[PATCH v2 07/42] misc/mei/hdcp: Get & Put for mei cl_device

[Winkler, Tomas]

> Interfaces to obtain and release the cl_device reference is developed.
> Using these interfaces intel hdcp driver will get the reference to the mei
> client devices, so that hdcp2.2 service calls can be routed to that client
> device.
> 
> During registration, call back function will be registered with mei_hdcp driver
> so that when the client device is removed intel hdcp driver can be informed.
> 
> At a time only one reference is allowed in this interfaces.
> 
> v2:
>   Rebased.
Linux kernel already provide notification chain,  please use that. 
This is not needed and I'm not sure it will ever work.

Tomas

 
> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> ---
>  drivers/misc/mei/hdcp/mei_hdcp.c | 55
> +++++++++++++++++++++++++++++++++++++++-
>  drivers/misc/mei/hdcp/mei_hdcp.h |  9 +++++++
>  include/linux/mei_hdcp.h         | 47 ++++++++++++++++++++++++++++++++++
>  3 files changed, 110 insertions(+), 1 deletion(-)  create mode 100644
> include/linux/mei_hdcp.h
> 
> diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c
> b/drivers/misc/mei/hdcp/mei_hdcp.c
> index 25df7034cfb4..63f77800a6f7 100644
> --- a/drivers/misc/mei/hdcp/mei_hdcp.c
> +++ b/drivers/misc/mei/hdcp/mei_hdcp.c
> @@ -55,18 +55,71 @@ static int mei_hdcp_probe(struct mei_cl_device
> *cldev,
>  	mei_cldev_set_drvdata(cldev, &mei_hdcp);
> 
>  	ret = mei_cldev_enable(cldev);
> -	if (ret < 0)
> +	if (ret < 0) {
>  		dev_err(&cldev->dev, "mei_cldev_enable Failed. %d\n", ret);
> +		goto err;
> +	}
> +
> +	if (mei_hdcp.notify_on_cldev_change)
> +		mei_hdcp.notify_on_cldev_change(mei_hdcp.client, cldev);
> +
> +	return 0;
> +err:
> +	if (mei_hdcp.notify_on_cldev_change)
> +		mei_hdcp.notify_on_cldev_change(mei_hdcp.client, NULL);
> 
>  	return ret;
>  }
> 
>  static int mei_hdcp_remove(struct mei_cl_device *cldev)  {
> +	struct mei_hdcp *mei_hdcp = mei_cldev_get_drvdata(cldev);
> +
> +	if (mei_hdcp->notify_on_cldev_change)
> +		mei_hdcp->notify_on_cldev_change(mei_hdcp->client, NULL);
> +
>  	mei_cldev_disable(cldev);
> +
>  	return 0;
>  }
> 
> +int mei_hdcp_cldev_get_reference(void *client_data,
> +				 struct mei_cl_device **cldev,
> +				 void (*notify_change)(void *client,
> +						       struct mei_cl_device
> +						       *cldev))
> +{
> +	if (!notify_change || !client_data)
> +		return -EINVAL;
> +
> +	if (mei_hdcp.ref_cnt)
> +		return -EBUSY;
> +
> +	if (!mei_cldev_active_and_enabled(mei_hdcp.cldev)) {
> +		if (!notify_change)
> +			return -EAGAIN;
> +	} else {
> +		*cldev = mei_hdcp.cldev;
> +	}
> +
> +	mei_hdcp.ref_cnt++;
> +	mei_hdcp.client = client_data;
> +	mei_hdcp.notify_on_cldev_change = notify_change;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(mei_hdcp_cldev_get_reference);
> +
> +void mei_hdcp_cldev_put_reference(struct mei_cl_device *cldev) {
> +	if (cldev == mei_hdcp.cldev) {
> +		mei_hdcp.ref_cnt--;
> +		mei_hdcp.client = NULL;
> +		mei_hdcp.notify_on_cldev_change = NULL;
> +	}
> +}
> +EXPORT_SYMBOL(mei_hdcp_cldev_put_reference);
> +
>  #define WIDI_HECI_CLIENT_GUID	UUID_LE(0xB638AB7E, 0x94E2,
> 0x4EA2, 0xA5, \
>  					0x52, 0xD1, 0xC5, 0x4B, \
>  					0x62, 0x7F, 0x04)
> diff --git a/drivers/misc/mei/hdcp/mei_hdcp.h
> b/drivers/misc/mei/hdcp/mei_hdcp.h
> index c06c0d767c4f..7d792b5ad703 100644
> --- a/drivers/misc/mei/hdcp/mei_hdcp.h
> +++ b/drivers/misc/mei/hdcp/mei_hdcp.h
> @@ -27,6 +27,15 @@
> 
>  struct mei_hdcp {
>  	struct mei_cl_device *cldev;
> +
> +	/* Reference to the HDCP2.2 service consumer */
> +	void *client;
> +
> +	/* Callback function for the consumer on cl_device state change */
> +	void (*notify_on_cldev_change)(void *client,
> +				      struct mei_cl_device *cldev);
> +
> +	int ref_cnt;
>  };
> 
>  #endif /* __MEI_HDCP_H__ */
> diff --git a/include/linux/mei_hdcp.h b/include/linux/mei_hdcp.h new file
> mode 100644 index 000000000000..774b26da0c26
> --- /dev/null
> +++ b/include/linux/mei_hdcp.h
> @@ -0,0 +1,47 @@
> +/*
> + * Copyright (c) 2017 Intel Corporation
> + *
> + * Permission to use, copy, modify, distribute, and sell this software
> +and its
> + * documentation for any purpose is hereby granted without fee,
> +provided that
> + * the above copyright notice appear in all copies and that both that
> +copyright
> + * notice and this permission notice appear in supporting
> +documentation, and
> + * that the name of the copyright holders not be used in advertising or
> + * publicity pertaining to distribution of the software without
> +specific,
> + * written prior permission.  The copyright holders make no
> +representations
> + * about the suitability of this software for any purpose.  It is
> +provided "as
> + * is" without express or implied warranty.
> + *
> + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO
> THIS
> +SOFTWARE,
> + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
> FITNESS, IN
> +NO
> + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL,
> +INDIRECT OR
> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
> FROM LOSS
> +OF USE,
> + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
> OR
> +OTHER
> + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
> OR
> +PERFORMANCE
> + * OF THIS SOFTWARE.
> + */
> +
> +#ifndef _LINUX_MEI_HDCP_H
> +#define _LINUX_MEI_HDCP_H
> +
> +#ifdef CONFIG_INTEL_MEI_HDCP
> +int mei_hdcp_cldev_get_reference(void *client_data,
> +				 struct mei_cl_device **cldev,
> +				 void (*notify_change)(void *client,
> +						       struct mei_cl_device
> +						       *cldev));
> +void mei_hdcp_cldev_put_reference(struct mei_cl_device *cldev); #else
> +static inline int mei_hdcp_cldev_get_reference(void *client_data,
> +				 struct mei_cl_device **cldev,
> +				 void (*notify_change)(void *client,
> +						       struct mei_cl_device
> +						       *cldev))
> +{
> +	return -ENODEV;
> +}
> +static inline
> +void mei_hdcp_cldev_put_reference(struct mei_cl_device *cldev) {}
> +#endif /* defined (CONFIG_INTEL_MEI_HDCP) */ #endif /* defined
> +(_LINUX_MEI_HDCP_H) */
> --
> 2.7.4