[PATCH] ARM: shmobile: r8a7740: Add Suspend-To-RAM modes and CPUIdle

Bastian Hecht hechtb at gmail.com
Thu Apr 11 03:07:10 EDT 2013


Hello Daniel,

thanks for the consolidation efforts.

2013/4/11 Daniel Lezcano <daniel.lezcano at linaro.org>:
> On 04/10/2013 05:51 PM, Bastian Hecht wrote:
>> We add 2 sleep modes and register a CPUIdle driver that uses them.
>>
>> - A3SM PLL0 on/off:     Power domain A3SM that contains the ARM core
>>                         and the 2nd level cache with either PLL0 on
>>                       or off
>>
>> As the suspend to memory mechanism we use A3SM PLL off.
>>
>> The setup of the SYSC regarding the external IRQs is taken from
>> pm-sh7372.c from Magnus Damm.
>>
>> Signed-off-by: Bastian Hecht <hechtb+renesas at gmail.com>
>> ---
>> Ok I need to add some remarks here:
>>
>> First this patch relies on a fix I've sent out today:
>> "ARM: hw_breakpoint: Do not use __cpuinitdata for dbg_cpu_pm_nb"
>> Without it we can't use suspend at all without a kernel panic.
>>
>> Next you can test this in two ways:
>> Either add IRQF_NO_SUSPEND to the touchscreen driver st1232 at IRQ registration
>> (hack) or extend the irqpin driver to support wakeup devices properly, meaning
>> adding suspend and resume callbacks that handle it (proper way). Or you can add
>> no_console_suspend to the boot options in r8a7740-armadillo800eva.dts. This way
>> you can use the serial console as wakeup device.
>>
>>
>>  arch/arm/mach-shmobile/Makefile               |    2 +-
>>  arch/arm/mach-shmobile/include/mach/r8a7740.h |    2 +
>>  arch/arm/mach-shmobile/pm-r8a7740.c           |  220 ++++++++++++++++++++++++-
>>  arch/arm/mach-shmobile/sleep-r8a7740.S        |   68 ++++++++
>>  4 files changed, 289 insertions(+), 3 deletions(-)
>>  create mode 100644 arch/arm/mach-shmobile/sleep-r8a7740.S
>>
>> diff --git a/arch/arm/mach-shmobile/Makefile b/arch/arm/mach-shmobile/Makefile
>> index 068f1da..0568894 100644
>> --- a/arch/arm/mach-shmobile/Makefile
>> +++ b/arch/arm/mach-shmobile/Makefile
>> @@ -30,7 +30,7 @@ obj-$(CONFIG_SUSPEND)               += suspend.o
>>  obj-$(CONFIG_CPU_IDLE)               += cpuidle.o
>>  obj-$(CONFIG_ARCH_SHMOBILE)  += pm-rmobile.o
>>  obj-$(CONFIG_ARCH_SH7372)    += pm-sh7372.o sleep-sh7372.o
>> -obj-$(CONFIG_ARCH_R8A7740)   += pm-r8a7740.o
>> +obj-$(CONFIG_ARCH_R8A7740)   += pm-r8a7740.o sleep-r8a7740.o
>>  obj-$(CONFIG_ARCH_R8A7779)   += pm-r8a7779.o
>>  obj-$(CONFIG_ARCH_SH73A0)    += pm-sh73a0.o
>>
>> diff --git a/arch/arm/mach-shmobile/include/mach/r8a7740.h b/arch/arm/mach-shmobile/include/mach/r8a7740.h
>> index abdc4d4..ba4707b 100644
>> --- a/arch/arm/mach-shmobile/include/mach/r8a7740.h
>> +++ b/arch/arm/mach-shmobile/include/mach/r8a7740.h
>> @@ -540,6 +540,8 @@ extern void r8a7740_add_standard_devices(void);
>>  extern void r8a7740_clock_init(u8 md_ck);
>>  extern void r8a7740_pinmux_init(void);
>>  extern void r8a7740_pm_init(void);
>> +extern void r8a7740_resume(void);
>> +extern void r8a7740_shutdown(void);
>>
>>  #ifdef CONFIG_PM
>>  extern void __init r8a7740_init_pm_domains(void);
>> diff --git a/arch/arm/mach-shmobile/pm-r8a7740.c b/arch/arm/mach-shmobile/pm-r8a7740.c
>> index 40b87aa..d4613f0 100644
>> --- a/arch/arm/mach-shmobile/pm-r8a7740.c
>> +++ b/arch/arm/mach-shmobile/pm-r8a7740.c
>> @@ -8,10 +8,54 @@
>>   * License.  See the file "COPYING" in the main directory of this archive
>>   * for more details.
>>   */
>> +#include <linux/bitrev.h>
>>  #include <linux/console.h>
>> +#include <linux/cpuidle.h>
>> +#include <linux/module.h>
>>  #include <linux/suspend.h>
>> +#include <linux/io.h>
>> +#include <asm/suspend.h>
>> +#include <asm/cacheflush.h>
>> +#include <asm/cpuidle.h>
>> +#include <asm/hardware/cache-l2x0.h>
>>  #include <mach/pm-rmobile.h>
>>  #include <mach/common.h>
>> +#include <mach/r8a7740.h>
>> +
>> +/* CPGA */
>> +#define PLLC01STPCR  IOMEM(0xe61500c8)
>> +#define SYSTBCR              IOMEM(0xe6150024)
>> +
>> +/* SYSC */
>> +#define STBCHR               IOMEM(0xe6180000)
>> +#define STBCHRB              IOMEM(0xe6180040)
>> +#define SPDCR                IOMEM(0xe6180008)
>> +#define SBAR         IOMEM(0xe6180020)
>> +#define SRSTFR               IOMEM(0xe61800B4)
>> +#define WUPSMSK              IOMEM(0xe618002c)
>> +#define WUPSMSK2     IOMEM(0xe6180048)
>> +#define WUPSFAC              IOMEM(0xe6180098)
>> +#define IRQCR                IOMEM(0xe618022c)
>> +#define IRQCR2               IOMEM(0xe6180238)
>> +#define IRQCR3               IOMEM(0xe6180244)
>> +#define IRQCR4               IOMEM(0xe6180248)
>> +
>> +/* SRSTFR flags */
>> +#define RAMST                (1 << 19)
>> +#define RCLNKA               (1 << 7)
>> +#define RCPRES               (1 << 5)
>> +#define RCWD1                (1 << 4)
>> +#define RPF          (1 << 0)
>> +
>> +/* INTC */
>> +#define ICR1A                IOMEM(0xe6900000)
>> +#define ICR2A                IOMEM(0xe6900004)
>> +#define ICR3A                IOMEM(0xe6900008)
>> +#define ICR4A                IOMEM(0xe690000c)
>> +#define INTMSK00A    IOMEM(0xe6900040)
>> +#define INTMSK10A    IOMEM(0xe6900044)
>> +#define INTMSK20A    IOMEM(0xe6900048)
>> +#define INTMSK30A    IOMEM(0xe690004c)
>>
>>  #ifdef CONFIG_PM
>>  static int r8a7740_pd_a4s_suspend(void)
>> @@ -58,12 +102,183 @@ void __init r8a7740_init_pm_domains(void)
>>       rmobile_init_domains(r8a7740_pm_domains, ARRAY_SIZE(r8a7740_pm_domains));
>>       pm_genpd_add_subdomain_names("A4S", "A3SP");
>>  }
>> -
>>  #endif /* CONFIG_PM */
>>
>> +#if defined(CONFIG_SUSPEND) || defined(CONFIG_CPU_IDLE)
>> +static void r8a7740_set_reset_vector(unsigned long address)
>> +{
>> +     __raw_writel(address, SBAR);
>> +}
>> +
>> +static void r8a7740_icr_to_irqcr(unsigned long icr, u16 *irqcr1p, u16 *irqcr2p)
>> +{
>> +     u16 tmp, irqcr1, irqcr2;
>> +     int k;
>> +
>> +     irqcr1 = 0;
>> +     irqcr2 = 0;
>> +
>> +     /* convert INTCA ICR register layout to SYSC IRQCR+IRQCR2 */
>> +     for (k = 0; k <= 7; k++) {
>> +             tmp = (icr >> ((7 - k) * 4)) & 0xf;
>> +             irqcr1 |= (tmp & 0x03) << (k * 2);
>> +             irqcr2 |= (tmp >> 2) << (k * 2);
>> +     }
>> +
>> +     *irqcr1p = irqcr1;
>> +     *irqcr2p = irqcr2;
>> +}
>> +
>> +static void r8a7740_setup_sysc(unsigned long msk, unsigned long msk2)
>> +{
>> +     u16 irqcrx_low, irqcrx_high, irqcry_low, irqcry_high;
>> +     unsigned long tmp;
>> +
>> +     /* read IRQ0A -> IRQ15A mask */
>> +     tmp = bitrev8(__raw_readb(INTMSK00A));
>> +     tmp |= bitrev8(__raw_readb(INTMSK10A)) << 8;
>> +
>> +     /* setup WUPSMSK from clocks and external IRQ mask */
>> +     msk = (~msk & 0xc030000f) | (tmp << 4);
>> +     __raw_writel(msk, WUPSMSK);
>> +
>> +     /* propage level/edge trigger for external IRQ 0->15 */
>> +     r8a7740_icr_to_irqcr(__raw_readl(ICR1A), &irqcrx_low, &irqcry_low);
>> +     r8a7740_icr_to_irqcr(__raw_readl(ICR2A), &irqcrx_high, &irqcry_high);
>> +     __raw_writel((irqcrx_high << 16) | irqcrx_low, IRQCR);
>> +     __raw_writel((irqcry_high << 16) | irqcry_low, IRQCR2);
>> +
>> +     /* read IRQ16A -> IRQ31A mask */
>> +     tmp = bitrev8(__raw_readb(INTMSK20A));
>> +     tmp |= bitrev8(__raw_readb(INTMSK30A)) << 8;
>> +
>> +     /* setup WUPSMSK2 from clocks and external IRQ mask */
>> +     msk2 = (~msk2 & 0x00030000) | tmp;
>> +     __raw_writel(msk2, WUPSMSK2);
>> +
>> +     /* propage level/edge trigger for external IRQ 16->31 */
>> +     r8a7740_icr_to_irqcr(__raw_readl(ICR3A), &irqcrx_low, &irqcry_low);
>> +     r8a7740_icr_to_irqcr(__raw_readl(ICR4A), &irqcrx_high, &irqcry_high);
>> +     __raw_writel((irqcrx_high << 16) | irqcrx_low, IRQCR3);
>> +     __raw_writel((irqcry_high << 16) | irqcry_low, IRQCR4);
>> +}
>> +
>> +static void r8a7740_prepare_wakeup(void)
>> +{
>> +     /* clear all flags that lead to a cold boot */
>> +     __raw_writel(~(RAMST | RCLNKA | RCPRES | RCWD1 | RPF), SRSTFR);
>> +     /* indicate warm boot */
>> +     __raw_writel(0x80000000, STBCHRB);
>> +     /* clear other flags checked by internal ROM boot loader */
>> +     __raw_writel(0x00000000, STBCHR);
>> +}
>> +
>> +static int r8a7740_do_suspend(unsigned long unused)
>> +{
>> +     /*
>> +      * cpu_suspend() guarantees that all data made it to the L2.
>> +      * Flush it out now and disable the cache controller.
>> +      */
>> +     outer_flush_all();
>> +     outer_disable();
>> +
>> +     r8a7740_shutdown();
>> +
>> +     /* in case WFI fails to enter the low power state, restore things */
>> +     outer_resume();
>> +
>> +     return 0;
>> +}
>> +
>> +static void r8a7740_enter_a3sm_common(int pllc0_on)
>> +{
>> +     u32 reg32;
>> +
>> +     if (pllc0_on)
>> +             __raw_writel(0, PLLC01STPCR);
>> +     else
>> +             __raw_writel(1 << 28, PLLC01STPCR);
>> +
>> +     r8a7740_set_reset_vector(__pa(r8a7740_resume));
>> +     r8a7740_prepare_wakeup();
>> +     r8a7740_setup_sysc(1 << 0, 0);
>> +
>> +     /* Activate delayed shutdown of A3SM */
>> +     reg32 = __raw_readl(SPDCR);
>> +     reg32 |= (1 << 31) | (1 << 12);
>> +     __raw_writel(reg32, SPDCR);
>> +
>> +     /* We activate CPU Core Standby as well here */
>> +     reg32 = __raw_readl(SYSTBCR);
>> +     reg32 |= (1 << 4);
>> +     __raw_writel(reg32, SYSTBCR);
>> +
>> +     /* Clear Wakeup Factors and do suspend */
>> +     reg32 = __raw_readl(WUPSFAC);
>> +     cpu_suspend(0, r8a7740_do_suspend);
>> +     outer_resume();
>> +     reg32 = __raw_readl(WUPSFAC);
>> +
>> +     /* Clear CPU Core Standby flag for other WFI instructions */
>> +     reg32 &= ~(1 << 4);
>> +     __raw_writel(reg32, SYSTBCR);
>> +
>> +}
>> +#endif /* CONFIG_SUSPEND || CONFIG_CPU_IDLE */
>> +
>> +#ifdef CONFIG_CPU_IDLE
>> +static int r8a7740_enter_a3sm_pll_on(struct cpuidle_device *dev,
>> +                                     struct cpuidle_driver *drv, int index)
>> +{
>> +     r8a7740_enter_a3sm_common(1);
>> +     return 1;
>> +}
>> +
>> +static int r8a7740_enter_a3sm_pll_off(struct cpuidle_device *dev,
>> +                                     struct cpuidle_driver *drv, int index)
>> +{
>> +     r8a7740_enter_a3sm_common(0);
>> +     return 2;
>> +}
>> +
>> +static struct cpuidle_driver r8a7740_cpuidle_driver = {
>> +     .name                   = "r8a7740_cpuidle",
>> +     .owner                  = THIS_MODULE,
>> +     .en_core_tk_irqen       = 1,
>> +     .state_count            = 3,
>> +     .safe_state_index       = 0, /* C1 */
>> +     .states[0] = ARM_CPUIDLE_WFI_STATE,
>> +     .states[0].enter = shmobile_enter_wfi,
>
> The WFI macro already set a simple enter function doing cpu_do_idle.

Oh yes, I'll remove it.

> We are trying to consolidate the cpuidle drivers across the different
> platforms [1]. One of the objective is to move the cpuidle drivers to
> drivers/cpuidle, a place where they belong to.
>
> Do you think it is possible you split your code to have one part with
> the cpuidle driver and another part with the PM code ?

Hmm. The CPUIdle part is enclosed in the #ifdef CONFIG_CPU_IDLE part anyway.
The other part (CONFIG_SUSPEND | CONFIG_CPU_IDLE) contains the part
that actually does drive down the hardware and is needed as soon as
SUSPEND or CPUIdle is used.

So is it split well enough already or does it help if I split my patch
into 2, first adding suspend and then CPUIdle to the same file? But
the outcome will be the same I think.

Cheers,

 Bastian



More information about the linux-arm-kernel mailing list