[PATCH v18 01/11] ARM: qcom: Add Subsystem Power Manager (SPM) driver
galak at codeaurora.org
Fri Mar 27 09:22:30 PDT 2015
On Mar 25, 2015, at 3:25 PM, Lina Iyer <lina.iyer at linaro.org> wrote:
> SPM is a hardware block that controls the peripheral logic surrounding
> the application cores (cpu/l$). When the core executes WFI instruction,
> the SPM takes over the putting the core in low power state as
> configured. The wake up for the SPM is an interrupt at the GIC, which
> then completes the rest of low power mode sequence and brings the core
> out of low power mode.
> The SPM has a set of control registers that configure the SPMs
> individually based on the type of the core and the runtime conditions.
> SPM is a finite state machine block to which a sequence is provided and
> it interprets the bytes and executes them in sequence. Each low power
> mode that the core can enter into is provided to the SPM as a sequence.
> Configure the SPM to set the core (cpu or L2) into its low power mode,
> the index of the first command in the sequence is set in the SPM_CTL
> register. When the core executes ARM wfi instruction, it triggers the
> SPM state machine to start executing from that index. The SPM state
> machine waits until the interrupt occurs and starts executing the rest
> of the sequence until it hits the end of the sequence. The end of the
> sequence jumps the core out of its low power mode.
> Add support for an idle driver to set up the SPM to place the core in
> Standby or Standalone power collapse mode when the core is idle.
> Based on work by: Mahesh Sivasubramanian <msivasub at codeaurora.org>,
> Ai Li <ali at codeaurora.org>, Praveen Chidambaram <pchidamb at codeaurora.org>
> Original tree available at -
> Cc: Stephen Boyd <sboyd at codeaurora.org>
> Cc: Arnd Bergmann <arnd at arndb.de>
> Cc: Kevin Hilman <khilman at linaro.org>
> Cc: Daniel Lezcano <daniel.lezcano at linaro.org>
> Signed-off-by: Lina Iyer <lina.iyer at linaro.org>
> drivers/soc/qcom/Kconfig | 7 +
> drivers/soc/qcom/Makefile | 1 +
> drivers/soc/qcom/spm.c | 385 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 393 insertions(+)
> create mode 100644 drivers/soc/qcom/spm.c
Acked-by: Kumar Gala <galak at codeaurora.org>
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
More information about the linux-arm-kernel