[Linux-stm32] [PATCH v3] media: ov5640: fix support of BT656 bus mode
Jacopo Mondi
jacopo at jmondi.org
Tue Oct 13 12:01:30 UTC 2020
Hi Hugues,
On Tue, Oct 13, 2020 at 11:02:23AM +0200, Hugues Fruchet wrote:
> Fix PCLK polarity not being taken into account.
> Add comments about BT656 register control.
> Remove useless ov5640_set_stream_bt656() function.
> Refine comments about MIPI IO register control.
>
> Fixes: 4039b03720f7 ("media: i2c: ov5640: Add support for BT656 mode")
> Signed-off-by: Hugues Fruchet <hugues.fruchet at st.com>
> ---
> version 3:
> - reformat code as per Jacopo's comments
> version 2:
> - keep reset to default without error check at power off
>
> drivers/media/i2c/ov5640.c | 82 +++++++++++++++++++++++++---------------------
> 1 file changed, 45 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index 8d0254d..8f0812e 100644
> --- a/drivers/media/i2c/ov5640.c
> +++ b/drivers/media/i2c/ov5640.c
> @@ -1216,20 +1216,6 @@ static int ov5640_set_autogain(struct ov5640_dev *sensor, bool on)
> BIT(1), on ? 0 : BIT(1));
> }
>
> -static int ov5640_set_stream_bt656(struct ov5640_dev *sensor, bool on)
> -{
> - int ret;
> -
> - ret = ov5640_write_reg(sensor, OV5640_REG_CCIR656_CTRL00,
> - on ? 0x1 : 0x00);
> - if (ret)
> - return ret;
> -
> - return ov5640_write_reg(sensor, OV5640_REG_SYS_CTRL0, on ?
> - OV5640_REG_SYS_CTRL0_SW_PWUP :
> - OV5640_REG_SYS_CTRL0_SW_PWDN);
> -}
> -
> static int ov5640_set_stream_dvp(struct ov5640_dev *sensor, bool on)
> {
> return ov5640_write_reg(sensor, OV5640_REG_SYS_CTRL0, on ?
> @@ -1994,13 +1980,13 @@ static int ov5640_set_power_mipi(struct ov5640_dev *sensor, bool on)
> static int ov5640_set_power_dvp(struct ov5640_dev *sensor, bool on)
> {
> unsigned int flags = sensor->ep.bus.parallel.flags;
> - u8 pclk_pol = 0;
> - u8 hsync_pol = 0;
> - u8 vsync_pol = 0;
> + bool bt656 = sensor->ep.bus_type == V4L2_MBUS_BT656;
> + u8 polarities = 0;
> int ret;
>
> if (!on) {
> /* Reset settings to their default values. */
> + ov5640_write_reg(sensor, OV5640_REG_CCIR656_CTRL00, 0x00);
> ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00, 0x58);
> ov5640_write_reg(sensor, OV5640_REG_POLARITY_CTRL00, 0x20);
> ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT_ENABLE01, 0x00);
> @@ -2024,7 +2010,35 @@ static int ov5640_set_power_dvp(struct ov5640_dev *sensor, bool on)
> * - VSYNC: active high
> * - HREF: active low
> * - PCLK: active low
> + *
> + * VSYNC & HREF are not configured if BT656 bus mode is selected
> */
> +
> + /*
> + * BT656 embedded synchronization configuration
> + *
> + * CCIR656 CTRL00
> + * - [7]: SYNC code selection (0: auto generate sync code,
> + * 1: sync code from regs 0x4732-0x4735)
> + * - [6]: f value in CCIR656 SYNC code when fixed f value
> + * - [5]: Fixed f value
> + * - [4:3]: Blank toggle data options (00: data=1'h040/1'h200,
> + * 01: data from regs 0x4736-0x4738, 10: always keep 0)
> + * - [1]: Clip data disable
> + * - [0]: CCIR656 mode enable
> + *
> + * Default CCIR656 SAV/EAV mode with default codes
> + * SAV=0xff000080 & EAV=0xff00009d is enabled here with settings:
> + * - CCIR656 mode enable
> + * - auto generation of sync codes
> + * - blank toggle data 1'h040/1'h200
> + * - clip reserved data (0x00 & 0xff changed to 0x01 & 0xfe)
> + */
> + ret = ov5640_write_reg(sensor, OV5640_REG_CCIR656_CTRL00,
> + bt656 ? 0x01 : 0x00);
> + if (ret)
> + return ret;
> +
> /*
> * configure parallel port control lines polarity
> *
> @@ -2035,29 +2049,26 @@ static int ov5640_set_power_dvp(struct ov5640_dev *sensor, bool on)
> * datasheet and hardware, 0 is active high
> * and 1 is active low...)
> */
> - if (sensor->ep.bus_type == V4L2_MBUS_PARALLEL) {
> - if (flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
> - pclk_pol = 1;
> + if (!bt656) {
> if (flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
> - hsync_pol = 1;
> + polarities |= BIT(1);
> if (flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
> - vsync_pol = 1;
Ups, this doesn't match what's reported in the manual version I have
(version 2.03, page 134) I read:
VSYNC polarity 0: Active low
1: Active high
Was this a bug already present in the code ?
Anyway, this has not been introduced by this patch, but might be a
good occasion to fix it.
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
Thanks
j
> -
> - ret = ov5640_write_reg(sensor, OV5640_REG_POLARITY_CTRL00,
> - (pclk_pol << 5) | (hsync_pol << 1) |
> - vsync_pol);
> -
> - if (ret)
> - return ret;
> + polarities |= BIT(0);
> }
> + if (flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
> + polarities |= BIT(5);
> +
> + ret = ov5640_write_reg(sensor, OV5640_REG_POLARITY_CTRL00, polarities);
> + if (ret)
> + return ret;
>
> /*
> - * powerdown MIPI TX/RX PHY & disable MIPI
> + * powerdown MIPI TX/RX PHY & enable DVP
> *
> * MIPI CONTROL 00
> - * 4: PWDN PHY TX
> - * 3: PWDN PHY RX
> - * 2: MIPI enable
> + * [4] = 1 : Power down MIPI HS Tx
> + * [3] = 1 : Power down MIPI LS Rx
> + * [2] = 0 : DVP enable (MIPI disable)
> */
> ret = ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00, 0x18);
> if (ret)
> @@ -2074,8 +2085,7 @@ static int ov5640_set_power_dvp(struct ov5640_dev *sensor, bool on)
> * - [3:0]: D[9:6] output enable
> */
> ret = ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT_ENABLE01,
> - sensor->ep.bus_type == V4L2_MBUS_PARALLEL ?
> - 0x7f : 0x1f);
> + bt656 ? 0x1f : 0x7f);
> if (ret)
> return ret;
>
> @@ -2925,8 +2935,6 @@ static int ov5640_s_stream(struct v4l2_subdev *sd, int enable)
>
> if (sensor->ep.bus_type == V4L2_MBUS_CSI2_DPHY)
> ret = ov5640_set_stream_mipi(sensor, enable);
> - else if (sensor->ep.bus_type == V4L2_MBUS_BT656)
> - ret = ov5640_set_stream_bt656(sensor, enable);
> else
> ret = ov5640_set_stream_dvp(sensor, enable);
>
> --
> 2.7.4
>
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