &psu->debugfs_entries[CFFPS_DEBUGFS_ON_OFF_CONFIG],
+			    &ibm_cffps_fops);
 
 	return 0;
 }