ucd9000.c

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/*
 * Hardware monitoring driver for UCD90xxx Sequencer and System Health
 * Controller series
 *
 * Copyright (C) 2011 Ericsson AB.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/i2c/pmbus.h>
#include "pmbus.h"

enum chips { ucd9000, ucd90120, ucd90124, ucd9090, ucd90910 };

#define UCD9000_MONITOR_CONFIG      0xd5
#define UCD9000_NUM_PAGES       0xd6
#define UCD9000_FAN_CONFIG_INDEX    0xe7
#define UCD9000_FAN_CONFIG      0xe8
#define UCD9000_DEVICE_ID       0xfd

#define UCD9000_MON_TYPE(x) (((x) >> 5) & 0x07)
#define UCD9000_MON_PAGE(x) ((x) & 0x0f)

#define UCD9000_MON_VOLTAGE 1
#define UCD9000_MON_TEMPERATURE 2
#define UCD9000_MON_CURRENT 3
#define UCD9000_MON_VOLTAGE_HW  4

#define UCD9000_NUM_FAN     4

struct ucd9000_data {
    u8 fan_data[UCD9000_NUM_FAN][I2C_SMBUS_BLOCK_MAX];
    struct pmbus_driver_info info;
};
#define to_ucd9000_data(_info) container_of(_info, struct ucd9000_data, info)

static int ucd9000_get_fan_config(struct i2c_client *client, int fan)
{
    int fan_config = 0;
    struct ucd9000_data *data
      = to_ucd9000_data(pmbus_get_driver_info(client));

    if (data->fan_data[fan][3] & 1)
        fan_config |= PB_FAN_2_INSTALLED;   /* Use lower bit position */

    /* Pulses/revolution */
    fan_config |= (data->fan_data[fan][3] & 0x06) >> 1;

    return fan_config;
}

static int ucd9000_read_byte_data(struct i2c_client *client, int page, int reg)
{
    int ret = 0;
    int fan_config;

    switch (reg) {
    case PMBUS_FAN_CONFIG_12:
        if (page > 0)
            return -ENXIO;

        ret = ucd9000_get_fan_config(client, 0);
        if (ret < 0)
            return ret;
        fan_config = ret << 4;
        ret = ucd9000_get_fan_config(client, 1);
        if (ret < 0)
            return ret;
        fan_config |= ret;
        ret = fan_config;
        break;
    case PMBUS_FAN_CONFIG_34:
        if (page > 0)
            return -ENXIO;

        ret = ucd9000_get_fan_config(client, 2);
        if (ret < 0)
            return ret;
        fan_config = ret << 4;
        ret = ucd9000_get_fan_config(client, 3);
        if (ret < 0)
            return ret;
        fan_config |= ret;
        ret = fan_config;
        break;
    default:
        ret = -ENODATA;
        break;
    }
    return ret;
}

static const struct i2c_device_id ucd9000_id[] = {
    {"ucd9000", ucd9000},
    {"ucd90120", ucd90120},
    {"ucd90124", ucd90124},
    {"ucd9090", ucd9090},
    {"ucd90910", ucd90910},
    {}
};
MODULE_DEVICE_TABLE(i2c, ucd9000_id);

static int ucd9000_probe(struct i2c_client *client,
             const struct i2c_device_id *id)
{
    u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
    struct ucd9000_data *data;
    struct pmbus_driver_info *info;
    const struct i2c_device_id *mid;
    int i, ret;

    if (!i2c_check_functionality(client->adapter,
                     I2C_FUNC_SMBUS_BYTE_DATA |
                     I2C_FUNC_SMBUS_BLOCK_DATA))
        return -ENODEV;

    ret = i2c_smbus_read_block_data(client, UCD9000_DEVICE_ID,
                    block_buffer);
    if (ret < 0) {
        dev_err(&client->dev, "Failed to read device ID\n");
        return ret;
    }
    block_buffer[ret] = '\0';
    dev_info(&client->dev, "Device ID %s\n", block_buffer);

    for (mid = ucd9000_id; mid->name[0]; mid++) {
        if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
            break;
    }
    if (!mid->name[0]) {
        dev_err(&client->dev, "Unsupported device\n");
        return -ENODEV;
    }

    if (id->driver_data != ucd9000 && id->driver_data != mid->driver_data)
        dev_notice(&client->dev,
               "Device mismatch: Configured %s, detected %s\n",
               id->name, mid->name);

    data = devm_kzalloc(&client->dev, sizeof(struct ucd9000_data),
                GFP_KERNEL);
    if (!data)
        return -ENOMEM;
    info = &data->info;

    ret = i2c_smbus_read_byte_data(client, UCD9000_NUM_PAGES);
    if (ret < 0) {
        dev_err(&client->dev,
            "Failed to read number of active pages\n");
        return ret;
    }
    info->pages = ret;
    if (!info->pages) {
        dev_err(&client->dev, "No pages configured\n");
        return -ENODEV;
    }

    /* The internal temperature sensor is always active */
    info->func[0] = PMBUS_HAVE_TEMP;

    /* Everything else is configurable */
    ret = i2c_smbus_read_block_data(client, UCD9000_MONITOR_CONFIG,
                    block_buffer);
    if (ret <= 0) {
        dev_err(&client->dev, "Failed to read configuration data\n");
        return -ENODEV;
    }
    for (i = 0; i < ret; i++) {
        int page = UCD9000_MON_PAGE(block_buffer[i]);

        if (page >= info->pages)
            continue;

        switch (UCD9000_MON_TYPE(block_buffer[i])) {
        case UCD9000_MON_VOLTAGE:
        case UCD9000_MON_VOLTAGE_HW:
            info->func[page] |= PMBUS_HAVE_VOUT
              | PMBUS_HAVE_STATUS_VOUT;
            break;
        case UCD9000_MON_TEMPERATURE:
            info->func[page] |= PMBUS_HAVE_TEMP2
              | PMBUS_HAVE_STATUS_TEMP;
            break;
        case UCD9000_MON_CURRENT:
            info->func[page] |= PMBUS_HAVE_IOUT
              | PMBUS_HAVE_STATUS_IOUT;
            break;
        default:
            break;
        }
    }

    /* Fan configuration */
    if (mid->driver_data == ucd90124) {
        for (i = 0; i < UCD9000_NUM_FAN; i++) {
            i2c_smbus_write_byte_data(client,
                          UCD9000_FAN_CONFIG_INDEX, i);
            ret = i2c_smbus_read_block_data(client,
                            UCD9000_FAN_CONFIG,
                            data->fan_data[i]);
            if (ret < 0)
                return ret;
        }
        i2c_smbus_write_byte_data(client, UCD9000_FAN_CONFIG_INDEX, 0);

        info->read_byte_data = ucd9000_read_byte_data;
        info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12
          | PMBUS_HAVE_FAN34 | PMBUS_HAVE_STATUS_FAN34;
    }

    return pmbus_do_probe(client, mid, info);
}

/* This is the driver that will be inserted */
static struct i2c_driver ucd9000_driver = {
    .driver = {
        .name = "ucd9000",
    },
    .probe = ucd9000_probe,
    .remove = pmbus_do_remove,
    .id_table = ucd9000_id,
};

module_i2c_driver(ucd9000_driver);

MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for TI UCD90xxx");
MODULE_LICENSE("GPL");