[media.git/next] media: atomisp: gc0310: Add link-frequency and pixelrate controls

[media-ci]

On Sun Jul 6 11:53:15 2025 +0200, Hans de Goede wrote:
> Add support for the pixelrate control as expected by libcamera,
> while at it also add the link-frequency control.
> 
> Signed-off-by: Hans de Goede <ha...@kernel.org>
> Link: https://lore.kernel.org/r/20250517114106.43494-8-hdego...@redhat.com
> Signed-off-by: Mauro Carvalho Chehab <mchehab+hua...@kernel.org>

Patch committed.

Thanks,
Mauro Carvalho Chehab

 drivers/staging/media/atomisp/i2c/atomisp-gc0310.c | 33 ++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

---

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c 
b/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c
index 15ca7bc82322..cff1db5390bc 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c
@@ -24,6 +24,17 @@
 #define GC0310_NATIVE_WIDTH                    656
 #define GC0310_NATIVE_HEIGHT                   496
 
+/*
+ * The actual PLL output rate is unknown, the datasheet
+ * says that the formula for the frame-time in pixels is:
+ * rowtime = win-width + hblank + sh-delay + 4
+ * frametime = rowtime * (win-height + vblank)
+ * Filling this in and multiplying by 30 fps gives:
+ * pixelrate = (660 + 178 + 42 + 4) * (498 + 27) * 30 = 13923000
+ */
+#define GC0310_PIXELRATE                       13923000
+/* single lane, bus-format is 8 bpp, CSI-2 is double data rate */
+#define GC0310_LINK_FREQ                       (GC0310_PIXELRATE * 8 / 2)
 #define GC0310_FPS                             30
 #define GC0310_SKIP_FRAMES                     3
 
@@ -76,6 +87,8 @@ struct gc0310_device {
                struct v4l2_ctrl_handler handler;
                struct v4l2_ctrl *exposure;
                struct v4l2_ctrl *gain;
+               struct v4l2_ctrl *link_freq;
+               struct v4l2_ctrl *pixel_rate;
        } ctrls;
 };
 
@@ -251,6 +264,10 @@ static const struct reg_sequence gc0310_VGA_30fps[] = {
        { 0xfe, 0x00 },
 };
 
+static const s64 link_freq_menu_items[] = {
+       GC0310_LINK_FREQ,
+};
+
 static int gc0310_gain_set(struct gc0310_device *sensor, u32 gain)
 {
        u8 again, dgain;
@@ -546,7 +563,7 @@ static int gc0310_init_controls(struct gc0310_device 
*sensor)
 {
        struct v4l2_ctrl_handler *hdl = &sensor->ctrls.handler;
 
-       v4l2_ctrl_handler_init(hdl, 2);
+       v4l2_ctrl_handler_init(hdl, 4);
 
        /* Use the same lock for controls as for everything else */
        hdl->lock = &sensor->input_lock;
@@ -559,7 +576,19 @@ static int gc0310_init_controls(struct gc0310_device 
*sensor)
        sensor->ctrls.gain =
                v4l2_ctrl_new_std(hdl, &ctrl_ops, V4L2_CID_ANALOGUE_GAIN, 0, 
95, 1, 31);
 
-       return hdl->error;
+       sensor->ctrls.link_freq =
+               v4l2_ctrl_new_int_menu(hdl, NULL, V4L2_CID_LINK_FREQ,
+                                      0, 0, link_freq_menu_items);
+       sensor->ctrls.pixel_rate =
+               v4l2_ctrl_new_std(hdl, NULL, V4L2_CID_PIXEL_RATE, 0,
+                                 GC0310_PIXELRATE, 1, GC0310_PIXELRATE);
+
+       if (hdl->error)
+               return hdl->error;
+
+       sensor->ctrls.pixel_rate->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+       sensor->ctrls.link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+       return 0;
 }
 
 static void gc0310_remove(struct i2c_client *client)