// SPDX-License-Identifier: GPL-2.0-or-later
/*
* thermal support for the cell processor
*
* This module adds some sysfs attributes to cpu and spu nodes.
* Base for measurements are the digital thermal sensors (DTS)
* located on the chip.
* The accuracy is 2 degrees, starting from 65 up to 125 degrees celsius
* The attributes can be found under
* /sys/devices/system/cpu/cpuX/thermal
* /sys/devices/system/spu/spuX/thermal
*
* The following attributes are added for each node:
* temperature:
* contains the current temperature measured by the DTS
* throttle_begin:
* throttling begins when temperature is greater or equal to
* throttle_begin. Setting this value to 125 prevents throttling.
* throttle_end:
* throttling is being ceased, if the temperature is lower than
* throttle_end. Due to a delay between applying throttling and
* a reduced temperature this value should be less than throttle_begin.
* A value equal to throttle_begin provides only a very little hysteresis.
* throttle_full_stop:
* If the temperatrue is greater or equal to throttle_full_stop,
* full throttling is applied to the cpu or spu. This value should be
* greater than throttle_begin and throttle_end. Setting this value to
* 65 prevents the unit from running code at all.
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
*
* Author: Christian Krafft <[email protected]>
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/cpu.h>
#include <linux/stringify.h>
#include <asm/spu.h>
#include <asm/io.h>
#include <asm/cell-regs.h>
#include "spu_priv1_mmio.h"
#define TEMP_MIN 65
#define TEMP_MAX 125
#define DEVICE_PREFIX_ATTR(_prefix,_name,_mode) \
struct device_attribute attr_ ## _prefix ## _ ## _name = { \
.attr = { .name = __stringify(_name), .mode = _mode }, \
.show = _prefix ## _show_ ## _name, \
.store = _prefix ## _store_ ## _name, \
};
static inline u8 reg_to_temp(u8 reg_value)
{
return ((reg_value & 0x3f) << 1) + TEMP_MIN;
}
static inline u8 temp_to_reg(u8 temp)
{
return ((temp - TEMP_MIN) >> 1) & 0x3f;
}
static struct cbe_pmd_regs __iomem *get_pmd_regs(struct device *dev)
{
struct spu *spu;
spu = container_of(dev, struct spu, dev);
return cbe_get_pmd_regs(spu_devnode(spu));
}
/* returns the value for a given spu in a given register */
static u8 spu_read_register_value(struct device *dev, union spe_reg __iomem *reg)
{
union spe_reg value;
struct spu *spu;
spu = container_of(dev, struct spu, dev);
value.val = in_be64(®->val);
return value.spe[spu->spe_id];
}
static ssize_t spu_show_temp(struct device *dev, struct device_attribute *attr,
char *buf)
{
u8 value;
struct cbe_pmd_regs __iomem *pmd_regs;
pmd_regs = get_pmd_regs(dev);
value = spu_read_register_value(dev, &pmd_regs->ts_ctsr1);
return sprintf(buf, "%d\n", reg_to_temp(value));
}
static ssize_t show_throttle(struct cbe_pmd_regs __iomem *pmd_regs, char *buf, int pos)
{
u64 value;
value = in_be64(&pmd_regs->tm_tpr.val);
/* access the corresponding byte */
value >>= pos;
value &= 0x3F;
return sprintf(buf, "%d\n", reg_to_temp(value));
}
static ssize_t store_throttle(struct cbe_pmd_regs __iomem *pmd_regs, const char *buf, size_t size, int pos)
{
u64 reg_value;
unsigned int temp;
u64 new_value;
int ret;
ret = sscanf(buf, "%u", &temp);
if (ret != 1 || temp < TEMP_MIN || temp > TEMP_MAX)
return -EINVAL;
new_value = temp_to_reg(temp);
reg_value = in_be64(&pmd_regs->tm_tpr.val);
/* zero out bits for new value */
reg_value &= ~(0xffull << pos);
/* set bits to new value */
reg_value |= new_value << pos;
out_be64(&pmd_regs->tm_tpr.val, reg_value);
return size;
}
static ssize_t spu_show_throttle_end(struct device *dev,
struct device_attribute *attr, char *buf)
{
return show_throttle(get_pmd_regs(dev), buf, 0);
}
static ssize_t spu_show_throttle_begin(struct device *dev,
struct device_attribute *attr, char *buf)
{
return show_throttle(get_pmd_regs(dev), buf, 8);
}
static ssize_t spu_show_throttle_full_stop(struct device *dev,
struct device_attribute *attr, char *buf)
{
return show_throttle(get_pmd_regs(dev), buf, 16);
}
static ssize_t spu_store_throttle_end(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
return store_throttle(get_pmd_regs(dev), buf, size, 0);
}
static ssize_t spu_store_throttle_begin(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
return store_throttle(get_pmd_regs(dev), buf, size, 8);
}
static ssize_t spu_store_throttle_full_stop(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
return store_throttle(get_pmd_regs(dev), buf, size, 16);
}
static ssize_t ppe_show_temp(struct device *dev, char *buf, int pos)
{
struct cbe_pmd_regs __iomem *pmd_regs;
u64 value;
pmd_regs = cbe_get_cpu_pmd_regs(dev->id);
value = in_be64(&pmd_regs->ts_ctsr2);
value = (value >> pos) & 0x3f;
return sprintf(buf, "%d\n", reg_to_temp(value));
}
/* shows the temperature of the DTS on the PPE,
* located near the linear thermal sensor */
static ssize_t ppe_show_temp0(struct device *dev,
struct device_attribute *attr, char *buf)
{
return ppe_show_temp(dev, buf, 32);
}
/* shows the temperature of the second DTS on the PPE */
static ssize_t ppe_show_temp1(struct device *dev,
struct device_attribute *attr, char *buf)
{
return ppe_show_temp(dev, buf, 0);
}
static ssize_t ppe_show_throttle_end(struct device *dev,
struct device_attribute *attr, char *buf)
{
return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 32);
}
static ssize_t ppe_show_throttle_begin(struct device *dev,
struct device_attribute *attr, char *buf)
{
return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 40);
}
static ssize_t ppe_show_throttle_full_stop(struct device *dev,
struct device_attribute *attr, char *buf)
{
return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 48);
}
static ssize_t ppe_store_throttle_end(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 32);
}
static ssize_t ppe_store_throttle_begin(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 40);
}
static ssize_t ppe_store_throttle_full_stop(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 48);
}
static struct device_attribute attr_spu_temperature = {
.attr = {.name = "temperature", .mode = 0400 },
.show = spu_show_temp,
};
static DEVICE_PREFIX_ATTR(spu, throttle_end, 0600);
static DEVICE_PREFIX_ATTR(spu, throttle_begin, 0600);
static DEVICE_PREFIX_ATTR(spu, throttle_full_stop, 0600);
static struct attribute *spu_attributes[] = {
&attr_spu_temperature.attr,
&attr_spu_throttle_end.attr,
&attr_spu_throttle_begin.attr,
&attr_spu_throttle_full_stop.attr,
NULL,
};
static const struct attribute_group spu_attribute_group = {
.name = "thermal",
.attrs = spu_attributes,
};
static struct device_attribute attr_ppe_temperature0 = {
.attr = {.name = "temperature0", .mode = 0400 },
.show = ppe_show_temp0,
};
static struct device_attribute attr_ppe_temperature1 = {
.attr = {.name = "temperature1", .mode = 0400 },
.show = ppe_show_temp1,
};
static DEVICE_PREFIX_ATTR(ppe, throttle_end, 0600);
static DEVICE_PREFIX_ATTR(ppe, throttle_begin, 0600);
static DEVICE_PREFIX_ATTR(ppe, throttle_full_stop, 0600);
static struct attribute *ppe_attributes[] = {
&attr_ppe_temperature0.attr,
&attr_ppe_temperature1.attr,
&attr_ppe_throttle_end.attr,
&attr_ppe_throttle_begin.attr,
&attr_ppe_throttle_full_stop.attr,
NULL,
};
static struct attribute_group ppe_attribute_group = {
.name = "thermal",
.attrs = ppe_attributes,
};
/*
* initialize throttling with default values
*/
static int __init init_default_values(void)
{
int cpu;
struct cbe_pmd_regs __iomem *pmd_regs;
struct device *dev;
union ppe_spe_reg tpr;
union spe_reg str1;
u64 str2;
union spe_reg cr1;
u64 cr2;
/* TPR defaults */
/* ppe
* 1F - no full stop
* 08 - dynamic throttling starts if over 80 degrees
* 03 - dynamic throttling ceases if below 70 degrees */
tpr.ppe = 0x1F0803;
/* spe
* 10 - full stopped when over 96 degrees
* 08 - dynamic throttling starts if over 80 degrees
* 03 - dynamic throttling ceases if below 70 degrees
*/
tpr.spe = 0x100803;
/* STR defaults */
/* str1
* 10 - stop 16 of 32 cycles
*/
str1.val = 0x1010101010101010ull;
/* str2
* 10 - stop 16 of 32 cycles
*/
str2 = 0x10;
/* CR defaults */
/* cr1
* 4 - normal operation
*/
cr1.val = 0x0404040404040404ull;
/* cr2
* 4 - normal operation
*/
cr2 = 0x04;
for_each_possible_cpu (cpu) {
pr_debug("processing cpu %d\n", cpu);
dev = get_cpu_device(cpu);
if (!dev) {
pr_info("invalid dev pointer for cbe_thermal\n");
return -EINVAL;
}
pmd_regs = cbe_get_cpu_pmd_regs(dev->id);
if (!pmd_regs) {
pr_info("invalid CBE regs pointer for cbe_thermal\n");
return -EINVAL;
}
out_be64(&pmd_regs->tm_str2, str2);
out_be64(&pmd_regs->tm_str1.val, str1.val);
out_be64(&pmd_regs->tm_tpr.val, tpr.val);
out_be64(&pmd_regs->tm_cr1.val, cr1.val);
out_be64(&pmd_regs->tm_cr2, cr2);
}
return 0;
}
static int __init thermal_init(void)
{
int rc = init_default_values();
if (rc == 0) {
spu_add_dev_attr_group(&spu_attribute_group);
cpu_add_dev_attr_group(&ppe_attribute_group);
}
return rc;
}
module_init(thermal_init);
static void __exit thermal_exit(void)
{
spu_remove_dev_attr_group(&spu_attribute_group);
cpu_remove_dev_attr_group(&ppe_attribute_group);
}
module_exit(thermal_exit);
MODULE_DESCRIPTION("Cell processor thermal driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Krafft <[email protected]>");
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