Re: [PATCH v8 2/7] Input: cros_ec_keyb - Stop handling interrupts directly

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, Apr 12, 2016 at 02:32:25PM +0200, Tomeu Vizoso wrote:
> 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.
> 

Hmm, where did Vic's sign-off go?

> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>

Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Please merge through whatever tree takes the rest of the patches.

> ---
> 
> Changes in v8: None
> Changes in v7: None
> Changes in v6: None
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
> 
>  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 b01966dc7eb3..b891503143dc 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(ec->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;
>  }
>  
>  /*
> @@ -266,12 +246,8 @@ 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(&pdev->dev, ckdev);
>  
> @@ -312,54 +288,6 @@ 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" },
> @@ -373,7 +301,6 @@ 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,
>  	},
>  };
>  
> -- 
> 2.5.5
> 

-- 
Dmitry