Hi Rafael,
On Sun, Jun 12, 2011 at 5:40 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> From: Rafael J. Wysocki <rjw@xxxxxxx>
>
> Use the generic power domains support introduced by the previous
> patch to implement support for power domains on SH7372.
>
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> ---
Thanks for your work on this. I just tried this on my Mackerel board,
but I can't seem to get the pd_power_up() and pd_power_down()
callbacks to be executed. It is probably a misconfiguration from my
side.
Here's some feedback on the sh7372-specific code:
> --- linux-2.6.orig/arch/arm/mach-shmobile/Kconfig
> +++ linux-2.6/arch/arm/mach-shmobile/Kconfig
> @@ -19,6 +19,7 @@ config ARCH_SH7372
> select CPU_V7
> select SH_CLK_CPG
> select ARCH_WANT_OPTIONAL_GPIOLIB
> + select PM_GENERIC_DOMAINS
We want to support a single ARM binary for multiple boards, so this
should be enabled for all SoCs in mach-shmobile as a whole.
> --- linux-2.6.orig/arch/arm/mach-shmobile/pm-sh7372.c
> +++ linux-2.6/arch/arm/mach-shmobile/pm-sh7372.c
> @@ -15,16 +15,97 @@
> #include <linux/list.h>
> #include <linux/err.h>
> #include <linux/slab.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/platform_device.h>
> #include <asm/system.h>
> #include <asm/io.h>
> #include <asm/tlbflush.h>
> #include <mach/common.h>
> +#include <mach/sh7372.h>
>
> #define SMFRAM 0xe6a70000
> #define SYSTBCR 0xe6150024
> #define SBAR 0xe6180020
> #define APARMBAREA 0xe6f10020
>
> +#define SPDCR 0xe6180008
> +#define SWUCR 0xe6180014
> +#define PSTR 0xe6180080
> +
> +struct sh7372_domain_data {
> + unsigned int bit_shift;
> +};
Is it possible to make struct sh7372_domain_data include struct
generic_pm_domain? I suspect so since these two data types seem to be
linked together. I guess container_of() can be used for conversion
between the types?
> +
> +static int pd_power_down(struct dev_pm_domain *domain)
> +{
> + struct sh7372_domain_data *dd = domain->platform_data;
> + unsigned int mask = 1 << dd->bit_shift;
> +
> + if (__raw_readl(PSTR) & mask) {
> + __raw_writel(mask, SPDCR);
> +
> + while (__raw_readl(SPDCR) & mask) {}
This probably wants a cpu_relax() in the polling loop. I realize that
my prototype hack lacked that...
> + pr_debug("sh7372 power domain down 0x%08x -> PSTR = 0x%08x\n",
> + mask, __raw_readl(PSTR));
> + }
> +
> + return 0;
> +}
> +
> +static int pd_power_up(struct dev_pm_domain *domain)
> +{
> + struct sh7372_domain_data *dd = domain->platform_data;
> + unsigned int mask = 1 << dd->bit_shift;
> +
> + if (!(__raw_readl(PSTR) & mask)) {
> + __raw_writel(mask, SWUCR);
> +
> + while (__raw_readl(SWUCR) & mask) {}
Same cpu_relax() here.
> +static int __init sh7372_power_domains_init(void)
> +{
> + sh7372_init_domain(&sh7372_a4lc_domain, &sh7372_a4lc_domain_data);
> + return 0;
> +}
> +core_initcall(sh7372_power_domains_init);
This initcall is going to be executed regardless which SoC we're
running on. We only want it called for sh7372 though.
If you look at other SoC-specific code then you will notice that
initcalls are only used for functions in mach-shmobile/ that are
common for all SoCs implemented under mach-shmobile.
You most likely want to initialize from sh7372_pm_init(), but for that
to work you probably have to reorder your code inside mackerel_init().
Thanks,
/ magnus
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