[PATCH] powerpc: Thermal control for dual core G5s

This patch adds a windfarm module, windfarm_pm112, for the dual core G5s
(both 2 and 4 core models), keeping the machine from getting into
vacuum-cleaner mode ;) For proper credits, the patch was initially
written by Paul Mackerras, and slightly reworked by me to add overtemp
handling among others. The patch also removes the sysfs attributes from
windfarm_pm81 and windfarm_pm91 and instead adds code to the windfarm
core to automagically expose attributes for sensor & controls.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 418 insertions, 0 deletions

diff --git a/drivers/macintosh/windfarm_smu_sat.c b/drivers/macintosh/windfarm_smu_sat.c
new file mode 100644
index 00000000000..3a32c59494f
--- /dev/null
+++ b/drivers/macintosh/windfarm_smu_sat.c
@@ -0,0 +1,418 @@
+/*
+ * 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/i2c-dev.h>
+#include <asm/semaphore.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 semaphore	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,
+};
+
+/*
+ * XXX i2c_smbus_read_i2c_block_data doesn't pass the requested
+ * length down to the low-level driver, so we use this, which
+ * works well enough with the SMU i2c driver code...
+ */
+static int sat_read_block(struct i2c_client *client, u8 command,
+			  u8 *values, int len)
+{
+	union i2c_smbus_data data;
+	int err;
+
+	data.block[0] = len;
+	err = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+			     I2C_SMBUS_READ, command, I2C_SMBUS_I2C_BLOCK_DATA,
+			     &data);
+	if (!err)
+		memcpy(values, data.block, len);
+	return err;
+}
+
+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 = sat_read_block(&sat->i2c, 0xa, data, 4);
+		if (err) {
+			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;
+}
+
+/* refresh the cache */
+static int wf_sat_read_cache(struct wf_sat *sat)
+{
+	int err;
+
+	err = sat_read_block(&sat->i2c, 0x3f, sat->cache, 16);
+	if (err)
+		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;
+
+	down(&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:
+	up(&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;
+	u32 *reg;
+	char *loc, *type;
+	u8 addr, chip, core;
+	struct device_node *child;
+	int shift, cpu, index;
+	char *name;
+	int vsens[2], isens[2];
+
+	reg = (u32 *) 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);
+	init_MUTEX(&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 = (u32 *) get_property(child, "reg", NULL);
+		type = get_property(child, "device_type", NULL);
+		loc = 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 (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)
+{
+	int err;
+
+	err = i2c_add_driver(&wf_sat_driver);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+static void __exit sat_sensors_exit(void)
+{
+	i2c_del_driver(&wf_sat_driver);
+}
+
+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");