[PATCH 5/5] media: imx8-isi: Enable ISI RAW10/12/14 output LSB alignment

From: Guoniu Zhou

Date: Wed Aug 26 2026 - 00:53:44 EST


V4L2 requires RAW formats to be LSB-aligned (right-aligned). Before
i.MX952, the ISI shifts RAW10/12/14 output left to MSB, so the driver
works around this by using RAW16 format instead.

The i.MX952 ISI introduces a RAW output LSB alignment bit. Enable it
along with the input MSB alignment on platforms that support this
feature, so that RAW10/12/14 output formats can be used directly
without the RAW16 workaround.

Signed-off-by: Guoniu Zhou <guoniu.zhou@xxxxxxxxxxx>
---
.../media/platform/nxp/imx8-isi/imx8-isi-core.c | 1 +
.../media/platform/nxp/imx8-isi/imx8-isi-core.h | 1 +
drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c | 39 ++++++++++++++++++++-
.../media/platform/nxp/imx8-isi/imx8-isi-regs.h | 3 ++
.../media/platform/nxp/imx8-isi/imx8-isi-video.c | 40 +++++++++++-----------
5 files changed, 63 insertions(+), 21 deletions(-)

diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c
index 5b19b581b38e..439c7bdecfa8 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c
@@ -403,6 +403,7 @@ static const struct mxc_isi_plat_data mxc_imx952_data = {
.format_mask = GENMASK(30, 24),
.buf_active_reverse = true,
.has_36bit_dma = true,
+ .raw_out_lsb = true,
};

/* -----------------------------------------------------------------------------
diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
index a4b638508522..39dbb35bc4cc 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
@@ -179,6 +179,7 @@ struct mxc_isi_plat_data {
u32 format_mask;
bool buf_active_reverse;
bool has_36bit_dma;
+ bool raw_out_lsb;
};

struct mxc_isi_dma_buffer {
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 2405f7d33d0a..4838b445f279 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c
@@ -308,6 +308,7 @@ static void mxc_isi_channel_set_control(struct mxc_isi_pipe *pipe,
unsigned int vc,
bool bypass)
{
+ const struct mxc_isi_plat_data *pdata = pipe->isi->pdata;
u32 val;

mutex_lock(&pipe->lock);
@@ -357,6 +358,20 @@ static void mxc_isi_channel_set_control(struct mxc_isi_pipe *pipe,
val |= CHNL_CTRL_VC_ID_1(vc >> 2);
}

+ if (pdata->raw_out_lsb) {
+ /*
+ * Enable RAW10/12/14 output LSB alignment to match the
+ * V4L2 requirement that RAW formats are LSB-aligned.
+ */
+ val |= CHNL_CTRL_RAW_OUT_LSB_ALIGN;
+
+ /*
+ * Align the data selection from pixel link to MSB to
+ * avoid data shift since the data from PL is MSB.
+ */
+ val |= CHNL_CTRL_RAW_IN_MSB_ALIGN;
+ }
+
mxc_isi_write(pipe, CHNL_CTRL, val);

mutex_unlock(&pipe->lock);
@@ -406,11 +421,19 @@ void mxc_isi_channel_set_input_format(struct mxc_isi_pipe *pipe,
CHNL_IN_BUF_PITCH_LINE_PITCH(bpl));
}

+static bool isi_out_raw(u32 format)
+{
+ return format == CHNL_IMG_CTRL_FORMAT_RAW10 ||
+ format == CHNL_IMG_CTRL_FORMAT_RAW12 ||
+ format == CHNL_IMG_CTRL_FORMAT_RAW14;
+}
+
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 fmt;
u32 val;

/* set outbuf format */
@@ -418,7 +441,21 @@ void mxc_isi_channel_set_output_format(struct mxc_isi_pipe *pipe,

val = mxc_isi_read(pipe, CHNL_IMG_CTRL);
val &= ~pdata->format_mask;
- val |= CHNL_IMG_CTRL_FORMAT(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.
+ * After i.MX952, ISI add RAW10/12/14 LSB output alignment, so skip
+ * the above workaround.
+ */
+ fmt = !pdata->raw_out_lsb && isi_out_raw(info->isi_out_format) ?
+ CHNL_IMG_CTRL_FORMAT_RAW16 :
+ info->isi_out_format;
+
+ val |= CHNL_IMG_CTRL_FORMAT(fmt);
mxc_isi_write(pipe, CHNL_IMG_CTRL, val);

/* line pitch */
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 35dec3a650ac..c9c22a3668f9 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-regs.h
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-regs.h
@@ -20,6 +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_OUT_LSB_ALIGN BIT(23) /* i.MX952 only */
+#define CHNL_CTRL_RAW_IN_MSB_ALIGN BIT(22) /* i.MX{91,93,95,952} only */
/*
* 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
@@ -88,6 +90,7 @@
#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,91,93,95,952} only */
#define CHNL_IMG_CTRL_GBL_ALPHA_VAL(n) ((n) << 16)
#define CHNL_IMG_CTRL_GBL_ALPHA_VAL_MASK GENMASK(23, 16)
#define CHNL_IMG_CTRL_GBL_ALPHA_EN BIT(15)
diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-video.c b/drivers/media/platform/nxp/imx8-isi/imx8-isi-video.c
index f45c2aae59ce..9a6a8302774c 100644
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-video.c
+++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-video.c
@@ -221,11 +221,11 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
/*
* RAW formats
*
- * The ISI shifts the 10-bit and 12-bit formats left by 6 and 4 bits
- * when using CHNL_IMG_CTRL_FORMAT_RAW10 or MXC_ISI_OUT_FMT_RAW12
- * 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.
+ * The format entries use the native RAW10/12/14 ISI format codes.
+ * On platforms without hardware LSB alignment, the driver
+ * substitutes RAW16 at runtime in
+ * mxc_isi_channel_set_output_format() to avoid the left shift
+ * that the ISI applies to RAW10/12/14 output.
*/
{
.mbus_code = MEDIA_BUS_FMT_Y8_1X8,
@@ -240,7 +240,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_Y10_1X10,
.fourcc = V4L2_PIX_FMT_Y10,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW10,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -249,7 +249,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_Y12_1X12,
.fourcc = V4L2_PIX_FMT_Y12,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW12,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -258,7 +258,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_Y14_1X14,
.fourcc = V4L2_PIX_FMT_Y14,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW14,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -312,7 +312,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SBGGR10_1X10,
.fourcc = V4L2_PIX_FMT_SBGGR10,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW10,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -321,7 +321,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SGBRG10_1X10,
.fourcc = V4L2_PIX_FMT_SGBRG10,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW10,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -330,7 +330,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SGRBG10_1X10,
.fourcc = V4L2_PIX_FMT_SGRBG10,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW10,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -339,7 +339,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SRGGB10_1X10,
.fourcc = V4L2_PIX_FMT_SRGGB10,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW10,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -348,7 +348,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SBGGR12_1X12,
.fourcc = V4L2_PIX_FMT_SBGGR12,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW12,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -357,7 +357,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SGBRG12_1X12,
.fourcc = V4L2_PIX_FMT_SGBRG12,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW12,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -366,7 +366,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SGRBG12_1X12,
.fourcc = V4L2_PIX_FMT_SGRBG12,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW12,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -375,7 +375,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SRGGB12_1X12,
.fourcc = V4L2_PIX_FMT_SRGGB12,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW12,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -384,7 +384,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SBGGR14_1X14,
.fourcc = V4L2_PIX_FMT_SBGGR14,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW14,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -393,7 +393,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SGBRG14_1X14,
.fourcc = V4L2_PIX_FMT_SGBRG14,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW14,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -402,7 +402,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SGRBG14_1X14,
.fourcc = V4L2_PIX_FMT_SGRBG14,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW14,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },
@@ -411,7 +411,7 @@ static const struct mxc_isi_format_info mxc_isi_formats[] = {
.mbus_code = MEDIA_BUS_FMT_SRGGB14_1X14,
.fourcc = V4L2_PIX_FMT_SRGGB14,
.type = MXC_ISI_VIDEO_CAP,
- .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW16,
+ .isi_out_format = CHNL_IMG_CTRL_FORMAT_RAW14,
.mem_planes = 1,
.color_planes = 1,
.depth = { 16 },

--
2.34.1