drivers/macintosh/windfarm_lm75_sensor.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Windfarm PowerMac thermal control. LM75 sensor
   4  *
   5  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   6  *                    <benh@kernel.crashing.org>
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/errno.h>
  11 #include <linux/kernel.h>
  12 #include <linux/delay.h>
  13 #include <linux/slab.h>
  14 #include <linux/init.h>
  15 #include <linux/wait.h>
  16 #include <linux/i2c.h>
  17 #include <asm/prom.h>
  18 #include <asm/machdep.h>
  19 #include <asm/io.h>
  20 #include <asm/sections.h>
  21 #include <asm/pmac_low_i2c.h>
  22
  23 #include "windfarm.h"
  24
  25 #define VERSION "1.0"
  26
  27 #undef DEBUG
  28
  29 #ifdef DEBUG
  30 #define DBG(args...)    printk(args)
  31 #else
  32 #define DBG(args...)    do { } while(0)
  33 #endif
  34
  35 struct wf_lm75_sensor {
  36         int                     ds1775 : 1;
  37         int                     inited : 1;
  38         struct i2c_client       *i2c;
  39         struct wf_sensor        sens;
  40 };
  41 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
  42
  43 static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
  44 {
  45         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
  46         s32 data;
  47
  48         if (lm->i2c == NULL)
  49                 return -ENODEV;
  50
  51         /* Init chip if necessary */
  52         if (!lm->inited) {
  53                 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);
  54
  55                 DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
  56                     sr->name, cfg);
  57
  58                 /* clear shutdown bit, keep other settings as left by
  59                  * the firmware for now
  60                  */
  61                 cfg_new = cfg & ~0x01;
  62                 i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
  63                 lm->inited = 1;
  64
  65                 /* If we just powered it up, let's wait 200 ms */
  66                 msleep(200);
  67         }
  68
  69         /* Read temperature register */
  70         data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
  71         data <<= 8;
  72         *value = data;
  73
  74         return 0;
  75 }
  76
  77 static void wf_lm75_release(struct wf_sensor *sr)
  78 {
  79         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
  80
  81         kfree(lm);
  82 }
  83
  84 static const struct wf_sensor_ops wf_lm75_ops = {
  85         .get_value      = wf_lm75_get,
  86         .release        = wf_lm75_release,
  87         .owner          = THIS_MODULE,
  88 };
  89
  90 static int wf_lm75_probe(struct i2c_client *client,
  91                          const struct i2c_device_id *id)
  92 {
  93         struct wf_lm75_sensor *lm;
  94         int rc, ds1775 = id->driver_data;
  95         const char *name, *loc;
  96
  97         DBG("wf_lm75: creating  %s device at address 0x%02x\n",
  98             ds1775 ? "ds1775" : "lm75", client->addr);
  99
 100         loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
 101         if (!loc) {
 102                 dev_warn(&client->dev, "Missing hwsensor-location property!\n");
 103                 return -ENXIO;
 104         }
 105
 106         /* Usual rant about sensor names not beeing very consistent in
 107          * the device-tree, oh well ...
 108          * Add more entries below as you deal with more setups
 109          */
 110         if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
 111                 name = "hd-temp";
 112         else if (!strcmp(loc, "Incoming Air Temp"))
 113                 name = "incoming-air-temp";
 114         else if (!strcmp(loc, "ODD Temp"))
 115                 name = "optical-drive-temp";
 116         else if (!strcmp(loc, "HD Temp"))
 117                 name = "hard-drive-temp";
 118         else if (!strcmp(loc, "PCI SLOTS"))
 119                 name = "slots-temp";
 120         else if (!strcmp(loc, "CPU A INLET"))
 121                 name = "cpu-inlet-temp-0";
 122         else if (!strcmp(loc, "CPU B INLET"))
 123                 name = "cpu-inlet-temp-1";
 124         else
 125                 return -ENXIO;
 126
 127
 128         lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
 129         if (lm == NULL)
 130                 return -ENODEV;
 131
 132         lm->inited = 0;
 133         lm->ds1775 = ds1775;
 134         lm->i2c = client;
 135         lm->sens.name = name;
 136         lm->sens.ops = &wf_lm75_ops;
 137         i2c_set_clientdata(client, lm);
 138
 139         rc = wf_register_sensor(&lm->sens);
 140         if (rc)
 141                 kfree(lm);
 142         return rc;
 143 }
 144
 145 static int wf_lm75_remove(struct i2c_client *client)
 146 {
 147         struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
 148
 149         DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
 150
 151         /* Mark client detached */
 152         lm->i2c = NULL;
 153
 154         /* release sensor */
 155         wf_unregister_sensor(&lm->sens);
 156
 157         return 0;
 158 }
 159
 160 static const struct i2c_device_id wf_lm75_id[] = {
 161         { "MAC,lm75", 0 },
 162         { "MAC,ds1775", 1 },
 163         { }
 164 };
 165 MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
 166
 167 static struct i2c_driver wf_lm75_driver = {
 168         .driver = {
 169                 .name   = "wf_lm75",
 170         },
 171         .probe          = wf_lm75_probe,
 172         .remove         = wf_lm75_remove,
 173         .id_table       = wf_lm75_id,
 174 };
 175
 176 module_i2c_driver(wf_lm75_driver);
 177
 178 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 179 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
 180 MODULE_LICENSE("GPL");
 181