linux/drivers/macintosh/windfarm_lm75_sensor.c
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   1/*
   2 * Windfarm PowerMac thermal control. LM75 sensor
   3 *
   4 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   5 *                    <benh@kernel.crashing.org>
   6 *
   7 * Released under the term of the GNU GPL v2.
   8 */
   9
  10#include <linux/types.h>
  11#include <linux/errno.h>
  12#include <linux/kernel.h>
  13#include <linux/delay.h>
  14#include <linux/slab.h>
  15#include <linux/init.h>
  16#include <linux/wait.h>
  17#include <linux/i2c.h>
  18#include <asm/prom.h>
  19#include <asm/machdep.h>
  20#include <asm/io.h>
  21#include <asm/sections.h>
  22#include <asm/pmac_low_i2c.h>
  23
  24#include "windfarm.h"
  25
  26#define VERSION "1.0"
  27
  28#undef DEBUG
  29
  30#ifdef DEBUG
  31#define DBG(args...)    printk(args)
  32#else
  33#define DBG(args...)    do { } while(0)
  34#endif
  35
  36struct wf_lm75_sensor {
  37        int                     ds1775 : 1;
  38        int                     inited : 1;
  39        struct i2c_client       *i2c;
  40        struct wf_sensor        sens;
  41};
  42#define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
  43
  44static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
  45{
  46        struct wf_lm75_sensor *lm = wf_to_lm75(sr);
  47        s32 data;
  48
  49        if (lm->i2c == NULL)
  50                return -ENODEV;
  51
  52        /* Init chip if necessary */
  53        if (!lm->inited) {
  54                u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);
  55
  56                DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
  57                    sr->name, cfg);
  58
  59                /* clear shutdown bit, keep other settings as left by
  60                 * the firmware for now
  61                 */
  62                cfg_new = cfg & ~0x01;
  63                i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
  64                lm->inited = 1;
  65
  66                /* If we just powered it up, let's wait 200 ms */
  67                msleep(200);
  68        }
  69
  70        /* Read temperature register */
  71        data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
  72        data <<= 8;
  73        *value = data;
  74
  75        return 0;
  76}
  77
  78static void wf_lm75_release(struct wf_sensor *sr)
  79{
  80        struct wf_lm75_sensor *lm = wf_to_lm75(sr);
  81
  82        kfree(lm);
  83}
  84
  85static struct wf_sensor_ops wf_lm75_ops = {
  86        .get_value      = wf_lm75_get,
  87        .release        = wf_lm75_release,
  88        .owner          = THIS_MODULE,
  89};
  90
  91static int wf_lm75_probe(struct i2c_client *client,
  92                         const struct i2c_device_id *id)
  93{       
  94        struct wf_lm75_sensor *lm;
  95        int rc, ds1775 = id->driver_data;
  96        const char *name, *loc;
  97
  98        DBG("wf_lm75: creating  %s device at address 0x%02x\n",
  99            ds1775 ? "ds1775" : "lm75", client->addr);
 100
 101        loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
 102        if (!loc) {
 103                dev_warn(&client->dev, "Missing hwsensor-location property!\n");
 104                return -ENXIO;
 105        }
 106
 107        /* Usual rant about sensor names not beeing very consistent in
 108         * the device-tree, oh well ...
 109         * Add more entries below as you deal with more setups
 110         */
 111        if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
 112                name = "hd-temp";
 113        else if (!strcmp(loc, "Incoming Air Temp"))
 114                name = "incoming-air-temp";
 115        else if (!strcmp(loc, "ODD Temp"))
 116                name = "optical-drive-temp";
 117        else if (!strcmp(loc, "HD Temp"))
 118                name = "hard-drive-temp";
 119        else if (!strcmp(loc, "PCI SLOTS"))
 120                name = "slots-temp";
 121        else if (!strcmp(loc, "CPU A INLET"))
 122                name = "cpu-inlet-temp-0";
 123        else if (!strcmp(loc, "CPU B INLET"))
 124                name = "cpu-inlet-temp-1";
 125        else
 126                return -ENXIO;
 127        
 128
 129        lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
 130        if (lm == NULL)
 131                return -ENODEV;
 132
 133        lm->inited = 0;
 134        lm->ds1775 = ds1775;
 135        lm->i2c = client;
 136        lm->sens.name = (char *)name; /* XXX fix constness in structure */
 137        lm->sens.ops = &wf_lm75_ops;
 138        i2c_set_clientdata(client, lm);
 139
 140        rc = wf_register_sensor(&lm->sens);
 141        if (rc)
 142                kfree(lm);
 143        return rc;
 144}
 145
 146static int wf_lm75_remove(struct i2c_client *client)
 147{
 148        struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
 149
 150        DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
 151
 152        /* Mark client detached */
 153        lm->i2c = NULL;
 154
 155        /* release sensor */
 156        wf_unregister_sensor(&lm->sens);
 157
 158        return 0;
 159}
 160
 161static const struct i2c_device_id wf_lm75_id[] = {
 162        { "MAC,lm75", 0 },
 163        { "MAC,ds1775", 1 },
 164        { }
 165};
 166MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
 167
 168static struct i2c_driver wf_lm75_driver = {
 169        .driver = {
 170                .name   = "wf_lm75",
 171        },
 172        .probe          = wf_lm75_probe,
 173        .remove         = wf_lm75_remove,
 174        .id_table       = wf_lm75_id,
 175};
 176
 177static int __init wf_lm75_sensor_init(void)
 178{
 179        return i2c_add_driver(&wf_lm75_driver);
 180}
 181
 182static void __exit wf_lm75_sensor_exit(void)
 183{
 184        i2c_del_driver(&wf_lm75_driver);
 185}
 186
 187
 188module_init(wf_lm75_sensor_init);
 189module_exit(wf_lm75_sensor_exit);
 190
 191MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 192MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
 193MODULE_LICENSE("GPL");
 194
 195
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