tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
powerpc/windfarm: Add lm87 sensor
For use by the upcoming windfarm_rm31
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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drivers/macintosh/windfarm_lm87_sensor.c
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drivers/macintosh/windfarm_lm87_sensor.c
···
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/*
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* Windfarm PowerMac thermal control. LM87 sensor
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*
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* Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
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*
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* Released under the term of the GNU GPL v2.
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*
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*/
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/wait.h>
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#include <linux/i2c.h>
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#include <asm/prom.h>
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#include <asm/machdep.h>
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#include <asm/io.h>
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#include <asm/sections.h>
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#include <asm/pmac_low_i2c.h>
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#include "windfarm.h"
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#define VERSION "1.0"
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#undef DEBUG
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#ifdef DEBUG
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#define DBG(args...) printk(args)
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#else
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#define DBG(args...) do { } while(0)
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#endif
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struct wf_lm87_sensor {
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struct i2c_client *i2c;
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struct wf_sensor sens;
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};
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#define wf_to_lm87(c) container_of(c, struct wf_lm87_sensor, sens)
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static int wf_lm87_read_reg(struct i2c_client *chip, int reg)
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{
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int rc, tries = 0;
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u8 buf;
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for (;;) {
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/* Set address */
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buf = (u8)reg;
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rc = i2c_master_send(chip, &buf, 1);
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if (rc <= 0)
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goto error;
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rc = i2c_master_recv(chip, &buf, 1);
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if (rc <= 0)
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goto error;
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return (int)buf;
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error:
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DBG("wf_lm87: Error reading LM87, retrying...\n");
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if (++tries > 10) {
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printk(KERN_ERR "wf_lm87: Error reading LM87 !\n");
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return -EIO;
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}
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msleep(10);
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}
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}
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static int wf_lm87_get(struct wf_sensor *sr, s32 *value)
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{
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struct wf_lm87_sensor *lm = sr->priv;
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s32 temp;
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if (lm->i2c == NULL)
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return -ENODEV;
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#define LM87_INT_TEMP 0x27
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/* Read temperature register */
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temp = wf_lm87_read_reg(lm->i2c, LM87_INT_TEMP);
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if (temp < 0)
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return temp;
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*value = temp << 16;
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return 0;
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}
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static void wf_lm87_release(struct wf_sensor *sr)
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{
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struct wf_lm87_sensor *lm = wf_to_lm87(sr);
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kfree(lm);
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}
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static struct wf_sensor_ops wf_lm87_ops = {
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.get_value = wf_lm87_get,
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.release = wf_lm87_release,
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.owner = THIS_MODULE,
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};
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static int wf_lm87_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct wf_lm87_sensor *lm;
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const char *name = NULL, *loc;
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struct device_node *np = NULL;
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int rc;
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/*
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* The lm87 contains a whole pile of sensors, additionally,
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* the Xserve G5 has several lm87's. However, for now we only
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* care about the internal temperature sensor
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*/
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while ((np = of_get_next_child(client->dev.of_node, np)) != NULL) {
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if (strcmp(np->name, "int-temp"))
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continue;
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loc = of_get_property(np, "location", NULL);
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if (!loc)
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continue;
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if (strstr(loc, "DIMM"))
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name = "dimms-temp";
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else if (strstr(loc, "Processors"))
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name = "between-cpus-temp";
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if (name) {
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of_node_put(np);
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break;
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}
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}
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if (!name) {
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pr_warning("wf_lm87: Unsupported sensor %s\n",
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client->dev.of_node->full_name);
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return -ENODEV;
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}
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lm = kzalloc(sizeof(struct wf_lm87_sensor), GFP_KERNEL);
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if (lm == NULL)
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return -ENODEV;
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lm->i2c = client;
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lm->sens.name = name;
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lm->sens.ops = &wf_lm87_ops;
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lm->sens.priv = lm;
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i2c_set_clientdata(client, lm);
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rc = wf_register_sensor(&lm->sens);
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if (rc)
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kfree(lm);
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return rc;
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}
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static int wf_lm87_remove(struct i2c_client *client)
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{
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struct wf_lm87_sensor *lm = i2c_get_clientdata(client);
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DBG("wf_lm87: i2c detatch called for %s\n", lm->sens.name);
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/* Mark client detached */
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lm->i2c = NULL;
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/* release sensor */
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wf_unregister_sensor(&lm->sens);
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return 0;
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}
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static const struct i2c_device_id wf_lm87_id[] = {
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{ "MAC,lm87cimt", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, wf_lm87_id);
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static struct i2c_driver wf_lm87_driver = {
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.driver = {
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.name = "wf_lm87",
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},
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.probe = wf_lm87_probe,
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.remove = wf_lm87_remove,
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.id_table = wf_lm87_id,
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};
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static int __init wf_lm87_sensor_init(void)
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{
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/* We only support this on the Xserve */
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if (!of_machine_is_compatible("RackMac3,1"))
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return -ENODEV;
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return i2c_add_driver(&wf_lm87_driver);
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}
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static void __exit wf_lm87_sensor_exit(void)
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{
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i2c_del_driver(&wf_lm87_driver);
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}
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module_init(wf_lm87_sensor_init);
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module_exit(wf_lm87_sensor_exit);
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MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
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MODULE_DESCRIPTION("LM87 sensor objects for PowerMacs thermal control");
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MODULE_LICENSE("GPL");
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