cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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windfarm_lm75_sensor.c (4344B)

      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 <linux/of_device.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
     35struct 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
     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 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
     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			 const struct i2c_device_id *id)
     92{	
     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	else
    100		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 in
    112	 * the device-tree, oh well ...
    113	 * Add more entries below as you deal with more setups
    114	 */
    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	else
    130		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 int 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	return 0;
    161}
    162
    163static const struct i2c_device_id wf_lm75_id[] = {
    164	{ "MAC,lm75", 0 },
    165	{ "MAC,ds1775", 1 },
    166	{ }
    167};
    168MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
    169
    170static const struct of_device_id wf_lm75_of_id[] = {
    171	{ .compatible = "lm75", .data = (void *)0},
    172	{ .compatible = "ds1775", .data = (void *)1 },
    173	{ }
    174};
    175MODULE_DEVICE_TABLE(of, wf_lm75_of_id);
    176
    177static struct i2c_driver wf_lm75_driver = {
    178	.driver = {
    179		.name	= "wf_lm75",
    180		.of_match_table = wf_lm75_of_id,
    181	},
    182	.probe		= wf_lm75_probe,
    183	.remove		= wf_lm75_remove,
    184	.id_table	= wf_lm75_id,
    185};
    186
    187module_i2c_driver(wf_lm75_driver);
    188
    189MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
    190MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
    191MODULE_LICENSE("GPL");
    192