From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Walmsley Subject: [PATCH 1/3] ARM: OMAP2xxx: PM: enter WFI via inline asm if CORE stays active Date: Sun, 30 Dec 2012 11:28:29 -0700 Message-ID: <20121230182826.30526.27155.stgit@dusk.lan> References: <20121230182745.30526.47072.stgit@dusk.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from utopia.booyaka.com ([74.50.51.50]:38195 "EHLO utopia.booyaka.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754787Ab2L3S24 (ORCPT ); Sun, 30 Dec 2012 13:28:56 -0500 In-Reply-To: <20121230182745.30526.47072.stgit@dusk.lan> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Kevin Hilman , Richard Woodruff There shouldn't be any need to jump to SRAM code if the OMAP CORE clockdomain (and consequently the SDRAM controller and CORE PLL) stays active during MPU WFI. The SRAM code should only be needed when the RAM enters self-refresh. So in the case where CORE stays active, just call WFI directly from the mach-omap2/pm24xx.c code. This removes some unnecessary SRAM code. Signed-off-by: Paul Walmsley Cc: Richard Woodruff Cc: Kevin Hilman --- arch/arm/mach-omap2/pm24xx.c | 9 +++------ arch/arm/mach-omap2/sleep24xx.S | 19 ------------------- 2 files changed, 3 insertions(+), 25 deletions(-) diff --git a/arch/arm/mach-omap2/pm24xx.c b/arch/arm/mach-omap2/pm24xx.c index c333fa6..659a2f5 100644 --- a/arch/arm/mach-omap2/pm24xx.c +++ b/arch/arm/mach-omap2/pm24xx.c @@ -54,7 +54,6 @@ #include "powerdomain.h" #include "clockdomain.h" -static void (*omap2_sram_idle)(void); static void (*omap2_sram_suspend)(u32 dllctrl, void __iomem *sdrc_dlla_ctrl, void __iomem *sdrc_power); @@ -196,7 +195,7 @@ static void omap2_enter_mpu_retention(void) OMAP2_PM_PWSTCTRL); } - omap2_sram_idle(); + asm("wfi" : : : "memory", "cc"); } static int omap2_can_sleep(void) @@ -356,11 +355,9 @@ int __init omap2_pm_init(void) /* * We copy the assembler sleep/wakeup routines to SRAM. * These routines need to be in SRAM as that's the only - * memory the MPU can see when it wakes up. + * memory the MPU can see when it wakes up after the entire + * chip enters idle. */ - omap2_sram_idle = omap_sram_push(omap24xx_idle_loop_suspend, - omap24xx_idle_loop_suspend_sz); - omap2_sram_suspend = omap_sram_push(omap24xx_cpu_suspend, omap24xx_cpu_suspend_sz); diff --git a/arch/arm/mach-omap2/sleep24xx.S b/arch/arm/mach-omap2/sleep24xx.S index ce0ccd2..1d3cb25 100644 --- a/arch/arm/mach-omap2/sleep24xx.S +++ b/arch/arm/mach-omap2/sleep24xx.S @@ -37,25 +37,6 @@ .text /* - * Forces OMAP into idle state - * - * omap24xx_idle_loop_suspend() - This bit of code just executes the WFI - * for normal idles. - * - * Note: This code get's copied to internal SRAM at boot. When the OMAP - * wakes up it continues execution at the point it went to sleep. - */ - .align 3 -ENTRY(omap24xx_idle_loop_suspend) - stmfd sp!, {r0, lr} @ save registers on stack - mov r0, #0 @ clear for mcr setup - mcr p15, 0, r0, c7, c0, 4 @ wait for interrupt - ldmfd sp!, {r0, pc} @ restore regs and return - -ENTRY(omap24xx_idle_loop_suspend_sz) - .word . - omap24xx_idle_loop_suspend - -/* * omap24xx_cpu_suspend() - Forces OMAP into deep sleep state by completing * SDRC shutdown then ARM shutdown. Upon wake MPU is back on so just restore * SDRC. From mboxrd@z Thu Jan 1 00:00:00 1970 From: paul@pwsan.com (Paul Walmsley) Date: Sun, 30 Dec 2012 11:28:29 -0700 Subject: [PATCH 1/3] ARM: OMAP2xxx: PM: enter WFI via inline asm if CORE stays active In-Reply-To: <20121230182745.30526.47072.stgit@dusk.lan> References: <20121230182745.30526.47072.stgit@dusk.lan> Message-ID: <20121230182826.30526.27155.stgit@dusk.lan> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org There shouldn't be any need to jump to SRAM code if the OMAP CORE clockdomain (and consequently the SDRAM controller and CORE PLL) stays active during MPU WFI. The SRAM code should only be needed when the RAM enters self-refresh. So in the case where CORE stays active, just call WFI directly from the mach-omap2/pm24xx.c code. This removes some unnecessary SRAM code. Signed-off-by: Paul Walmsley Cc: Richard Woodruff Cc: Kevin Hilman --- arch/arm/mach-omap2/pm24xx.c | 9 +++------ arch/arm/mach-omap2/sleep24xx.S | 19 ------------------- 2 files changed, 3 insertions(+), 25 deletions(-) diff --git a/arch/arm/mach-omap2/pm24xx.c b/arch/arm/mach-omap2/pm24xx.c index c333fa6..659a2f5 100644 --- a/arch/arm/mach-omap2/pm24xx.c +++ b/arch/arm/mach-omap2/pm24xx.c @@ -54,7 +54,6 @@ #include "powerdomain.h" #include "clockdomain.h" -static void (*omap2_sram_idle)(void); static void (*omap2_sram_suspend)(u32 dllctrl, void __iomem *sdrc_dlla_ctrl, void __iomem *sdrc_power); @@ -196,7 +195,7 @@ static void omap2_enter_mpu_retention(void) OMAP2_PM_PWSTCTRL); } - omap2_sram_idle(); + asm("wfi" : : : "memory", "cc"); } static int omap2_can_sleep(void) @@ -356,11 +355,9 @@ int __init omap2_pm_init(void) /* * We copy the assembler sleep/wakeup routines to SRAM. * These routines need to be in SRAM as that's the only - * memory the MPU can see when it wakes up. + * memory the MPU can see when it wakes up after the entire + * chip enters idle. */ - omap2_sram_idle = omap_sram_push(omap24xx_idle_loop_suspend, - omap24xx_idle_loop_suspend_sz); - omap2_sram_suspend = omap_sram_push(omap24xx_cpu_suspend, omap24xx_cpu_suspend_sz); diff --git a/arch/arm/mach-omap2/sleep24xx.S b/arch/arm/mach-omap2/sleep24xx.S index ce0ccd2..1d3cb25 100644 --- a/arch/arm/mach-omap2/sleep24xx.S +++ b/arch/arm/mach-omap2/sleep24xx.S @@ -37,25 +37,6 @@ .text /* - * Forces OMAP into idle state - * - * omap24xx_idle_loop_suspend() - This bit of code just executes the WFI - * for normal idles. - * - * Note: This code get's copied to internal SRAM at boot. When the OMAP - * wakes up it continues execution at the point it went to sleep. - */ - .align 3 -ENTRY(omap24xx_idle_loop_suspend) - stmfd sp!, {r0, lr} @ save registers on stack - mov r0, #0 @ clear for mcr setup - mcr p15, 0, r0, c7, c0, 4 @ wait for interrupt - ldmfd sp!, {r0, pc} @ restore regs and return - -ENTRY(omap24xx_idle_loop_suspend_sz) - .word . - omap24xx_idle_loop_suspend - -/* * omap24xx_cpu_suspend() - Forces OMAP into deep sleep state by completing * SDRC shutdown then ARM shutdown. Upon wake MPU is back on so just restore * SDRC.