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/sysdev.h>
50 #include <linux/kernel.h>
51 #include <linux/cpu.h>
57 #include "spu_priv1_mmio.h"
62 #define SYSDEV_PREFIX_ATTR(_prefix,_name,_mode) \
63 struct sysdev_attribute attr_ ## _prefix ## _ ## _name = { \
64 .attr = { .name = __stringify(_name), .mode = _mode }, \
65 .show = _prefix ## _show_ ## _name, \
66 .store = _prefix ## _store_ ## _name, \
69 static inline u8 reg_to_temp(u8 reg_value)
71 return ((reg_value & 0x3f) << 1) + TEMP_MIN;
74 static inline u8 temp_to_reg(u8 temp)
76 return ((temp - TEMP_MIN) >> 1) & 0x3f;
79 static struct cbe_pmd_regs __iomem *get_pmd_regs(struct sys_device *sysdev)
83 spu = container_of(sysdev, struct spu, sysdev);
85 return cbe_get_pmd_regs(spu_devnode(spu));
88 /* returns the value for a given spu in a given register */
89 static u8 spu_read_register_value(struct sys_device *sysdev, union spe_reg __iomem *reg)
91 const unsigned int *id;
95 /* getting the id from the reg attribute will not work on future device-tree layouts
96 * in future we should store the id to the spu struct and use it here */
97 spu = container_of(sysdev, struct spu, sysdev);
98 id = of_get_property(spu_devnode(spu), "reg", NULL);
99 value.val = in_be64(®->val);
101 return value.spe[*id];
104 static ssize_t spu_show_temp(struct sys_device *sysdev, char *buf)
107 struct cbe_pmd_regs __iomem *pmd_regs;
109 pmd_regs = get_pmd_regs(sysdev);
111 value = spu_read_register_value(sysdev, &pmd_regs->ts_ctsr1);
113 return sprintf(buf, "%d\n", reg_to_temp(value));
116 static ssize_t show_throttle(struct cbe_pmd_regs __iomem *pmd_regs, char *buf, int pos)
120 value = in_be64(&pmd_regs->tm_tpr.val);
121 /* access the corresponding byte */
125 return sprintf(buf, "%d\n", reg_to_temp(value));
128 static ssize_t store_throttle(struct cbe_pmd_regs __iomem *pmd_regs, const char *buf, size_t size, int pos)
135 ret = sscanf(buf, "%u", &temp);
137 if (ret != 1 || temp < TEMP_MIN || temp > TEMP_MAX)
140 new_value = temp_to_reg(temp);
142 reg_value = in_be64(&pmd_regs->tm_tpr.val);
144 /* zero out bits for new value */
145 reg_value &= ~(0xffull << pos);
146 /* set bits to new value */
147 reg_value |= new_value << pos;
149 out_be64(&pmd_regs->tm_tpr.val, reg_value);
153 static ssize_t spu_show_throttle_end(struct sys_device *sysdev, char *buf)
155 return show_throttle(get_pmd_regs(sysdev), buf, 0);
158 static ssize_t spu_show_throttle_begin(struct sys_device *sysdev, char *buf)
160 return show_throttle(get_pmd_regs(sysdev), buf, 8);
163 static ssize_t spu_show_throttle_full_stop(struct sys_device *sysdev, char *buf)
165 return show_throttle(get_pmd_regs(sysdev), buf, 16);
168 static ssize_t spu_store_throttle_end(struct sys_device *sysdev, const char *buf, size_t size)
170 return store_throttle(get_pmd_regs(sysdev), buf, size, 0);
173 static ssize_t spu_store_throttle_begin(struct sys_device *sysdev, const char *buf, size_t size)
175 return store_throttle(get_pmd_regs(sysdev), buf, size, 8);
178 static ssize_t spu_store_throttle_full_stop(struct sys_device *sysdev, const char *buf, size_t size)
180 return store_throttle(get_pmd_regs(sysdev), buf, size, 16);
183 static ssize_t ppe_show_temp(struct sys_device *sysdev, char *buf, int pos)
185 struct cbe_pmd_regs __iomem *pmd_regs;
188 pmd_regs = cbe_get_cpu_pmd_regs(sysdev->id);
189 value = in_be64(&pmd_regs->ts_ctsr2);
191 value = (value >> pos) & 0x3f;
193 return sprintf(buf, "%d\n", reg_to_temp(value));
197 /* shows the temperature of the DTS on the PPE,
198 * located near the linear thermal sensor */
199 static ssize_t ppe_show_temp0(struct sys_device *sysdev, char *buf)
201 return ppe_show_temp(sysdev, buf, 32);
204 /* shows the temperature of the second DTS on the PPE */
205 static ssize_t ppe_show_temp1(struct sys_device *sysdev, char *buf)
207 return ppe_show_temp(sysdev, buf, 0);
210 static ssize_t ppe_show_throttle_end(struct sys_device *sysdev, char *buf)
212 return show_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, 32);
215 static ssize_t ppe_show_throttle_begin(struct sys_device *sysdev, char *buf)
217 return show_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, 40);
220 static ssize_t ppe_show_throttle_full_stop(struct sys_device *sysdev, char *buf)
222 return show_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, 48);
225 static ssize_t ppe_store_throttle_end(struct sys_device *sysdev, const char *buf, size_t size)
227 return store_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, size, 32);
230 static ssize_t ppe_store_throttle_begin(struct sys_device *sysdev, const char *buf, size_t size)
232 return store_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, size, 40);
235 static ssize_t ppe_store_throttle_full_stop(struct sys_device *sysdev, const char *buf, size_t size)
237 return store_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, size, 48);
241 static struct sysdev_attribute attr_spu_temperature = {
242 .attr = {.name = "temperature", .mode = 0400 },
243 .show = spu_show_temp,
246 static SYSDEV_PREFIX_ATTR(spu, throttle_end, 0600);
247 static SYSDEV_PREFIX_ATTR(spu, throttle_begin, 0600);
248 static SYSDEV_PREFIX_ATTR(spu, throttle_full_stop, 0600);
251 static struct attribute *spu_attributes[] = {
252 &attr_spu_temperature.attr,
253 &attr_spu_throttle_end.attr,
254 &attr_spu_throttle_begin.attr,
255 &attr_spu_throttle_full_stop.attr,
259 static struct attribute_group spu_attribute_group = {
261 .attrs = spu_attributes,
264 static struct sysdev_attribute attr_ppe_temperature0 = {
265 .attr = {.name = "temperature0", .mode = 0400 },
266 .show = ppe_show_temp0,
269 static struct sysdev_attribute attr_ppe_temperature1 = {
270 .attr = {.name = "temperature1", .mode = 0400 },
271 .show = ppe_show_temp1,
274 static SYSDEV_PREFIX_ATTR(ppe, throttle_end, 0600);
275 static SYSDEV_PREFIX_ATTR(ppe, throttle_begin, 0600);
276 static SYSDEV_PREFIX_ATTR(ppe, throttle_full_stop, 0600);
278 static struct attribute *ppe_attributes[] = {
279 &attr_ppe_temperature0.attr,
280 &attr_ppe_temperature1.attr,
281 &attr_ppe_throttle_end.attr,
282 &attr_ppe_throttle_begin.attr,
283 &attr_ppe_throttle_full_stop.attr,
287 static struct attribute_group ppe_attribute_group = {
289 .attrs = ppe_attributes,
293 * initialize throttling with default values
295 static void __init init_default_values(void)
298 struct cbe_pmd_regs __iomem *pmd_regs;
299 struct sys_device *sysdev;
300 union ppe_spe_reg tpr;
309 * 08 - dynamic throttling starts if over 80 degrees
310 * 03 - dynamic throttling ceases if below 70 degrees */
313 * 10 - full stopped when over 96 degrees
314 * 08 - dynamic throttling starts if over 80 degrees
315 * 03 - dynamic throttling ceases if below 70 degrees
321 * 10 - stop 16 of 32 cycles
323 str1.val = 0x1010101010101010ull;
325 * 10 - stop 16 of 32 cycles
331 * 4 - normal operation
333 cr1.val = 0x0404040404040404ull;
335 * 4 - normal operation
339 for_each_possible_cpu (cpu) {
340 pr_debug("processing cpu %d\n", cpu);
341 sysdev = get_cpu_sysdev(cpu);
342 pmd_regs = cbe_get_cpu_pmd_regs(sysdev->id);
344 out_be64(&pmd_regs->tm_str2, str2);
345 out_be64(&pmd_regs->tm_str1.val, str1.val);
346 out_be64(&pmd_regs->tm_tpr.val, tpr.val);
347 out_be64(&pmd_regs->tm_cr1.val, cr1.val);
348 out_be64(&pmd_regs->tm_cr2, cr2);
353 static int __init thermal_init(void)
355 init_default_values();
357 spu_add_sysdev_attr_group(&spu_attribute_group);
358 cpu_add_sysdev_attr_group(&ppe_attribute_group);
362 module_init(thermal_init);
364 static void __exit thermal_exit(void)
366 spu_remove_sysdev_attr_group(&spu_attribute_group);
367 cpu_remove_sysdev_attr_group(&ppe_attribute_group);
369 module_exit(thermal_exit);
371 MODULE_LICENSE("GPL");
372 MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");