On Wednesday 29 June 2016 00:44:46, Alexandre Belloni wrote: > Using the PIE infrastructure allows to write the whole suspend/resume > functions in C instead of assembly. > > The only remaining assembly instruction is wfi for armv5 > It makes the code shorter and clearer. > > Signed-off-by: Alexandre Belloni <[email protected]> > --- > arch/arm/mach-at91/Kconfig | 1 + > arch/arm/mach-at91/Makefile | 2 +- > arch/arm/mach-at91/pm.c | 31 ++-- > arch/arm/mach-at91/pm/.gitignore | 2 + > arch/arm/mach-at91/pm/Makefile | 3 + > arch/arm/mach-at91/pm/atmel_pm.c | 97 +++++++++++ > arch/arm/mach-at91/pm_suspend.S | 338 > [...] > --- /dev/null > +++ b/arch/arm/mach-at91/pm/atmel_pm.c > @@ -0,0 +1,97 @@ > +#include <linux/io.h> > +#include <linux/clk/at91_pmc.h> > +#include <linux/mfd/syscon/atmel-mc.h> > +#include <linux/pie.h> > +#include "../pm.h" > + > +#define SRAMC_SELF_FRESH_ACTIVE 0x01 > +#define SRAMC_SELF_FRESH_EXIT 0x00 > + > +static void at91_sramc_self_refresh(unsigned int is_active, > + unsigned int memtype, > + void __iomem *sdramc_base, > + void __iomem *sdramc_base1) > +{ > + static unsigned int lpr, mdr, lpr1, mdr1; > + > + switch (memtype) { > + case AT91_MEMCTRL_MC: > + /* > + * at91rm9200 Memory controller > + */ > + if (is_active) > + __raw_writel(1, sdramc_base + AT91_MC_SDRAMC_SRR); > + break; > + > + case AT91_MEMCTRL_DDRSDR: > + if (is_active) { > + mdr = __raw_readl(sdramc_base + AT91_DDRSDRC_MDR); > + lpr = __raw_readl(sdramc_base + AT91_DDRSDRC_LPR); > + > + if ((mdr & AT91_DDRSDRC_MD) == > AT91_DDRSDRC_MD_LOW_POWER_DDR) > + __raw_writel((mdr & ~AT91_DDRSDRC_MD) | > + AT91_DDRSDRC_MD_DDR2, sdramc_base + > + AT91_DDRSDRC_MDR); > + __raw_writel((lpr & ~AT91_DDRSDRC_LPCB) | > + AT91_DDRSDRC_LPCB_SELF_REFRESH, sdramc_base > + + AT91_DDRSDRC_LPR); > + > + if (sdramc_base1) { > + mdr1 = __raw_readl(sdramc_base1 + > AT91_DDRSDRC_MDR); > + lpr1 = __raw_readl(sdramc_base1 + > AT91_DDRSDRC_LPR); > + if ((mdr1 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR) > + __raw_writel((mdr1 & ~AT91_DDRSDRC_MD) | > + AT91_DDRSDRC_MD_DDR2, > + sdramc_base1 + > + AT91_DDRSDRC_MDR); > + __raw_writel((lpr1 & ~AT91_DDRSDRC_LPCB) | > + AT91_DDRSDRC_LPCB_SELF_REFRESH, > + sdramc_base1 + AT91_DDRSDRC_LPR); > + } > + } else { > + __raw_writel(mdr, sdramc_base + AT91_DDRSDRC_MDR); > + __raw_writel(lpr, sdramc_base + AT91_DDRSDRC_LPR); > + if (sdramc_base1) { > + __raw_writel(mdr, sdramc_base1 + > AT91_DDRSDRC_MDR); > + __raw_writel(lpr, sdramc_base1 + > AT91_DDRSDRC_LPR); > + } > + } > + break; > + > + case AT91_MEMCTRL_SDRAMC: > + if (is_active) { > + lpr = __raw_readl(sdramc_base + AT91_SDRAMC_LPR); > + > + __raw_writel((lpr & ~AT91_SDRAMC_LPCB) | > + AT91_SDRAMC_LPCB_SELF_REFRESH, sdramc_base > + + AT91_SDRAMC_LPR); > + } else { > + __raw_writel(lpr, sdramc_base + AT91_SDRAMC_LPR); > + } > + break; > + } > +} > + > +void atmel_pm_suspend(void __iomem *pmc, void __iomem *ramc0, > + void __iomem *ramc1, int memctrl) > +{ > + int memtype, pm_mode; > + > + memtype = memctrl & AT91_PM_MEMTYPE_MASK; > + pm_mode = (memctrl >> AT91_PM_MODE_OFFSET) & AT91_PM_MODE_MASK; > + > + dsb(); > + > + at91_sramc_self_refresh(1, memtype, ramc0, ramc1); > + > +#if defined(CONFIG_CPU_V7) > + dsb(); > + wfi(); > +#else > + asm volatile ("mcr p15, 0, %0, c7, c0, 4" \ > + : : "r" (0) : "memory"); > +#endif
Why not defining wfi() for __LINUX_ARM_ARCH__ < 7 as it is done for dsb() and friends in arch/arm/include/asm/barrier.h? So you can get rid of that #if completly. > + at91_sramc_self_refresh(0, memtype, ramc0, ramc1); > +} > +EXPORT_PIE_SYMBOL(atmel_pm_suspend); Best regards, Alexander
