@@ -7,14 +7,16 @@
* Tushar Dave <tushar.n.dave@intel.com>
*/
+#include <linux/acpi.h>
+#include <linux/delay.h>
#include <linux/module.h>
-#include <linux/types.h>
#include <linux/init.h>
#include <linux/pci.h>
-#include <linux/acpi.h>
+#include <linux/pm.h>
+#include <linux/suspend.h>
#include <linux/thermal.h>
+#include <linux/types.h>
#include <linux/units.h>
-#include <linux/pm.h>
/* Intel PCH thermal Device IDs */
#define PCH_THERMAL_DID_HSW_1 0x9C24 /* Haswell PCH */
@@ -35,6 +37,7 @@
#define WPT_TSREL 0x0A /* Thermal Sensor Report Enable and Lock */
#define WPT_TSMIC 0x0C /* Thermal Sensor SMI Control */
#define WPT_CTT 0x0010 /* Catastrophic Trip Point */
+#define WPT_TSPM 0x001C /* Thermal Sensor Power Management */
#define WPT_TAHV 0x0014 /* Thermal Alert High Value */
#define WPT_TALV 0x0018 /* Thermal Alert Low Value */
#define WPT_TL 0x00000040 /* Throttle Value */
@@ -55,6 +58,22 @@
#define WPT_TL_T1L 0x1ff00000 /* T1 Level */
#define WPT_TL_TTEN 0x20000000 /* TT Enable */
+/* Resolution of 1/2 degree C and an offset of -50C */
+#define PCH_TEMP_OFFSET (-50)
+#define GET_WPT_TEMP(x) ((x) * MILLIDEGREE_PER_DEGREE / 2 + WPT_TEMP_OFFSET)
+#define WPT_TEMP_OFFSET (PCH_TEMP_OFFSET * MILLIDEGREE_PER_DEGREE)
+#define GET_PCH_TEMP(x) (((x) / 2) + PCH_TEMP_OFFSET)
+
+/* Amount of time for each cooling delay, 100ms by default for now */
+static unsigned int delay_timeout = 100;
+module_param(delay_timeout, int, 0644);
+MODULE_PARM_DESC(delay_timeout, "amount of time delay for each iteration.");
+
+/* Number of iterations for cooling delay, 10 counts by default for now */
+static unsigned int delay_cnt = 10;
+module_param(delay_cnt, int, 0644);
+MODULE_PARM_DESC(delay_cnt, "total number of iterations for time delay.");
+
static char driver_name[] = "Intel PCH thermal driver";
struct pch_thermal_device {
@@ -183,13 +202,58 @@ static int pch_wpt_get_temp(struct pch_thermal_device *ptd, int *temp)
static int pch_wpt_suspend(struct pch_thermal_device *ptd)
{
u8 tsel;
+ u8 pch_delay_cnt = 1;
+ u16 pch_thr_temp, pch_cur_temp;
- if (ptd->bios_enabled)
+ /* Shutdown the thermal sensor if it is not enabled by BIOS */
+ if (!ptd->bios_enabled) {
+ tsel = readb(ptd->hw_base + WPT_TSEL);
+ writeb(tsel & 0xFE, ptd->hw_base + WPT_TSEL);
+ return 0;
+ }
+
+ /* Do not check temperature if it is not a S0ix capable platform */
+ if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
return 0;
- tsel = readb(ptd->hw_base + WPT_TSEL);
+ /* Do not check temperature if it is not s2idle */
+ if (pm_suspend_via_firmware())
+ return 0;
+
+ /* Get the PCH temperature threshold value */
+ pch_thr_temp = GET_PCH_TEMP(WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TSPM));
+
+ /* Get the PCH current temperature value */
+ pch_cur_temp = GET_PCH_TEMP(WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TEMP));
- writeb(tsel & 0xFE, ptd->hw_base + WPT_TSEL);
+ /*
+ * If current PCH temperature is higher than configured PCH threshold
+ * value, run some delay loop with sleep to let the current temperature
+ * go down below the threshold value which helps to allow system enter
+ * lower power S0ix suspend state. Even after delay loop if PCH current
+ * temperature stays above threshold, notify the warning message
+ * which helps to indentify the reason why S0ix entry was rejected.
+ */
+ while (pch_delay_cnt <= delay_cnt) {
+ if (pch_cur_temp <= pch_thr_temp)
+ break;
+
+ dev_warn(&ptd->pdev->dev,
+ "CPU-PCH current temp [%dC] higher than the threshold temp [%dC], sleep %d times for %d ms duration\n",
+ pch_cur_temp, pch_thr_temp, pch_delay_cnt, delay_timeout);
+ msleep(delay_timeout);
+ /* Read the PCH current temperature for next cycle. */
+ pch_cur_temp = GET_PCH_TEMP(WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TEMP));
+ pch_delay_cnt++;
+ }
+
+ if (pch_cur_temp > pch_thr_temp)
+ dev_warn(&ptd->pdev->dev,
+ "CPU-PCH is hot [%dC] even after delay, continue to suspend. S0ix might fail\n",
+ pch_cur_temp);
+ else
+ dev_info(&ptd->pdev->dev,
+ "CPU-PCH is cool [%dC], continue to suspend\n", pch_cur_temp);
return 0;
}