| author | Menon, Nishanth <nm@ti.com> | |
| Mon, 5 Jan 2015 19:16:40 +0000 (19:16 +0000) | ||
| committer | Dave Gerlach <d-gerlach@ti.com> | |
| Tue, 6 Jan 2015 19:29:36 +0000 (13:29 -0600) | ||
| commit | c0c86cccd1e1c72c855ffff4a8411b8fc29b6544 | |
| tree | 9d5dd51834734890cfa52579d9c9517a6c0e69c4 | tree | snapshot (tar.xz tar.gz zip) |
| parent | ee998a6ea82822938898aca192b3ba2332cf779d | commit | diff |
PM / Voltagedomain: OMAP: Add support for absolute max voltage for a domain
We need to mark the voltage domain absolute maximum rating. This allows
us to setup voltage for a domain from min to max absolute rating.
Unfortunately, it is not possible to solely depend on maximum OPP
allowed for a domain due to the following:
in the case of a ganged voltage rail, where SMPS_x is shared between
VDD_A and VDD_B, setting voltage_tol for VDD_A can prevent VDD_B from
achieving voltage required for the domain. example:
vdd_A requires voltage Z, vdd_B requires voltage Y,
setting Z-tol to Z + tol will not work when Y is > or < the range.
instead, we look for absolute max for the voltage domains A and B.
setting Z-tol to MAX_A and Y-tol to MAX_B allows voltage ranges which
fall in the intermediate ranges and work for both VDD_A and VDD_B even
if it may be suboptimal for one of them.
If the max range is not provided the mandatory tolerance is used.
Reported-by: Ravikumar Kattekola <rk@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
We need to mark the voltage domain absolute maximum rating. This allows
us to setup voltage for a domain from min to max absolute rating.
Unfortunately, it is not possible to solely depend on maximum OPP
allowed for a domain due to the following:
in the case of a ganged voltage rail, where SMPS_x is shared between
VDD_A and VDD_B, setting voltage_tol for VDD_A can prevent VDD_B from
achieving voltage required for the domain. example:
vdd_A requires voltage Z, vdd_B requires voltage Y,
setting Z-tol to Z + tol will not work when Y is > or < the range.
instead, we look for absolute max for the voltage domains A and B.
setting Z-tol to MAX_A and Y-tol to MAX_B allows voltage ranges which
fall in the intermediate ranges and work for both VDD_A and VDD_B even
if it may be suboptimal for one of them.
If the max range is not provided the mandatory tolerance is used.
Reported-by: Ravikumar Kattekola <rk@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
| Documentation/devicetree/bindings/power/voltdm/voltdm_omap.txt | diff | blob | history | |
| drivers/power/voltdm/voltdm_omap.c | diff | blob | history |