[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, 479 insertions, 0 deletions

diff --git a/drivers/macintosh/windfarm_smu_sensors.c b/drivers/macintosh/windfarm_smu_sensors.c
new file mode 100644
index 0000000..b558cc2
--- /dev/null
+++ b/drivers/macintosh/windfarm_smu_sensors.c
@@ -0,0 +1,479 @@
+/*
+ * Windfarm PowerMac thermal control. SMU based sensors
+ *
+ * (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 <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/sections.h>
+#include <asm/smu.h>
+
+#include "windfarm.h"
+
+#define VERSION "0.2"
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(args...)	printk(args)
+#else
+#define DBG(args...)	do { } while(0)
+#endif
+
+/*
+ * Various SMU "partitions" calibration objects for which we
+ * keep pointers here for use by bits & pieces of the driver
+ */
+static struct smu_sdbp_cpuvcp *cpuvcp;
+static int  cpuvcp_version;
+static struct smu_sdbp_cpudiode *cpudiode;
+static struct smu_sdbp_slotspow *slotspow;
+static u8 *debugswitches;
+
+/*
+ * SMU basic sensors objects
+ */
+
+static LIST_HEAD(smu_ads);
+
+struct smu_ad_sensor {
+	struct list_head	link;
+	u32			reg;		/* index in SMU */
+	struct wf_sensor	sens;
+};
+#define to_smu_ads(c) container_of(c, struct smu_ad_sensor, sens)
+
+static void smu_ads_release(struct wf_sensor *sr)
+{
+	struct smu_ad_sensor *ads = to_smu_ads(sr);
+
+	kfree(ads);
+}
+
+static int smu_read_adc(u8 id, s32 *value)
+{
+	struct smu_simple_cmd	cmd;
+	DECLARE_COMPLETION(comp);
+	int rc;
+
+	rc = smu_queue_simple(&cmd, SMU_CMD_READ_ADC, 1,
+			      smu_done_complete, &comp, id);
+	if (rc)
+		return rc;
+	wait_for_completion(&comp);
+	if (cmd.cmd.status != 0)
+		return cmd.cmd.status;
+	if (cmd.cmd.reply_len != 2) {
+		printk(KERN_ERR "winfarm: read ADC 0x%x returned %d bytes !\n",
+		       id, cmd.cmd.reply_len);
+		return -EIO;
+	}
+	*value = *((u16 *)cmd.buffer);
+	return 0;
+}
+
+static int smu_cputemp_get(struct wf_sensor *sr, s32 *value)
+{
+	struct smu_ad_sensor *ads = to_smu_ads(sr);
+	int rc;
+	s32 val;
+	s64 scaled;
+
+	rc = smu_read_adc(ads->reg, &val);
+	if (rc) {
+		printk(KERN_ERR "windfarm: read CPU temp failed, err %d\n",
+		       rc);
+		return rc;
+	}
+
+	/* Ok, we have to scale & adjust, taking units into account */
+	scaled = (s64)(((u64)val) * (u64)cpudiode->m_value);
+	scaled >>= 3;
+	scaled += ((s64)cpudiode->b_value) << 9;
+	*value = (s32)(scaled << 1);
+
+	return 0;
+}
+
+static int smu_cpuamp_get(struct wf_sensor *sr, s32 *value)
+{
+	struct smu_ad_sensor *ads = to_smu_ads(sr);
+	s32 val, scaled;
+	int rc;
+
+	rc = smu_read_adc(ads->reg, &val);
+	if (rc) {
+		printk(KERN_ERR "windfarm: read CPU current failed, err %d\n",
+		       rc);
+		return rc;
+	}
+
+	/* Ok, we have to scale & adjust, taking units into account */
+	scaled = (s32)(val * (u32)cpuvcp->curr_scale);
+	scaled += (s32)cpuvcp->curr_offset;
+	*value = scaled << 4;
+
+	return 0;
+}
+
+static int smu_cpuvolt_get(struct wf_sensor *sr, s32 *value)
+{
+	struct smu_ad_sensor *ads = to_smu_ads(sr);
+	s32 val, scaled;
+	int rc;
+
+	rc = smu_read_adc(ads->reg, &val);
+	if (rc) {
+		printk(KERN_ERR "windfarm: read CPU voltage failed, err %d\n",
+		       rc);
+		return rc;
+	}
+
+	/* Ok, we have to scale & adjust, taking units into account */
+	scaled = (s32)(val * (u32)cpuvcp->volt_scale);
+	scaled += (s32)cpuvcp->volt_offset;
+	*value = scaled << 4;
+
+	return 0;
+}
+
+static int smu_slotspow_get(struct wf_sensor *sr, s32 *value)
+{
+	struct smu_ad_sensor *ads = to_smu_ads(sr);
+	s32 val, scaled;
+	int rc;
+
+	rc = smu_read_adc(ads->reg, &val);
+	if (rc) {
+		printk(KERN_ERR "windfarm: read slots power failed, err %d\n",
+		       rc);
+		return rc;
+	}
+
+	/* Ok, we have to scale & adjust, taking units into account */
+	scaled = (s32)(val * (u32)slotspow->pow_scale);
+	scaled += (s32)slotspow->pow_offset;
+	*value = scaled << 4;
+
+	return 0;
+}
+
+
+static struct wf_sensor_ops smu_cputemp_ops = {
+	.get_value	= smu_cputemp_get,
+	.release	= smu_ads_release,
+	.owner		= THIS_MODULE,
+};
+static struct wf_sensor_ops smu_cpuamp_ops = {
+	.get_value	= smu_cpuamp_get,
+	.release	= smu_ads_release,
+	.owner		= THIS_MODULE,
+};
+static struct wf_sensor_ops smu_cpuvolt_ops = {
+	.get_value	= smu_cpuvolt_get,
+	.release	= smu_ads_release,
+	.owner		= THIS_MODULE,
+};
+static struct wf_sensor_ops smu_slotspow_ops = {
+	.get_value	= smu_slotspow_get,
+	.release	= smu_ads_release,
+	.owner		= THIS_MODULE,
+};
+
+
+static struct smu_ad_sensor *smu_ads_create(struct device_node *node)
+{
+	struct smu_ad_sensor *ads;
+	char *c, *l;
+	u32 *v;
+
+	ads = kmalloc(sizeof(struct smu_ad_sensor), GFP_KERNEL);
+	if (ads == NULL)
+		return NULL;
+	c = (char *)get_property(node, "device_type", NULL);
+	l = (char *)get_property(node, "location", NULL);
+	if (c == NULL || l == NULL)
+		goto fail;
+
+	/* We currently pick the sensors based on the OF name and location
+	 * properties, while Darwin uses the sensor-id's.
+	 * The problem with the IDs is that they are model specific while it
+	 * looks like apple has been doing a reasonably good job at keeping
+	 * the names and locations consistents so I'll stick with the names
+	 * and locations for now.
+	 */
+	if (!strcmp(c, "temp-sensor") &&
+	    !strcmp(l, "CPU T-Diode")) {
+		ads->sens.ops = &smu_cputemp_ops;
+		ads->sens.name = "cpu-temp";
+	} else if (!strcmp(c, "current-sensor") &&
+		   !strcmp(l, "CPU Current")) {
+		ads->sens.ops = &smu_cpuamp_ops;
+		ads->sens.name = "cpu-current";
+	} else if (!strcmp(c, "voltage-sensor") &&
+		   !strcmp(l, "CPU Voltage")) {
+		ads->sens.ops = &smu_cpuvolt_ops;
+		ads->sens.name = "cpu-voltage";
+	} else if (!strcmp(c, "power-sensor") &&
+		   !strcmp(l, "Slots Power")) {
+		ads->sens.ops = &smu_slotspow_ops;
+		ads->sens.name = "slots-power";
+		if (slotspow == NULL) {
+			DBG("wf: slotspow partition (%02x) not found\n",
+			    SMU_SDB_SLOTSPOW_ID);
+			goto fail;
+		}
+	} else
+		goto fail;
+
+	v = (u32 *)get_property(node, "reg", NULL);
+	if (v == NULL)
+		goto fail;
+	ads->reg = *v;
+
+	if (wf_register_sensor(&ads->sens))
+		goto fail;
+	return ads;
+ fail:
+	kfree(ads);
+	return NULL;
+}
+
+/*
+ * SMU Power combo sensor object
+ */
+
+struct smu_cpu_power_sensor {
+	struct list_head	link;
+	struct wf_sensor	*volts;
+	struct wf_sensor	*amps;
+	int			fake_volts : 1;
+	int			quadratic : 1;
+	struct wf_sensor	sens;
+};
+#define to_smu_cpu_power(c) container_of(c, struct smu_cpu_power_sensor, sens)
+
+static struct smu_cpu_power_sensor *smu_cpu_power;
+
+static void smu_cpu_power_release(struct wf_sensor *sr)
+{
+	struct smu_cpu_power_sensor *pow = to_smu_cpu_power(sr);
+
+	if (pow->volts)
+		wf_put_sensor(pow->volts);
+	if (pow->amps)
+		wf_put_sensor(pow->amps);
+	kfree(pow);
+}
+
+static int smu_cpu_power_get(struct wf_sensor *sr, s32 *value)
+{
+	struct smu_cpu_power_sensor *pow = to_smu_cpu_power(sr);
+	s32 volts, amps, power;
+	u64 tmps, tmpa, tmpb;
+	int rc;
+
+	rc = pow->amps->ops->get_value(pow->amps, &amps);
+	if (rc)
+		return rc;
+
+	if (pow->fake_volts) {
+		*value = amps * 12 - 0x30000;
+		return 0;
+	}
+
+	rc = pow->volts->ops->get_value(pow->volts, &volts);
+	if (rc)
+		return rc;
+
+	power = (s32)((((u64)volts) * ((u64)amps)) >> 16);
+	if (!pow->quadratic) {
+		*value = power;
+		return 0;
+	}
+	tmps = (((u64)power) * ((u64)power)) >> 16;
+	tmpa = ((u64)cpuvcp->power_quads[0]) * tmps;
+	tmpb = ((u64)cpuvcp->power_quads[1]) * ((u64)power);
+	*value = (tmpa >> 28) + (tmpb >> 28) + (cpuvcp->power_quads[2] >> 12);
+
+	return 0;
+}
+
+static struct wf_sensor_ops smu_cpu_power_ops = {
+	.get_value	= smu_cpu_power_get,
+	.release	= smu_cpu_power_release,
+	.owner		= THIS_MODULE,
+};
+
+
+static struct smu_cpu_power_sensor *
+smu_cpu_power_create(struct wf_sensor *volts, struct wf_sensor *amps)
+{
+	struct smu_cpu_power_sensor *pow;
+
+	pow = kmalloc(sizeof(struct smu_cpu_power_sensor), GFP_KERNEL);
+	if (pow == NULL)
+		return NULL;
+	pow->sens.ops = &smu_cpu_power_ops;
+	pow->sens.name = "cpu-power";
+
+	wf_get_sensor(volts);
+	pow->volts = volts;
+	wf_get_sensor(amps);
+	pow->amps = amps;
+
+	/* Some early machines need a faked voltage */
+	if (debugswitches && ((*debugswitches) & 0x80)) {
+		printk(KERN_INFO "windfarm: CPU Power sensor using faked"
+		       " voltage !\n");
+		pow->fake_volts = 1;
+	} else
+		pow->fake_volts = 0;
+
+	/* Try to use quadratic transforms on PowerMac8,1 and 9,1 for now,
+	 * I yet have to figure out what's up with 8,2 and will have to
+	 * adjust for later, unless we can 100% trust the SDB partition...
+	 */
+	if ((machine_is_compatible("PowerMac8,1") ||
+	     machine_is_compatible("PowerMac8,2") ||
+	     machine_is_compatible("PowerMac9,1")) &&
+	    cpuvcp_version >= 2) {
+		pow->quadratic = 1;
+		DBG("windfarm: CPU Power using quadratic transform\n");
+	} else
+		pow->quadratic = 0;
+
+	if (wf_register_sensor(&pow->sens))
+		goto fail;
+	return pow;
+ fail:
+	kfree(pow);
+	return NULL;
+}
+
+static int smu_fetch_param_partitions(void)
+{
+	struct smu_sdbp_header *hdr;
+
+	/* Get CPU voltage/current/power calibration data */
+	hdr = smu_get_sdb_partition(SMU_SDB_CPUVCP_ID, NULL);
+	if (hdr == NULL) {
+		DBG("wf: cpuvcp partition (%02x) not found\n",
+		    SMU_SDB_CPUVCP_ID);
+		return -ENODEV;
+	}
+	cpuvcp = (struct smu_sdbp_cpuvcp *)&hdr[1];
+	/* Keep version around */
+	cpuvcp_version = hdr->version;
+
+	/* Get CPU diode calibration data */
+	hdr = smu_get_sdb_partition(SMU_SDB_CPUDIODE_ID, NULL);
+	if (hdr == NULL) {
+		DBG("wf: cpudiode partition (%02x) not found\n",
+		    SMU_SDB_CPUDIODE_ID);
+		return -ENODEV;
+	}
+	cpudiode = (struct smu_sdbp_cpudiode *)&hdr[1];
+
+	/* Get slots power calibration data if any */
+	hdr = smu_get_sdb_partition(SMU_SDB_SLOTSPOW_ID, NULL);
+	if (hdr != NULL)
+		slotspow = (struct smu_sdbp_slotspow *)&hdr[1];
+
+	/* Get debug switches if any */
+	hdr = smu_get_sdb_partition(SMU_SDB_DEBUG_SWITCHES_ID, NULL);
+	if (hdr != NULL)
+		debugswitches = (u8 *)&hdr[1];
+
+	return 0;
+}
+
+static int __init smu_sensors_init(void)
+{
+	struct device_node *smu, *sensors, *s;
+	struct smu_ad_sensor *volt_sensor = NULL, *curr_sensor = NULL;
+	int rc;
+
+	if (!smu_present())
+		return -ENODEV;
+
+	/* Get parameters partitions */
+	rc = smu_fetch_param_partitions();
+	if (rc)
+		return rc;
+
+	smu = of_find_node_by_type(NULL, "smu");
+	if (smu == NULL)
+		return -ENODEV;
+
+	/* Look for sensors subdir */
+	for (sensors = NULL;
+	     (sensors = of_get_next_child(smu, sensors)) != NULL;)
+		if (!strcmp(sensors->name, "sensors"))
+			break;
+
+	of_node_put(smu);
+
+	/* Create basic sensors */
+	for (s = NULL;
+	     sensors && (s = of_get_next_child(sensors, s)) != NULL;) {
+		struct smu_ad_sensor *ads;
+
+		ads = smu_ads_create(s);
+		if (ads == NULL)
+			continue;
+		list_add(&ads->link, &smu_ads);
+		/* keep track of cpu voltage & current */
+		if (!strcmp(ads->sens.name, "cpu-voltage"))
+			volt_sensor = ads;
+		else if (!strcmp(ads->sens.name, "cpu-current"))
+			curr_sensor = ads;
+	}
+
+	of_node_put(sensors);
+
+	/* Create CPU power sensor if possible */
+	if (volt_sensor && curr_sensor)
+		smu_cpu_power = smu_cpu_power_create(&volt_sensor->sens,
+						     &curr_sensor->sens);
+
+	return 0;
+}
+
+static void __exit smu_sensors_exit(void)
+{
+	struct smu_ad_sensor *ads;
+
+	/* dispose of power sensor */
+	if (smu_cpu_power)
+		wf_unregister_sensor(&smu_cpu_power->sens);
+
+	/* dispose of basic sensors */
+	while (!list_empty(&smu_ads)) {
+		ads = list_entry(smu_ads.next, struct smu_ad_sensor, link);
+		list_del(&ads->link);
+		wf_unregister_sensor(&ads->sens);
+	}
+}
+
+
+module_init(smu_sensors_init);
+module_exit(smu_sensors_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("SMU sensor objects for PowerMacs thermal control");
+MODULE_LICENSE("GPL");
+