Subject: [PATCH v4 1/2] ARM: socfpga: support suspend to ram

From: [email-masked] (Dinh Nguyen)
Date: Tue, 26 May 2015 08:48:57 -0500

Hi Alan,

On 5/22/15 1:02 PM, Alan Tull wrote:
> Add code that requests that the sdr controller go into
> self-refresh mode.  This code is run from ocram.
> 
> This patch assumes that u-boot has already configured sdr:
>   sdr.ctrlcfg.lowpwreq.selfrfshmask = 3
>   sdr.ctrlcfg.lowpwrtiming.clkdisablecycles = 8
>   sdr.ctrlcfg.dramtiming4.selfrfshexit = 512
> 
> Suspend-to-RAM and EDAC support are mutually exclusive on SOCFPGA
> platforms.  CONFIG_SOCFPGA_SUSPEND enables suspend-to-RAM and
> prevents selecting CONFIG_EDAC_ALTERA_MC.
> 
> How to suspend to ram:
>  $ echo enabled > \
> /sys/devices/soc/ffc02000.serial0/tty/ttyS0/power/wakeup
> 
>  $ echo -n mem > /sys/power/state
> 
> Signed-off-by: Alan Tull <[email-masked]>
> Cc: Pavel Machek <[email-masked]>
> Cc: Arnd Bergmann <[email-masked]>
> Cc: Dinh Nguyen <[email-masked]>
> Cc: Steffen Trumtrar <[email-masked]>
> ---
> v2: use Generic on-chip SRAM driver to allocate ocram
>     rm fncpy_align since generic allocator handles alignment
>     check __arm_ioremap_exec return code
>     check for NULL pointers
>     add a comment regarding sdram controller configuration
> v3: fix renamed #define
>     propagate socfpga_setup_ocram_self_refresh error code
> v4: Kconfig: don't need to select GENERIC_ALLOCATER
>     add CONFIG_SOCFPGA_SUSPEND
>     make s2r and EDAC support mutually exclusive
>     socfpga.c: add sdr_ctl_base_addr
>     return error if ocram not available in device tree
>     update copyright years
> ---

<snip>

> +
> +static int socfpga_pm_suspend(unsigned long arg)
> +{
> +	u32 ret;
> +
> +	if (!sdr_ctl_base_addr || !socfpga_scu_base_addr)
> +		return -EFAULT;
> +
> +	ret = socfpga_sdram_self_refresh_in_ocram(
> +		(u32)sdr_ctl_base_addr, (u32)socfpga_scu_base_addr);
> +

I had a patch that removed socfpga_scu_base_addr from being a global and
just a local variable in:

f6e14376fb20 ARM: socfpga: use of_iomap to map the SCU

This patch will be in v4.2 and is currently in arm-soc/next or
at my fork: kernel/git/dinguyen/linux.git socfpga_for_next_arria10

So you will either need to make socfpga_scu_base_addr global again, or
you can use the asm instruction to get the SCU base addr.

Sorry about that..

Dinh