/*
* 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 <linux/clk.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/export.h>
#include <asm/cacheflush.h>
#include <asm/system_misc.h>
#include <asm/tlbflush.h>
#include "common.h"
#include "cpuidle.h"
#include "crm-regs-imx5.h"
#include "hardware.h"
/*
* The WAIT_UNCLOCKED_POWER_OFF state only requires <= 500ns to exit.
* This is also the lowest power state possible without affecting
* non-cpu parts of the system. For these reasons, imx5 should default
* to always using this state for cpu idling. The PM_SUSPEND_STANDBY also
* uses this state and needs to take no action when registers remain confgiured
* for this state.
*/
#define IMX5_DEFAULT_CPU_IDLE_STATE WAIT_UNCLOCKED_POWER_OFF
/*
* set cpu low power mode before WFI instruction. This function is called
* mx5 because it can be used for mx50, mx51, and mx53.
*/
static 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;
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);
}
}
static int mx5_suspend_enter(suspend_state_t state)
{
switch (state) {
case PM_SUSPEND_MEM:
mx5_cpu_lp_set(STOP_POWER_OFF);
break;
case PM_SUSPEND_STANDBY:
/* DEFAULT_IDLE_STATE already configured */
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();
/* return registers to default idle state */
mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
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 inline int imx5_cpu_do_idle(void)
{
int ret = tzic_enable_wake();
if (likely(!ret))
cpu_do_idle();
return ret;
}
static void imx5_pm_idle(void)
{
imx5_cpu_do_idle();
}
static int imx5_cpuidle_enter(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int idx)
{
int ret;
ret = imx5_cpu_do_idle();
if (ret < 0)
return ret;
return idx;
}
static struct cpuidle_driver imx5_cpuidle_driver = {
.name = "imx5_cpuidle",
.owner = THIS_MODULE,
.en_core_tk_irqen = 1,
.states[0] = {
.enter = imx5_cpuidle_enter,
.exit_latency = 2,
.target_residency = 1,
.flags = CPUIDLE_FLAG_TIME_VALID,
.name = "IMX5 SRPG",
.desc = "CPU state retained,powered off",
},
.state_count = 1,
};
static int __init imx5_pm_common_init(void)
{
int ret;
struct clk *gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
if (IS_ERR(gpc_dvfs_clk))
return PTR_ERR(gpc_dvfs_clk);
ret = clk_prepare_enable(gpc_dvfs_clk);
if (ret)
return ret;
arm_pm_idle = imx5_pm_idle;
/* Set the registers to the default cpu idle state. */
mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
imx_cpuidle_init(&imx5_cpuidle_driver);
return 0;
}
void __init imx51_pm_init(void)
{
int ret = imx5_pm_common_init();
if (!ret)
suspend_set_ops(&mx5_suspend_ops);
}
void __init imx53_pm_init(void)
{
imx5_pm_common_init();
}
