[PATCH v2 2/2] Input: drv260x: Fix suspend and resume sequencing

[Maurizio Casciano]

Force-feedback playback is queued asynchronously, but system suspend
can cut the enable GPIO and vbat supply while the worker is pending.
Quiesce the worker and reject new playback requests after suspend
begins.

The enable pin also disables I2C and resets volatile configuration.
Raise it before communicating on resume, observe the startup delay,
and rerun device initialization. Restore the same state if regulator
shutdown aborts suspend.

Assisted-by: Codex:gpt-5.6-sol sparse
Signed-off-by: Maurizio Casciano <mauriziocasciano7@xxxxxxxxx>
---
 drivers/input/misc/drv260x.c | 42 ++++++++++++++++++++++++++++--------
 1 file changed, 33 insertions(+), 9 deletions(-)

diff --git a/drivers/input/misc/drv260x.c b/drivers/input/misc/drv260x.c
index f26a9052edd2..c64a86bc9bfd 100644
--- a/drivers/input/misc/drv260x.c
+++ b/drivers/input/misc/drv260x.c
@@ -181,6 +181,7 @@
  * @work: Work item used to off load the enable/disable of the vibration
  * @enable_gpio: Pointer to the gpio used for enable/disabling
  * @regulator: Pointer to the regulator for the IC
+ * @suspended: Whether force-feedback work must remain quiesced
  * @magnitude: Magnitude of the vibration event
  * @mode: The operating mode of the IC (LRA_NO_CAL, ERM or LRA)
  * @library: The vibration library to be used
@@ -194,6 +195,7 @@ struct drv260x_data {
 	struct work_struct work;
 	struct gpio_desc *enable_gpio;
 	struct regulator *regulator;
+	bool suspended;
 	u8 magnitude;
 	u32 mode;
 	u32 library;
@@ -215,6 +217,13 @@ static int drv260x_calculate_voltage(unsigned int voltage)
 	return (voltage * 255 / 5600);
 }
 
+static void drv260x_set_suspended(struct drv260x_data *haptics,
+				  bool suspended)
+{
+	scoped_guard(spinlock_irqsave, &haptics->input_dev->event_lock)
+		haptics->suspended = suspended;
+}
+
 static void drv260x_worker(struct work_struct *work)
 {
 	struct drv260x_data *haptics = container_of(work, struct drv260x_data, work);
@@ -243,6 +252,9 @@ static int drv260x_haptics_play(struct input_dev *input, void *data,
 {
 	struct drv260x_data *haptics = input_get_drvdata(input);
 
+	if (haptics->suspended)
+		return 0;
+
 	/* Scale u16 magnitude into u8 register value */
 	if (effect->u.rumble.strong_magnitude > 0)
 		haptics->magnitude = effect->u.rumble.strong_magnitude >> 8;
@@ -583,17 +595,21 @@ static int drv260x_probe(struct i2c_client *client)
 static int drv260x_suspend(struct device *dev)
 {
 	struct drv260x_data *haptics = dev_get_drvdata(dev);
-	int error;
+	int error, restore_error;
 
 	guard(mutex)(&haptics->input_dev->mutex);
 
 	if (input_device_enabled(haptics->input_dev)) {
+		drv260x_set_suspended(haptics, true);
+		cancel_work_sync(&haptics->work);
+
 		error = regmap_update_bits(haptics->regmap,
 					   DRV260X_MODE,
 					   DRV260X_STANDBY_MASK,
 					   DRV260X_STANDBY);
 		if (error) {
 			dev_err(dev, "Failed to set standby mode\n");
+			drv260x_set_suspended(haptics, false);
 			return error;
 		}
 
@@ -602,9 +618,15 @@ static int drv260x_suspend(struct device *dev)
 		error = regulator_disable(haptics->regulator);
 		if (error) {
 			dev_err(dev, "Failed to disable regulator\n");
-			regmap_update_bits(haptics->regmap,
-					   DRV260X_MODE,
-					   DRV260X_STANDBY_MASK, 0);
+
+			gpiod_set_value(haptics->enable_gpio, 1);
+			usleep_range(250, 500);
+			restore_error = drv260x_init(haptics);
+			if (restore_error)
+				dev_err(dev, "Failed to restore configuration: %d\n",
+					restore_error);
+
+			drv260x_set_suspended(haptics, false);
 			return error;
 		}
 	}
@@ -626,16 +648,18 @@ static int drv260x_resume(struct device *dev)
 			return error;
 		}
 
-		error = regmap_update_bits(haptics->regmap,
-					   DRV260X_MODE,
-					   DRV260X_STANDBY_MASK, 0);
+		gpiod_set_value(haptics->enable_gpio, 1);
+		usleep_range(250, 500);
+
+		error = drv260x_init(haptics);
 		if (error) {
-			dev_err(dev, "Failed to unset standby mode\n");
+			dev_err(dev, "Failed to restore configuration: %d\n", error);
+			gpiod_set_value(haptics->enable_gpio, 0);
 			regulator_disable(haptics->regulator);
 			return error;
 		}
 
-		gpiod_set_value(haptics->enable_gpio, 1);
+		drv260x_set_suspended(haptics, false);
 	}
 
 	return 0;
-- 
2.53.0