Add support of BT656 embedded synchronization bus. This mode allows to save hardware synchro lines hsync & vsync by replacing them with synchro codes embedded in data stream. This bus type is only compatible with 8 bits width data bus. Due to reserved values 0x00 & 0xff used for synchro codes, valid data only vary from 0x1 to 0xfe, this is up to sensor to clip accordingly pixel data. As a consequence of this clipping, JPEG is not supported when using this bus type. DCMI crop feature is also not available with this bus type.
Signed-off-by: Hugues Fruchet <hugues.fruc...@st.com> --- drivers/media/platform/stm32/stm32-dcmi.c | 37 +++++++++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c index fd1c41c..d7d7cdb 100644 --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c @@ -157,6 +157,7 @@ struct stm32_dcmi { struct vb2_queue queue; struct v4l2_fwnode_bus_parallel bus; + enum v4l2_mbus_type bus_type; struct completion complete; struct clk *mclk; enum state state; @@ -777,6 +778,23 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) if (dcmi->bus.flags & V4L2_MBUS_PCLK_SAMPLE_RISING) val |= CR_PCKPOL; + /* + * BT656 embedded synchronisation bus mode. + * + * Default SAV/EAV mode is supported here with default codes + * SAV=0xff000080 & EAV=0xff00009d. + * With DCMI this means LSC=SAV=0x80 & LEC=EAV=0x9d. + */ + if (dcmi->bus_type == V4L2_MBUS_BT656) { + val |= CR_ESS; + + /* Unmask all codes */ + reg_write(dcmi->regs, DCMI_ESUR, 0xffffffff);/* FEC:LEC:LSC:FSC */ + + /* Trig on LSC=0x80 & LEC=0x9d codes, ignore FSC and FEC */ + reg_write(dcmi->regs, DCMI_ESCR, 0xff9d80ff);/* FEC:LEC:LSC:FSC */ + } + reg_write(dcmi->regs, DCMI_CR, val); /* Set crop */ @@ -1067,8 +1085,9 @@ static int dcmi_set_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f) if (ret) return ret; - /* Disable crop if JPEG is requested */ - if (pix->pixelformat == V4L2_PIX_FMT_JPEG) + /* Disable crop if JPEG is requested or BT656 bus is selected */ + if (pix->pixelformat == V4L2_PIX_FMT_JPEG && + dcmi->bus_type != V4L2_MBUS_BT656) dcmi->do_crop = false; /* pix to mbus format */ @@ -1592,6 +1611,11 @@ static int dcmi_formats_init(struct stm32_dcmi *dcmi) if (dcmi_formats[i].mbus_code != mbus_code.code) continue; + /* Exclude JPEG if BT656 bus is selected */ + if (dcmi_formats[i].fourcc == V4L2_PIX_FMT_JPEG && + dcmi->bus_type == V4L2_MBUS_BT656) + continue; + /* Code supported, have we got this fourcc yet? */ for (j = 0; j < num_fmts; j++) if (sd_fmts[j]->fourcc == @@ -1873,9 +1897,18 @@ static int dcmi_probe(struct platform_device *pdev) dev_err(&pdev->dev, "CSI bus not supported\n"); return -ENODEV; } + + if (ep.bus_type == V4L2_MBUS_BT656 && + ep.bus.parallel.bus_width != 8) { + dev_err(&pdev->dev, "BT656 bus conflicts with %d bits bus width (8 bits required)\n", + ep.bus.parallel.bus_width); + return -ENODEV; + } + dcmi->bus.flags = ep.bus.parallel.flags; dcmi->bus.bus_width = ep.bus.parallel.bus_width; dcmi->bus.data_shift = ep.bus.parallel.data_shift; + dcmi->bus_type = ep.bus_type; irq = platform_get_irq(pdev, 0); if (irq <= 0) -- 2.7.4