[PATCH v2 2/2] Input: cros_ec_keyb - Stop handling interrupts directly

[Enric Balletbo i Serra <enric.balletbo@collabora.com>]

From: Vic Yang <victoryang@google.com>

Because events other that keyboard ones will be handled by now on by
other drivers, stop directly handling interrupts and instead listen to
the new notifier in the MFD driver.

Signed-off-by: Vic Yang <victoryang@google.com>
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/keyboard/cros_ec_keyb.c | 135 ++++++++--------------------------
 1 file changed, 31 insertions(+), 104 deletions(-)

diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
index 4b0878f..25943e9 100644
--- a/drivers/input/keyboard/cros_ec_keyb.c
+++ b/drivers/input/keyboard/cros_ec_keyb.c
@@ -27,6 +27,7 @@
 #include <linux/input.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
+#include <linux/notifier.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/input/matrix_keypad.h>
@@ -44,6 +45,7 @@
  * @dev: Device pointer
  * @idev: Input device
  * @ec: Top level ChromeOS device to use to talk to EC
+ * @notifier: interrupt event notifier for transport devices
  */
 struct cros_ec_keyb {
 	unsigned int rows;
@@ -57,6 +59,7 @@ struct cros_ec_keyb {
 	struct device *dev;
 	struct input_dev *idev;
 	struct cros_ec_device *ec;
+	struct notifier_block notifier;
 };
 
 
@@ -146,67 +149,44 @@ static void cros_ec_keyb_process(struct cros_ec_keyb *ckdev,
 	input_sync(ckdev->idev);
 }
 
-static int cros_ec_keyb_get_state(struct cros_ec_keyb *ckdev, uint8_t *kb_state)
-{
-	int ret = 0;
-	struct cros_ec_command *msg;
-
-	msg = kmalloc(sizeof(*msg) + ckdev->cols, GFP_KERNEL);
-	if (!msg)
-		return -ENOMEM;
-
-	msg->version = 0;
-	msg->command = EC_CMD_MKBP_STATE;
-	msg->insize = ckdev->cols;
-	msg->outsize = 0;
-
-	ret = cros_ec_cmd_xfer(ckdev->ec, msg);
-	if (ret < 0) {
-		dev_err(ckdev->dev, "Error transferring EC message %d\n", ret);
-		goto exit;
-	}
-
-	memcpy(kb_state, msg->data, ckdev->cols);
-exit:
-	kfree(msg);
-	return ret;
-}
-
-static irqreturn_t cros_ec_keyb_irq(int irq, void *data)
+static int cros_ec_keyb_open(struct input_dev *dev)
 {
-	struct cros_ec_keyb *ckdev = data;
-	struct cros_ec_device *ec = ckdev->ec;
-	int ret;
-	uint8_t kb_state[ckdev->cols];
-
-	if (device_may_wakeup(ec->dev))
-		pm_wakeup_event(ec->dev, 0);
-
-	ret = cros_ec_keyb_get_state(ckdev, kb_state);
-	if (ret >= 0)
-		cros_ec_keyb_process(ckdev, kb_state, ret);
-	else
-		dev_err(ckdev->dev, "failed to get keyboard state: %d\n", ret);
+	struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
 
-	return IRQ_HANDLED;
+	return blocking_notifier_chain_register(&ckdev->ec->event_notifier,
+						&ckdev->notifier);
 }
 
-static int cros_ec_keyb_open(struct input_dev *dev)
+static void cros_ec_keyb_close(struct input_dev *dev)
 {
 	struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
-	struct cros_ec_device *ec = ckdev->ec;
 
-	return request_threaded_irq(ec->irq, NULL, cros_ec_keyb_irq,
-					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
-					"cros_ec_keyb", ckdev);
+	blocking_notifier_chain_unregister(&ckdev->ec->event_notifier,
+					   &ckdev->notifier);
 }
 
-static void cros_ec_keyb_close(struct input_dev *dev)
+static int cros_ec_keyb_work(struct notifier_block *nb,
+			     unsigned long queued_during_suspend, void *_notify)
 {
-	struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
-	struct cros_ec_device *ec = ckdev->ec;
+	struct cros_ec_keyb *ckdev = container_of(nb, struct cros_ec_keyb,
+						  notifier);
 
-	free_irq(ec->irq, ckdev);
+	if (ckdev->ec->event_data.event_type != EC_MKBP_EVENT_KEY_MATRIX)
+		return NOTIFY_DONE;
+	/*
+	 * If EC is not the wake source, discard key state changes during
+	 * suspend.
+	 */
+	if (queued_during_suspend)
+		return NOTIFY_OK;
+	if (ckdev->ec->event_size != ckdev->cols) {
+		dev_err(ckdev->dev,
+			"Discarded incomplete key matrix event.\n");
+		return NOTIFY_OK;
+	}
+	cros_ec_keyb_process(ckdev, ckdev->ec->event_data.data.key_matrix,
+			     ckdev->ec->event_size);
+	return NOTIFY_OK;
 }
 
 /*
@@ -265,12 +245,8 @@ static int cros_ec_keyb_probe(struct platform_device *pdev)
 	if (!idev)
 		return -ENOMEM;
 
-	if (!ec->irq) {
-		dev_err(dev, "no EC IRQ specified\n");
-		return -EINVAL;
-	}
-
 	ckdev->ec = ec;
+	ckdev->notifier.notifier_call = cros_ec_keyb_work;
 	ckdev->dev = dev;
 	dev_set_drvdata(dev, ckdev);
 
@@ -311,54 +287,6 @@ static int cros_ec_keyb_probe(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
-/* Clear any keys in the buffer */
-static void cros_ec_keyb_clear_keyboard(struct cros_ec_keyb *ckdev)
-{
-	uint8_t old_state[ckdev->cols];
-	uint8_t new_state[ckdev->cols];
-	unsigned long duration;
-	int i, ret;
-
-	/*
-	 * Keep reading until we see that the scan state does not change.
-	 * That indicates that we are done.
-	 *
-	 * Assume that the EC keyscan buffer is at most 32 deep.
-	 */
-	duration = jiffies;
-	ret = cros_ec_keyb_get_state(ckdev, new_state);
-	for (i = 1; !ret && i < 32; i++) {
-		memcpy(old_state, new_state, sizeof(old_state));
-		ret = cros_ec_keyb_get_state(ckdev, new_state);
-		if (0 == memcmp(old_state, new_state, sizeof(old_state)))
-			break;
-	}
-	duration = jiffies - duration;
-	dev_info(ckdev->dev, "Discarded %d keyscan(s) in %dus\n", i,
-		jiffies_to_usecs(duration));
-}
-
-static int cros_ec_keyb_resume(struct device *dev)
-{
-	struct cros_ec_keyb *ckdev = dev_get_drvdata(dev);
-
-	/*
-	 * When the EC is not a wake source, then it could not have caused the
-	 * resume, so we clear the EC's key scan buffer. If the EC was a
-	 * wake source (e.g. the lid is open and the user might press a key to
-	 * wake) then the key scan buffer should be preserved.
-	 */
-	if (!ckdev->ec->was_wake_device)
-		cros_ec_keyb_clear_keyboard(ckdev);
-
-	return 0;
-}
-
-#endif
-
-static SIMPLE_DEV_PM_OPS(cros_ec_keyb_pm_ops, NULL, cros_ec_keyb_resume);
-
 #ifdef CONFIG_OF
 static const struct of_device_id cros_ec_keyb_of_match[] = {
 	{ .compatible = "google,cros-ec-keyb" },
@@ -372,7 +300,6 @@ static struct platform_driver cros_ec_keyb_driver = {
 	.driver = {
 		.name = "cros-ec-keyb",
 		.of_match_table = of_match_ptr(cros_ec_keyb_of_match),
-		.pm	= &cros_ec_keyb_pm_ops,
 	},
 };
 
-- 
2.1.0