[Intel-gfx] [PATCH v8 22/38] drm/i915/icl: Load DSI packet payload to queue

[Madhav Chauhan]

On 10/30/2018 5:26 PM, Jani Nikula wrote:
> This patch adds DSI packet payload to command payload
> queue using credit based mechanism for *long* packets.
>
> v2 by Jani:
>   - Add intel_dsi local variable for better code flow
>   - Use the new credit available helper
>   - Use int for free_credits, i, and j

v2 changes are fine.

Regards,
Madhav

>
> Signed-off-by: Madhav Chauhan <madhav.chauhan at intel.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>   drivers/gpu/drm/i915/icl_dsi.c | 57 ++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 57 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/icl_dsi.c b/drivers/gpu/drm/i915/icl_dsi.c
> index c7b77cd81e45..58774a1ac84b 100644
> --- a/drivers/gpu/drm/i915/icl_dsi.c
> +++ b/drivers/gpu/drm/i915/icl_dsi.c
> @@ -107,6 +107,33 @@ static void wait_for_cmds_dispatched_to_panel(struct intel_encoder *encoder)
>   	}
>   }
>   
> +static bool add_payld_to_queue(struct intel_dsi_host *host, const u8 *data,
> +			       u32 len)
> +{
> +	struct intel_dsi *intel_dsi = host->intel_dsi;
> +	struct drm_i915_private *dev_priv = to_i915(intel_dsi->base.base.dev);
> +	enum transcoder dsi_trans = dsi_port_to_transcoder(host->port);
> +	int free_credits;
> +	int i, j;
> +
> +	for (i = 0; i < len; i += 4) {
> +		u32 tmp = 0;
> +
> +		free_credits = payload_credits_available(dev_priv, dsi_trans);
> +		if (free_credits < 1) {
> +			DRM_ERROR("Payload credit not available\n");
> +			return false;
> +		}
> +
> +		for (j = 0; j < min_t(u32, len - i, 4); j++)
> +			tmp |= *data++ << 8 * j;
> +
> +		I915_WRITE(DSI_CMD_TXPYLD(dsi_trans), tmp);
> +	}
> +
> +	return true;
> +}
> +
>   static int dsi_send_pkt_hdr(struct intel_dsi_host *host,
>   			    struct mipi_dsi_packet pkt, bool enable_lpdt)
>   {
> @@ -145,6 +172,25 @@ static int dsi_send_pkt_hdr(struct intel_dsi_host *host,
>   	return 0;
>   }
>   
> +static int dsi_send_pkt_payld(struct intel_dsi_host *host,
> +			      struct mipi_dsi_packet pkt)
> +{
> +	/* payload queue can accept *256 bytes*, check limit */
> +	if (pkt.payload_length > MAX_PLOAD_CREDIT * 4) {
> +		DRM_ERROR("payload size exceeds max queue limit\n");
> +		return -1;
> +	}
> +
> +	/* load data into command payload queue */
> +	if (!add_payld_to_queue(host, pkt.payload,
> +				pkt.payload_length)) {
> +		DRM_ERROR("adding payload to queue failed\n");
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
>   static void dsi_program_swing_and_deemphasis(struct intel_encoder *encoder)
>   {
>   	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> @@ -1052,6 +1098,17 @@ static ssize_t gen11_dsi_host_transfer(struct mipi_dsi_host *host,
>   	if (ret < 0)
>   		return ret;
>   
> +	/* only long packet contains payload */
> +	if (mipi_dsi_packet_format_is_long(msg->type)) {
> +		ret = dsi_send_pkt_payld(intel_dsi_host, dsi_pkt);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	//TODO: add payload receive code if needed
> +
> +	ret = sizeof(dsi_pkt.header) + dsi_pkt.payload_length;
> +
>   	return ret;
>   }
>