From mboxrd@z Thu Jan 1 00:00:00 1970 From: s.hauer@pengutronix.de (Sascha Hauer) Date: Wed, 23 Mar 2011 11:24:05 +0100 Subject: [PATCHv5 4/4] ARM: mx51: Add support for low power suspend on MX51 In-Reply-To: <1300743038-3901-4-git-send-email-Dinh.Nguyen@freescale.com> References: <1300743038-3901-1-git-send-email-Dinh.Nguyen@freescale.com> <1300743038-3901-2-git-send-email-Dinh.Nguyen@freescale.com> <1300743038-3901-3-git-send-email-Dinh.Nguyen@freescale.com> <1300743038-3901-4-git-send-email-Dinh.Nguyen@freescale.com> Message-ID: <20110323102405.GG29521@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Mar 21, 2011 at 04:30:38PM -0500, Dinh.Nguyen at freescale.com wrote: > From: Dinh Nguyen > > Adds initial low power suspend functionality to MX51. > Supports "mem" and "standby" modes. > > Tested on mx51-babbage. > > Signed-off-by: Dinh Nguyen > --- > arch/arm/mach-mx5/Makefile | 1 + > arch/arm/mach-mx5/pm-imx51.c | 74 ++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 75 insertions(+), 0 deletions(-) > create mode 100644 arch/arm/mach-mx5/pm-imx51.c > > diff --git a/arch/arm/mach-mx5/Makefile b/arch/arm/mach-mx5/Makefile > index 0b9338c..787cb80 100644 > --- a/arch/arm/mach-mx5/Makefile > +++ b/arch/arm/mach-mx5/Makefile > @@ -6,6 +6,7 @@ > obj-y := cpu.o mm.o clock-mx51-mx53.o devices.o ehci.o system.o > obj-$(CONFIG_SOC_IMX50) += mm-mx50.o > > +obj-$(CONFIG_PM) += pm-imx51.o > obj-$(CONFIG_CPU_FREQ_IMX) += cpu_op-mx51.o > obj-$(CONFIG_MACH_MX51_BABBAGE) += board-mx51_babbage.o > obj-$(CONFIG_MACH_MX51_3DS) += board-mx51_3ds.o > diff --git a/arch/arm/mach-mx5/pm-imx51.c b/arch/arm/mach-mx5/pm-imx51.c > new file mode 100644 > index 0000000..f5164b2 > --- /dev/null > +++ b/arch/arm/mach-mx5/pm-imx51.c > @@ -0,0 +1,74 @@ > +/* > + * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved. > + * > + * The code contained herein is licensed under the GNU General Public > + * License. You may obtain a copy of the GNU General Public License > + * Version 2 or later at the following locations: > + * > + * http://www.opensource.org/licenses/gpl-license.html > + * http://www.gnu.org/copyleft/gpl.html > + */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include "crm_regs.h" > + > +static struct clk *gpc_dvfs_clk; > + > +static int mx5_suspend_enter(suspend_state_t state) Either the name of the file or the name of this function is wrong. You should decide for imx5 or imx51. > +{ > + if (gpc_dvfs_clk == NULL) > + gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs"); > + > + if (gpc_dvfs_clk) { > + clk_enable(gpc_dvfs_clk); > + switch (state) { > + case PM_SUSPEND_MEM: > + mx5_cpu_lp_set(STOP_POWER_OFF); > + break; > + case PM_SUSPEND_STANDBY: > + mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF); > + break; > + default: > + return -EINVAL; > + } > + > + if (state == PM_SUSPEND_MEM) { > + local_flush_tlb_all(); > + flush_cache_all(); > + > + /*clear the EMPGC0/1 bits */ > + __raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR); > + __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR); > + } > + cpu_do_idle(); > + clk_disable(gpc_dvfs_clk); > + }else { > + printk(KERN_ERR "Cannot enter SRPG suspend -no gpc_dvfs clock!\n"); > + return -EPERM; > + } > + > + return 0; > +} > + > +static int mx5_pm_valid(suspend_state_t state) > +{ > + return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX); > +} > + > +static const struct platform_suspend_ops mx5_suspend_ops = { > + .valid = mx5_pm_valid, > + .enter = mx5_suspend_enter, > +}; > + > +static int __init mx5_pm_init(void) > +{ You should call clk_get here. Then you don't have to do the test for the clock over and over again and can print the warning only once. Also, NULL can be a valid clock. Please use IS_ERR(). Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |