![Benjamin Herrenschmidt](/assets/img/avatar_default.png)
Some of the windfarm sensor modules can initialize on old machines that don't have full windfarm support like non-dual core desktop G5s. Unfortunately, by doing so, they would trigger a bug in their matching algorithm causing them to attach to the wrong bus, thus triggering issues with the i2c core and breaking the thermal driver. This patch fixes the probing issue (so that they will work when a windfarm port is done to these machines) and also prevents for now windfarm to load at all on these machines that still use therm_pm72 to avoid wasting resources. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
181 lines
4.2 KiB
C
181 lines
4.2 KiB
C
/*
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* Windfarm PowerMac thermal control. MAX6690 sensor.
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*
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* Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
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*
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* Use and redistribute under the terms of the GNU GPL v2.
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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/init.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/i2c-dev.h>
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#include <asm/prom.h>
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#include <asm/pmac_low_i2c.h>
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#include "windfarm.h"
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#define VERSION "0.2"
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/* This currently only exports the external temperature sensor,
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since that's all the control loops need. */
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/* Some MAX6690 register numbers */
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#define MAX6690_INTERNAL_TEMP 0
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#define MAX6690_EXTERNAL_TEMP 1
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struct wf_6690_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_6690(x) container_of((x), struct wf_6690_sensor, sens)
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#define i2c_to_6690(x) container_of((x), struct wf_6690_sensor, i2c)
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static int wf_max6690_attach(struct i2c_adapter *adapter);
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static int wf_max6690_detach(struct i2c_client *client);
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static struct i2c_driver wf_max6690_driver = {
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.driver = {
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.name = "wf_max6690",
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},
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.attach_adapter = wf_max6690_attach,
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.detach_client = wf_max6690_detach,
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};
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static int wf_max6690_get(struct wf_sensor *sr, s32 *value)
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{
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struct wf_6690_sensor *max = wf_to_6690(sr);
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s32 data;
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if (max->i2c.adapter == NULL)
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return -ENODEV;
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/* chip gets initialized by firmware */
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data = i2c_smbus_read_byte_data(&max->i2c, MAX6690_EXTERNAL_TEMP);
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if (data < 0)
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return data;
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*value = data << 16;
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return 0;
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}
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static void wf_max6690_release(struct wf_sensor *sr)
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{
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struct wf_6690_sensor *max = wf_to_6690(sr);
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if (max->i2c.adapter) {
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i2c_detach_client(&max->i2c);
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max->i2c.adapter = NULL;
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}
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kfree(max);
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}
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static struct wf_sensor_ops wf_max6690_ops = {
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.get_value = wf_max6690_get,
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.release = wf_max6690_release,
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.owner = THIS_MODULE,
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};
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static void wf_max6690_create(struct i2c_adapter *adapter, u8 addr)
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{
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struct wf_6690_sensor *max;
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char *name = "backside-temp";
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max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
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if (max == NULL) {
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printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor %s: "
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"no memory\n", name);
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return;
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}
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max->sens.ops = &wf_max6690_ops;
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max->sens.name = name;
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max->i2c.addr = addr >> 1;
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max->i2c.adapter = adapter;
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max->i2c.driver = &wf_max6690_driver;
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strncpy(max->i2c.name, name, I2C_NAME_SIZE-1);
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if (i2c_attach_client(&max->i2c)) {
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printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n");
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goto fail;
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}
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if (wf_register_sensor(&max->sens)) {
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i2c_detach_client(&max->i2c);
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goto fail;
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}
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return;
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fail:
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kfree(max);
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}
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static int wf_max6690_attach(struct i2c_adapter *adapter)
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{
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struct device_node *busnode, *dev = NULL;
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struct pmac_i2c_bus *bus;
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const char *loc;
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bus = pmac_i2c_adapter_to_bus(adapter);
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if (bus == NULL)
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return -ENODEV;
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busnode = pmac_i2c_get_bus_node(bus);
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while ((dev = of_get_next_child(busnode, dev)) != NULL) {
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u8 addr;
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/* We must re-match the adapter in order to properly check
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* the channel on multibus setups
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*/
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if (!pmac_i2c_match_adapter(dev, adapter))
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continue;
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if (!device_is_compatible(dev, "max6690"))
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continue;
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addr = pmac_i2c_get_dev_addr(dev);
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loc = get_property(dev, "hwsensor-location", NULL);
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if (loc == NULL || addr == 0)
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continue;
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printk("found max6690, loc=%s addr=0x%02x\n", loc, addr);
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if (strcmp(loc, "BACKSIDE"))
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continue;
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wf_max6690_create(adapter, addr);
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}
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return 0;
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}
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static int wf_max6690_detach(struct i2c_client *client)
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{
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struct wf_6690_sensor *max = i2c_to_6690(client);
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max->i2c.adapter = NULL;
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wf_unregister_sensor(&max->sens);
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return 0;
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}
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static int __init wf_max6690_sensor_init(void)
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{
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/* Don't register on old machines that use therm_pm72 for now */
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if (machine_is_compatible("PowerMac7,2") ||
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machine_is_compatible("PowerMac7,3") ||
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machine_is_compatible("RackMac3,1"))
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return -ENODEV;
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return i2c_add_driver(&wf_max6690_driver);
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}
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static void __exit wf_max6690_sensor_exit(void)
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{
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i2c_del_driver(&wf_max6690_driver);
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}
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module_init(wf_max6690_sensor_init);
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module_exit(wf_max6690_sensor_exit);
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MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
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MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
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MODULE_LICENSE("GPL");
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