// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Hardware monitoring driver for ucd9200 series Digital PWM System Controllers
 *
 * Copyright (C) 2011 Ericsson AB.
 */

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

#define UCD9200_PHASE_INFO      0xd2
#define UCD9200_DEVICE_ID       0xfd

enum chips { ucd9200, ucd9220, ucd9222, ucd9224, ucd9240, ucd9244, ucd9246,
             ucd9248 };

static const struct i2c_device_id ucd9200_id[] = {
        {"ucd9200", ucd9200},
        {"ucd9220", ucd9220},
        {"ucd9222", ucd9222},
        {"ucd9224", ucd9224},
        {"ucd9240", ucd9240},
        {"ucd9244", ucd9244},
        {"ucd9246", ucd9246},
        {"ucd9248", ucd9248},
        {}
};
MODULE_DEVICE_TABLE(i2c, ucd9200_id);

static const struct of_device_id __maybe_unused ucd9200_of_match[] = {
        {
                .compatible = "ti,cd9200",
                .data = (void *)ucd9200
        },
        {
                .compatible = "ti,cd9220",
                .data = (void *)ucd9220
        },
        {
                .compatible = "ti,cd9222",
                .data = (void *)ucd9222
        },
        {
                .compatible = "ti,cd9224",
                .data = (void *)ucd9224
        },
        {
                .compatible = "ti,cd9240",
                .data = (void *)ucd9240
        },
        {
                .compatible = "ti,cd9244",
                .data = (void *)ucd9244
        },
        {
                .compatible = "ti,cd9246",
                .data = (void *)ucd9246
        },
        {
                .compatible = "ti,cd9248",
                .data = (void *)ucd9248
        },
        { },
};
MODULE_DEVICE_TABLE(of, ucd9200_of_match);

static int ucd9200_probe(struct i2c_client *client)
{
        u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
        struct pmbus_driver_info *info;
        const struct i2c_device_id *mid;
        enum chips chip;
        int i, j, 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, UCD9200_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 = ucd9200_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 (client->dev.of_node)
                chip = (uintptr_t)of_device_get_match_data(&client->dev);
        else
                chip = mid->driver_data;

        if (chip != ucd9200 && strcmp(client->name, mid->name) != 0)
                dev_notice(&client->dev,
                           "Device mismatch: Configured %s, detected %s\n",
                           client->name, mid->name);

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

        ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO,
                                        block_buffer);
        if (ret < 0) {
                dev_err(&client->dev, "Failed to read phase information\n");
                return ret;
        }

        /*
         * Calculate number of configured pages (rails) from PHASE_INFO
         * register.
         * Rails have to be sequential, so we can abort after finding
         * the first unconfigured rail.
         */
        info->pages = 0;
        for (i = 0; i < ret; i++) {
                if (!block_buffer[i])
                        break;
                info->pages++;
        }
        if (!info->pages) {
                dev_err(&client->dev, "No rails configured\n");
                return -ENODEV;
        }
        dev_info(&client->dev, "%d rails configured\n", info->pages);

        /*
         * Set PHASE registers on all pages to 0xff to ensure that phase
         * specific commands will apply to all phases of a given page (rail).
         * This only affects the READ_IOUT and READ_TEMPERATURE2 registers.
         * READ_IOUT will return the sum of currents of all phases of a rail,
         * and READ_TEMPERATURE2 will return the maximum temperature detected
         * for the phases of the rail.
         */
        for (i = 0; i < info->pages; i++) {
                /*
                 * Setting PAGE & PHASE fails once in a while for no obvious
                 * reason, so we need to retry a couple of times.
                 */
                for (j = 0; j < 3; j++) {
                        ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
                        if (ret < 0)
                                continue;
                        ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE,
                                                        0xff);
                        if (ret < 0)
                                continue;
                        break;
                }
                if (ret < 0) {
                        dev_err(&client->dev,
                                "Failed to initialize PHASE registers\n");
                        return ret;
                }
        }
        if (info->pages > 1)
                i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);

        info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
                        PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
                        PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
                        PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
                        PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP |
                        PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;

        for (i = 1; i < info->pages; i++)
                info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
                        PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
                        PMBUS_HAVE_POUT |
                        PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;

        /* ucd9240 supports a single fan */
        if (mid->driver_data == ucd9240)
                info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12;

        return pmbus_do_probe(client, info);
}

/* This is the driver that will be inserted */
static struct i2c_driver ucd9200_driver = {
        .driver = {
                .name = "ucd9200",
                .of_match_table = of_match_ptr(ucd9200_of_match),
        },
        .probe = ucd9200_probe,
        .id_table = ucd9200_id,
};

module_i2c_driver(ucd9200_driver);

MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("PMBUS");