udelay_range(1, 2) is inefficient and as discussions with Jani Nikula
<jani.nikula@linux.intel.com> unnecessary here. This replaces this
tight setting with a relaxed delay of min=20 and max=50 which helps
the hrtimer subsystem optimize timer handling.

Fixes: commit be4fc046 ("drm/i915: add VLV DSI PLL Calculations")
Link: http://lkml.org/lkml/2016/12/15/147Signed-off-by: NNicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481853578-19834-1-git-send-email-hofrat@osadl.org

Geminilake is mostly backwards compatible with broxton, so change most
of the IS_BROXTON() checks to IS_GEN9_LP(). Differences between the
platforms will be implemented in follow-up patches.

v2: Don't reuse broxton's path in intel_update_max_cdclk().
    Don't set plane count as in broxton.

v3: Rebase

v4: Include the check intel_bios_is_port_hpd_inverted().
    Commit message.

v5: Leave i915_dmc_info() out; glk's csr version != bxt's. (Rodrigo)

v6: Rebase.

v7: Convert a few mode IS_BROXTON() occurances in pps, ddi, dsi and pll
    code. (Rodrigo)

v8: Squash a couple of DDI patches with more conversions. (Rodrigo)

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480667037-11215-2-git-send-email-ander.conselvan.de.oliveira@intel.com

Saves 1392 bytes of .rodata strings.

Also change a few function/macro prototypes in i915_gem_gtt.c
from dev to dev_priv where it made more sense to do so.

v2: Add parantheses around dev_priv. (Ville Syrjala)
v3: Mention function prototype changes. (David Weinehall)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: David Weinehall <david.weinehall@linux.intel.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@linux.intel.com>

Since we now subclass struct drm_device, we can save pointer dances by
noting the equivalence of struct drm_device and struct drm_i915_private,
i.e. by using to_i915().

   text    data     bss     dec     hex filename
1073824    4562     416 1078802  107612 drivers/gpu/drm/i915/i915.ko
1068976    4562     416 1073954  106322 drivers/gpu/drm/i915/i915.ko

Created by the coccinelle script:

@@
expression E;
identifier p;
@@
- struct drm_i915_private *p = E->dev_private;
+ struct drm_i915_private *p = to_i915(E);
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467628477-25379-1-git-send-email-chris@chris-wilson.co.uk

smatch complain:

	drivers/gpu/drm/i915/intel_dsi_pll.c:101 dsi_calc_mnp() error: buffer
	overflow 'lfsr_converts' 39 <= 4294967234

and looks justified in doing so.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1467470166-31717-7-git-send-email-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.auld@intel.com>

By using the out-of-line intel_wait_for_register() not only do we can
efficiency from using the hybrid wait_for() contained within, but we
avoid code bloat from the numerous inlined loops, in total (all patches):

   text    data     bss     dec     hex filename
1078551    4557     416 1083524  108884 drivers/gpu/drm/i915/i915.ko
1070775    4557     416 1075748  106a24 drivers/gpu/drm/i915/i915.ko
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467297225-21379-37-git-send-email-chris@chris-wilson.co.uk

By using the out-of-line intel_wait_for_register() not only do we can
efficiency from using the hybrid wait_for() contained within, but we
avoid code bloat from the numerous inlined loops, in total (all patches):

   text    data     bss     dec     hex filename
1078551    4557     416 1083524  108884 drivers/gpu/drm/i915/i915.ko
1070775    4557     416 1075748  106a24 drivers/gpu/drm/i915/i915.ko
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467297225-21379-36-git-send-email-chris@chris-wilson.co.uk

Fold the DSI PLL configuration functions into the DSI PLL
enable functions since they are small and not called from anywhere else.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460488478-18311-4-git-send-email-ville.syrjala@linux.intel.comTested-by: NJani Nikula <jani.nikula@intel.com>

Compute the DSI PLL parameters during .compute_config() rather than
.pre_pll_enable() so that we can fail gracefully if we can't find
suitable parameters.

In order to do that we need to store the DSI PLL parameters in
pipe_config.

v2: Handle BXT too
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460488478-18311-3-git-send-email-ville.syrjala@linux.intel.comTested-by: NJani Nikula <jani.nikula@intel.com>

Use the proper refclock frequency (100MHz) when reading out the
current DSI clock on CHV.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458052809-23426-13-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJani Nikula <jani.nikula@intel.com>

On VLV at least, the BIOS may leave the DSI PLL enabled in some wonky
state where it just refuses to lock. Simply disabling the PLL before
reconfiguring it is not enough to fix it, but power gating the PLL
prior to reconfiguring does work.

This happens on BYT FFRD8 when booting with HDMI connected so the DSI
display will not be lit up by the BIOS.

Also we can remove the code for BXT that disables the PLL before
enabling it again.

v2: s/vlv/intel/ since BXT made thing generic
v3: Remove the BXT disable PLL before enable trick
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458052809-23426-11-git-send-email-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>

All the values in the DSI PLL LFSR seed table fit into 9bits, so change
the type to u16 from u32 to save a bit of space.

 drivers/gpu/drm/i915/i915.ko:
-.rodata                        90824
+.rodata                        90760
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458052809-23426-10-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJani Nikula <jani.nikula@intel.com>

Currently the machine hangs during booting while accessing the
BXT_MIPI_PORT_CTRL register during pipe HW state readout. After some
experimentation I found that the hang is caused by the DSI PLL being
disabled, or it being enabled but with an incorrect divider
configuration. Enabling the PLL got rid of the boot problem, so fix
this by checking the PLL enabled state/configuration before attempting
to read out the HW state.

The DSI_PLL_ENABLE register is in the always-on power well, while the
BXT_DSI_PLL_CTL is in power well 0. This isn't exactly matched by the
transcoder power domain, but what we really need is just a runtime PM
reference, which is provided by any power domain.

Ville also found this dependency specified in BSpec, so I added a
reference to that too.

v2:
- Make sure we hold a power reference while accessing the PLL registers.
v3: (Jani)
- Simplify check in bxt_get_dsi_transcoder_state()
- Add comment explaining why we check for valid dividers in
  bxt_dsi_pll_is_enabled()

CC: Shashank Sharma <shashank.sharma@intel.com>
CC: Uma Shankar <uma.shankar@intel.com>
CC: Jani Nikula <jani.nikula@intel.com>
Fixes: c6c794a2 ("drm/i915/bxt: Initialize MIPI DSI for BXT")
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NShashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458816100-31269-1-git-send-email-imre.deak@intel.com

A small step moving us closer to DRM MIPI DSI code. Use enum
mipi_dsi_pixel_format instead of our own. The first benefit is being
able to use common mipi_dsi_pixel_format_to_bpp().

There's a little back and forth conversion with the VBT -> enum ->
register, since we have just shoved the VBT value into the register
directly. Longer term, all the VBT parsing and deciphering should be
done in intel_bios.c, and abstracted there.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458123700-16003-2-git-send-email-jani.nikula@intel.com

The enum mipi_dsi_pixel_format defines MIPI_DSI_FMT_RGB666 for the
"loose" 24 bpp format and MIPI_DSI_FMT_RGB666_PACKED for the 18 bpp
format. We have this the other way round, defining a loose version for
24 bpp.

Follow suit with what's in enum mipi_dsi_pixel_format to avoid future
confusion. Rename

VID_MODE_FORMAT_RGB666 -> VID_MODE_FORMAT_RGB666_PACKED
VID_MODE_FORMAT_RGB666_LOOSE -> VID_MODE_FORMAT_RGB666
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458123700-16003-1-git-send-email-jani.nikula@intel.com

The MIPI clock calculations for the addtional clock
are revised from B0 stepping onwards, the bit definitions
have changed compared to old stepping.

v2: Fixing compilation warning.
v3: Retained the old Macros (Jani)
Signed-off-by: NDeepak M <m.deepak@intel.com>
Tested-by: Ramalingam C <ramalingam.c@intel.com> # BXT-T with Tianma panel
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455556437-29267-1-git-send-email-m.deepak@intel.com

The bpp value which is used while calulating the txbyteclkhs values
should be wrt the pixel format value. Currently bpp is coming
from pipe config to calculate txbyteclkhs. Fix it in this patch.

V2: dsi_pixel_format_bpp is used to retrieve the bpp from pixel_format
	[Review: Jani]
Signed-off-by: NDeepak M <m.deepak@intel.com>
Signed-off-by: NYogesh Mohan Marimuthu <yogesh.mohan.marimuthu@intel.com>
Signed-off-by: NRamalingam C <ramalingam.c@intel.com>
Tested-by: Mika Kahola <mika.kahola@intel.com> # BYT
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455203007-10850-1-git-send-email-ramalingam.c@intel.com

The dsi_rr_formula() function has been unused for almost two years,
since

commit 44d4c6ee
Author: Shobhit Kumar <shobhit.kumar@intel.com>
Date:   Tue Dec 10 12:14:56 2013 +0530

    drm/i915: Compute dsi_clk from pixel clock

citing the reason as pixel clock based calculation being recommended in
the MIPI host controller documentation. Remove the dead code, we can
always bring it back if it's needed.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452249940-2605-2-git-send-email-jani.nikula@intel.com

Hide away the platform differences in intel_dsi_get_pckl() within
intel_dsi_pll.c. No functional changes.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452249940-2605-1-git-send-email-jani.nikula@intel.com

The cherryview device shares many characteristics with the valleyview
device.  When support was added to the driver for cherryview, the
corresponding device info structure included .is_valleyview = 1.
This is not correct and leads to some confusion.

This patch changes .is_valleyview to .is_cherryview in the cherryview
device info structure and simplifies the IS_CHERRYVIEW macro.
Then where appropriate, instances of IS_VALLEYVIEW are replaced with
IS_VALLEYVIEW || IS_CHERRYVIEW or equivalent.

v2: Use IS_VALLEYVIEW || IS_CHERRYVIEW instead of defining a new macro.
    Also add followup patches to fix issues discovered during the first
    review. (Ville)
v3: Fix some style issues and one gen check. Remove CRT related changes
    as CRT is not supported on CHV. (Imre, Ville)
v4: Make a few more optimizations. (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NWayne Boyer <wayne.boyer@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449692975-14803-1-git-send-email-wayne.boyer@intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NJani Nikula <jani.nikula@intel.com>

Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

BXT's DSI PLL is different from that of VLV. So this patch
adds a new function to get the current DSI pixel clock based
on the PLL divider ratio and lane count.

This function is required for intel_dsi_get_config() function.

v2: Fixed Jani's review comments.
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: NUma Shankar <uma.shankar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch contains changes to support DSI disble sequence in BXT.
The changes are:
1. BXT specific changes in clear_device_ready function.
2. BXT specific changes in DSI disable and post-disable functions.
3. Add a new function to reset BXT Dphy clock and dividers
   (bxt_dsi_reset_clocks).
4. Moved some part of the vlv clock reset code, in a new function
   (vlv_dsi_reset_clocks) maintaining the exact same sequence.
5. Wrapper function to call corresponding reset clock function.

v2: Fixed Jani's review comments.

v3: Removed the GET_DSI_PORT_CTRL Macro for consistency with earlier
    implementations as per Jani's suggestion.
Signed-off-by: NUma Shankar <uma.shankar@intel.com>
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

BXT DSI clocks are different than previous platforms. So adding a
new function to program following clocks and dividers:
1. Program variable divider to generate input to Tx clock divider
   (Output value must be < 39.5Mhz)
2. Select divide by 2 option to get < 20Mhz for Tx clock
3. Program 8by3 divider to generate Rx clock

v2: Fixed Jani's review comments. Adjusted the Macro definition as
    per convention. Simplified the logic for bit definitions for
    MIPI PORT A and PORT C in same registers.

v3: Refactored the macros for TX, RX Escape and DPHY clocks as per
    Jani's suggestion.

v4: Addressed Jani's review comments.
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: NUma Shankar <uma.shankar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch adds two new functions:
- disable_dsi_pll.
  BXT DSI disable sequence and registers are
  different from previous platforms.
- intel_disable_dsi_pll
  wrapper function to re-use the same code for
  multiple platforms. It checks platform type and
  calls appropriate core pll disable function.

v2: Fixed Jani's review comments.

v3: Rebased on latest drm-nightly branch.
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: NUma Shankar <uma.shankar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch adds new functions for BXT clock and PLL programming.
They are:
1. configure_dsi_pll for BXT.
   This function does the basic math and generates the divider ratio
   based on requested pixclock, and program clock registers.
2. enable_dsi_pll function.
   This function programs the calculated clock values on the PLL.
3. intel_enable_dsi_pll
   Wrapper function to use same code for multiple platforms. It checks the
   platform and calls appropriate core pll enable function.

v2: Fixed Jani's review comments. Macros are adjusted as per convention.

v3: Removed a redundant change wrt code comment.
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: NUma Shankar <uma.shankar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On CHT, changes are required for calculating the correct m,n & p with
minimal error +/- for the required DSI clock, so that the correct
dividor & ctrl values are written in cck regs for DSI. This patch has
been tested on CHT RVP with 1200 x 1920 panel.

v2 by Jani, rebased on earlier refactoring, original at [1].

[1] http://mid.gmane.org/1431368400-1942-5-git-send-email-rodrigo.vivi@intel.comSigned-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For MIPI panels requiring higher DSI clk, values needs to be added
in lfsr_converts table for getting the correct values of pll ctrl
and dividor values which gets programmed in cck regs, otherwise DSI
PLL does not get locked leading to no display on the MIPI panel.
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Nuke three copies of the same switch case.

Hopefully we can switch to a drm generic function later on, but that
will require us to swich to enum mipi_dsi_pixel_format first.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Rename dpio_lock to sb_lock to inform the reader that its primary
purpose is to protect the sideband mailbox rather than some DPIO
state.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently DSI PLL N1 is hardcoded off. Make it possible to use it
later. This should have no functional changes for now.

v2: s/ffz(~(n))/ffs(n) - 1/ (Ville)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Improve readability. No functional changes.

v2: use more rational types (Ville)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

DSI Pll1 is used for enabling DSI on Port C.

v2: Addressed review comments of Jani
    - Used & operator instead of == for intel_dsi->ports
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of pipe configuration reg, cck reg to be used for checking whether
DSI Pll is getting locked or not.

v2: dpio_lock unlocked now in case DSI PLL lock fails
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For Dual link MIPI Panels, dsipll clock for both DSI0 and DSI1 needs to be enabled.

v2: Address review comments by Jani
    - Added wait time for PLL to be locked.

v3: separate patch created for cck read for checking PLL to be locked
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I'm not really that insisting on checkpath compliance, but ragged
function paramter alignment does get me. Please adjust your editor to
just do this for you.

Cc: Shobhit Kumar <shobhit.kumar@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

v2: Updated the error log as suggested by Imre
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Check in vlv_crtc_clock_get if DPLL is enabled before calling dpio read.
It will not be enabled for DSI and avoid dpio read WARN dumps.

Absence of ->get_config was causing other WARN dumps as well. Update
dpll_hw_state as well correctly

v2: Address review comments by Daniel
    - Check if DPLL is enabled rather than checking pipe output type
    - set adjusted_mode->flags to 0 in compute_config rather than using
      pipe_config->quirks
    - Add helper function in intel_dsi_pll.c and use that in intel_dsi.c
    - updated dpll_hw_state correctly
    - Updated commit message and title

v3: Address review comments by Imre
    - Proper masking of P1, M1 fields while computing divisors
    - assert in case of bpp mismatch
    - guard for divide by 0 while computing pclk
    - Use ARRAY_SIZE instead of direct calculation
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Basically check for both +ive and -ive deviation from target clock and
pick the one with minimal error. If we get a direct match, break from
loop to acheive some optimization.

v2: Use signed variable for target and calculated dsi clock values
Signed-off-by: NVijayakumar Balakrishnan <vijayakumar.balakrishnan@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pixel clock based calculation is recommended in the MIPI host controller
documentation

v2: Based on review comments from Jani and Ville
    - Use dsi_clk in KHz rather than converting in Hz and back to MHz
    - RR formula is retained though not used but return dsi_clk in KHz now
    - Moved the m-n-p changes into a separate patch
    - Removed the parameter check for intel_dsi->dsi_clock_freq. This will be
      bought back in if needed when appropriate panel drivers are done

v3: Removed the unused mnp calculation from static table
Signed-off-by: NVijayakumar Balakrishnan <vijayakumar.balakrishnan@intel.com>
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>