Re: [PATCHv1] ARM: imx: Add support for low power suspend on MX51.

From: Uwe Kleine-König
Date: Wed Mar 02 2011 - 16:52:43 EST


On Wed, Mar 02, 2011 at 11:17:58AM -0600, Dinh.Nguyen@xxxxxxxxxxxxx wrote:
> From: Dinh Nguyen <Dinh.Nguyen@xxxxxxxxxxxxx>
>
> Adds initial low power suspend functionality to MX51.
> Supports "mem" and "standby" modes.
>
> Signed-off-by: Dinh Nguyen <Dinh.Nguyen@xxxxxxxxxxxxx>
> ---
> arch/arm/mach-mx5/Makefile | 1 +
> arch/arm/mach-mx5/pm.c | 75 ++++++++++++++++++++++++++++++++++
> arch/arm/plat-mxc/include/mach/mxc.h | 1 +
> 3 files changed, 77 insertions(+), 0 deletions(-)
> create mode 100644 arch/arm/mach-mx5/pm.c
>
> diff --git a/arch/arm/mach-mx5/Makefile b/arch/arm/mach-mx5/Makefile
> index 4f63048..7f9435d 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
> obj-$(CONFIG_SOC_IMX50) += mm-mx50.o
>
> +obj-$(CONFIG_PM) += pm.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.c b/arch/arm/mach-mx5/pm.c
> new file mode 100644
> index 0000000..137d204
> --- /dev/null
> +++ b/arch/arm/mach-mx5/pm.c
I'd like to have that called pm-imx51.c

> @@ -0,0 +1,75 @@
> +/*
> + * 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 <linux/suspend.h>
> +#include <asm/mach/map.h>
> +#include <mach/system.h>
> +#include "crm_regs.h"
> +
> +static int mx5_suspend_enter(suspend_state_t state)
> +{
> + u32 plat_lpc, arm_srpgcr, ccm_clpcr;
> +
> + /* always allow platform to issue a deep sleep mode request */
> + plat_lpc = __raw_readl(MXC_CORTEXA8_PLAT_LPC) &
> + ~(MXC_CORTEXA8_PLAT_LPC_DSM);
> + ccm_clpcr = __raw_readl(MXC_CCM_CLPCR) & ~(MXC_CCM_CLPCR_LPM_MASK);
> + arm_srpgcr = __raw_readl(MXC_SRPG_ARM_SRPGCR) & ~(MXC_SRPGCR_PCR);
> +
> + switch (state) {
> + case PM_SUSPEND_MEM:
> + ccm_clpcr |= (0x2 << MXC_CCM_CLPCR_LPM_OFFSET);
> + ccm_clpcr |= (0x3 << MXC_CCM_CLPCR_STBY_COUNT_OFFSET);
the parentheses aren't needed here

> + ccm_clpcr |= MXC_CCM_CLPCR_VSTBY;
> + ccm_clpcr |= MXC_CCM_CLPCR_SBYOS;
> + break;
> + case PM_SUSPEND_STANDBY:
> + ccm_clpcr |= (0x1 << MXC_CCM_CLPCR_LPM_OFFSET);
ditto

> + ccm_clpcr &= ~MXC_CCM_CLPCR_VSTBY;
> + ccm_clpcr &= ~MXC_CCM_CLPCR_SBYOS;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + plat_lpc |= MXC_CORTEXA8_PLAT_LPC_DSM
> + | MXC_CORTEXA8_PLAT_LPC_DBG_DSM;
> + arm_srpgcr |= MXC_SRPGCR_PCR;
> +
> + __raw_writel(plat_lpc, MXC_CORTEXA8_PLAT_LPC);
> + __raw_writel(ccm_clpcr, MXC_CCM_CLPCR);
> + __raw_writel(arm_srpgcr, MXC_SRPG_ARM_SRPGCR);
> + __raw_writel(arm_srpgcr, MXC_SRPG_NEON_SRPGCR);
> +
> + if (tzic_enable_wake(0) != 0)
> + return -EAGAIN;
> +
> + cpu_do_idle();
> + 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)
> +{
> + if (cpu_is_mx51())
> + suspend_set_ops(&mx5_suspend_ops);
I'd prefer to have that called by imx51_init_early.

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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