The bspec lays out legal cdclk frequencies, PLL ratios, and CD2X
dividers in an easy-to-read table for most recent platforms. We've been
translating the data from that table into platform-specific code logic,
but it's easy to overlook an area we need to update when adding new
cdclk values or enabling new platforms. Let's just add a form of the
bspec table to the code and then adjust our functions to pull what they
need directly out of the table.
v2: Fix comparison when finding best cdclk.
v3: Another logic fix for calc_cdclk.
v4:
- Use named initializers for cdclk tables. (Ville)
- Include refclk as a field in the table instead of adding all three
ratios for each entry. (Ville)
- Terminate tables with an empty entry to avoid needing to store the
table size. (Ville)
- Don't try so hard to return reasonable values from our lookup
functions if we get impossible inputs; just WARN and return 0.
(Ville)
- Keep a bxt_ prefix on the lookup functions since they're still only
used on bxt+ for now. We can rename them later if we extend this
table-based approach back to older platforms. (Ville)
v5:
- Fix cnl table's ratios for 24mhz refclk. (Ville)
- Don't miss the named initializers on the cnl table. (Ville)
- Represent refclk in table as u16 rather than u32. (Ville)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190910161506.7158-1-matthew.d.roper@intel.com
Aside from a few minor register changes and some different clock values,
cdclk design hasn't changed much since gen9lp. Let's consolidate the
handlers for bxt, cnl, and icl to keep the codeflow consistent.
Also, while we're at it, s/bxt_de_pll_update/bxt_de_pll_readout/ since
"update" makes me think we should be writing to hardware rather than
reading from it.
v2:
- Fix icl_calc_voltage_level() limits. (Ville)
- Use CNL_CDCLK_PLL_RATIO_MASK rather than BXT_DE_PLL_RATIO_MASK on
gen10+ to avoid confusion. (Ville)
v3:
- Also fix ehl_calc_voltage_level() limits. (Ville)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190910160520.6587-1-matthew.d.roper@intel.com
The bspec has just recently been updated with new cdclk values that
require the use of a /2 CD2X divider rather than a /1 divider. Once we
add the divider selection logic to ICL+ cdclk programming, we have
pretty much the same logic we were already using on CNL, so it's simpler
to drop icl_set_cdclk() completely and reuse cnl_set_cdclk() on gen11+
platforms as well.
v2:
- Using ICL_CDCLK_CD2X_PIPE_NONE + BXT_CDCLK_CD2X_PIPE(pipe) for TGL is
correct, but looks really confusing. Add some TGL_ macros that alias
these to avoid confusion. (Ville)
- Use DIV_ROUND_CLOSEST rather than / when applying the divider. (Ville)
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190830004828.19359-1-matthew.d.roper@intel.com
On VLV/CHV there is some kind of linkage between the cdclk frequency
and the DP link frequency. The spec says:
"For DP audio configuration, cdclk frequency shall be set to
meet the following requirements:
DP Link Frequency(MHz) | Cdclk frequency(MHz)
270 | 320 or higher
162 | 200 or higher"
I suspect that would more accurately be expressed as
"cdclk >= DP link clock", and in any case we can express it like
that in the code because of the limited set of cdclk (200, 266,
320, 400 MHz) and link frequencies (162 and 270 MHz) we support.
Without this we can end up in a situation where the cdclk
is too low and enabling DP audio will kill the pipe. Happens
eg. with 2560x1440 modes where the 266MHz cdclk is sufficient
to pump the pixels (241.5 MHz dotclock) but is too low for
the DP audio due to the link frequency being 270 MHz.
v2: Spell out the cdclk and link frequencies we actually support
Cc: stable@vger.kernel.org
Tested-by: Stefan Gottwald <gottwald@igel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111149
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190717114536.22937-1-ville.syrjala@linux.intel.com
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
