linux/arch/arm/mach-imx/pm-imx6q.c

/*
 * Copyright 2011-2013 Freescale Semiconductor, Inc.
 * Copyright 2011 Linaro Ltd.
 *
 * 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/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/suspend.h>
#include <asm/cacheflush.h>
#include <asm/proc-fns.h>
#include <asm/suspend.h>
#include <asm/hardware/cache-l2x0.h>

#include "common.h"
#include "hardware.h"

#define CCR				0x0
#define BM_CCR_WB_COUNT			(0x7 << 16)
#define BM_CCR_RBC_BYPASS_COUNT		(0x3f << 21)
#define BM_CCR_RBC_EN			(0x1 << 27)

#define CLPCR				0x54
#define BP_CLPCR_LPM			0
#define BM_CLPCR_LPM			(0x3 << 0)
#define BM_CLPCR_BYPASS_PMIC_READY	(0x1 << 2)
#define BM_CLPCR_ARM_CLK_DIS_ON_LPM	(0x1 << 5)
#define BM_CLPCR_SBYOS			(0x1 << 6)
#define BM_CLPCR_DIS_REF_OSC		(0x1 << 7)
#define BM_CLPCR_VSTBY			(0x1 << 8)
#define BP_CLPCR_STBY_COUNT		9
#define BM_CLPCR_STBY_COUNT		(0x3 << 9)
#define BM_CLPCR_COSC_PWRDOWN		(0x1 << 11)
#define BM_CLPCR_WB_PER_AT_LPM		(0x1 << 16)
#define BM_CLPCR_WB_CORE_AT_LPM		(0x1 << 17)
#define BM_CLPCR_BYP_MMDC_CH0_LPM_HS	(0x1 << 19)
#define BM_CLPCR_BYP_MMDC_CH1_LPM_HS	(0x1 << 21)
#define BM_CLPCR_MASK_CORE0_WFI		(0x1 << 22)
#define BM_CLPCR_MASK_CORE1_WFI		(0x1 << 23)
#define BM_CLPCR_MASK_CORE2_WFI		(0x1 << 24)
#define BM_CLPCR_MASK_CORE3_WFI		(0x1 << 25)
#define BM_CLPCR_MASK_SCU_IDLE		(0x1 << 26)
#define BM_CLPCR_MASK_L2CC_IDLE		(0x1 << 27)

#define CGPR				0x64
#define BM_CGPR_CHICKEN_BIT		(0x1 << 17)

static void __iomem *ccm_base;

void imx6q_set_chicken_bit(void)
{
	u32 val = readl_relaxed(ccm_base + CGPR);

	val |= BM_CGPR_CHICKEN_BIT;
	writel_relaxed(val, ccm_base + CGPR);
}

static void imx6q_enable_rbc(bool enable)
{
	u32 val;
	static bool last_rbc_mode;

	if (last_rbc_mode == enable)
		return;
	/*
	 * need to mask all interrupts in GPC before
	 * operating RBC configurations
	 */
	imx_gpc_mask_all();

	/* configure RBC enable bit */
	val = readl_relaxed(ccm_base + CCR);
	val &= ~BM_CCR_RBC_EN;
	val |= enable ? BM_CCR_RBC_EN : 0;
	writel_relaxed(val, ccm_base + CCR);

	/* configure RBC count */
	val = readl_relaxed(ccm_base + CCR);
	val &= ~BM_CCR_RBC_BYPASS_COUNT;
	val |= enable ? BM_CCR_RBC_BYPASS_COUNT : 0;
	writel(val, ccm_base + CCR);

	/*
	 * need to delay at least 2 cycles of CKIL(32K)
	 * due to hardware design requirement, which is
	 * ~61us, here we use 65us for safe
	 */
	udelay(65);

	/* restore GPC interrupt mask settings */
	imx_gpc_restore_all();

	last_rbc_mode = enable;
}

static void imx6q_enable_wb(bool enable)
{
	u32 val;
	static bool last_wb_mode;

	if (last_wb_mode == enable)
		return;

	/* configure well bias enable bit */
	val = readl_relaxed(ccm_base + CLPCR);
	val &= ~BM_CLPCR_WB_PER_AT_LPM;
	val |= enable ? BM_CLPCR_WB_PER_AT_LPM : 0;
	writel_relaxed(val, ccm_base + CLPCR);

	/* configure well bias count */
	val = readl_relaxed(ccm_base + CCR);
	val &= ~BM_CCR_WB_COUNT;
	val |= enable ? BM_CCR_WB_COUNT : 0;
	writel_relaxed(val, ccm_base + CCR);

	last_wb_mode = enable;
}

int imx6q_set_lpm(enum mxc_cpu_pwr_mode mode)
{
	u32 val = readl_relaxed(ccm_base + CLPCR);

	val &= ~BM_CLPCR_LPM;
	switch (mode) {
	case WAIT_CLOCKED:
		imx6q_enable_wb(false);
		imx6q_enable_rbc(false);
		break;
	case WAIT_UNCLOCKED:
		val |= 0x1 << BP_CLPCR_LPM;
		val |= BM_CLPCR_ARM_CLK_DIS_ON_LPM;
		break;
	case STOP_POWER_ON:
		val |= 0x2 << BP_CLPCR_LPM;
		break;
	case WAIT_UNCLOCKED_POWER_OFF:
		val |= 0x1 << BP_CLPCR_LPM;
		val &= ~BM_CLPCR_VSTBY;
		val &= ~BM_CLPCR_SBYOS;
		break;
	case STOP_POWER_OFF:
		val |= 0x2 << BP_CLPCR_LPM;
		val |= 0x3 << BP_CLPCR_STBY_COUNT;
		val |= BM_CLPCR_VSTBY;
		val |= BM_CLPCR_SBYOS;
		imx6q_enable_wb(true);
		imx6q_enable_rbc(true);
		break;
	default:
		return -EINVAL;
	}

	writel_relaxed(val, ccm_base + CLPCR);

	return 0;
}

static int imx6q_suspend_finish(unsigned long val)
{
	cpu_do_idle();
	return 0;
}

static int imx6q_pm_enter(suspend_state_t state)
{
	switch (state) {
	case PM_SUSPEND_MEM:
		imx6q_set_lpm(STOP_POWER_OFF);
		imx_gpc_pre_suspend();
		imx_anatop_pre_suspend();
		imx_set_cpu_jump(0, v7_cpu_resume);
		/* Zzz ... */
		cpu_suspend(0, imx6q_suspend_finish);
		imx_smp_prepare();
		imx_anatop_post_resume();
		imx_gpc_post_resume();
		imx6q_set_lpm(WAIT_CLOCKED);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static const struct platform_suspend_ops imx6q_pm_ops = {
	.enter = imx6q_pm_enter,
	.valid = suspend_valid_only_mem,
};

void __init imx6q_pm_set_ccm_base(void __iomem *base)
{
	ccm_base = base;
}

void __init imx6q_pm_init(void)
{
	WARN_ON(!ccm_base);

	/* Set initial power mode */
	imx6q_set_lpm(WAIT_CLOCKED);

	suspend_set_ops(&imx6q_pm_ops);
}