From 7b78fa862296f8931e42ecaec3703e307e4044d2 Mon Sep 17 00:00:00 2001 From: Jai Luthra Date: Mon, 11 Aug 2025 13:50:17 +0530 Subject: media: cadence: cdns-csi2rx: Support multiple pixels per clock cycle The output pixel interface is a parallel bus (32 bits), which supports sending multiple pixels (1, 2 or 4) per clock cycle for smaller pixel widths like RAW8-RAW16. Dual-pixel and Quad-pixel modes can be a requirement if the export rate of the Cadence IP in Single-pixel mode maxes out before the maximum supported DPHY-RX frequency, which is the case with TI's integration of this IP [1]. So, we export a function that lets the downstream hardware block request a higher pixel-per-clock on a particular output pad. We check if we can support the requested pixels per clock given the known maximum for the currently configured format. If not, we set it to the highest feasible value and return this value to the caller. [1] Section 12.6.1.4.8.14 CSI_RX_IF Programming Restrictions of AM62 TRM Link: https://www.ti.com/lit/pdf/spruj16 Tested-by: Yemike Abhilash Chandra (on SK-AM68) Signed-off-by: Jai Luthra Signed-off-by: Sakari Ailus Signed-off-by: Hans Verkuil --- include/media/cadence/cdns-csi2rx.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 include/media/cadence/cdns-csi2rx.h (limited to 'include') diff --git a/include/media/cadence/cdns-csi2rx.h b/include/media/cadence/cdns-csi2rx.h new file mode 100644 index 000000000000..782d03fc36d1 --- /dev/null +++ b/include/media/cadence/cdns-csi2rx.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +#ifndef _CDNS_CSI2RX_H +#define _CDNS_CSI2RX_H + +#include + +/** + * cdns_csi2rx_negotiate_ppc - Negotiate pixel-per-clock on output interface + * + * @subdev: point to &struct v4l2_subdev + * @pad: pad number of the source pad + * @ppc: pointer to requested pixel-per-clock value + * + * Returns 0 on success, negative error code otherwise. + */ +int cdns_csi2rx_negotiate_ppc(struct v4l2_subdev *subdev, unsigned int pad, + u8 *ppc); + +#endif -- cgit v1.2.3