media: ov5640: Re-work MIPI startup sequence
commit aa4bb8b8838ffcc776a79f49a4d7476b82405349 upstream.
Rework the MIPI interface startup sequence with the following changes:
- Remove MIPI bus initialization from the initial settings blob
- At set_power(1) time power up MIPI Tx/Rx and set data and clock lanes in
LP11 during 'sleep' and 'idle' with MIPI clock in non-continuous mode.
- At s_stream time enable/disable the MIPI interface output.
- Restore default settings at set_power(0) time.
Before this commit the sensor MIPI interface was initialized with settings
that require a start/stop sequence at power-up time in order to force lanes
into LP11 state, as they were initialized in LP00 when in 'sleep mode',
which is assumed to be the sensor manual definition for the D-PHY defined
stop mode.
The stream start/stop was performed by enabling disabling clock gating,
and had the side effect to change the lanes sleep mode configuration when
stream was stopped.
Clock gating/ungating:
- ret = ov5640_mod_reg(sensor, OV5640_REG_MIPI_CTRL00, BIT(5),
- on ? 0 : BIT(5));
- if (ret)
Set lanes in LP11 when in 'sleep mode':
- ret = ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT00,
- on ? 0x00 : 0x70);
This commit fixes an issue reported by Jagan Teki on i.MX6 platforms that
prevents the host interface from powering up correctly:
https://lkml.org/lkml/2018/6/1/38
It also improves MIPI capture operations stability on my testing platform
where MIPI capture often failed and returned all-purple frames.
Fixes: f22996db44e2 ("media: ov5640: add support of DVP parallel interface")
Tested-by: Steve Longerbeam <slongerbeam@gmail.com> (i.MX6q SabreSD, CSI-2)
Tested-by: Loic Poulain <loic.poulain@linaro.org> (Dragonboard-410c, CSI-2)
Reported-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed