[RFC PATCH 0/2] Add Mediatek MMDVFS driver

Anthony Huang
2019-10-22T03:54:58Z

This RFC patch adds the Mediatek MMDVFS(Multimedia Dynamic Voltage and
Frequency Scaling) driver. The multimedia HWs, such as display, camera,
share the same power supplier, and on some platforms, they share the
same clock MUX. If each HW needs different clock frequency at the same
time, the clock MUX must be set to the clock source which can meet the
highest required clock frequency.

Following implementation is used to achieve the goal. There are OPP tables
for all the clock MUXs for MM HWs defined in DTS, ant these OPP tables have
the same number of levels. The MMDVFS registers the regulator callback and
the MM HWs can get available clock frequencies from OPP tables and set
corresponding voltage by regulor API. The MMDVFS's callback will be
triggered if the voltage is changed and this voltage represents the highest
required OPP level. The MMDVFS has a mapping table: which clock source
should be set to each clock MUX for every OPP level. So all the clock MUXs
will be set to the clock sources according to the current OPP level in the
MMDVFS's regulator callback.

Anthony Huang (2):
dt-bindings: soc: mediatek: Add document for mmdvfs driver
soc: mediatek: Add mtk-mmdvfs driver

.../devicetree/bindings/soc/mediatek/mmdvfs.txt | 149 ++++++++++
drivers/soc/mediatek/Kconfig | 9 +
drivers/soc/mediatek/Makefile | 1 +
drivers/soc/mediatek/mtk-mmdvfs.c | 313 ++++++++++++++++++++
4 files changed, 472 insertions(+)
create mode 100644 Documentation/devicetree/bindings/soc/mediatek/mmdvfs.txt
create mode 100644 drivers/soc/mediatek/mtk-mmdvfs.c