[Linux-stm32] [PATCH v2] media: ov5640: fix support of BT656 bus mode
Hugues FRUCHET
hugues.fruchet at st.com
Tue Oct 13 08:45:04 UTC 2020
Hi Jacopo,
On 10/12/20 5:48 PM, Jacopo Mondi wrote:
> 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 ?
Fully agree.
>
>> + /*
>> + * 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
>>
BR,
Hugues.
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