Re: [PATCH v8 13/35] drm/i915: Implement the HDCP2.2 support for HDMI

[Daniel Vetter <daniel@ffwll.ch>]

On Tue, Nov 27, 2018 at 04:13:11PM +0530, Ramalingam C wrote:
> Implements the HDMI adaptation specific HDCP2.2 operations.
> 
> Basically these are DDC read and write for authenticating through
> HDCP2.2 messages.
> 
> v2:
>   Rebased.
> v3:
>   No Changes.
> v4:
>   No more special handling of Gmbus burst read for AKE_SEND_CERT.
>   Style fixed with few naming. [Uma]
>   %s/PARING/PAIRING
> v5:
>   msg_sz is initialized at definition.
>   Lookup table is defined for HDMI HDCP2.2 msgs [Daniel].
> v6:
>   Rebased.
> v7:
>   Make a function as inline [Uma]
>   %s/uintxx_t/uxx
> v8:
>   Errors due to sinks are reported as DEBUG logs.
>   Adjust to the new mei interface.
> 
> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_hdmi.c | 190 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 190 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> index e755a3370bca..912f50133645 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -30,6 +30,7 @@
>  #include <linux/slab.h>
>  #include <linux/delay.h>
>  #include <linux/hdmi.h>
> +#include <linux/mei_hdcp.h>
>  #include <drm/drmP.h>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_crtc.h>
> @@ -1117,6 +1118,190 @@ bool intel_hdmi_hdcp_check_link(struct intel_digital_port *intel_dig_port)
>  	return true;
>  }
>  
> +static struct hdcp2_hdmi_msg_data {
> +	u8 msg_id;
> +	u32 timeout;
> +	u32 timeout2;
> +	} hdcp2_msg_data[] = {
> +		{HDCP_2_2_AKE_INIT, 0, 0},
> +		{HDCP_2_2_AKE_SEND_CERT, HDCP_2_2_CERT_TIMEOUT_MS, 0},
> +		{HDCP_2_2_AKE_NO_STORED_KM, 0, 0},
> +		{HDCP_2_2_AKE_STORED_KM, 0, 0},
> +		{HDCP_2_2_AKE_SEND_HPRIME, HDCP_2_2_HPRIME_PAIRED_TIMEOUT_MS,
> +				HDCP_2_2_HPRIME_NO_PAIRED_TIMEOUT_MS},
> +		{HDCP_2_2_AKE_SEND_PAIRING_INFO, HDCP_2_2_PAIRING_TIMEOUT_MS,
> +				0},
> +		{HDCP_2_2_LC_INIT, 0, 0},
> +		{HDCP_2_2_LC_SEND_LPRIME, HDCP_2_2_HDMI_LPRIME_TIMEOUT_MS, 0},
> +		{HDCP_2_2_SKE_SEND_EKS, 0, 0},
> +		{HDCP_2_2_REP_SEND_RECVID_LIST,
> +				HDCP_2_2_RECVID_LIST_TIMEOUT_MS, 0},
> +		{HDCP_2_2_REP_SEND_ACK, 0, 0},
> +		{HDCP_2_2_REP_STREAM_MANAGE, 0, 0},
> +		{HDCP_2_2_REP_STREAM_READY, HDCP_2_2_STREAM_READY_TIMEOUT_MS,
> +				0},
> +	};
> +
> +static
> +int intel_hdmi_hdcp2_read_rx_status(struct intel_digital_port *intel_dig_port,
> +				    uint8_t *rx_status)
> +{
> +	return intel_hdmi_hdcp_read(intel_dig_port,
> +				    HDCP_2_2_HDMI_REG_RXSTATUS_OFFSET,
> +				    rx_status,
> +				    HDCP_2_2_HDMI_RXSTATUS_LEN);
> +}
> +
> +static int get_hdcp2_msg_timeout(u8 msg_id, bool is_paired)
> +{
> +	int i;
> +
> +	for (i = 0; i < sizeof(hdcp2_msg_data); i++)
> +		if (hdcp2_msg_data[i].msg_id == msg_id &&
> +		    (msg_id != HDCP_2_2_AKE_SEND_HPRIME || is_paired))
> +			return hdcp2_msg_data[i].timeout;
> +		else if (hdcp2_msg_data[i].msg_id == msg_id)
> +			return hdcp2_msg_data[i].timeout2;
> +
> +	return -EINVAL;
> +}
> +
> +static inline
> +int hdcp2_detect_msg_availability(struct intel_digital_port *intel_digital_port,
> +				  u8 msg_id, bool *msg_ready,
> +				  ssize_t *msg_sz)
> +{
> +	u8 rx_status[HDCP_2_2_HDMI_RXSTATUS_LEN];
> +	int ret;
> +
> +	ret = intel_hdmi_hdcp2_read_rx_status(intel_digital_port, rx_status);
> +	if (ret < 0) {
> +		DRM_DEBUG_KMS("rx_status read failed. Err %d\n", ret);
> +		return ret;
> +	}
> +
> +	*msg_sz = ((HDCP_2_2_HDMI_RXSTATUS_MSG_SZ_HI(rx_status[1]) << 8) |
> +		  rx_status[0]);
> +
> +	if (msg_id == HDCP_2_2_REP_SEND_RECVID_LIST)
> +		*msg_ready = (HDCP_2_2_HDMI_RXSTATUS_READY(rx_status[1]) &&
> +			     *msg_sz);
> +	else
> +		*msg_ready = *msg_sz;
> +
> +	return 0;
> +}
> +
> +static ssize_t
> +intel_hdmi_hdcp2_wait_for_msg(struct intel_digital_port *intel_dig_port,
> +			      u8 msg_id, bool paired)
> +{
> +	bool msg_ready = false;
> +	int timeout, ret;
> +	ssize_t msg_sz = 0;
> +
> +	timeout = get_hdcp2_msg_timeout(msg_id, paired);
> +	if (timeout < 0)
> +		return timeout;
> +
> +	ret = __wait_for(ret = hdcp2_detect_msg_availability(intel_dig_port,
> +							     msg_id, &msg_ready,
> +							     &msg_sz),
> +			 !ret && msg_ready && msg_sz, timeout * 1000,
> +			 1000, 5 * 1000);

Yeah, doing this also for DP is imo much simpler.

lgtm.
-Daniel

> +	if (ret)
> +		DRM_DEBUG_KMS("msg_id: %d, ret: %d, timeout: %d\n",
> +			      msg_id, ret, timeout);
> +
> +	return ret ? ret : msg_sz;
> +}
> +
> +static
> +int intel_hdmi_hdcp2_write_msg(struct intel_digital_port *intel_dig_port,
> +			       void *buf, size_t size)
> +{
> +	unsigned int offset;
> +
> +	offset = HDCP_2_2_HDMI_REG_WR_MSG_OFFSET;
> +	return intel_hdmi_hdcp_write(intel_dig_port, offset, buf, size);
> +}
> +
> +static
> +int intel_hdmi_hdcp2_read_msg(struct intel_digital_port *intel_dig_port,
> +			      u8 msg_id, void *buf, size_t size)
> +{
> +	struct intel_hdmi *hdmi = &intel_dig_port->hdmi;
> +	struct intel_hdcp *hdcp = &hdmi->attached_connector->hdcp;
> +	unsigned int offset;
> +	ssize_t ret;
> +
> +	ret = intel_hdmi_hdcp2_wait_for_msg(intel_dig_port, msg_id,
> +					    hdcp->is_paired);
> +	if (ret < 0)
> +		return ret;
> +
> +	/*
> +	 * Available msg size should be equal to or lesser than the
> +	 * available buffer.
> +	 */
> +	if (ret > size) {
> +		DRM_DEBUG_KMS("msg_sz(%zd) is more than exp size(%zu)\n",
> +			      ret, size);
> +		return -1;
> +	}
> +
> +	offset = HDCP_2_2_HDMI_REG_RD_MSG_OFFSET;
> +	ret = intel_hdmi_hdcp_read(intel_dig_port, offset, buf, ret);
> +	if (ret)
> +		DRM_DEBUG_KMS("Failed to read msg_id: %d(%zd)\n", msg_id, ret);
> +
> +	return ret;
> +}
> +
> +static
> +int intel_hdmi_hdcp2_check_link(struct intel_digital_port *intel_dig_port)
> +{
> +	u8 rx_status[HDCP_2_2_HDMI_RXSTATUS_LEN];
> +	int ret;
> +
> +	ret = intel_hdmi_hdcp2_read_rx_status(intel_dig_port, rx_status);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * Re-auth request and Link Integrity Failures are represented by
> +	 * same bit. i.e reauth_req.
> +	 */
> +	if (HDCP_2_2_HDMI_RXSTATUS_REAUTH_REQ(rx_status[1]))
> +		ret = DRM_HDCP_REAUTH_REQUEST;
> +	else if (HDCP_2_2_HDMI_RXSTATUS_READY(rx_status[1]))
> +		ret = DRM_HDCP_TOPOLOGY_CHANGE;
> +
> +	return ret;
> +}
> +
> +static
> +int intel_hdmi_hdcp2_capable(struct intel_digital_port *intel_dig_port,
> +			     bool *capable)
> +{
> +	u8 hdcp2_version;
> +	int ret;
> +
> +	*capable = false;
> +	ret = intel_hdmi_hdcp_read(intel_dig_port, HDCP_2_2_HDMI_REG_VER_OFFSET,
> +				   &hdcp2_version, sizeof(hdcp2_version));
> +	if (!ret && hdcp2_version & HDCP_2_2_HDMI_SUPPORT_MASK)
> +		*capable = true;
> +
> +	return ret;
> +}
> +
> +static inline
> +enum mei_hdcp_wired_protocol intel_hdmi_hdcp2_protocol(void)
> +{
> +	return MEI_HDCP_PROTOCOL_HDMI;
> +}
> +
>  static const struct intel_hdcp_shim intel_hdmi_hdcp_shim = {
>  	.write_an_aksv = intel_hdmi_hdcp_write_an_aksv,
>  	.read_bksv = intel_hdmi_hdcp_read_bksv,
> @@ -1128,6 +1313,11 @@ static const struct intel_hdcp_shim intel_hdmi_hdcp_shim = {
>  	.read_v_prime_part = intel_hdmi_hdcp_read_v_prime_part,
>  	.toggle_signalling = intel_hdmi_hdcp_toggle_signalling,
>  	.check_link = intel_hdmi_hdcp_check_link,
> +	.write_2_2_msg = intel_hdmi_hdcp2_write_msg,
> +	.read_2_2_msg = intel_hdmi_hdcp2_read_msg,
> +	.check_2_2_link	= intel_hdmi_hdcp2_check_link,
> +	.hdcp_2_2_capable = intel_hdmi_hdcp2_capable,
> +	.hdcp_protocol = intel_hdmi_hdcp2_protocol,
>  };
>  
>  static void intel_hdmi_prepare(struct intel_encoder *encoder,
> -- 
> 2.7.4
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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