Re: [PATCH v2 2/4] media: i2c: ov5640: Enable data pins on poweron for DVP mode

From: Lad, Prabhakar
Date: Mon Aug 10 2020 - 03:41:00 EST

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Hi Jacopo,

Thank you for the review.

On Fri, Aug 7, 2020 at 9:42 AM Jacopo Mondi <jacopo@xxxxxxxxxx> wrote:
>
> Hi Prabhakar,
> + Paul who is working with this chip on a parallel setup
>
> On Thu, Aug 06, 2020 at 05:38:57PM +0100, Lad, Prabhakar wrote:
> > Hi Jacopo,
> >
> > Thank you for the review.
> >
> > On Thu, Aug 6, 2020 at 5:27 PM Jacopo Mondi <jacopo@xxxxxxxxxx> wrote:
> > >
> > > Hi Prabhakar,
> > >
> > > On Mon, Aug 03, 2020 at 03:31:45PM +0100, Lad Prabhakar wrote:
> > > > During testing this sensor on iW-RainboW-G21D-Qseven platform in 8-bit DVP
> > > > mode with rcar-vin bridge noticed the capture worked fine for the first run
> > > > (with yavta), but for subsequent runs the bridge driver waited for the
> > > > frame to be captured. Debugging further noticed the data lines were
> > > > enabled/disabled in stream on/off callback and dumping the register
> > > > contents 0x3017/0x3018 in ov5640_set_stream_dvp() reported the correct
> > > > values, but yet frame capturing failed.
> > >
> > > That's pretty weird, I wonder if that's not an issue in the bridge, as
> > > I expect someone tryed to capture more than 1 image in DVP mode with
> > > this driver already.
> > >
> > I did try the bridge driver with an ov7725 sensor and it works fine in
> > both the modes (DVP and BT656).
> >
> > > I didn't get from your commit message if you have been able to
> > > identify where the issue is. You said register values are correct, but
> > > did you try to plug a scope and see if data are actually put on the
> > > bus ? Does this happen with full parallel too or BT.656 only ?
> > >
> > unfortunately I didn't scope the pins, but this issue happened in both
> > the modes. And with this patch it improves handling the sensor in
> > s_stream call.
> >
>
> For the record, I tested this one with my CSI-2 setup and capture
> still works as expected.
>
Thank you for testing this.

> > Cheers,
> > Prabhakar
> >
> > > >
> > > > To get around this issue the following actions are performed for
> > > > parallel mode (DVP):
> > > > 1: Keeps the sensor in software power down mode and is woken up only in
> > > > ov5640_set_stream_dvp() callback.
> > > > 2: Enables data lines in s_power callback
> > > > 3: Configures HVP lines in s_power callback instead of configuring
> > > > everytime in ov5640_set_stream_dvp().
> > > > 4: Disables MIPI interface.
> > > >
> > > > Fixes: f22996db44e2d ("media: ov5640: add support of DVP parallel interface")
> > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > > > Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > > ---
> > > > drivers/media/i2c/ov5640.c | 321 ++++++++++++++++++++-----------------
> > > > 1 file changed, 172 insertions(+), 149 deletions(-)
> > > >
> > > > diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> > > > index 2fe4a7ac0592..ec444bee2ce9 100644
> > > > --- a/drivers/media/i2c/ov5640.c
> > > > +++ b/drivers/media/i2c/ov5640.c
> > > > @@ -94,6 +94,9 @@
> > > > #define OV5640_REG_SDE_CTRL5 0x5585
> > > > #define OV5640_REG_AVG_READOUT 0x56a1
> > > >
> > > > +#define OV5640_SOFTWARE_PWDN 0x42
> > > > +#define OV5640_SOFTWARE_WAKEUP 0x02
>
> These two are bitmasks to apply to register 0x3008. I would place them
> below the register definition and name them:
>
> #define OV5640_REG_SYS_CTRL0_SW_PWDN 0x42
> #define OV5640_REG_SYS_CTRL0_SW_PWUP 0x02
>
> or even:
> #define OV5640_REG_SYS_CTRL0_SW_POWER(on) (0x2 | (on ? 0x40 : 0x00))
>
> Up to you, but I would keep them close to the register definition.
>
Agreed shall pick up the second option.

> > > > +
> > > > enum ov5640_mode_id {
> > > > OV5640_MODE_QCIF_176_144 = 0,
> > > > OV5640_MODE_QVGA_320_240,
> > > > @@ -274,7 +277,7 @@ static inline struct v4l2_subdev *ctrl_to_sd(struct v4l2_ctrl *ctrl)
> > > > /* YUV422 UYVY VGA@30fps */
> > > > static const struct reg_value ov5640_init_setting_30fps_VGA[] = {
> > > > {0x3103, 0x11, 0, 0}, {0x3008, 0x82, 0, 5}, {0x3008, 0x42, 0, 0},
> > > > - {0x3103, 0x03, 0, 0}, {0x3017, 0x00, 0, 0}, {0x3018, 0x00, 0, 0},
> > > > + {0x3103, 0x03, 0, 0},
> > > > {0x3630, 0x36, 0, 0},
>
> Could you reflow this lines to not leave holes ?
>
Will do.

> > > > {0x3631, 0x0e, 0, 0}, {0x3632, 0xe2, 0, 0}, {0x3633, 0x12, 0, 0},
> > > > {0x3621, 0xe0, 0, 0}, {0x3704, 0xa0, 0, 0}, {0x3703, 0x5a, 0, 0},
> > > > @@ -1120,6 +1123,11 @@ static int ov5640_load_regs(struct ov5640_dev *sensor,
> > > > val = regs->val;
> > > > mask = regs->mask;
> > > >
> > > > + /* remain in power down mode for DVP */
> > > > + if (regs->reg_addr == OV5640_REG_SYS_CTRL0 && val == OV5640_SOFTWARE_WAKEUP &&
> > > > + sensor->ep.bus_type != V4L2_MBUS_CSI2_DPHY)
> > > > + continue;
> > > > +
>
> I'm not yet convinced this is a good idea. This will cause the
> ov5640_set_dvp() function to be called while the chip is still in
> 'software power-down' mode. I tried to do the same for CSI-2 as well
> and indeed I have LP-11 errors from the CSI-2 receiver, but then
> capture works fine (puzzling! it might indicate that register values
> as actually retained between software power up/down)
>
> This driver is such a mess I won't mind this 'special' dvp handling,
> but it really puzzles me.
>
> From what I see here the bulk of this patch is about moving the
> parallel bus configuration from s_stream() to s_power(), is this bit
> here really required for that to work or is it a leftover ? Have you
> tested it without the above hunk ?
>
Yes I have and it does work. but the idea behind this is to keep the
sensor in powerdon mode all the time when nor streaming for DVP mode.

> Paul, would you be able to test this series with your parallel setup
> as well ?
>
> Also, if not strictly necessary, let's try to remain in the 80 cols limit.
>
OK.

>
> > > > if (mask)
> > > > ret = ov5640_mod_reg(sensor, reg_addr, mask, val);
> > > > else
> > > > @@ -1210,96 +1218,8 @@ static int ov5640_set_autogain(struct ov5640_dev *sensor, bool on)
> > > >
> > > > static int ov5640_set_stream_dvp(struct ov5640_dev *sensor, bool on)
> > > > {
> > > > - int ret;
> > > > - unsigned int flags = sensor->ep.bus.parallel.flags;
> > > > - u8 pclk_pol = 0;
> > > > - u8 hsync_pol = 0;
> > > > - u8 vsync_pol = 0;
> > > > -
> > > > - /*
> > > > - * Note about parallel port configuration.
> > > > - *
> > > > - * When configured in parallel mode, the OV5640 will
> > > > - * output 10 bits data on DVP data lines [9:0].
> > > > - * If only 8 bits data are wanted, the 8 bits data lines
> > > > - * of the camera interface must be physically connected
> > > > - * on the DVP data lines [9:2].
> > > > - *
> > > > - * Control lines polarity can be configured through
> > > > - * devicetree endpoint control lines properties.
> > > > - * If no endpoint control lines properties are set,
> > > > - * polarity will be as below:
> > > > - * - VSYNC: active high
> > > > - * - HREF: active low
> > > > - * - PCLK: active low
> > > > - */
> > > > -
> > > > - if (on) {
> > > > - /*
> > > > - * 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)
> > > > - hsync_pol = 1;
> > > > - if (flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
> > > > - vsync_pol = 1;
> > > > -
> > > > - ret = ov5640_write_reg(sensor,
> > > > - OV5640_REG_POLARITY_CTRL00,
> > > > - (pclk_pol << 5) |
> > > > - (hsync_pol << 1) |
> > > > - vsync_pol);
> > > > -
> > > > - if (ret)
> > > > - return ret;
> > > > - }
> > > > -
> > > > - /*
> > > > - * powerdown MIPI TX/RX PHY & disable MIPI
> > > > - *
> > > > - * MIPI CONTROL 00
> > > > - * 4: PWDN PHY TX
> > > > - * 3: PWDN PHY RX
> > > > - * 2: MIPI enable
> > > > - */
> > > > - ret = ov5640_write_reg(sensor,
> > > > - OV5640_REG_IO_MIPI_CTRL00, on ? 0x18 : 0);
> > > > - if (ret)
> > > > - return ret;
> > > > -
> > > > - /*
> > > > - * enable VSYNC/HREF/PCLK DVP control lines
> > > > - * & D[9:6] DVP data lines
> > > > - *
> > > > - * PAD OUTPUT ENABLE 01
> > > > - * - 6: VSYNC output enable
> > > > - * - 5: HREF output enable
> > > > - * - 4: PCLK output enable
> > > > - * - [3:0]: D[9:6] output enable
> > > > - */
> > > > - ret = ov5640_write_reg(sensor,
> > > > - OV5640_REG_PAD_OUTPUT_ENABLE01,
> > > > - on ? 0x7f : 0);
> > > > - if (ret)
> > > > - return ret;
> > > > -
> > > > - /*
> > > > - * enable D[5:0] DVP data lines
> > > > - *
> > > > - * PAD OUTPUT ENABLE 02
> > > > - * - [7:2]: D[5:0] output enable
> > > > - */
> > > > - return ov5640_write_reg(sensor,
> > > > - OV5640_REG_PAD_OUTPUT_ENABLE02,
> > > > - on ? 0xfc : 0);
> > > > + return ov5640_write_reg(sensor, OV5640_REG_SYS_CTRL0, on ?
> > > > + OV5640_SOFTWARE_WAKEUP : OV5640_SOFTWARE_PWDN);
>
> I'm surprised entering/exiting from what is called "Software power
> down" in the chip manual retains the registers state!
>
In fact as part of the initial register sequence the sensor is put
into power down mode, the required registers are set and then the
sensor is woken up.

> > > > }
> > > >
> > > > static int ov5640_set_stream_mipi(struct ov5640_dev *sensor, bool on)
> > > > @@ -2001,6 +1921,159 @@ static void ov5640_set_power_off(struct ov5640_dev *sensor)
> > > > clk_disable_unprepare(sensor->xclk);
> > > > }
> > > >
> > > > +static int ov5640_set_mipi(struct ov5640_dev *sensor, bool on)
>
> Maybe 'ov5640_set_power_mipi()' ? (same for dvp)
>
OK will replace it.

> > > > +{
> > > > + int ret = 0;
> > > > +
> > > > + if (!on) {
> > > > + /* Reset MIPI bus settings to their default values. */
> > > > + ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00, 0x58);
> > > > + ov5640_write_reg(sensor, OV5640_REG_MIPI_CTRL00, 0x04);
> > > > + ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT00, 0x00);
> > > > +
> > > > + return ret;
> > > > + }
>
> I know this was there already, but I wonder if this is now necessary
> (same for the DVP counterpart).
>
> We call this from the power up/down routine, if we get here with on=1
> we are exiting from the chip powerdown mode and I expect registers to
> be restored to their default values.
>
No waking up the sensor from power down mode doesnt restore the
register to default values, infact it will retain the values which are
already set to. Fyi I picked up the datasheet from [1]

[1] http://e2e.ti.com/cfs-file.ashx/__key/communityserver-discussions-components-files/100/2604.OV7725_5F00_CSP2_5F00_DS-_2800_1_5B00_1_5D00_.31_2900_.pdf

> > > > +
> > > > + /*
> > > > + * Power up MIPI HS Tx and LS Rx; 2 data lanes mode
> > > > + *
> > > > + * 0x300e = 0x40
> > > > + * [7:5] = 010 : 2 data lanes mode (see FIXME note in
> > > > + * "ov5640_set_stream_mipi()")
> > > > + * [4] = 0 : Power up MIPI HS Tx
> > > > + * [3] = 0 : Power up MIPI LS Rx
> > > > + * [2] = 0 : MIPI interface disabled
> > > > + */
> > > > + ret = ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00, 0x40);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + /*
> > > > + * Gate clock and set LP11 in 'no packets mode' (idle)
> > > > + *
> > > > + * 0x4800 = 0x24
> > > > + * [5] = 1 : Gate clock when 'no packets'
> > > > + * [2] = 1 : MIPI bus in LP11 when 'no packets'
> > > > + */
> > > > + ret = ov5640_write_reg(sensor, OV5640_REG_MIPI_CTRL00, 0x24);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + /*
> > > > + * Set data lanes and clock in LP11 when 'sleeping'
> > > > + *
> > > > + * 0x3019 = 0x70
> > > > + * [6] = 1 : MIPI data lane 2 in LP11 when 'sleeping'
> > > > + * [5] = 1 : MIPI data lane 1 in LP11 when 'sleeping'
> > > > + * [4] = 1 : MIPI clock lane in LP11 when 'sleeping'
> > > > + */
> > > > + ret = ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT00, 0x70);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + /* Give lanes some time to coax into LP11 state. */
> > > > + usleep_range(500, 1000);
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static int ov5640_set_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;
> > > > + int ret = 0;
> > > > +
> > > > + if (!on) {
> > > > + /* Reset settings to their default values. */
> > > > + 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);
> > > > + ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT_ENABLE02, 0x00);
> > > > +
> > > > + return ret;
> > > > + }
> > > > +
> > > > + /*
> > > > + * Note about parallel port configuration.
> > > > + *
> > > > + * When configured in parallel mode, the OV5640 will
> > > > + * output 10 bits data on DVP data lines [9:0].
> > > > + * If only 8 bits data are wanted, the 8 bits data lines
> > > > + * of the camera interface must be physically connected
> > > > + * on the DVP data lines [9:2].
> > > > + *
> > > > + * Control lines polarity can be configured through
> > > > + * devicetree endpoint control lines properties.
> > > > + * If no endpoint control lines properties are set,
> > > > + * polarity will be as below:
> > > > + * - VSYNC: active high
> > > > + * - HREF: active low
> > > > + * - PCLK: active low
> > > > + */
> > > > + /*
> > > > + * 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)
> > > > + hsync_pol = 1;
> > > > + if (flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
> > > > + vsync_pol = 1;
> > > > +
> > > > + ret = ov5640_write_reg(sensor, OV5640_REG_POLARITY_CTRL00,
> > > > + (pclk_pol << 5) | (hsync_pol << 1) | vsync_pol);
> > > > +
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + /*
> > > > + * powerdown MIPI TX/RX PHY & disable MIPI
> > > > + *
> > > > + * MIPI CONTROL 00
> > > > + * 4: PWDN PHY TX
> > > > + * 3: PWDN PHY RX
> > > > + * 2: MIPI enable
> > > > + */
> > > > + ret = ov5640_write_reg(sensor, OV5640_REG_IO_MIPI_CTRL00, 0x18);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + /*
> > > > + * enable VSYNC/HREF/PCLK DVP control lines
> > > > + * & D[9:6] DVP data lines
> > > > + *
> > > > + * PAD OUTPUT ENABLE 01
> > > > + * - 6: VSYNC output enable
> > > > + * - 5: HREF output enable
> > > > + * - 4: PCLK output enable
> > > > + * - [3:0]: D[9:6] output enable
> > > > + */
> > > > + ret = ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT_ENABLE01, 0x7f);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + /*
> > > > + * enable D[5:0] DVP data lines
> > > > + *
> > > > + * PAD OUTPUT ENABLE 02
> > > > + * - [7:2]: D[5:0] output enable
> > > > + */
> > > > + ret = ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT_ENABLE02, 0xfc);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > static int ov5640_set_power(struct ov5640_dev *sensor, bool on)
> > > > {
> > > > int ret = 0;
> > > > @@ -2013,67 +2086,17 @@ static int ov5640_set_power(struct ov5640_dev *sensor, bool on)
> > > > ret = ov5640_restore_mode(sensor);
> > > > if (ret)
> > > > goto power_off;
> > > > + }
> > > >
> > > > - /* We're done here for DVP bus, while CSI-2 needs setup. */
> > > > - if (sensor->ep.bus_type != V4L2_MBUS_CSI2_DPHY)
> > > > - return 0;
> > > > -
> > > > - /*
> > > > - * Power up MIPI HS Tx and LS Rx; 2 data lanes mode
> > > > - *
> > > > - * 0x300e = 0x40
> > > > - * [7:5] = 010 : 2 data lanes mode (see FIXME note in
> > > > - * "ov5640_set_stream_mipi()")
> > > > - * [4] = 0 : Power up MIPI HS Tx
> > > > - * [3] = 0 : Power up MIPI LS Rx
> > > > - * [2] = 0 : MIPI interface disabled
> > > > - */
> > > > - ret = ov5640_write_reg(sensor,
> > > > - OV5640_REG_IO_MIPI_CTRL00, 0x40);
> > > > - if (ret)
> > > > - goto power_off;
> > > > -
> > > > - /*
> > > > - * Gate clock and set LP11 in 'no packets mode' (idle)
> > > > - *
> > > > - * 0x4800 = 0x24
> > > > - * [5] = 1 : Gate clock when 'no packets'
> > > > - * [2] = 1 : MIPI bus in LP11 when 'no packets'
> > > > - */
> > > > - ret = ov5640_write_reg(sensor,
> > > > - OV5640_REG_MIPI_CTRL00, 0x24);
> > > > - if (ret)
> > > > - goto power_off;
> > > > -
> > > > - /*
> > > > - * Set data lanes and clock in LP11 when 'sleeping'
> > > > - *
> > > > - * 0x3019 = 0x70
> > > > - * [6] = 1 : MIPI data lane 2 in LP11 when 'sleeping'
> > > > - * [5] = 1 : MIPI data lane 1 in LP11 when 'sleeping'
> > > > - * [4] = 1 : MIPI clock lane in LP11 when 'sleeping'
> > > > - */
> > > > - ret = ov5640_write_reg(sensor,
> > > > - OV5640_REG_PAD_OUTPUT00, 0x70);
> > > > - if (ret)
> > > > - goto power_off;
> > > > -
> > > > - /* Give lanes some time to coax into LP11 state. */
> > > > - usleep_range(500, 1000);
> > > > -
> > > > - } else {
> > > > - if (sensor->ep.bus_type == V4L2_MBUS_CSI2_DPHY) {
> > > > - /* Reset MIPI bus settings to their default values. */
> > > > - ov5640_write_reg(sensor,
> > > > - OV5640_REG_IO_MIPI_CTRL00, 0x58);
> > > > - ov5640_write_reg(sensor,
> > > > - OV5640_REG_MIPI_CTRL00, 0x04);
> > > > - ov5640_write_reg(sensor,
> > > > - OV5640_REG_PAD_OUTPUT00, 0x00);
> > > > - }
> > > > + if (sensor->ep.bus_type == V4L2_MBUS_CSI2_DPHY)
> > > > + ret = ov5640_set_mipi(sensor, on);
> > > > + else
> > > > + ret = ov5640_set_dvp(sensor, on);
> > > > + if (ret)
> > > > + goto power_off;
>
> If you agree the if (!on) case in the two set_mipi()/set_dvp() functions
> above can be removed, this function should become
>
I would keep it, as mentioned above.

Cheers,
Prabhakar

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