// SPDX-License-Identifier: GPL-2.0-only
/*
 * Windfarm PowerMac thermal control. LM75 sensor
 *
 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
 *                    <benh@kernel.crashing.org>
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/i2c.h>
#include <linux/of.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/sections.h>
#include <asm/pmac_low_i2c.h>

#include "windfarm.h"

#define VERSION "1.0"

#undef DEBUG

#ifdef DEBUG
#define DBG(args...)    printk(args)
#else
#define DBG(args...)    do { } while(0)
#endif

struct wf_lm75_sensor {
        unsigned int            ds1775 : 1;
        unsigned int            inited : 1;
        struct i2c_client       *i2c;
        struct wf_sensor        sens;
};
#define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)

static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
{
        struct wf_lm75_sensor *lm = wf_to_lm75(sr);
        s32 data;

        if (lm->i2c == NULL)
                return -ENODEV;

        /* Init chip if necessary */
        if (!lm->inited) {
                u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);

                DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
                    sr->name, cfg);

                /* clear shutdown bit, keep other settings as left by
                 * the firmware for now
                 */
                cfg_new = cfg & ~0x01;
                i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
                lm->inited = 1;

                /* If we just powered it up, let's wait 200 ms */
                msleep(200);
        }

        /* Read temperature register */
        data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
        data <<= 8;
        *value = data;

        return 0;
}

static void wf_lm75_release(struct wf_sensor *sr)
{
        struct wf_lm75_sensor *lm = wf_to_lm75(sr);

        kfree(lm);
}

static const struct wf_sensor_ops wf_lm75_ops = {
        .get_value      = wf_lm75_get,
        .release        = wf_lm75_release,
        .owner          = THIS_MODULE,
};

static int wf_lm75_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        struct wf_lm75_sensor *lm;
        int rc, ds1775;
        const char *name, *loc;

        if (id)
                ds1775 = id->driver_data;
        else
                ds1775 = !!of_device_get_match_data(&client->dev);

        DBG("wf_lm75: creating  %s device at address 0x%02x\n",
            ds1775 ? "ds1775" : "lm75", client->addr);

        loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
        if (!loc) {
                dev_warn(&client->dev, "Missing hwsensor-location property!\n");
                return -ENXIO;
        }

        /* Usual rant about sensor names not beeing very consistent in
         * the device-tree, oh well ...
         * Add more entries below as you deal with more setups
         */
        if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
                name = "hd-temp";
        else if (!strcmp(loc, "Incoming Air Temp"))
                name = "incoming-air-temp";
        else if (!strcmp(loc, "ODD Temp"))
                name = "optical-drive-temp";
        else if (!strcmp(loc, "HD Temp"))
                name = "hard-drive-temp";
        else if (!strcmp(loc, "PCI SLOTS"))
                name = "slots-temp";
        else if (!strcmp(loc, "CPU A INLET"))
                name = "cpu-inlet-temp-0";
        else if (!strcmp(loc, "CPU B INLET"))
                name = "cpu-inlet-temp-1";
        else
                return -ENXIO;
        

        lm = kzalloc_obj(struct wf_lm75_sensor);
        if (lm == NULL)
                return -ENODEV;

        lm->inited = 0;
        lm->ds1775 = ds1775;
        lm->i2c = client;
        lm->sens.name = name;
        lm->sens.ops = &wf_lm75_ops;
        i2c_set_clientdata(client, lm);

        rc = wf_register_sensor(&lm->sens);
        if (rc)
                kfree(lm);
        return rc;
}

static void wf_lm75_remove(struct i2c_client *client)
{
        struct wf_lm75_sensor *lm = i2c_get_clientdata(client);

        /* Mark client detached */
        lm->i2c = NULL;

        /* release sensor */
        wf_unregister_sensor(&lm->sens);
}

static const struct i2c_device_id wf_lm75_id[] = {
        { "MAC,lm75", 0 },
        { "MAC,ds1775", 1 },
        { }
};
MODULE_DEVICE_TABLE(i2c, wf_lm75_id);

static const struct of_device_id wf_lm75_of_id[] = {
        { .compatible = "lm75", .data = (void *)0},
        { .compatible = "ds1775", .data = (void *)1 },
        { }
};
MODULE_DEVICE_TABLE(of, wf_lm75_of_id);

static struct i2c_driver wf_lm75_driver = {
        .driver = {
                .name   = "wf_lm75",
                .of_match_table = wf_lm75_of_id,
        },
        .probe          = wf_lm75_probe,
        .remove         = wf_lm75_remove,
        .id_table       = wf_lm75_id,
};

module_i2c_driver(wf_lm75_driver);

MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
MODULE_LICENSE("GPL");