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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Windfarm PowerMac thermal control. LM75 sensor4 *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 <linux/of.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 DEBUG28 29#ifdef DEBUG30#define DBG(args...) printk(args)31#else32#define DBG(args...) do { } while(0)33#endif34 35struct wf_lm75_sensor {36 unsigned int ds1775 : 1;37 unsigned 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 43static 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 by59 * the firmware for now60 */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 77static 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 84static 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 90static int wf_lm75_probe(struct i2c_client *client)91{92 const struct i2c_device_id *id = i2c_client_get_device_id(client);93 struct wf_lm75_sensor *lm;94 int rc, ds1775;95 const char *name, *loc;96 97 if (id)98 ds1775 = id->driver_data;99 else100 ds1775 = !!of_device_get_match_data(&client->dev);101 102 DBG("wf_lm75: creating %s device at address 0x%02x\n",103 ds1775 ? "ds1775" : "lm75", client->addr);104 105 loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);106 if (!loc) {107 dev_warn(&client->dev, "Missing hwsensor-location property!\n");108 return -ENXIO;109 }110 111 /* Usual rant about sensor names not beeing very consistent in112 * the device-tree, oh well ...113 * Add more entries below as you deal with more setups114 */115 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))116 name = "hd-temp";117 else if (!strcmp(loc, "Incoming Air Temp"))118 name = "incoming-air-temp";119 else if (!strcmp(loc, "ODD Temp"))120 name = "optical-drive-temp";121 else if (!strcmp(loc, "HD Temp"))122 name = "hard-drive-temp";123 else if (!strcmp(loc, "PCI SLOTS"))124 name = "slots-temp";125 else if (!strcmp(loc, "CPU A INLET"))126 name = "cpu-inlet-temp-0";127 else if (!strcmp(loc, "CPU B INLET"))128 name = "cpu-inlet-temp-1";129 else130 return -ENXIO;131 132 133 lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);134 if (lm == NULL)135 return -ENODEV;136 137 lm->inited = 0;138 lm->ds1775 = ds1775;139 lm->i2c = client;140 lm->sens.name = name;141 lm->sens.ops = &wf_lm75_ops;142 i2c_set_clientdata(client, lm);143 144 rc = wf_register_sensor(&lm->sens);145 if (rc)146 kfree(lm);147 return rc;148}149 150static void wf_lm75_remove(struct i2c_client *client)151{152 struct wf_lm75_sensor *lm = i2c_get_clientdata(client);153 154 /* Mark client detached */155 lm->i2c = NULL;156 157 /* release sensor */158 wf_unregister_sensor(&lm->sens);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 const struct of_device_id wf_lm75_of_id[] = {169 { .compatible = "lm75", .data = (void *)0},170 { .compatible = "ds1775", .data = (void *)1 },171 { }172};173MODULE_DEVICE_TABLE(of, wf_lm75_of_id);174 175static struct i2c_driver wf_lm75_driver = {176 .driver = {177 .name = "wf_lm75",178 .of_match_table = wf_lm75_of_id,179 },180 .probe = wf_lm75_probe,181 .remove = wf_lm75_remove,182 .id_table = wf_lm75_id,183};184 185module_i2c_driver(wf_lm75_driver);186 187MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");188MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");189MODULE_LICENSE("GPL");190 191