media: imx-jpeg: Constify static struct mxc_jpeg_fmt

It is only read-from, so make it const. In order to be able to do this,
constify all places where mxc_jpeg_fmt is used, in function arguments,
return values and pointers. On top of that, make the name a pointer to
const char.

On aarch64, this shrinks object code size with 550 bytes with gcc 11.1.0,
and almost 2kB with clang 12.0.0.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/platform/imx-jpeg/mxc-jpeg.c b/drivers/media/platform/imx-jpeg/mxc-jpeg.c
index 3a49007..7551380 100644 (file)
--- a/drivers/media/platform/imx-jpeg/mxc-jpeg.c
+++ b/drivers/media/platform/imx-jpeg/mxc-jpeg.c
@@ -62,7 +62,7 @@
 #include "mxc-jpeg-hw.h"
 #include "mxc-jpeg.h"
 
-static struct mxc_jpeg_fmt mxc_formats[] = {
+static const struct mxc_jpeg_fmt mxc_formats[] = {
        {
                .name           = "JPEG",
                .fourcc         = V4L2_PIX_FMT_JPEG,
@@ -341,7 +341,7 @@ static inline struct mxc_jpeg_ctx *mxc_jpeg_fh_to_ctx(struct v4l2_fh *fh)
        return container_of(fh, struct mxc_jpeg_ctx, fh);
 }
 
-static int enum_fmt(struct mxc_jpeg_fmt *mxc_formats, int n,
+static int enum_fmt(const struct mxc_jpeg_fmt *mxc_formats, int n,
                    struct v4l2_fmtdesc *f, u32 type)
 {
        int i, num = 0;
@@ -368,13 +368,13 @@ static int enum_fmt(struct mxc_jpeg_fmt *mxc_formats, int n,
        return 0;
 }
 
-static struct mxc_jpeg_fmt *mxc_jpeg_find_format(struct mxc_jpeg_ctx *ctx,
-                                                u32 pixelformat)
+static const struct mxc_jpeg_fmt *mxc_jpeg_find_format(struct mxc_jpeg_ctx *ctx,
+                                                      u32 pixelformat)
 {
        unsigned int k;
 
        for (k = 0; k < MXC_JPEG_NUM_FORMATS; k++) {
-               struct mxc_jpeg_fmt *fmt = &mxc_formats[k];
+               const struct mxc_jpeg_fmt *fmt = &mxc_formats[k];
 
                if (fmt->fourcc == pixelformat)
                        return fmt;
@@ -1536,7 +1536,7 @@ static int mxc_jpeg_enum_fmt_vid_out(struct file *file, void *priv,
                                MXC_JPEG_FMT_TYPE_RAW);
 }
 
-static int mxc_jpeg_try_fmt(struct v4l2_format *f, struct mxc_jpeg_fmt *fmt,
+static int mxc_jpeg_try_fmt(struct v4l2_format *f, const struct mxc_jpeg_fmt *fmt,
                            struct mxc_jpeg_ctx *ctx, int q_type)
 {
        struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
@@ -1612,7 +1612,7 @@ static int mxc_jpeg_try_fmt_vid_cap(struct file *file, void *priv,
        struct mxc_jpeg_ctx *ctx = mxc_jpeg_fh_to_ctx(priv);
        struct mxc_jpeg_dev *jpeg = ctx->mxc_jpeg;
        struct device *dev = jpeg->dev;
-       struct mxc_jpeg_fmt *fmt;
+       const struct mxc_jpeg_fmt *fmt;
        u32 fourcc = f->fmt.pix_mp.pixelformat;
 
        int q_type = (jpeg->mode == MXC_JPEG_DECODE) ?
@@ -1643,7 +1643,7 @@ static int mxc_jpeg_try_fmt_vid_out(struct file *file, void *priv,
        struct mxc_jpeg_ctx *ctx = mxc_jpeg_fh_to_ctx(priv);
        struct mxc_jpeg_dev *jpeg = ctx->mxc_jpeg;
        struct device *dev = jpeg->dev;
-       struct mxc_jpeg_fmt *fmt;
+       const struct mxc_jpeg_fmt *fmt;
        u32 fourcc = f->fmt.pix_mp.pixelformat;
 
        int q_type = (jpeg->mode == MXC_JPEG_ENCODE) ?

diff --git a/drivers/media/platform/imx-jpeg/mxc-jpeg.h b/drivers/media/platform/imx-jpeg/mxc-jpeg.h
index 7697de4..4c21085 100644 (file)
--- a/drivers/media/platform/imx-jpeg/mxc-jpeg.h
+++ b/drivers/media/platform/imx-jpeg/mxc-jpeg.h
@@ -51,7 +51,7 @@ enum mxc_jpeg_mode {
  * @flags:     flags describing format applicability
  */
 struct mxc_jpeg_fmt {
-       char                                    *name;
+       const char                              *name;
        u32                                     fourcc;
        enum v4l2_jpeg_chroma_subsampling       subsampling;
        int                                     nc;
@@ -74,14 +74,14 @@ struct mxc_jpeg_desc {
 } __packed;
 
 struct mxc_jpeg_q_data {
-       struct mxc_jpeg_fmt     *fmt;
-       u32                     sizeimage[MXC_JPEG_MAX_PLANES];
-       u32                     bytesperline[MXC_JPEG_MAX_PLANES];
-       int                     w;
-       int                     w_adjusted;
-       int                     h;
-       int                     h_adjusted;
-       unsigned int            sequence;
+       const struct mxc_jpeg_fmt       *fmt;
+       u32                             sizeimage[MXC_JPEG_MAX_PLANES];
+       u32                             bytesperline[MXC_JPEG_MAX_PLANES];
+       int                             w;
+       int                             w_adjusted;
+       int                             h;
+       int                             h_adjusted;
+       unsigned int                    sequence;
 };
 
 struct mxc_jpeg_ctx {