From e5e3df06ac98d15cfb10bb5c12356709365e91b2 Mon Sep 17 00:00:00 2001 From: Frank Li Date: Fri, 1 Dec 2023 17:25:29 -0500 Subject: [PATCH] i3c: add actual_len in i3c_priv_xfer MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In MIPI I3C Specification: "Ninth Bit of SDR Target Returned (Read) Data as End-of-Data: In I2C, the ninth Data bit from Target to Controller is an ACK by the Controller. By contrast, in I3C this bit allows the Target to end a Read, and allows the Controller to Abort a Read. In SDR terms, the ninth bit of Read data is referred to as the T-Bit (for ‘Transition’)" I3C allow devices early terminate data transfer. So need "actual_len" field to indicate how much get by i3c_priv_xfer. Reviewed-by: Miquel Raynal Signed-off-by: Frank Li Link: https://lore.kernel.org/r/20231201222532.2431484-4-Frank.Li@nxp.com Signed-off-by: Alexandre Belloni --- include/linux/i3c/device.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h index 84ed77c049400..e119f11948efe 100644 --- a/include/linux/i3c/device.h +++ b/include/linux/i3c/device.h @@ -54,6 +54,7 @@ enum i3c_hdr_mode { * struct i3c_priv_xfer - I3C SDR private transfer * @rnw: encodes the transfer direction. true for a read, false for a write * @len: transfer length in bytes of the transfer + * @actual_len: actual length in bytes are transferred by the controller * @data: input/output buffer * @data.in: input buffer. Must point to a DMA-able buffer * @data.out: output buffer. Must point to a DMA-able buffer @@ -62,6 +63,7 @@ enum i3c_hdr_mode { struct i3c_priv_xfer { u8 rnw; u16 len; + u16 actual_len; union { void *in; const void *out; -- 2.30.2