[PATCHv2 1/2] ARM: mx51: Implement code to allow mx51 to enter WFI
Nguyen Dinh-R00091
R00091 at freescale.com
Thu Mar 10 10:12:42 EST 2011
Hi Uwe/Sascha,
Just wondering if you had a chance to review this patch series?
Thanks,
Dinh
>-----Original Message-----
>From: Nguyen Dinh-R00091
>Sent: Friday, March 04, 2011 5:30 PM
>To: linux-kernel at vger.kernel.org
>Cc: linux-arm-kernel at lists.infradead.org; linux at arm.linux.org.uk; s.hauer at pengutronix.de; u.kleine-
>koenig at pengutronix.de; Zhang Lily-R58066; Vaidyanathan Ranjani-RA5478; Nguyen Dinh-R00091
>Subject: [PATCHv2 1/2] ARM: mx51: Implement code to allow mx51 to enter WFI
>
>From: Dinh Nguyen <Dinh.Nguyen at freescale.com>
>
>Implement code for MX51 that allows the SoC to enter WFI when
>arch_idle is called.
>
>This patch is also necessary for correctly suspending the system.
>
>Signed-off-by: Dinh Nguyen <Dinh.Nguyen at freescale.com>
>---
> arch/arm/mach-mx5/Makefile | 2 +-
> arch/arm/mach-mx5/system.c | 84 +++++++++++++++++++++++++++++++
> arch/arm/plat-mxc/include/mach/mxc.h | 9 +++
> arch/arm/plat-mxc/include/mach/system.h | 6 ++-
> 4 files changed, 99 insertions(+), 2 deletions(-)
> create mode 100644 arch/arm/mach-mx5/system.c
>
>diff --git a/arch/arm/mach-mx5/Makefile b/arch/arm/mach-mx5/Makefile
>index 0d43be9..1106acd 100644
>--- a/arch/arm/mach-mx5/Makefile
>+++ b/arch/arm/mach-mx5/Makefile
>@@ -3,7 +3,7 @@
> #
>
> # Object file lists.
>-obj-y := cpu.o mm.o clock-mx51-mx53.o devices.o
>+obj-y := cpu.o mm.o clock-mx51-mx53.o devices.o system.o
> obj-$(CONFIG_SOC_IMX50) += mm-mx50.o
>
> obj-$(CONFIG_CPU_FREQ_IMX) += cpu_op-mx51.o
>diff --git a/arch/arm/mach-mx5/system.c b/arch/arm/mach-mx5/system.c
>new file mode 100644
>index 0000000..06d306b
>--- /dev/null
>+++ b/arch/arm/mach-mx5/system.c
>@@ -0,0 +1,84 @@
>+/*
>+ * 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/platform_device.h>
>+#include <asm/io.h>
>+#include <mach/hardware.h>
>+#include "crm_regs.h"
>+
>+/* set cpu low power mode before WFI instruction. This function is called mx5 because
>+ it can be used for mx50, mx51, and mx53.*/
>+void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
>+{
>+ u32 plat_lpc, arm_srpgcr, ccm_clpcr;
>+ u32 empgc0, empgc1;
>+ int stop_mode = 0;
>+
>+ /* 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);
>+ empgc0 = __raw_readl(MXC_SRPG_EMPGC0_SRPGCR) & ~(MXC_SRPGCR_PCR);
>+ empgc1 = __raw_readl(MXC_SRPG_EMPGC1_SRPGCR) & ~(MXC_SRPGCR_PCR);
>+
>+ switch (mode) {
>+ case WAIT_CLOCKED:
>+ break;
>+ case WAIT_UNCLOCKED:
>+ ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
>+ break;
>+ case WAIT_UNCLOCKED_POWER_OFF:
>+ case STOP_POWER_OFF:
>+ plat_lpc |= MXC_CORTEXA8_PLAT_LPC_DSM
>+ | MXC_CORTEXA8_PLAT_LPC_DBG_DSM;
>+ if (mode == WAIT_UNCLOCKED_POWER_OFF) {
>+ ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
>+ ccm_clpcr &= ~MXC_CCM_CLPCR_VSTBY;
>+ ccm_clpcr &= ~MXC_CCM_CLPCR_SBYOS;
>+ stop_mode = 0;
>+ } else {
>+ ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
>+ ccm_clpcr |= 0x3 << MXC_CCM_CLPCR_STBY_COUNT_OFFSET;
>+ ccm_clpcr |= MXC_CCM_CLPCR_VSTBY;
>+ ccm_clpcr |= MXC_CCM_CLPCR_SBYOS;
>+ stop_mode = 1;
>+ }
>+
>+ arm_srpgcr |= MXC_SRPGCR_PCR;
>+ if (stop_mode) {
>+ empgc0 |= MXC_SRPGCR_PCR;
>+ empgc1 |= MXC_SRPGCR_PCR;
>+ }
>+
>+ if (tzic_enable_wake(1) != 0)
>+ return;
>+ break;
>+ case STOP_POWER_ON:
>+ ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
>+ break;
>+ default:
>+ printk(KERN_WARNING "UNKNOWN cpu power mode: %d\n", mode);
>+ return;
>+ }
>+
>+ __raw_writel(plat_lpc, MXC_CORTEXA8_PLAT_LPC);
>+ __raw_writel(ccm_clpcr, MXC_CCM_CLPCR);
>+ __raw_writel(arm_srpgcr, MXC_SRPG_ARM_SRPGCR);
>+ /* Enable NEON SRPG for all but MX50TO1.0. */
>+ __raw_writel(arm_srpgcr, MXC_SRPG_NEON_SRPGCR);
>+ if (stop_mode) {
>+ __raw_writel(empgc0, MXC_SRPG_EMPGC0_SRPGCR);
>+ __raw_writel(empgc1, MXC_SRPG_EMPGC1_SRPGCR);
>+ }
>+}
>+
>diff --git a/arch/arm/plat-mxc/include/mach/mxc.h b/arch/arm/plat-mxc/include/mach/mxc.h
>index 04c7a26..8a8970d 100644
>--- a/arch/arm/plat-mxc/include/mach/mxc.h
>+++ b/arch/arm/plat-mxc/include/mach/mxc.h
>@@ -181,6 +181,15 @@ struct cpu_op {
> u32 cpu_rate;
> };
>
>+int tzic_enable_wake(int is_idle);
>+enum mxc_cpu_pwr_mode {
>+ WAIT_CLOCKED, /* wfi only */
>+ WAIT_UNCLOCKED, /* WAIT */
>+ WAIT_UNCLOCKED_POWER_OFF, /* WAIT + SRPG */
>+ STOP_POWER_ON, /* just STOP */
>+ STOP_POWER_OFF, /* STOP + SRPG */
>+};
>+
> extern struct cpu_op *(*get_cpu_op)(int *op);
> #endif
>
>diff --git a/arch/arm/plat-mxc/include/mach/system.h b/arch/arm/plat-mxc/include/mach/system.h
>index 95be51b..35283a4 100644
>--- a/arch/arm/plat-mxc/include/mach/system.h
>+++ b/arch/arm/plat-mxc/include/mach/system.h
>@@ -20,6 +20,8 @@
> #include <mach/hardware.h>
> #include <mach/common.h>
>
>+extern void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode);
>+
> static inline void arch_idle(void)
> {
> #ifdef CONFIG_ARCH_MXC91231
>@@ -54,7 +56,9 @@ static inline void arch_idle(void)
> "orr %0, %0, #0x00000004\n"
> "mcr p15, 0, %0, c1, c0, 0\n"
> : "=r" (reg));
>- } else
>+ } else if (cpu_is_mx51())
>+ mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
>+ else
> cpu_do_idle();
> }
>
>--
>1.6.0.4
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