2 * thermal support for the cell processor
4 * This module adds some sysfs attributes to cpu and spu nodes.
5 * Base for measurements are the digital thermal sensors (DTS)
7 * The accuracy is 2 degrees, starting from 65 up to 125 degrees celsius
8 * The attributes can be found under
9 * /sys/devices/system/cpu/cpuX/thermal
10 * /sys/devices/system/spu/spuX/thermal
12 * The following attributes are added for each node:
14 * contains the current temperature measured by the DTS
16 * throttling begins when temperature is greater or equal to
17 * throttle_begin. Setting this value to 125 prevents throttling.
19 * throttling is being ceased, if the temperature is lower than
20 * throttle_end. Due to a delay between applying throttling and
21 * a reduced temperature this value should be less than throttle_begin.
22 * A value equal to throttle_begin provides only a very little hysteresis.
24 * If the temperatrue is greater or equal to throttle_full_stop,
25 * full throttling is applied to the cpu or spu. This value should be
26 * greater than throttle_begin and throttle_end. Setting this value to
27 * 65 prevents the unit from running code at all.
29 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
31 * Author: Christian Krafft <krafft@de.ibm.com>
33 * This program is free software; you can redistribute it and/or modify
34 * it under the terms of the GNU General Public License as published by
35 * the Free Software Foundation; either version 2, or (at your option)
38 * This program is distributed in the hope that it will be useful,
39 * but WITHOUT ANY WARRANTY; without even the implied warranty of
40 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
41 * GNU General Public License for more details.
43 * You should have received a copy of the GNU General Public License
44 * along with this program; if not, write to the Free Software
45 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
48 #include <linux/module.h>
49 #include <linux/device.h>
50 #include <linux/kernel.h>
51 #include <linux/cpu.h>
52 #include <linux/stringify.h>
56 #include <asm/cell-regs.h>
58 #include "spu_priv1_mmio.h"
63 #define DEVICE_PREFIX_ATTR(_prefix,_name,_mode) \
64 struct device_attribute attr_ ## _prefix ## _ ## _name = { \
65 .attr = { .name = __stringify(_name), .mode = _mode }, \
66 .show = _prefix ## _show_ ## _name, \
67 .store = _prefix ## _store_ ## _name, \
70 static inline u8 reg_to_temp(u8 reg_value)
72 return ((reg_value & 0x3f) << 1) + TEMP_MIN;
75 static inline u8 temp_to_reg(u8 temp)
77 return ((temp - TEMP_MIN) >> 1) & 0x3f;
80 static struct cbe_pmd_regs __iomem *get_pmd_regs(struct device *dev)
84 spu = container_of(dev, struct spu, dev);
86 return cbe_get_pmd_regs(spu_devnode(spu));
89 /* returns the value for a given spu in a given register */
90 static u8 spu_read_register_value(struct device *dev, union spe_reg __iomem *reg)
95 spu = container_of(dev, struct spu, dev);
96 value.val = in_be64(®->val);
98 return value.spe[spu->spe_id];
101 static ssize_t spu_show_temp(struct device *dev, struct device_attribute *attr,
105 struct cbe_pmd_regs __iomem *pmd_regs;
107 pmd_regs = get_pmd_regs(dev);
109 value = spu_read_register_value(dev, &pmd_regs->ts_ctsr1);
111 return sprintf(buf, "%d\n", reg_to_temp(value));
114 static ssize_t show_throttle(struct cbe_pmd_regs __iomem *pmd_regs, char *buf, int pos)
118 value = in_be64(&pmd_regs->tm_tpr.val);
119 /* access the corresponding byte */
123 return sprintf(buf, "%d\n", reg_to_temp(value));
126 static ssize_t store_throttle(struct cbe_pmd_regs __iomem *pmd_regs, const char *buf, size_t size, int pos)
133 ret = sscanf(buf, "%u", &temp);
135 if (ret != 1 || temp < TEMP_MIN || temp > TEMP_MAX)
138 new_value = temp_to_reg(temp);
140 reg_value = in_be64(&pmd_regs->tm_tpr.val);
142 /* zero out bits for new value */
143 reg_value &= ~(0xffull << pos);
144 /* set bits to new value */
145 reg_value |= new_value << pos;
147 out_be64(&pmd_regs->tm_tpr.val, reg_value);
151 static ssize_t spu_show_throttle_end(struct device *dev,
152 struct device_attribute *attr, char *buf)
154 return show_throttle(get_pmd_regs(dev), buf, 0);
157 static ssize_t spu_show_throttle_begin(struct device *dev,
158 struct device_attribute *attr, char *buf)
160 return show_throttle(get_pmd_regs(dev), buf, 8);
163 static ssize_t spu_show_throttle_full_stop(struct device *dev,
164 struct device_attribute *attr, char *buf)
166 return show_throttle(get_pmd_regs(dev), buf, 16);
169 static ssize_t spu_store_throttle_end(struct device *dev,
170 struct device_attribute *attr, const char *buf, size_t size)
172 return store_throttle(get_pmd_regs(dev), buf, size, 0);
175 static ssize_t spu_store_throttle_begin(struct device *dev,
176 struct device_attribute *attr, const char *buf, size_t size)
178 return store_throttle(get_pmd_regs(dev), buf, size, 8);
181 static ssize_t spu_store_throttle_full_stop(struct device *dev,
182 struct device_attribute *attr, const char *buf, size_t size)
184 return store_throttle(get_pmd_regs(dev), buf, size, 16);
187 static ssize_t ppe_show_temp(struct device *dev, char *buf, int pos)
189 struct cbe_pmd_regs __iomem *pmd_regs;
192 pmd_regs = cbe_get_cpu_pmd_regs(dev->id);
193 value = in_be64(&pmd_regs->ts_ctsr2);
195 value = (value >> pos) & 0x3f;
197 return sprintf(buf, "%d\n", reg_to_temp(value));
201 /* shows the temperature of the DTS on the PPE,
202 * located near the linear thermal sensor */
203 static ssize_t ppe_show_temp0(struct device *dev,
204 struct device_attribute *attr, char *buf)
206 return ppe_show_temp(dev, buf, 32);
209 /* shows the temperature of the second DTS on the PPE */
210 static ssize_t ppe_show_temp1(struct device *dev,
211 struct device_attribute *attr, char *buf)
213 return ppe_show_temp(dev, buf, 0);
216 static ssize_t ppe_show_throttle_end(struct device *dev,
217 struct device_attribute *attr, char *buf)
219 return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 32);
222 static ssize_t ppe_show_throttle_begin(struct device *dev,
223 struct device_attribute *attr, char *buf)
225 return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 40);
228 static ssize_t ppe_show_throttle_full_stop(struct device *dev,
229 struct device_attribute *attr, char *buf)
231 return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 48);
234 static ssize_t ppe_store_throttle_end(struct device *dev,
235 struct device_attribute *attr, const char *buf, size_t size)
237 return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 32);
240 static ssize_t ppe_store_throttle_begin(struct device *dev,
241 struct device_attribute *attr, const char *buf, size_t size)
243 return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 40);
246 static ssize_t ppe_store_throttle_full_stop(struct device *dev,
247 struct device_attribute *attr, const char *buf, size_t size)
249 return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 48);
253 static struct device_attribute attr_spu_temperature = {
254 .attr = {.name = "temperature", .mode = 0400 },
255 .show = spu_show_temp,
258 static DEVICE_PREFIX_ATTR(spu, throttle_end, 0600);
259 static DEVICE_PREFIX_ATTR(spu, throttle_begin, 0600);
260 static DEVICE_PREFIX_ATTR(spu, throttle_full_stop, 0600);
263 static struct attribute *spu_attributes[] = {
264 &attr_spu_temperature.attr,
265 &attr_spu_throttle_end.attr,
266 &attr_spu_throttle_begin.attr,
267 &attr_spu_throttle_full_stop.attr,
271 static struct attribute_group spu_attribute_group = {
273 .attrs = spu_attributes,
276 static struct device_attribute attr_ppe_temperature0 = {
277 .attr = {.name = "temperature0", .mode = 0400 },
278 .show = ppe_show_temp0,
281 static struct device_attribute attr_ppe_temperature1 = {
282 .attr = {.name = "temperature1", .mode = 0400 },
283 .show = ppe_show_temp1,
286 static DEVICE_PREFIX_ATTR(ppe, throttle_end, 0600);
287 static DEVICE_PREFIX_ATTR(ppe, throttle_begin, 0600);
288 static DEVICE_PREFIX_ATTR(ppe, throttle_full_stop, 0600);
290 static struct attribute *ppe_attributes[] = {
291 &attr_ppe_temperature0.attr,
292 &attr_ppe_temperature1.attr,
293 &attr_ppe_throttle_end.attr,
294 &attr_ppe_throttle_begin.attr,
295 &attr_ppe_throttle_full_stop.attr,
299 static struct attribute_group ppe_attribute_group = {
301 .attrs = ppe_attributes,
305 * initialize throttling with default values
307 static int __init init_default_values(void)
310 struct cbe_pmd_regs __iomem *pmd_regs;
312 union ppe_spe_reg tpr;
321 * 08 - dynamic throttling starts if over 80 degrees
322 * 03 - dynamic throttling ceases if below 70 degrees */
325 * 10 - full stopped when over 96 degrees
326 * 08 - dynamic throttling starts if over 80 degrees
327 * 03 - dynamic throttling ceases if below 70 degrees
333 * 10 - stop 16 of 32 cycles
335 str1.val = 0x1010101010101010ull;
337 * 10 - stop 16 of 32 cycles
343 * 4 - normal operation
345 cr1.val = 0x0404040404040404ull;
347 * 4 - normal operation
351 for_each_possible_cpu (cpu) {
352 pr_debug("processing cpu %d\n", cpu);
353 dev = get_cpu_device(cpu);
356 pr_info("invalid dev pointer for cbe_thermal\n");
360 pmd_regs = cbe_get_cpu_pmd_regs(dev->id);
363 pr_info("invalid CBE regs pointer for cbe_thermal\n");
367 out_be64(&pmd_regs->tm_str2, str2);
368 out_be64(&pmd_regs->tm_str1.val, str1.val);
369 out_be64(&pmd_regs->tm_tpr.val, tpr.val);
370 out_be64(&pmd_regs->tm_cr1.val, cr1.val);
371 out_be64(&pmd_regs->tm_cr2, cr2);
378 static int __init thermal_init(void)
380 int rc = init_default_values();
383 spu_add_dev_attr_group(&spu_attribute_group);
384 cpu_add_dev_attr_group(&ppe_attribute_group);
389 module_init(thermal_init);
391 static void __exit thermal_exit(void)
393 spu_remove_dev_attr_group(&spu_attribute_group);
394 cpu_remove_dev_attr_group(&ppe_attribute_group);
396 module_exit(thermal_exit);
398 MODULE_LICENSE("GPL");
399 MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");