06 Jul, 2016

2 commits


03 May, 2016

3 commits

  • - Typo in comments fixed
    - Unnecessary return statement removed

    Signed-off-by: MyungJoo Ham

    MyungJoo Ham
     
  • This patch adds the support of bus frequency feature for sub-blocks which share
    the one power line. If each bus depends on the power line, each bus is not able
    to change the voltage by oneself. To optimize the power-consumption on runtime,
    some buses using the same power line should change the source clock and
    regulator at the same time. So, this patch uses the passive governor to support
    the bus frequency for all buses which sharing the one power line.

    For example,

    Exynos3250 include the two power line for AXI buses as following:
    : VDD_MIF : MIF (Memory Interface) provide the DMC (Dynamic Memory Controller)
    with the power (regulator).
    : VDD_INT : INT (Internal) provide the various sub-blocks with the power
    (regulator).

    Each bus is included in as follwoing block. In the case of VDD_MIF, only DMC bus
    use the power line. So, there is no any depencency between buese. But, in the
    case of VDD_INT, various buses share the one power line of VDD_INT. We need to
    make the depenency between buses. When using passive governor, there is no
    problem to support the bus frequency as DVFS for all buses. One bus should be
    operated as the parent bus device which gathering the current load of INT block
    and then decides the new frequency with some governors except of passive
    governor. After deciding the new frequency by the parent bus device, the rest
    bus devices will change the each source clock according to new frequency of the
    parent bus device.

    - MIF (Memory Interface) block
    : VDD_MIF |--- DMC

    - INT (Internal) block
    : VDD_INT |--- LEFTBUS (parent)
    |--- PERIL
    |--- MFC
    |--- G3D
    |--- RIGHTBUS
    |--- FSYS
    |--- LCD0
    |--- PERIR
    |--- ISP
    |--- CAM

    Signed-off-by: Chanwoo Choi
    [tjakobi: Reported debugfs error during booting and cw00.choi fix it.]
    Reported-by: Tobias Jakobi
    Signed-off-by: MyungJoo Ham
    Acked-by: Krzysztof Kozlowski

    Chanwoo Choi
     
  • This patch adds the generic exynos bus frequency driver for AMBA AXI bus
    of sub-blocks in exynos SoC with DEVFREQ framework. The Samsung Exynos SoC
    have the common architecture for bus between DRAM and sub-blocks in SoC.
    This driver can support the generic bus frequency driver for Exynos SoCs.

    In devicetree, Each bus block has a bus clock, regulator, operation-point
    and devfreq-event devices which measure the utilization of each bus block.

    Signed-off-by: Chanwoo Choi
    [m.reichl and linux.amoon: Tested it on exynos4412-odroidu3 board]
    Tested-by: Markus Reichl
    Tested-by: Anand Moon
    Signed-off-by: MyungJoo Ham
    Acked-by: Krzysztof Kozlowski

    Chanwoo Choi