Since commit 9e8147bb5e
"ARM: imx6q: move low-power code out of clock driver"
the kernel fails to boot on i.MX6Q/D if preemption is
enabled (CONFIG_PREEMPT=y). The kernel just hangs
before the console comes up.
The above commit moved the initalization of the low-power
mode setting (enabling clocked WAIT states), which was
introduced in commit 83ae20981a
"ARM: imx: correct low-power mode setting", from
imx6q_clks_init to imx6q_pm_init. Now it is called
much later, after all cores are enabled.
This patch moves the low-power mode initialization back
to imx6q_clks_init again (and to imx6sl_clks_init).
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Improve the comment of SW workaround for CCM lpm issue using
hardware errata description to avoid confusion.
ERR007265: CCM: When improper low-power sequence is used, the SoC
enters low power mode before the ARM core executes WFI.
Software workaround:
1) Software should trigger IRQ #32 (IOMUX) to be always pending
by setting IOMUX_GPR1_GINT.
2) Software should then unmask IRQ #32 in GPC before setting CCM
Low-Power mode.
3) Software should mask IRQ #32 right after CCM Low-Power mode is
set (set bits 0-1 of CCM_CLPCR).
Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
The imx6sl low power mode implementation inherits imx6q/dl one,
and pm-imx6q.c can just work for imx6sl with some minor updates.
Let's enable imx6sl suspend support by reusing pm-imx6q.c and use
cpu_is_imxXX() to handle the those minor differences between imx6sl
and imx6q/dl.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
There is a defect in imx6 LPM design. When SW tries to enter low power
mode with following sequence, the chip will enter low power mode before
A9 CPU execute WFI instruction:
1. Set CCM_CLPCR[1:0] to 2'b00;
2. ARM CPU enters WFI;
3. ARM CPU wakeup from an interrupt event, which is masked by GPC or not
visible to GPC, such as interrupt from local timer;
4. Set CCM_CLPCR[1:0] to 2'b01 or 2'b10;
5. ARM CPU execute WFI.
Before the last step, the chip will enter WAIT mode if CCM_CLPCR[1:0] is
set to 2'b01, or enter STOP mode if CCM_CLPCR[1:0] is set to 2'b10.
The patch implements a recommended workaround for this issue.
1. SW triggers irq #32(IOMUX) to be always pending manually by setting
IOMUX_GPR1_GINT bit;
2. SW should then unmask it in GPC before setting CCM LPM;
3. SW should mask it right after CCM LPM is set (bit0-1 of CCM_CLPCR).
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
The WB and RBC configuration calls are currently made from
imx6q_set_lpm() for WAIT_CLOCKED and WAIT_UNCLOCKED mode with a simple
state tracking. This becomes unnecessary since we can make the calls
from imx6q_pm_enter() directly now for suspend.
More importantly, the current call of imx6q_enable_wb() from
imx6q_set_lpm() is buggy. The CLPCR register bits configured by
imx6q_enable_wb() will get lost, because imx6q_set_lpm() caches the same
register and write it back at the end of the function. That's why the
imx6dl suspend/resume does not work currently - the wakeup from suspend
triggers a reset on imx6dl.
Moves the WB and RBC calls into imx6q_pm_enter() to save the state
tracking and fixes above bug, so that suspend/resume can start working
on imx6dl.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
The LPM (Low Power Mode) code that currently sits in imx6q clock driver
will be reused by imx6sl. Let's move it into pm-imx6q.c, so that we
can keep clock driver SoC specific and reuse pm-imx6q.c on imx6sl.
In order to avoid adding another ioremap for CCM block,
imx6q_pm_set_ccm_base() is created to let clock driver set up ccm_base
for pm code.
During the move, the unused CCGR macros get removed.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Anatop module have sereval configurations for user
to reduce the power consumption in suspend, provide
suspend/resume interface for further use and enable
fet_odrive to reduce CORE LDO leakage during suspend.
As we have a common anatop file, remove all the operations
of anatop module in other files, use anatop interfaces to
do that.
Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Building the kernel with allyesconfig fails because the i.mx early
resume code located in the .data section is unable to fixup the bl
relocation as the branch target gets too far away.
The idea of having code in the .data section allows for easy access to
nearby data using relative addressing while the MMU is off. However it
is probably best to move the code back to the .text section where it
belongs and fixup the data access instead. This solves the bl reloc
issue (at least until this becomes a general problem) and simplifies
the code as well.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
The hardware reset value of bit CCM_CLPCR_LPM enables WAIT mode
(WAIT_UNCLOCKED) by default. However this is undesirable because
WAIT mode should only be enabled when there is a driver managing
ARM clock gating. Correct the initial power mode to WAIT_CLOCKED
(disable WAIT mode). While at it, the power mode after resuming
is also set back to WAIT_CLOCKED from STOP_POWER_OFF.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
It moves a bunch of header files included in hardware.h and itself
from mach-imx/include/mach to mach-imx, and updates users to include
hardware.h rather than mach/hardware.h. The files in mach-imx/devices
will need to include "../hardware.h".
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Rename mach-imx/include/mach/common.h to mach-imx/common.h and update
all users to include common.h rather than mach/common.h.
It also removes an unneeded inclusion to common.h in
mach-imx/devices/devices.c.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Original patch from Lothar Waßmann, this patch fixes a building error
when CONFIG_CACHE_L2X0 is not defined.
Cc: Lothar Waßmann <lw@karo-electronics.de>
Signed-off-by: Eric Miao <eric.miao@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Philipp Zabel
Anson Huang
Shawn Guo
Nicolas Pitre
Eric Miao