From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Gonzalez Subject: [RFC PATCH v2] ARM: tango: add Suspend-to-RAM support Date: Thu, 30 Jun 2016 10:44:14 +0200 Message-ID: <5774DBDE.1070605@sigmadesigns.com> References: <5773D3FB.4030101@sigmadesigns.com> <577409E2.7020106@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from a.mx.sdesigns.eu ([78.31.43.6]:57551 "EHLO a.mx.sdesigns.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752171AbcF3IoS (ORCPT ); Thu, 30 Jun 2016 04:44:18 -0400 In-Reply-To: <577409E2.7020106@arm.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Sudeep Holla , linux-pm , Linux ARM Cc: Mark Rutland , Thomas Petazzoni , Kevin Hilman , Thibaud Cornic , Mason , Sebastian Frias , Robin Murphy Ask firmware to put RAM in self-refresh mode and power system down. echo mem > /sys/power/state See Documentation/power/states.txt Signed-off-by: Marc Gonzalez --- This is a RFC because I have a few doubts: 1) return value when tango_suspend() fails and unexpectedly returns (I used -EIO) Is there a better error to return? 2) conditionally building pm.c (using CONFIG_SUSPEND? CONFIG_PM_SLEEP? other?) Is there a better config knob to use? 3) .valid is required, right? AFAICS, the answer is "yes", .valid is indeed required: ("no valid callback implies that none are valid") static bool valid_state(suspend_state_t state) { /* * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level * support and need to be valid to the low level * implementation, no valid callback implies that none are valid. */ return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); } --- arch/arm/mach-tango/Makefile | 1 + arch/arm/mach-tango/pm.c | 32 ++++++++++++++++++++++++++++++++ arch/arm/mach-tango/smc.h | 1 + 3 files changed, 34 insertions(+) create mode 100644 arch/arm/mach-tango/pm.c diff --git a/arch/arm/mach-tango/Makefile b/arch/arm/mach-tango/Makefile index 7ca753aa9fb6..822b7ca803c6 100644 --- a/arch/arm/mach-tango/Makefile +++ b/arch/arm/mach-tango/Makefile @@ -3,3 +3,4 @@ AFLAGS_smc.o := -Wa,-march=armv7-a$(plus_sec) obj-y += setup.o smc.o xenv.o obj-$(CONFIG_SMP) += platsmp.o +obj-$(CONFIG_SUSPEND) += pm.o diff --git a/arch/arm/mach-tango/pm.c b/arch/arm/mach-tango/pm.c new file mode 100644 index 000000000000..b05c6d6f99d0 --- /dev/null +++ b/arch/arm/mach-tango/pm.c @@ -0,0 +1,32 @@ +#include +#include +#include +#include "smc.h" + +static int tango_pm_powerdown(unsigned long arg) +{ + tango_suspend(virt_to_phys(cpu_resume)); + + return -EIO; /* tango_suspend has failed */ +} + +static int tango_pm_enter(suspend_state_t state) +{ + if (state == PM_SUSPEND_MEM) + return cpu_suspend(0, tango_pm_powerdown); + + return -EINVAL; +} + +static const struct platform_suspend_ops tango_pm_ops = { + .enter = tango_pm_enter, + .valid = suspend_valid_only_mem, +}; + +static int __init tango_pm_init(void) +{ + suspend_set_ops(&tango_pm_ops); + return 0; +} + +late_initcall(tango_pm_init); diff --git a/arch/arm/mach-tango/smc.h b/arch/arm/mach-tango/smc.h index 3d31f984f44c..57919539da1b 100644 --- a/arch/arm/mach-tango/smc.h +++ b/arch/arm/mach-tango/smc.h @@ -3,5 +3,6 @@ extern int tango_smc(unsigned int val, unsigned int service); #define tango_set_l2_control(val) tango_smc(val, 0x102) #define tango_start_aux_core(val) tango_smc(val, 0x104) #define tango_set_aux_boot_addr(val) tango_smc(val, 0x105) +#define tango_suspend(val) tango_smc(val, 0x120) #define tango_aux_core_die(val) tango_smc(val, 0x121) #define tango_aux_core_kill(val) tango_smc(val, 0x122) -- 2.9.0