On 9/9/20 7:16 PM, Hugues FRUCHET wrote: > Hi Prabhakar, > > As discussed separately I would prefer to better understand issue before > going to this patch. > Nevertheless I have some remarks in code in case we'll need it at the end. > > On 9/4/20 10:18 PM, Lad Prabhakar wrote: >> Keep the sensor in software power down mode and wake up only in >> ov5640_set_stream_dvp() callback. >> >> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> >> Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx> >> Tested-by: Jacopo Mondi <jacopo@xxxxxxxxxx> >> --- >> drivers/media/i2c/ov5640.c | 19 ++++++++++++++++--- >> 1 file changed, 16 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c >> index 2fe4a7ac0592..880fde73a030 100644 >> --- a/drivers/media/i2c/ov5640.c >> +++ b/drivers/media/i2c/ov5640.c >> @@ -34,6 +34,8 @@ >> #define OV5640_REG_SYS_RESET02 0x3002 >> #define OV5640_REG_SYS_CLOCK_ENABLE02 0x3006 >> #define OV5640_REG_SYS_CTRL0 0x3008 >> +#define OV5640_REG_SYS_CTRL0_SW_PWDN 0x42 >> +#define OV5640_REG_SYS_CTRL0_SW_PWUP 0x02 > > For the time being this section was only referring to registers > addresses and bit details was explained into a comment right before > affectation, see OV5640_REG_IO_MIPI_CTRL00 for example. > >> #define OV5640_REG_CHIP_ID 0x300a >> #define OV5640_REG_IO_MIPI_CTRL00 0x300e >> #define OV5640_REG_PAD_OUTPUT_ENABLE01 0x3017 >> @@ -1120,6 +1122,12 @@ 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_REG_SYS_CTRL0_SW_PWUP && >> + sensor->ep.bus_type != V4L2_MBUS_CSI2_DPHY) >> + continue; >> + > > I understand that more or less register OV5640_REG_SYS_CTRL0 (0x3008) > has been partially removed from big init sequence: for power-up part, > but power-dwn remains at very beginning of sequence. > We should completely remove 0x3008 from init sequence, including > power-dwn, and introduce a new function ov5640_sw_powerdown(on/off) that > should be called at the right place instead. > > >> if (mask) >> ret = ov5640_mod_reg(sensor, reg_addr, mask, val); >> else >> @@ -1297,9 +1305,14 @@ static int ov5640_set_stream_dvp(struct ov5640_dev *sensor, bool on) >> * PAD OUTPUT ENABLE 02 >> * - [7:2]: D[5:0] output enable >> */ >> - return ov5640_write_reg(sensor, >> - OV5640_REG_PAD_OUTPUT_ENABLE02, >> - on ? 0xfc : 0); >> + ret = ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT_ENABLE02, >> + on ? 0xfc : 0); >> + 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_mipi(struct ov5640_dev *sensor, bool on) >> > > > BR, > Hugues. > Hello everyone, When I updated driver in my tree with this patch, I noticed that my setup using the ATMEL isc platform + ov5640 in parallel bus mode stopped working. It looks like the culprit is this patch. I am not sure which is the best way to fix it. It looks like initially things work fine when probing the driver, but when we want to start streaming at a later point, the register SYS_CTRL0 cannot be written anymore. Here is an output of the log: --- Opening /dev/video0... Trying source module v4l2... /dev/video0 opened. No input was specified, using the first. ov5640 1-003c: ov5640_write_reg: error: reg=3008, val=2 atmel-sama5d2-isc f0008000.isc: stream on failed in subdev -121 Error starting stream. VIDIOC_STREAMON: Remote I/O error Unable to use mmap. Using read instead. Unable to use read. I am using a simple application to read from /dev/video0 (which is registered by the atmel-isc once the sensor probed) I have a feeling that something is wrong related to power, but I cannot tell for sure. Reverting this patch makes it work fine again. Help is appreciated, Thanks, Eugen