phy: dphy: add support to calculate the timing based on hs_clk_rate

For MIPI-CSI sender use-case it is common to specify the allowed
link-frequencies which should be used for the MIPI link and is
half the hs-clock rate.

This commit adds a helper to calculate the D-PHY timing based on the
hs-clock rate so we don't need to calculate the timings within the
driver.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

phy: dphy: Clarify lanes parameter documentation

The lanes parameter is not solely about the number of lanes, but it also
carries the fact that those are the first lanes in use during the
transmission.

It was implicit so far, so make sure it's explicit now.

Suggested-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

phy: dphy: Change units of wakeup and init parameters

The Init and wakeup D-PHY parameters are in the micro/milliseconds range,
putting the values real close to the types limits if they were in
picoseconds.

Move them to microseconds which should be better fit.

Suggested-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

phy: dphy: Remove unused header

The videomode.h header inclusion is an artifact from the patches
development, remove it.

Suggested-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

phy: dphy: Add configuration helpers

The MIPI D-PHY spec defines default values and boundaries for most of the
parameters it defines. Introduce helpers to help drivers get meaningful
values based on their current parameters, and validate the boundaries of
these parameters if needed.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

phy: Add MIPI D-PHY configuration options

Now that we have some infrastructure for it, allow the MIPI D-PHY phy's to
be configured through the generic functions through a custom structure
added to the generic union.

The parameters added here are the ones defined in the MIPI D-PHY spec, plus
the number of lanes in use. The current set of parameters should cover all
the potential users.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>