drivers/hwmon/pmbus/ibm-cffps.c - linux - Git at Google

 /*
  * Copyright 2017 IBM Corp.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */

 #include <linux/bitops.h>
 #include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/fs.h>
 #include <linux/i2c.h>
 #include <linux/jiffies.h>
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/pmbus.h>

 #include "pmbus.h"

 #define CFFPS_FRU_CMD				0x9A
 #define CFFPS_PN_CMD				0x9B
 #define CFFPS_SN_CMD				0x9E
 #define CFFPS_CCIN_CMD				0xBD
 #define CFFPS_FW_CMD_START			0xFA
 #define CFFPS_FW_NUM_BYTES			4
 #define CFFPS_SYS_CONFIG_CMD			0xDA

 #define CFFPS_INPUT_HISTORY_CMD			0xD6
 #define CFFPS_INPUT_HISTORY_SIZE		100

 /* STATUS_MFR_SPECIFIC bits */
 #define CFFPS_MFR_FAN_FAULT			BIT(0)
 #define CFFPS_MFR_THERMAL_FAULT			BIT(1)
 #define CFFPS_MFR_OV_FAULT			BIT(2)
 #define CFFPS_MFR_UV_FAULT			BIT(3)
 #define CFFPS_MFR_PS_KILL			BIT(4)
 #define CFFPS_MFR_OC_FAULT			BIT(5)
 #define CFFPS_MFR_VAUX_FAULT			BIT(6)
 #define CFFPS_MFR_CURRENT_SHARE_WARNING		BIT(7)

 #define CFFPS_LED_BLINK				BIT(0)
 #define CFFPS_LED_ON				BIT(1)
 #define CFFPS_LED_OFF				BIT(2)
 #define CFFPS_BLINK_RATE_MS			250

 enum {
 	CFFPS_DEBUGFS_INPUT_HISTORY = 0,
 	CFFPS_DEBUGFS_FRU,
 	CFFPS_DEBUGFS_PN,
 	CFFPS_DEBUGFS_SN,
 	CFFPS_DEBUGFS_CCIN,
 	CFFPS_DEBUGFS_FW,
 	CFFPS_DEBUGFS_NUM_ENTRIES
 };

 struct ibm_cffps_input_history {
 	struct mutex update_lock;
 	unsigned long last_update;

 	u8 byte_count;
 	u8 data[CFFPS_INPUT_HISTORY_SIZE];
 };

 struct ibm_cffps {
 	struct i2c_client *client;

 	struct ibm_cffps_input_history input_history;

 	int debugfs_entries[CFFPS_DEBUGFS_NUM_ENTRIES];

 	char led_name[32];
 	u8 led_state;
 	struct led_classdev led;
 };

 #define to_psu(x, y) container_of((x), struct ibm_cffps, debugfs_entries[(y)])

 static ssize_t ibm_cffps_read_input_history(struct ibm_cffps *psu,
 					    char __user *buf, size_t count,
 					    loff_t *ppos)
 {
 	int rc;
 	u8 msgbuf0[1] = { CFFPS_INPUT_HISTORY_CMD };
 	u8 msgbuf1[CFFPS_INPUT_HISTORY_SIZE + 1] = { 0 };
 	struct i2c_msg msg[2] = {
 		{
 			.addr = psu->client->addr,
 			.flags = psu->client->flags,
 			.len = 1,
 			.buf = msgbuf0,
 		}, {
 			.addr = psu->client->addr,
 			.flags = psu->client->flags | I2C_M_RD,
 			.len = CFFPS_INPUT_HISTORY_SIZE + 1,
 			.buf = msgbuf1,
 		},
 	};

 	if (!*ppos) {
 		mutex_lock(&psu->input_history.update_lock);
 		if (time_after(jiffies, psu->input_history.last_update + HZ)) {
 			/*
 			 * Use a raw i2c transfer, since we need more bytes
 			 * than Linux I2C supports through smbus xfr (only 32).
 			 */
 			rc = i2c_transfer(psu->client->adapter, msg, 2);
 			if (rc < 0) {
 				mutex_unlock(&psu->input_history.update_lock);
 				return rc;
 			}

 			psu->input_history.byte_count = msgbuf1[0];
 			memcpy(psu->input_history.data, &msgbuf1[1],
 			       CFFPS_INPUT_HISTORY_SIZE);
 			psu->input_history.last_update = jiffies;
 		}

 		mutex_unlock(&psu->input_history.update_lock);
 	}

 	return simple_read_from_buffer(buf, count, ppos,
 				       psu->input_history.data,
 				       psu->input_history.byte_count);
 }

 static ssize_t ibm_cffps_debugfs_op(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 };

 	switch (idx) {
 	case CFFPS_DEBUGFS_INPUT_HISTORY:
 		return ibm_cffps_read_input_history(psu, buf, count, ppos);
 	case CFFPS_DEBUGFS_FRU:
 		cmd = CFFPS_FRU_CMD;
 		break;
 	case CFFPS_DEBUGFS_PN:
 		cmd = CFFPS_PN_CMD;
 		break;
 	case CFFPS_DEBUGFS_SN:
 		cmd = CFFPS_SN_CMD;
 		break;
 	case CFFPS_DEBUGFS_CCIN:
 		rc = i2c_smbus_read_word_swapped(psu->client, CFFPS_CCIN_CMD);
 		if (rc < 0)
 			return rc;

 		rc = snprintf(data, 5, "%04X", rc);
 		goto done;
 	case CFFPS_DEBUGFS_FW:
 		for (i = 0; i < CFFPS_FW_NUM_BYTES; ++i) {
 			rc = i2c_smbus_read_byte_data(psu->client,
 						      CFFPS_FW_CMD_START + i);
 			if (rc < 0)
 				return rc;

 			snprintf(&data[i * 2], 3, "%02X", rc);
 		}

 		rc = i * 2;
 		goto done;
 	default:
 		return -EINVAL;
 	}

 	rc = i2c_smbus_read_block_data(psu->client, cmd, data);
 	if (rc < 0)
 		return rc;

 done:
 	data[rc] = '\n';
 	rc += 2;

 	return simple_read_from_buffer(buf, count, ppos, data, rc);
 }

 static const struct file_operations ibm_cffps_fops = {
 	.llseek = noop_llseek,
 	.read = ibm_cffps_debugfs_op,
 	.open = simple_open,
 };

 static int ibm_cffps_read_byte_data(struct i2c_client *client, int page,
 				    int reg)
 {
 	int rc, mfr;

 	switch (reg) {
 	case PMBUS_STATUS_VOUT:
 	case PMBUS_STATUS_IOUT:
 	case PMBUS_STATUS_TEMPERATURE:
 	case PMBUS_STATUS_FAN_12:
 		rc = pmbus_read_byte_data(client, page, reg);
 		if (rc < 0)
 			return rc;

 		mfr = pmbus_read_byte_data(client, page,
 					   PMBUS_STATUS_MFR_SPECIFIC);
 		if (mfr < 0)
 			/*
 			 * Return the status register instead of an error,
 			 * since we successfully read status.
 			 */
 			return rc;

 		/* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
 		if (reg == PMBUS_STATUS_FAN_12) {
 			if (mfr & CFFPS_MFR_FAN_FAULT)
 				rc |= PB_FAN_FAN1_FAULT;
 		} else if (reg == PMBUS_STATUS_TEMPERATURE) {
 			if (mfr & CFFPS_MFR_THERMAL_FAULT)
 				rc |= PB_TEMP_OT_FAULT;
 		} else if (reg == PMBUS_STATUS_VOUT) {
 			if (mfr & (CFFPS_MFR_OV_FAULT | CFFPS_MFR_VAUX_FAULT))
 				rc |= PB_VOLTAGE_OV_FAULT;
 			if (mfr & CFFPS_MFR_UV_FAULT)
 				rc |= PB_VOLTAGE_UV_FAULT;
 		} else if (reg == PMBUS_STATUS_IOUT) {
 			if (mfr & CFFPS_MFR_OC_FAULT)
 				rc |= PB_IOUT_OC_FAULT;
 			if (mfr & CFFPS_MFR_CURRENT_SHARE_WARNING)
 				rc |= PB_CURRENT_SHARE_FAULT;
 		}
 		break;
 	default:
 		rc = -ENODATA;
 		break;
 	}

 	return rc;
 }

 static int ibm_cffps_read_word_data(struct i2c_client *client, int page,
 				    int reg)
 {
 	int rc, mfr;

 	switch (reg) {
 	case PMBUS_STATUS_WORD:
 		rc = pmbus_read_word_data(client, page, reg);
 		if (rc < 0)
 			return rc;

 		mfr = pmbus_read_byte_data(client, page,
 					   PMBUS_STATUS_MFR_SPECIFIC);
 		if (mfr < 0)
 			/*
 			 * Return the status register instead of an error,
 			 * since we successfully read status.
 			 */
 			return rc;

 		if (mfr & CFFPS_MFR_PS_KILL)
 			rc |= PB_STATUS_OFF;
 		break;
 	default:
 		rc = -ENODATA;
 		break;
 	}

 	return rc;
 }

 static void ibm_cffps_led_brightness_set(struct led_classdev *led_cdev,
 					 enum led_brightness brightness)
 {
 	int rc;
 	struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);

 	if (brightness == LED_OFF) {
 		psu->led_state = CFFPS_LED_OFF;
 	} else {
 		brightness = LED_FULL;
 		if (psu->led_state != CFFPS_LED_BLINK)
 			psu->led_state = CFFPS_LED_ON;
 	}

 	rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
 				       psu->led_state);
 	if (rc < 0)
 		return;

 	led_cdev->brightness = brightness;
 }

 static int ibm_cffps_led_blink_set(struct led_classdev *led_cdev,
 				   unsigned long *delay_on,
 				   unsigned long *delay_off)
 {
 	int rc;
 	struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);

 	psu->led_state = CFFPS_LED_BLINK;

 	if (led_cdev->brightness == LED_OFF)
 		return 0;

 	rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
 				       CFFPS_LED_BLINK);
 	if (rc < 0)
 		return rc;

 	*delay_on = CFFPS_BLINK_RATE_MS;
 	*delay_off = CFFPS_BLINK_RATE_MS;

 	return 0;
 }

 static void ibm_cffps_create_led_class(struct ibm_cffps *psu)
 {
 	int rc;
 	struct i2c_client *client = psu->client;
 	struct device *dev = &client->dev;

 	snprintf(psu->led_name, sizeof(psu->led_name), "%s-%02x", client->name,
 		 client->addr);
 	psu->led.name = psu->led_name;
 	psu->led.max_brightness = LED_FULL;
 	psu->led.brightness_set = ibm_cffps_led_brightness_set;
 	psu->led.blink_set = ibm_cffps_led_blink_set;

 	rc = devm_led_classdev_register(dev, &psu->led);
 	if (rc)
 		dev_warn(dev, "failed to register led class: %d\n", rc);
 }

 static struct pmbus_driver_info ibm_cffps_info = {
 	.pages = 1,
 	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
 		PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
 		PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_VOUT |
 		PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT |
 		PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_STATUS_FAN12,
 	.read_byte_data = ibm_cffps_read_byte_data,
 	.read_word_data = ibm_cffps_read_word_data,
 };

 static struct pmbus_platform_data ibm_cffps_pdata = {
 	.flags = PMBUS_SKIP_STATUS_CHECK,
 };

 static int ibm_cffps_probe(struct i2c_client *client,
 			   const struct i2c_device_id *id)
 {
 	int i, rc;
 	struct dentry *debugfs;
 	struct dentry *ibm_cffps_dir;
 	struct ibm_cffps *psu;

 	client->dev.platform_data = &ibm_cffps_pdata;
 	rc = pmbus_do_probe(client, id, &ibm_cffps_info);
 	if (rc)
 		return rc;

 	/*
 	 * Don't fail the probe if there isn't enough memory for leds and
 	 * debugfs.
 	 */
 	psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL);
 	if (!psu)
 		return 0;

 	psu->client = client;
 	mutex_init(&psu->input_history.update_lock);
 	psu->input_history.last_update = jiffies - HZ;

 	ibm_cffps_create_led_class(psu);

 	/* Don't fail the probe if we can't create debugfs */
 	debugfs = pmbus_get_debugfs_dir(client);
 	if (!debugfs)
 		return 0;

 	ibm_cffps_dir = debugfs_create_dir(client->name, debugfs);
 	if (!ibm_cffps_dir)
 		return 0;

 	for (i = 0; i < CFFPS_DEBUGFS_NUM_ENTRIES; ++i)
 		psu->debugfs_entries[i] = i;

 	debugfs_create_file("input_history", 0444, ibm_cffps_dir,
 			    &psu->debugfs_entries[CFFPS_DEBUGFS_INPUT_HISTORY],
 			    &ibm_cffps_fops);
 	debugfs_create_file("fru", 0444, ibm_cffps_dir,
 			    &psu->debugfs_entries[CFFPS_DEBUGFS_FRU],
 			    &ibm_cffps_fops);
 	debugfs_create_file("part_number", 0444, ibm_cffps_dir,
 			    &psu->debugfs_entries[CFFPS_DEBUGFS_PN],
 			    &ibm_cffps_fops);
 	debugfs_create_file("serial_number", 0444, ibm_cffps_dir,
 			    &psu->debugfs_entries[CFFPS_DEBUGFS_SN],
 			    &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);

 	return 0;
 }

 static const struct i2c_device_id ibm_cffps_id[] = {
 	{ "ibm_cffps1", 1 },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, ibm_cffps_id);

 static const struct of_device_id ibm_cffps_of_match[] = {
 	{ .compatible = "ibm,cffps1" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, ibm_cffps_of_match);

 static struct i2c_driver ibm_cffps_driver = {
 	.driver = {
 		.name = "ibm-cffps",
 		.of_match_table = ibm_cffps_of_match,
 	},
 	.probe = ibm_cffps_probe,
 	.remove = pmbus_do_remove,
 	.id_table = ibm_cffps_id,
 };

 module_i2c_driver(ibm_cffps_driver);

 MODULE_AUTHOR("Eddie James");
 MODULE_DESCRIPTION("PMBus driver for IBM Common Form Factor power supplies");
 MODULE_LICENSE("GPL");
	/*
	* Copyright 2017 IBM Corp.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*/

	#include <linux/bitops.h>
	#include <linux/debugfs.h>
	#include <linux/device.h>
	#include <linux/fs.h>
	#include <linux/i2c.h>
	#include <linux/jiffies.h>
	#include <linux/leds.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/pmbus.h>

	#include "pmbus.h"

	#define CFFPS_FRU_CMD 0x9A
	#define CFFPS_PN_CMD 0x9B
	#define CFFPS_SN_CMD 0x9E
	#define CFFPS_CCIN_CMD 0xBD
	#define CFFPS_FW_CMD_START 0xFA
	#define CFFPS_FW_NUM_BYTES 4
	#define CFFPS_SYS_CONFIG_CMD 0xDA

	#define CFFPS_INPUT_HISTORY_CMD 0xD6
	#define CFFPS_INPUT_HISTORY_SIZE 100

	/* STATUS_MFR_SPECIFIC bits */
	#define CFFPS_MFR_FAN_FAULT BIT(0)
	#define CFFPS_MFR_THERMAL_FAULT BIT(1)
	#define CFFPS_MFR_OV_FAULT BIT(2)
	#define CFFPS_MFR_UV_FAULT BIT(3)
	#define CFFPS_MFR_PS_KILL BIT(4)
	#define CFFPS_MFR_OC_FAULT BIT(5)
	#define CFFPS_MFR_VAUX_FAULT BIT(6)
	#define CFFPS_MFR_CURRENT_SHARE_WARNING BIT(7)

	#define CFFPS_LED_BLINK BIT(0)
	#define CFFPS_LED_ON BIT(1)
	#define CFFPS_LED_OFF BIT(2)
	#define CFFPS_BLINK_RATE_MS 250

	enum {
	CFFPS_DEBUGFS_INPUT_HISTORY = 0,
	CFFPS_DEBUGFS_FRU,
	CFFPS_DEBUGFS_PN,
	CFFPS_DEBUGFS_SN,
	CFFPS_DEBUGFS_CCIN,
	CFFPS_DEBUGFS_FW,
	CFFPS_DEBUGFS_NUM_ENTRIES
	};

	struct ibm_cffps_input_history {
	struct mutex update_lock;
	unsigned long last_update;

	u8 byte_count;
	u8 data[CFFPS_INPUT_HISTORY_SIZE];
	};

	struct ibm_cffps {
	struct i2c_client *client;

	struct ibm_cffps_input_history input_history;

	int debugfs_entries[CFFPS_DEBUGFS_NUM_ENTRIES];

	char led_name[32];
	u8 led_state;
	struct led_classdev led;
	};

	#define to_psu(x, y) container_of((x), struct ibm_cffps, debugfs_entries[(y)])

	static ssize_t ibm_cffps_read_input_history(struct ibm_cffps *psu,
	char __user *buf, size_t count,
	loff_t *ppos)
	{
	int rc;
	u8 msgbuf0[1] = { CFFPS_INPUT_HISTORY_CMD };
	u8 msgbuf1[CFFPS_INPUT_HISTORY_SIZE + 1] = { 0 };
	struct i2c_msg msg[2] = {
	{
	.addr = psu->client->addr,
	.flags = psu->client->flags,
	.len = 1,
	.buf = msgbuf0,
	}, {
	.addr = psu->client->addr,
	.flags = psu->client->flags \| I2C_M_RD,
	.len = CFFPS_INPUT_HISTORY_SIZE + 1,
	.buf = msgbuf1,
	},
	};

	if (!*ppos) {
	mutex_lock(&psu->input_history.update_lock);
	if (time_after(jiffies, psu->input_history.last_update + HZ)) {
	/*
	* Use a raw i2c transfer, since we need more bytes
	* than Linux I2C supports through smbus xfr (only 32).
	*/
	rc = i2c_transfer(psu->client->adapter, msg, 2);
	if (rc < 0) {
	mutex_unlock(&psu->input_history.update_lock);
	return rc;
	}

	psu->input_history.byte_count = msgbuf1[0];
	memcpy(psu->input_history.data, &msgbuf1[1],
	CFFPS_INPUT_HISTORY_SIZE);
	psu->input_history.last_update = jiffies;
	}

	mutex_unlock(&psu->input_history.update_lock);
	}

	return simple_read_from_buffer(buf, count, ppos,
	psu->input_history.data,
	psu->input_history.byte_count);
	}

	static ssize_t ibm_cffps_debugfs_op(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 };

	switch (idx) {
	case CFFPS_DEBUGFS_INPUT_HISTORY:
	return ibm_cffps_read_input_history(psu, buf, count, ppos);
	case CFFPS_DEBUGFS_FRU:
	cmd = CFFPS_FRU_CMD;
	break;
	case CFFPS_DEBUGFS_PN:
	cmd = CFFPS_PN_CMD;
	break;
	case CFFPS_DEBUGFS_SN:
	cmd = CFFPS_SN_CMD;
	break;
	case CFFPS_DEBUGFS_CCIN:
	rc = i2c_smbus_read_word_swapped(psu->client, CFFPS_CCIN_CMD);
	if (rc < 0)
	return rc;

	rc = snprintf(data, 5, "%04X", rc);
	goto done;
	case CFFPS_DEBUGFS_FW:
	for (i = 0; i < CFFPS_FW_NUM_BYTES; ++i) {
	rc = i2c_smbus_read_byte_data(psu->client,
	CFFPS_FW_CMD_START + i);
	if (rc < 0)
	return rc;

	snprintf(&data[i * 2], 3, "%02X", rc);
	}

	rc = i * 2;
	goto done;
	default:
	return -EINVAL;
	}

	rc = i2c_smbus_read_block_data(psu->client, cmd, data);
	if (rc < 0)
	return rc;

	done:
	data[rc] = '\n';
	rc += 2;

	return simple_read_from_buffer(buf, count, ppos, data, rc);
	}

	static const struct file_operations ibm_cffps_fops = {
	.llseek = noop_llseek,
	.read = ibm_cffps_debugfs_op,
	.open = simple_open,
	};

	static int ibm_cffps_read_byte_data(struct i2c_client *client, int page,
	int reg)
	{
	int rc, mfr;

	switch (reg) {
	case PMBUS_STATUS_VOUT:
	case PMBUS_STATUS_IOUT:
	case PMBUS_STATUS_TEMPERATURE:
	case PMBUS_STATUS_FAN_12:
	rc = pmbus_read_byte_data(client, page, reg);
	if (rc < 0)
	return rc;

	mfr = pmbus_read_byte_data(client, page,
	PMBUS_STATUS_MFR_SPECIFIC);
	if (mfr < 0)
	/*
	* Return the status register instead of an error,
	* since we successfully read status.
	*/
	return rc;

	/* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
	if (reg == PMBUS_STATUS_FAN_12) {
	if (mfr & CFFPS_MFR_FAN_FAULT)
	rc \|= PB_FAN_FAN1_FAULT;
	} else if (reg == PMBUS_STATUS_TEMPERATURE) {
	if (mfr & CFFPS_MFR_THERMAL_FAULT)
	rc \|= PB_TEMP_OT_FAULT;
	} else if (reg == PMBUS_STATUS_VOUT) {
	if (mfr & (CFFPS_MFR_OV_FAULT \| CFFPS_MFR_VAUX_FAULT))
	rc \|= PB_VOLTAGE_OV_FAULT;
	if (mfr & CFFPS_MFR_UV_FAULT)
	rc \|= PB_VOLTAGE_UV_FAULT;
	} else if (reg == PMBUS_STATUS_IOUT) {
	if (mfr & CFFPS_MFR_OC_FAULT)
	rc \|= PB_IOUT_OC_FAULT;
	if (mfr & CFFPS_MFR_CURRENT_SHARE_WARNING)
	rc \|= PB_CURRENT_SHARE_FAULT;
	}
	break;
	default:
	rc = -ENODATA;
	break;
	}

	return rc;
	}

	static int ibm_cffps_read_word_data(struct i2c_client *client, int page,
	int reg)
	{
	int rc, mfr;

	switch (reg) {
	case PMBUS_STATUS_WORD:
	rc = pmbus_read_word_data(client, page, reg);
	if (rc < 0)
	return rc;

	mfr = pmbus_read_byte_data(client, page,
	PMBUS_STATUS_MFR_SPECIFIC);
	if (mfr < 0)
	/*
	* Return the status register instead of an error,
	* since we successfully read status.
	*/
	return rc;

	if (mfr & CFFPS_MFR_PS_KILL)
	rc \|= PB_STATUS_OFF;
	break;
	default:
	rc = -ENODATA;
	break;
	}

	return rc;
	}

	static void ibm_cffps_led_brightness_set(struct led_classdev *led_cdev,
	enum led_brightness brightness)
	{
	int rc;
	struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);

	if (brightness == LED_OFF) {
	psu->led_state = CFFPS_LED_OFF;
	} else {
	brightness = LED_FULL;
	if (psu->led_state != CFFPS_LED_BLINK)
	psu->led_state = CFFPS_LED_ON;
	}

	rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
	psu->led_state);
	if (rc < 0)
	return;

	led_cdev->brightness = brightness;
	}

	static int ibm_cffps_led_blink_set(struct led_classdev *led_cdev,
	unsigned long *delay_on,
	unsigned long *delay_off)
	{
	int rc;
	struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);

	psu->led_state = CFFPS_LED_BLINK;

	if (led_cdev->brightness == LED_OFF)
	return 0;

	rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
	CFFPS_LED_BLINK);
	if (rc < 0)
	return rc;

	*delay_on = CFFPS_BLINK_RATE_MS;
	*delay_off = CFFPS_BLINK_RATE_MS;

	return 0;
	}

	static void ibm_cffps_create_led_class(struct ibm_cffps *psu)
	{
	int rc;
	struct i2c_client *client = psu->client;
	struct device *dev = &client->dev;

	snprintf(psu->led_name, sizeof(psu->led_name), "%s-%02x", client->name,
	client->addr);
	psu->led.name = psu->led_name;
	psu->led.max_brightness = LED_FULL;
	psu->led.brightness_set = ibm_cffps_led_brightness_set;
	psu->led.blink_set = ibm_cffps_led_blink_set;

	rc = devm_led_classdev_register(dev, &psu->led);
	if (rc)
	dev_warn(dev, "failed to register led class: %d\n", rc);
	}

	static struct pmbus_driver_info ibm_cffps_info = {
	.pages = 1,
	.func[0] = PMBUS_HAVE_VIN \| PMBUS_HAVE_VOUT \| PMBUS_HAVE_IOUT \|
	PMBUS_HAVE_PIN \| PMBUS_HAVE_FAN12 \| PMBUS_HAVE_TEMP \|
	PMBUS_HAVE_TEMP2 \| PMBUS_HAVE_TEMP3 \| PMBUS_HAVE_STATUS_VOUT \|
	PMBUS_HAVE_STATUS_IOUT \| PMBUS_HAVE_STATUS_INPUT \|
	PMBUS_HAVE_STATUS_TEMP \| PMBUS_HAVE_STATUS_FAN12,
	.read_byte_data = ibm_cffps_read_byte_data,
	.read_word_data = ibm_cffps_read_word_data,
	};

	static struct pmbus_platform_data ibm_cffps_pdata = {
	.flags = PMBUS_SKIP_STATUS_CHECK,
	};

	static int ibm_cffps_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int i, rc;
	struct dentry *debugfs;
	struct dentry *ibm_cffps_dir;
	struct ibm_cffps *psu;

	client->dev.platform_data = &ibm_cffps_pdata;
	rc = pmbus_do_probe(client, id, &ibm_cffps_info);
	if (rc)
	return rc;

	/*
	* Don't fail the probe if there isn't enough memory for leds and
	* debugfs.
	*/
	psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL);
	if (!psu)
	return 0;

	psu->client = client;
	mutex_init(&psu->input_history.update_lock);
	psu->input_history.last_update = jiffies - HZ;

	ibm_cffps_create_led_class(psu);

	/* Don't fail the probe if we can't create debugfs */
	debugfs = pmbus_get_debugfs_dir(client);
	if (!debugfs)
	return 0;

	ibm_cffps_dir = debugfs_create_dir(client->name, debugfs);
	if (!ibm_cffps_dir)
	return 0;

	for (i = 0; i < CFFPS_DEBUGFS_NUM_ENTRIES; ++i)
	psu->debugfs_entries[i] = i;

	debugfs_create_file("input_history", 0444, ibm_cffps_dir,
	&psu->debugfs_entries[CFFPS_DEBUGFS_INPUT_HISTORY],
	&ibm_cffps_fops);
	debugfs_create_file("fru", 0444, ibm_cffps_dir,
	&psu->debugfs_entries[CFFPS_DEBUGFS_FRU],
	&ibm_cffps_fops);
	debugfs_create_file("part_number", 0444, ibm_cffps_dir,
	&psu->debugfs_entries[CFFPS_DEBUGFS_PN],
	&ibm_cffps_fops);
	debugfs_create_file("serial_number", 0444, ibm_cffps_dir,
	&psu->debugfs_entries[CFFPS_DEBUGFS_SN],
	&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);

	return 0;
	}

	static const struct i2c_device_id ibm_cffps_id[] = {
	{ "ibm_cffps1", 1 },
	{}
	};
	MODULE_DEVICE_TABLE(i2c, ibm_cffps_id);

	static const struct of_device_id ibm_cffps_of_match[] = {
	{ .compatible = "ibm,cffps1" },
	{}
	};
	MODULE_DEVICE_TABLE(of, ibm_cffps_of_match);

	static struct i2c_driver ibm_cffps_driver = {
	.driver = {
	.name = "ibm-cffps",
	.of_match_table = ibm_cffps_of_match,
	},
	.probe = ibm_cffps_probe,
	.remove = pmbus_do_remove,
	.id_table = ibm_cffps_id,
	};

	module_i2c_driver(ibm_cffps_driver);

	MODULE_AUTHOR("Eddie James");
	MODULE_DESCRIPTION("PMBus driver for IBM Common Form Factor power supplies");
	MODULE_LICENSE("GPL");