[PATCH v4 11/11] media: imx8-isi: Enable RAW10/12/14 output LSB alignment on i.MX952
From: Guoniu Zhou
Date: Tue Sep 29 2026 - 04:56:16 EST
Before i.MX952, the ISI RAW10/12/14 output formats are always
MSB-aligned, which is not compatible with the V4L2 RAW format
definition that requires LSB alignment.
>From i.MX952 onwards, the ISI introduces CHNL_CTRL_RAW_OUT_LSB_ALIGN
to select whether RAW10/12/14 outputs are MSB or LSB aligned. Enable
it so the driver produces correct V4L2-compatible LSB-aligned output.
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
Signed-off-by: Guoniu Zhou <guoniu.zhou@xxxxxxxxxxx>
---
Changes in v4:
- Split RAW_IN_MSB_ALIGN into a separate preceding patch
- Split RAW format table and RAW14 changes into separate preceding patches
- Move isi_out_raw_shifted() to regs.h in the preceding workaround patch
- Rewrite commit message
Changes in v3:
- Use CHNL_IMG_CTRL_FORMAT_MASK instead of the removed per-platform format_mask (Laurent)
- Derive raw_out_lsb from the model field instead of dedicated platform data (Laurent)
- Clarify the CHNL_IMG_CTRL_FORMAT_RAW14 comment: the format is
documented on i.MX{8ULP,91,93,95,952} but only used on i.MX952
- Update the mxc_isi_channel_set_output_format() comment wording
- Rewrite commit message
- Add Reviewed-by tag from Frank
---
drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c | 37 +++++++++++++++++++---
.../media/platform/nxp/imx8-isi/imx8-isi-regs.h | 5 +--
2 files changed, 36 insertions(+), 6 deletions(-)
diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c b/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c
index b3f32b9796d5..6733776e72aa 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c
@@ -311,12 +311,24 @@ static void mxc_isi_channel_set_panic_threshold(struct mxc_isi_pipe *pipe)
* RAW samples from either the high or low bits, as both LSB and MSB
* alignment can be selected in the gasket.
*
- * On i.MX95, the CSI formatter provides MSB-aligned RAW data, so the ISI
- * must select RAW samples from the high bits of the Pixel Link bus.
+ * Starting with i.MX95, the CSI formatter provides MSB-aligned RAW data,
+ * so the ISI must select RAW samples from the high bits of the Pixel Link
+ * bus.
*/
static bool isi_raw_in_msb(const struct mxc_isi_plat_data *pdata)
{
- return pdata->model == MXC_ISI_IMX95;
+ return pdata->model == MXC_ISI_IMX95 ||
+ pdata->model == MXC_ISI_IMX952;
+}
+
+/*
+ * Starting with i.MX952, the ISI can output RAW10/12/14 formats with LSB
+ * alignment, matching the V4L2 requirement. Older platforms lack this
+ * capability and need the RAW16 workaround.
+ */
+static bool isi_raw_out_lsb(const struct mxc_isi_plat_data *pdata)
+{
+ return pdata->model == MXC_ISI_IMX952;
}
static void mxc_isi_channel_set_control(struct mxc_isi_pipe *pipe,
@@ -377,6 +389,13 @@ static void mxc_isi_channel_set_control(struct mxc_isi_pipe *pipe,
if (isi_raw_in_msb(pipe->isi->pdata))
val |= CHNL_CTRL_RAW_IN_MSB_ALIGN;
+ /*
+ * Enable RAW10/12/14 output LSB alignment to match the
+ * V4L2 requirement that RAW formats are LSB-aligned.
+ */
+ if (isi_raw_out_lsb(pipe->isi->pdata))
+ val |= CHNL_CTRL_RAW_OUT_LSB_ALIGN;
+
mxc_isi_write(pipe, CHNL_CTRL, val);
mutex_unlock(&pipe->lock);
@@ -430,13 +449,23 @@ void mxc_isi_channel_set_output_format(struct mxc_isi_pipe *pipe,
const struct mxc_isi_format_info *info,
struct v4l2_pix_format_mplane *format)
{
+ const struct mxc_isi_plat_data *pdata = pipe->isi->pdata;
u32 val;
u32 fmt;
/* set outbuf format */
dev_dbg(pipe->isi->dev, "output format %p4cc", &format->pixelformat);
- fmt = isi_out_raw_shifted(info->isi_out_format)
+ /*
+ * Before i.MX952, the ISI shifts the 10/12/14-bit formats left
+ * by 6, 4 and 2 bits when using CHNL_IMG_CTRL_FORMAT_RAW10/12/14
+ * respectively, to align the bits to the left and pad with zeros in
+ * the LSBs. The corresponding V4L2 formats are however right-aligned,
+ * we have to use CHNL_IMG_CTRL_FORMAT_RAW16 to avoid the left shift.
+ * Starting with i.MX952, the ISI supports RAW10/12/14 LSB output
+ * alignment, so skip the above workaround.
+ */
+ fmt = !isi_raw_out_lsb(pdata) && isi_out_raw_shifted(info->isi_out_format)
? CHNL_IMG_CTRL_FORMAT_RAW16
: info->isi_out_format;
diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-regs.h b/drivers/media/platform/nxp/imx8-isi/imx8-isi-regs.h
index d2b8a26b7c21..075fc6848213 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-regs.h
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-regs.h
@@ -20,7 +20,8 @@
#define CHNL_CTRL_CHAIN_BUF_NO_CHAIN 0
#define CHNL_CTRL_CHAIN_BUF_2_CHAIN 1
#define CHNL_CTRL_SW_RST BIT(24)
-#define CHNL_CTRL_RAW_IN_MSB_ALIGN BIT(22) /* i.MX{91,93,95} */
+#define CHNL_CTRL_RAW_OUT_LSB_ALIGN BIT(23) /* i.MX952 only */
+#define CHNL_CTRL_RAW_IN_MSB_ALIGN BIT(22) /* i.MX{91,93,95,952} */
/*
* CHNL_CTRL_BLANK_PXL: i.MX8{QM,QXP} only
* CHNL_CTRL_VC_ID_1, CHNL_CTRL_VC_ID_1_MASK: i.MX{95,952} only
@@ -90,7 +91,7 @@
#define CHNL_IMG_CTRL_FORMAT_YUV420_3P10P 0x3a
#define CHNL_IMG_CTRL_FORMAT_YUV420_2P12 0x3d
#define CHNL_IMG_CTRL_FORMAT_YUV420_3P12 0x3e
-#define CHNL_IMG_CTRL_FORMAT_RAW14 0x41 /* i.MX{8ULP,91,93,95} */
+#define CHNL_IMG_CTRL_FORMAT_RAW14 0x41 /* i.MX{8ULP,91,93,95,952}, used on i.MX952 only */
#define CHNL_IMG_CTRL_GBL_ALPHA_VAL(n) ((n) << 16)
#define CHNL_IMG_CTRL_GBL_ALPHA_VAL_MASK GENMASK(23, 16)
--
2.34.1