[Linux-stm32] [PATCH v2] media: ov5640: fix support of BT656 bus mode
Jacopo Mondi
jacopo at jmondi.org
Mon Oct 12 15:48:26 UTC 2020
Hi Hugues,
On Mon, Oct 12, 2020 at 04:51:43PM +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>
> ---
> drivers/media/i2c/ov5640.c | 77 +++++++++++++++++++++++++++-------------------
> 1 file changed, 45 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index 8d0254d..c0ebf4c 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 ?
> @@ -1994,6 +1980,7 @@ 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;
> + bool bt656 = sensor->ep.bus_type == V4L2_MBUS_BT656;
> u8 pclk_pol = 0;
> u8 hsync_pol = 0;
> u8 vsync_pol = 0;
> @@ -2001,6 +1988,7 @@ static int ov5640_set_power_dvp(struct ov5640_dev *sensor, bool on)
>
> 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);
> @@ -2024,23 +2012,51 @@ 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
> */
> +
> /*
> - * configure parallel port control lines polarity
> + * BT656 embedded synchronization configuration
> *
> - * POLARITY CTRL0
> - * - [5]: PCLK polarity (0: active low, 1: active high)
> - * - [1]: HREF polarity (0: active low, 1: active high)
> - * - [0]: VSYNC polarity (mismatch here between
> - * datasheet and hardware, 0 is active high
> - * and 1 is active low...)
> + * 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)
> */
> - if (sensor->ep.bus_type == V4L2_MBUS_PARALLEL) {
> + ret = ov5640_write_reg(sensor, OV5640_REG_CCIR656_CTRL00,
> + bt656 ? 0x01 : 0x00);
> + if (ret)
> + return ret;
All good so far
> +
> + if (on) {
But don't you have retained
if (!on)
at the beginning of the function ?
I would reflow this as:
static int ov5640_set_power_dvp(struct ov5640_dev *sensor, bool on) {
if (!on) {
...
}
uint8_t polarities = 0;
if (!bt656) {
if (flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
polarities |= BIT(1);
if (flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
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;
if (bt656) {
write_reg(CCIR656);
}
....
To make it more readable. What do you think ?
> + /*
> + * configure parallel port control lines polarity
> + *
> + * POLARITY CTRL0
> + * - [5]: PCLK polarity (0: active low, 1: active high)
> + * - [1]: HREF polarity (0: active low, 1: active high)
> + * - [0]: VSYNC polarity (mismatch here between
> + * datasheet and hardware, 0 is active high
> + * and 1 is active low...)
> + */
> if (flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
> pclk_pol = 1;
> - if (flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
> + if (!bt656 && flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
> hsync_pol = 1;
> - if (flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
> + if (!bt656 && flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
> vsync_pol = 1;
>
> ret = ov5640_write_reg(sensor, OV5640_REG_POLARITY_CTRL00,
> @@ -2052,12 +2068,12 @@ static int ov5640_set_power_dvp(struct ov5640_dev *sensor, bool on)
> }
>
The part here below looks good!
> /*
> - * 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 +2090,7 @@ 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 +2940,6 @@ 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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