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_lm87_sensor.c (4137B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Windfarm PowerMac thermal control. LM87 sensor
      4 *
      5 * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
      6 */
      7
      8#include <linux/types.h>
      9#include <linux/errno.h>
     10#include <linux/kernel.h>
     11#include <linux/delay.h>
     12#include <linux/slab.h>
     13#include <linux/init.h>
     14#include <linux/wait.h>
     15#include <linux/i2c.h>
     16
     17#include <asm/machdep.h>
     18#include <asm/io.h>
     19#include <asm/sections.h>
     20#include <asm/pmac_low_i2c.h>
     21
     22#include "windfarm.h"
     23
     24#define VERSION "1.0"
     25
     26#undef DEBUG
     27
     28#ifdef DEBUG
     29#define DBG(args...)	printk(args)
     30#else
     31#define DBG(args...)	do { } while(0)
     32#endif
     33
     34struct wf_lm87_sensor {
     35	struct i2c_client	*i2c;
     36	struct wf_sensor	sens;
     37};
     38#define wf_to_lm87(c) container_of(c, struct wf_lm87_sensor, sens)
     39
     40
     41static int wf_lm87_read_reg(struct i2c_client *chip, int reg)
     42{
     43	int rc, tries = 0;
     44	u8 buf;
     45
     46	for (;;) {
     47		/* Set address */
     48		buf = (u8)reg;
     49		rc = i2c_master_send(chip, &buf, 1);
     50		if (rc <= 0)
     51			goto error;
     52		rc = i2c_master_recv(chip, &buf, 1);
     53		if (rc <= 0)
     54			goto error;
     55		return (int)buf;
     56	error:
     57		DBG("wf_lm87: Error reading LM87, retrying...\n");
     58		if (++tries > 10) {
     59			printk(KERN_ERR "wf_lm87: Error reading LM87 !\n");
     60			return -EIO;
     61		}
     62		msleep(10);
     63	}
     64}
     65
     66static int wf_lm87_get(struct wf_sensor *sr, s32 *value)
     67{
     68	struct wf_lm87_sensor *lm = sr->priv;
     69	s32 temp;
     70
     71	if (lm->i2c == NULL)
     72		return -ENODEV;
     73
     74#define LM87_INT_TEMP		0x27
     75
     76	/* Read temperature register */
     77	temp = wf_lm87_read_reg(lm->i2c, LM87_INT_TEMP);
     78	if (temp < 0)
     79		return temp;
     80	*value = temp << 16;
     81
     82	return 0;
     83}
     84
     85static void wf_lm87_release(struct wf_sensor *sr)
     86{
     87	struct wf_lm87_sensor *lm = wf_to_lm87(sr);
     88
     89	kfree(lm);
     90}
     91
     92static const struct wf_sensor_ops wf_lm87_ops = {
     93	.get_value	= wf_lm87_get,
     94	.release	= wf_lm87_release,
     95	.owner		= THIS_MODULE,
     96};
     97
     98static int wf_lm87_probe(struct i2c_client *client,
     99			 const struct i2c_device_id *id)
    100{	
    101	struct wf_lm87_sensor *lm;
    102	const char *name = NULL, *loc;
    103	struct device_node *np = NULL;
    104	int rc;
    105
    106	/*
    107	 * The lm87 contains a whole pile of sensors, additionally,
    108	 * the Xserve G5 has several lm87's. However, for now we only
    109	 * care about the internal temperature sensor
    110	 */
    111	for_each_child_of_node(client->dev.of_node, np) {
    112		if (!of_node_name_eq(np, "int-temp"))
    113			continue;
    114		loc = of_get_property(np, "location", NULL);
    115		if (!loc)
    116			continue;
    117		if (strstr(loc, "DIMM"))
    118			name = "dimms-temp";
    119		else if (strstr(loc, "Processors"))
    120			name = "between-cpus-temp";
    121		if (name) {
    122			of_node_put(np);
    123			break;
    124		}
    125	}
    126	if (!name) {
    127		pr_warn("wf_lm87: Unsupported sensor %pOF\n",
    128			client->dev.of_node);
    129		return -ENODEV;
    130	}
    131
    132	lm = kzalloc(sizeof(struct wf_lm87_sensor), GFP_KERNEL);
    133	if (lm == NULL)
    134		return -ENODEV;
    135
    136	lm->i2c = client;
    137	lm->sens.name = name;
    138	lm->sens.ops = &wf_lm87_ops;
    139	lm->sens.priv = lm;
    140	i2c_set_clientdata(client, lm);
    141
    142	rc = wf_register_sensor(&lm->sens);
    143	if (rc)
    144		kfree(lm);
    145	return rc;
    146}
    147
    148static int wf_lm87_remove(struct i2c_client *client)
    149{
    150	struct wf_lm87_sensor *lm = i2c_get_clientdata(client);
    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_lm87_id[] = {
    162	{ "MAC,lm87cimt", 0 },
    163	{ }
    164};
    165MODULE_DEVICE_TABLE(i2c, wf_lm87_id);
    166
    167static const struct of_device_id wf_lm87_of_id[] = {
    168	{ .compatible = "lm87cimt", },
    169	{ }
    170};
    171MODULE_DEVICE_TABLE(of, wf_lm87_of_id);
    172
    173static struct i2c_driver wf_lm87_driver = {
    174	.driver = {
    175		.name	= "wf_lm87",
    176		.of_match_table = wf_lm87_of_id,
    177	},
    178	.probe		= wf_lm87_probe,
    179	.remove		= wf_lm87_remove,
    180	.id_table	= wf_lm87_id,
    181};
    182
    183static int __init wf_lm87_sensor_init(void)
    184{
    185	/* We only support this on the Xserve */
    186	if (!of_machine_is_compatible("RackMac3,1"))
    187		return -ENODEV;
    188
    189	return i2c_add_driver(&wf_lm87_driver);
    190}
    191
    192static void __exit wf_lm87_sensor_exit(void)
    193{
    194	i2c_del_driver(&wf_lm87_driver);
    195}
    196
    197
    198module_init(wf_lm87_sensor_init);
    199module_exit(wf_lm87_sensor_exit);
    200
    201MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
    202MODULE_DESCRIPTION("LM87 sensor objects for PowerMacs thermal control");
    203MODULE_LICENSE("GPL");
    204