ARM: mx51: Implement code to allow mx51 to enter WFI

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@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Dinh Nguyen 2011-03-21 16:30:37 -05:00 committed by Sascha Hauer
parent b6e89b2182
commit 0adf882b68
4 changed files with 99 additions and 2 deletions

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@ -3,7 +3,7 @@
#
# Object file lists.
obj-y := cpu.o mm.o clock-mx51-mx53.o devices.o ehci.o
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_CPU_FREQ_IMX) += cpu_op-mx51.o

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@ -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 <linux/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 (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. */
if (mx50_revision() != IMX_CHIP_REVISION_1_0)
__raw_writel(arm_srpgcr, MXC_SRPG_NEON_SRPGCR);
if (stop_mode) {
empgc0 |= MXC_SRPGCR_PCR;
empgc1 |= MXC_SRPGCR_PCR;
__raw_writel(empgc0, MXC_SRPG_EMPGC0_SRPGCR);
__raw_writel(empgc1, MXC_SRPG_EMPGC1_SRPGCR);
}
}

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@ -195,6 +195,15 @@ 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

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@ -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();
}