/*
* Windfarm PowerMac thermal control. SMU "satellite" controller sensors.
*
* Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
*
* Released under the terms of the GNU GPL v2.
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <asm/prom.h>
#include <asm/smu.h>
#include <asm/pmac_low_i2c.h>
#include "windfarm.h"
#define VERSION "0.2"
#define DEBUG
#ifdef DEBUG
#define DBG(args...) printk(args)
#else
#define DBG(args...) do { } while(0)
#endif
/* If the cache is older than 800ms we'll refetch it */
#define MAX_AGE msecs_to_jiffies(800)
struct wf_sat {
int nr;
atomic_t refcnt;
struct mutex mutex;
unsigned long last_read; /* jiffies when cache last updated */
u8 cache[16];
struct i2c_client i2c;
struct device_node *node;
};
static struct wf_sat *sats[2];
struct wf_sat_sensor {
int index;
int index2; /* used for power sensors */
int shift;
struct wf_sat *sat;
struct wf_sensor sens;
};
#define wf_to_sat(c) container_of(c, struct wf_sat_sensor, sens)
#define i2c_to_sat(c) container_of(c, struct wf_sat, i2c)
static int wf_sat_attach(struct i2c_adapter *adapter);
static int wf_sat_detach(struct i2c_client *client);
static struct i2c_driver wf_sat_driver = {
.driver = {
.name = "wf_smu_sat",
},
.attach_adapter = wf_sat_attach,
.detach_client = wf_sat_detach,
};
struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
unsigned int *size)
{
struct wf_sat *sat;
int err;
unsigned int i, len;
u8 *buf;
u8 data[4];
/* TODO: Add the resulting partition to the device-tree */
if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
return NULL;
err = i2c_smbus_write_word_data(&sat->i2c, 8, id << 8);
if (err) {
printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
return NULL;
}
len = i2c_smbus_read_word_data(&sat->i2c, 9);
if (len < 0) {
printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
return NULL;
}
if (len == 0) {
printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
return NULL;
}
len = le16_to_cpu(len);
len = (len + 3) & ~3;
buf = kmalloc(len, GFP_KERNEL);
if (buf == NULL)
return NULL;
for (i = 0; i < len; i += 4) {
err = i2c_smbus_read_i2c_block_data(&sat->i2c, 0xa, 4, data);
if (err < 0) {
printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
err);
goto fail;
}
buf[i] = data[1];
buf[i+1] = data[0];
buf[i+2] = data[3];
buf[i+3] = data[2];
}
#ifdef DEBUG
DBG(KERN_DEBUG "sat %d partition %x:", sat_id, id);
for (i = 0; i < len; ++i)
DBG(" %x", buf[i]);
DBG("\n");
#endif
if (size)
*size = len;
return (struct smu_sdbp_header *) buf;
fail:
kfree(buf);
return NULL;
}
EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
/* refresh the cache */
static int wf_sat_read_cache(struct wf_sat *sat)
{
int err;
err = i2c_smbus_read_i2c_block_data(&sat->i2c, 0x3f, 16, sat->cache);
if (err < 0)
return err;
sat->last_read = jiffies;
#ifdef LOTSA_DEBUG
{
int i;
DBG(KERN_DEBUG "wf_sat_get: data is");
for (i = 0; i < 16; ++i)
DBG(" %.2x", sat->cache[i]);
DBG("\n");
}
#endif
return 0;
}
static int wf_sat_get(struct wf_sensor *sr, s32 *value)
{
struct wf_sat_sensor *sens = wf_to_sat(sr);
struct wf_sat *sat = sens->sat;
int i, err;
s32 val;
if (sat->i2c.adapter == NULL)
return -ENODEV;
mutex_lock(&sat->mutex);
if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
err = wf_sat_read_cache(sat);
if (err)
goto fail;
}
i = sens->index * 2;
val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
if (sens->index2 >= 0) {
i = sens->index2 * 2;
/* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
}
*value = val;
err = 0;
fail:
mutex_unlock(&sat->mutex);
return err;
}
static void wf_sat_release(struct wf_sensor *sr)
{
struct wf_sat_sensor *sens = wf_to_sat(sr);
struct wf_sat *sat = sens->sat;
if (atomic_dec_and_test(&sat->refcnt)) {
if (sat->i2c.adapter) {
i2c_detach_client(&sat->i2c);
sat->i2c.adapter = NULL;
}
if (sat->nr >= 0)
sats[sat->nr] = NULL;
kfree(sat);
}
kfree(sens);
}
static struct wf_sensor_ops wf_sat_ops = {
.get_value = wf_sat_get,
.release = wf_sat_release,
.owner = THIS_MODULE,
};
static void wf_sat_create(struct i2c_adapter *adapter, struct device_node *dev)
{
struct wf_sat *sat;
struct wf_sat_sensor *sens;
const u32 *reg;
const char *loc, *type;
u8 addr, chip, core;
struct device_node *child;
int shift, cpu, index;
char *name;
int vsens[2], isens[2];
reg = of_get_property(dev, "reg", NULL);
if (reg == NULL)
return;
addr = *reg;
DBG(KERN_DEBUG "wf_sat: creating sat at address %x\n", addr);
sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
if (sat == NULL)
return;
sat->nr = -1;
sat->node = of_node_get(dev);
atomic_set(&sat->refcnt, 0);
mutex_init(&sat->mutex);
sat->i2c.addr = (addr >> 1) & 0x7f;
sat->i2c.adapter = adapter;
sat->i2c.driver = &wf_sat_driver;
strncpy(sat->i2c.name, "smu-sat", I2C_NAME_SIZE-1);
if (i2c_attach_client(&sat->i2c)) {
printk(KERN_ERR "windfarm: failed to attach smu-sat to i2c\n");
goto fail;
}
vsens[0] = vsens[1] = -1;
isens[0] = isens[1] = -1;
child = NULL;
while ((child = of_get_next_child(dev, child)) != NULL) {
reg = of_get_property(child, "reg", NULL);
type = of_get_property(child, "device_type", NULL);
loc = of_get_property(child, "location", NULL);
if (reg == NULL || loc == NULL)
continue;
/* the cooked sensors are between 0x30 and 0x37 */
if (*reg < 0x30 || *reg > 0x37)
continue;
index = *reg - 0x30;
/* expect location to be CPU [AB][01] ... */
if (strncmp(loc, "CPU ", 4) != 0)
continue;
chip = loc[4] - 'A';
core = loc[5] - '0';
if (chip > 1 || core > 1) {
printk(KERN_ERR "wf_sat_create: don't understand "
"location %s for %s\n", loc, child->full_name);
continue;
}
cpu = 2 * chip + core;
if (sat->nr < 0)
sat->nr = chip;
else if (sat->nr != chip) {
printk(KERN_ERR "wf_sat_create: can't cope with "
"multiple CPU chips on one SAT (%s)\n", loc);
continue;
}
if (strcmp(type, "voltage-sensor") == 0) {
name = "cpu-voltage";
shift = 4;
vsens[core] = index;
} else if (strcmp(type, "current-sensor") == 0) {
name = "cpu-current";
shift = 8;
isens[core] = index;
} else if (strcmp(type, "temp-sensor") == 0) {
name = "cpu-temp";
shift = 10;
} else
continue; /* hmmm shouldn't happen */
/* the +16 is enough for "cpu-voltage-n" */
sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
if (sens == NULL) {
printk(KERN_ERR "wf_sat_create: couldn't create "
"%s sensor %d (no memory)\n", name, cpu);
continue;
}
sens->index = index;
sens->index2 = -1;
sens->shift = shift;
sens->sat = sat;
atomic_inc(&sat->refcnt);
sens->sens.ops = &wf_sat_ops;
sens->sens.name = (char *) (sens + 1);
snprintf(sens->sens.name, 16, "%s-%d", name, cpu);
if (wf_register_sensor(&sens->sens)) {
atomic_dec(&sat->refcnt);
kfree(sens);
}
}
/* make the power sensors */
for (core = 0; core < 2; ++core) {
if (vsens[core] < 0 || isens[core] < 0)
continue;
cpu = 2 * sat->nr + core;
sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
if (sens == NULL) {
printk(KERN_ERR "wf_sat_create: couldn't create power "
"sensor %d (no memory)\n", cpu);
continue;
}
sens->index = vsens[core];
sens->index2 = isens[core];
sens->shift = 0;
sens->sat = sat;
atomic_inc(&sat->refcnt);
sens->sens.ops = &wf_sat_ops;
sens->sens.name = (char *) (sens + 1);
snprintf(sens->sens.name, 16, "cpu-power-%d", cpu);
if (wf_register_sensor(&sens->sens)) {
atomic_dec(&sat->refcnt);
kfree(sens);
}
}
if (sat->nr >= 0)
sats[sat->nr] = sat;
return;
fail:
kfree(sat);
}
static int wf_sat_attach(struct i2c_adapter *adapter)
{
struct device_node *busnode, *dev = NULL;
struct pmac_i2c_bus *bus;
bus = pmac_i2c_adapter_to_bus(adapter);
if (bus == NULL)
return -ENODEV;
busnode = pmac_i2c_get_bus_node(bus);
while ((dev = of_get_next_child(busnode, dev)) != NULL)
if (of_device_is_compatible(dev, "smu-sat"))
wf_sat_create(adapter, dev);
return 0;
}
static int wf_sat_detach(struct i2c_client *client)
{
struct wf_sat *sat = i2c_to_sat(client);
/* XXX TODO */
sat->i2c.adapter = NULL;
return 0;
}
static int __init sat_sensors_init(void)
{
return i2c_add_driver(&wf_sat_driver);
}
#if 0 /* uncomment when module_exit() below is uncommented */
static void __exit sat_sensors_exit(void)
{
i2c_del_driver(&wf_sat_driver);
}
#endif
module_init(sat_sensors_init);
/*module_exit(sat_sensors_exit); Uncomment when cleanup is implemented */
MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
MODULE_LICENSE("GPL");
