fan: Enable fan on chipset resume

Always enable the fan on chipset resume. If the DPTF is enabled,
AP will disable/throttle the fan upon booting to S0.

BUG=b:139882986
BRANCH=none
TEST=Manually tested on intelrvp.
     fan is able to run in auto mode on chipset resume.

Change-Id: I986c983fde550f797b3aaa3e06c6b958535b2769
Signed-off-by: Vijay Hiremath <vijay.p.hiremath@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1768917
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

1 files changed, 34 insertions, 42 deletions

diff --git a/common/fan.c b/common/fan.c
index ab90c79dce..a3748c2d1b 100644
--- a/common/fan.c
+++ b/common/fan.c
@@ -557,56 +557,48 @@ static void pwm_fan_preserve_state(void)
 }
 DECLARE_HOOK(HOOK_SYSJUMP, pwm_fan_preserve_state, HOOK_PRIO_DEFAULT);
 
-static void pwm_fan_resume(void)
+static void pwm_fan_control(int enable)
 {
 	int fan;
+
+	/* TODO(crosbug.com/p/23530): Still treating all fans as one. */
 	for (fan = 0; fan < fan_count; fan++) {
-		/* We don't enable or disable thermal control here.
-		 * It should be already enabled by pwm_fan_init on cold boot
-		 * or by pwm_fan_S3_S5 on warm reboot. If it needs
-		 * to be disabled, DPTF and host command will do so. */
-		fan_set_rpm_target(FAN_CH(fan),
-				   fan_percent_to_rpm(FAN_CH(fan),
-						      CONFIG_FAN_INIT_SPEED));
-		set_enabled(fan, 1);
+		set_thermal_control_enabled(fan, enable);
+		fan_set_rpm_target(FAN_CH(fan), enable ?
+			fan_percent_to_rpm(FAN_CH(fan), CONFIG_FAN_INIT_SPEED) :
+			0);
+		set_enabled(fan, enable);
 	}
 }
-DECLARE_HOOK(HOOK_CHIPSET_RESUME, pwm_fan_resume, HOOK_PRIO_DEFAULT);
 
-static void pwm_fan_startup(void)
+static void pwm_fan_stop(void)
 {
-	int fan;
-	/* Turn on fan control when the processor boots up (for BIOS screens) */
-	for (fan = 0; fan < fan_count; fan++)
-		set_thermal_control_enabled(fan, 1);
+	/*
+	 * There is no need to cool CPU in S3 or S5. We currently don't
+	 * have fans for battery or charger chip. Battery systems will
+	 * control charge current based on its own temperature readings.
+	 * Thus, we do not need to keep fans running in S3 or S5.
+	 *
+	 * Even with a fan on charging system, it's questionable to run
+	 * a fan in S3/S5. Under an extreme heat condition, spinning a
+	 * fan would create more heat as it draws current from a
+	 * battery and heat would come from ambient air instead of CPU.
+	 *
+	 * Thermal control may be already disabled if DPTF is used.
+	 */
+	pwm_fan_control(0); /* crosbug.com/p/8097 */
 }
-/* We need to cover cold boot and warm boot. */
-DECLARE_HOOK(HOOK_CHIPSET_STARTUP, pwm_fan_startup, HOOK_PRIO_DEFAULT);
-DECLARE_HOOK(HOOK_CHIPSET_RESET, pwm_fan_startup, HOOK_PRIO_FIRST);
+DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, pwm_fan_stop, HOOK_PRIO_DEFAULT);
+DECLARE_HOOK(HOOK_CHIPSET_SHUTDOWN, pwm_fan_stop, HOOK_PRIO_DEFAULT);
 
-static void pwm_fan_s3_s5(void)
+static void pwm_fan_start(void)
 {
-	int fan;
-
-	/* TODO(crosbug.com/p/23530): Still treating all fans as one. */
-	for (fan = 0; fan < fan_count; fan++) {
-		/*
-		 * There is no need to cool CPU in S3 or S5. We currently don't
-		 * have fans for battery or charger chip. Battery systems will
-		 * control charge current based on its own temperature readings.
-		 * Thus, we do not need to keep fans running in S3 or S5.
-		 *
-		 * Even with a fan on charging system, it's questionable to run
-		 * a fan in S3/S5. Under an extreme heat condition, spinning a
-		 * fan would create more heat as it draws current from a
-		 * battery and heat would come from ambient air instead of CPU.
-		 *
-		 * Thermal control may be already disabled if DPTF is used.
-		 */
-		set_thermal_control_enabled(fan, 0);
-		fan_set_rpm_target(FAN_CH(fan), 0);
-		set_enabled(fan, 0); /* crosbug.com/p/8097 */
-	}
+	/*
+	 * Even if the DPTF is enabled, enable thermal control here.
+	 * Upon booting to S0, if needed AP will disable/throttle it using
+	 * host commands.
+	 */
+	pwm_fan_control(1);
 }
-DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, pwm_fan_s3_s5, HOOK_PRIO_DEFAULT);
-DECLARE_HOOK(HOOK_CHIPSET_SHUTDOWN, pwm_fan_s3_s5, HOOK_PRIO_DEFAULT);
+DECLARE_HOOK(HOOK_CHIPSET_RESET, pwm_fan_start, HOOK_PRIO_FIRST);
+DECLARE_HOOK(HOOK_CHIPSET_RESUME, pwm_fan_start, HOOK_PRIO_DEFAULT);