[PATCH] ppc64: Thermal control for SMU based machines

This adds a new thermal control framework for PowerMac, along with the
implementation for PowerMac8,1, PowerMac8,2 (iMac G5 rev 1 and 2), and
PowerMac9,1 (latest single CPU desktop). In the future, I expect to move
the older G5 thermal control to the new framework as well.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 263 insertions, 0 deletions

diff --git a/drivers/macintosh/windfarm_lm75_sensor.c b/drivers/macintosh/windfarm_lm75_sensor.c
new file mode 100644
index 0000000..a0a41ad
--- /dev/null
+++ b/drivers/macintosh/windfarm_lm75_sensor.c
@@ -0,0 +1,263 @@
+/*
+ * Windfarm PowerMac thermal control. LM75 sensor
+ *
+ * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ *
+ * Released under the term of the GNU GPL v2.
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/i2c.h>
+#include <linux/i2c-dev.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/sections.h>
+
+#include "windfarm.h"
+
+#define VERSION "0.1"
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(args...)	printk(args)
+#else
+#define DBG(args...)	do { } while(0)
+#endif
+
+struct wf_lm75_sensor {
+	int			ds1775 : 1;
+	int			inited : 1;
+	struct 	i2c_client	i2c;
+	struct 	wf_sensor	sens;
+};
+#define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
+#define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c)
+
+static int wf_lm75_attach(struct i2c_adapter *adapter);
+static int wf_lm75_detach(struct i2c_client *client);
+
+static struct i2c_driver wf_lm75_driver = {
+	.owner		= THIS_MODULE,
+	.name		= "wf_lm75",
+	.flags		= I2C_DF_NOTIFY,
+	.attach_adapter	= wf_lm75_attach,
+	.detach_client	= wf_lm75_detach,
+};
+
+static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
+{
+	struct wf_lm75_sensor *lm = wf_to_lm75(sr);
+	s32 data;
+
+	if (lm->i2c.adapter == NULL)
+		return -ENODEV;
+
+	/* Init chip if necessary */
+	if (!lm->inited) {
+		u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(&lm->i2c, 1);
+
+		DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
+		    sr->name, cfg);
+
+		/* clear shutdown bit, keep other settings as left by
+		 * the firmware for now
+		 */
+		cfg_new = cfg & ~0x01;
+		i2c_smbus_write_byte_data(&lm->i2c, 1, cfg_new);
+		lm->inited = 1;
+
+		/* If we just powered it up, let's wait 200 ms */
+		msleep(200);
+	}
+
+	/* Read temperature register */
+	data = (s32)le16_to_cpu(i2c_smbus_read_word_data(&lm->i2c, 0));
+	data <<= 8;
+	*value = data;
+
+	return 0;
+}
+
+static void wf_lm75_release(struct wf_sensor *sr)
+{
+	struct wf_lm75_sensor *lm = wf_to_lm75(sr);
+
+	/* check if client is registered and detach from i2c */
+	if (lm->i2c.adapter) {
+		i2c_detach_client(&lm->i2c);
+		lm->i2c.adapter = NULL;
+	}
+
+	kfree(lm);
+}
+
+static struct wf_sensor_ops wf_lm75_ops = {
+	.get_value	= wf_lm75_get,
+	.release	= wf_lm75_release,
+	.owner		= THIS_MODULE,
+};
+
+static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter,
+					     u8 addr, int ds1775,
+					     const char *loc)
+{
+	struct wf_lm75_sensor *lm;
+
+	DBG("wf_lm75: creating  %s device at address 0x%02x\n",
+	    ds1775 ? "ds1775" : "lm75", addr);
+
+	lm = kmalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
+	if (lm == NULL)
+		return NULL;
+	memset(lm, 0, sizeof(struct wf_lm75_sensor));
+
+	/* Usual rant about sensor names not beeing very consistent in
+	 * the device-tree, oh well ...
+	 * Add more entries below as you deal with more setups
+	 */
+	if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
+		lm->sens.name = "hd-temp";
+	else
+		goto fail;
+
+	lm->inited = 0;
+	lm->sens.ops = &wf_lm75_ops;
+	lm->ds1775 = ds1775;
+	lm->i2c.addr = (addr >> 1) & 0x7f;
+	lm->i2c.adapter = adapter;
+	lm->i2c.driver = &wf_lm75_driver;
+	strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1);
+
+	if (i2c_attach_client(&lm->i2c)) {
+		printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n",
+		       ds1775 ? "ds1775" : "lm75", lm->i2c.name);
+		goto fail;
+	}
+
+	if (wf_register_sensor(&lm->sens)) {
+		i2c_detach_client(&lm->i2c);
+		goto fail;
+	}
+
+	return lm;
+ fail:
+	kfree(lm);
+	return NULL;
+}
+
+static int wf_lm75_attach(struct i2c_adapter *adapter)
+{
+	u8 bus_id;
+	struct device_node *smu, *bus, *dev;
+
+	/* We currently only deal with LM75's hanging off the SMU
+	 * i2c busses. If we extend that driver to other/older
+	 * machines, we should split this function into SMU-i2c,
+	 * keywest-i2c, PMU-i2c, ...
+	 */
+
+	DBG("wf_lm75: adapter %s detected\n", adapter->name);
+
+	if (strncmp(adapter->name, "smu-i2c-", 8) != 0)
+		return 0;
+	smu = of_find_node_by_type(NULL, "smu");
+	if (smu == NULL)
+		return 0;
+
+	/* Look for the bus in the device-tree */
+	bus_id = (u8)simple_strtoul(adapter->name + 8, NULL, 16);
+
+	DBG("wf_lm75: bus ID is %x\n", bus_id);
+
+	/* Look for sensors subdir */
+	for (bus = NULL;
+	     (bus = of_get_next_child(smu, bus)) != NULL;) {
+		u32 *reg;
+
+		if (strcmp(bus->name, "i2c"))
+			continue;
+		reg = (u32 *)get_property(bus, "reg", NULL);
+		if (reg == NULL)
+			continue;
+		if (bus_id == *reg)
+			break;
+	}
+	of_node_put(smu);
+	if (bus == NULL) {
+		printk(KERN_WARNING "windfarm: SMU i2c bus 0x%x not found"
+		       " in device-tree !\n", bus_id);
+		return 0;
+	}
+
+	DBG("wf_lm75: bus found, looking for device...\n");
+
+	/* Now look for lm75(s) in there */
+	for (dev = NULL;
+	     (dev = of_get_next_child(bus, dev)) != NULL;) {
+		const char *loc =
+			get_property(dev, "hwsensor-location", NULL);
+		u32 *reg = (u32 *)get_property(dev, "reg", NULL);
+		DBG(" dev: %s... (loc: %p, reg: %p)\n", dev->name, loc, reg);
+		if (loc == NULL || reg == NULL)
+			continue;
+		/* real lm75 */
+		if (device_is_compatible(dev, "lm75"))
+			wf_lm75_create(adapter, *reg, 0, loc);
+		/* ds1775 (compatible, better resolution */
+		else if (device_is_compatible(dev, "ds1775"))
+			wf_lm75_create(adapter, *reg, 1, loc);
+	}
+
+	of_node_put(bus);
+
+	return 0;
+}
+
+static int wf_lm75_detach(struct i2c_client *client)
+{
+	struct wf_lm75_sensor *lm = i2c_to_lm75(client);
+
+	DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
+
+	/* Mark client detached */
+	lm->i2c.adapter = NULL;
+
+	/* release sensor */
+	wf_unregister_sensor(&lm->sens);
+
+	return 0;
+}
+
+static int __init wf_lm75_sensor_init(void)
+{
+	int rc;
+
+	rc = i2c_add_driver(&wf_lm75_driver);
+	if (rc < 0)
+		return rc;
+	return 0;
+}
+
+static void __exit wf_lm75_sensor_exit(void)
+{
+	i2c_del_driver(&wf_lm75_driver);
+}
+
+
+module_init(wf_lm75_sensor_init);
+module_exit(wf_lm75_sensor_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
+MODULE_LICENSE("GPL");
+