I'm trying to add code to a 2.6.32 kernel to extract the OMAP core
temperature for thermal testing, and section 7.4.6 of the OMAP3 TRM
(spug98g.pdf) explains the CONTROL_TEMP_SENSOR register.
I've added the following code:
static void omap3logic_fetch_temp(char *temp_buf)
{
int temp_val;
unsigned int temp;
static short temp_table[] = {
-400, -400, -400, -400, -400,
-400, -389, -375, -361, -333, /* 0-9 */
-318, -304, -290, -275, -261,
-247, -233, -219, -205, -191, /* 10-19 */
-177, -163, -149, -134, -120,
-106, -92, -78, -64, -50, /* 20-29 */
-35, -21, -7, +8, +23,
+37, +51, +66, +80, +94, /* 30-39 */
+108, +123, +137, +151, +165,
+179, +194, +208, +222, +236, /* 40-49 */
+251, +265, +279, +293, +307,
+321, +335, +349, +364, +378, /* 50-59 */
+392, +406, +420, +424, +449,
+463, +447, +491, +505, +519, /* 60-69 */
+533, +546, +560, +574, +588,
+602, +616, +630, +644, +657, /* 70-79 */
+671, +685, +699, +713, +727,
+741, +755, +769, +783, +797, /* 80-89 */
+811, +823, +838, +852, +865,
+879, +893, +906, +920, +934, /* 90-99 */
+947, +961, +975, +989, +1002,
+1016, +1030, +1043, +1057, +1071, /* 100-109 */
+1085, +1098, +1112, +1126, +1140,
+1153, +1167, +1181, +1194, +1208, /* 110-119 */
+1222, +1235, +1249, +1250, +1250,
+1250, +1250, +1250, +1250, /* 120-128 */
};
temp = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR);
temp_val = (temp_table[temp&0x7f] + temp_table[(temp&0x7f)+1]) / 2;
sprintf(temp_buf, "%d.%1d (%02x)", temp_val/10, ((unsigned
int)temp_val)%10, temp);
}
static ssize_t
omap3logic_show_temp(struct class *class, char *buf)
{
ssize_t retval;
char temp[128];
omap3logic_fetch_temp(temp);
retval = sprintf(buf, "%s\n", temp);
return retval;
}
static struct class_attribute temp_attr =
__ATTR(temp, S_IRUGO, omap3logic_show_temp, NULL);
static struct class *omap3logic_temp_class;
void omap3logic_temp_init(void)
{
int rc;
omap3logic_temp_class = class_create(THIS_MODULE, "temp");
if (IS_ERR(omap3logic_temp_class)) {
printk(KERN_ERR "%s: couldn't create temp class\n", __FUNCTION__);
return;
}
rc = class_create_file(omap3logic_temp_class, &temp_attr);
if (unlikely(rc)) {
printk(KERN_ERR "%s: couldn't create temp class file\n",
__FUNCTION__);
return;
}
/* Set CONTCONV and SOC to start continuous temperature measurements */
omap_ctrl_writel(0x300, OMAP343X_CONTROL_TEMP_SENSOR);
}
But when I read the register back, I see only a fixed temperature value,
even if I fire up some video demos to crank up the load. If I reboot
I'll see the temperature jump up, but then it stays constant whether I
increase/decrease the CPU load.
Any ideas why this isn't working?
Thanks in advance!
--
Peter Barada
peterb@xxxxxxxxxxx
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