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/irq.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/regmap.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;

	/*
	 * 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();
}

static void imx6q_enable_wb(bool enable)
{
	u32 val;

	/* 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);
}

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

	val &= ~BM_CLPCR_LPM;
	switch (mode) {
	case WAIT_CLOCKED:
		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;
		if (cpu_is_imx6sl()) {
			val |= BM_CLPCR_BYPASS_PMIC_READY;
			val |= BM_CLPCR_BYP_MMDC_CH0_LPM_HS;
		} else {
			val |= BM_CLPCR_BYP_MMDC_CH1_LPM_HS;
		}
		break;
	default:
		return -EINVAL;
	}

	/*
	 * ERR007265: CCM: When improper low-power sequence is used,
	 * the SoC enters low power mode before the ARM core executes WFI.
	 *
	 * Software workaround:
	 * 1) Software should trigger IRQ #32 (IOMUX) to be always pending
	 *    by setting IOMUX_GPR1_GINT.
	 * 2) Software should then unmask IRQ #32 in GPC before setting CCM
	 *    Low-Power mode.
	 * 3) Software should mask IRQ #32 right after CCM Low-Power mode
	 *    is set (set bits 0-1 of CCM_CLPCR).
	 */
	iomuxc_irq_desc = irq_to_desc(32);
	imx_gpc_irq_unmask(&iomuxc_irq_desc->irq_data);
	writel_relaxed(val, ccm_base + CLPCR);
	imx_gpc_irq_mask(&iomuxc_irq_desc->irq_data);

	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);
		imx6q_enable_wb(true);
		imx6q_enable_rbc(true);
		imx_gpc_pre_suspend();
		imx_anatop_pre_suspend();
		imx_set_cpu_jump(0, v7_cpu_resume);
		/* Zzz ... */
		cpu_suspend(0, imx6q_suspend_finish);
		if (cpu_is_imx6q() || cpu_is_imx6dl())
			imx_smp_prepare();
		imx_anatop_post_resume();
		imx_gpc_post_resume();
		imx6q_enable_rbc(false);
		imx6q_enable_wb(false);
		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)
{
	struct regmap *gpr;

	WARN_ON(!ccm_base);

	/*
	 * This is for SW workaround step #1 of ERR007265, see comments
	 * in imx6q_set_lpm for details of this errata.
	 * Force IOMUXC irq pending, so that the interrupt to GPC can be
	 * used to deassert dsm_request signal when the signal gets
	 * asserted unexpectedly.
	 */
	gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
	if (!IS_ERR(gpr))
		regmap_update_bits(gpr, IOMUXC_GPR1, IMX6Q_GPR1_GINT,
				   IMX6Q_GPR1_GINT);

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

	suspend_set_ops(&imx6q_pm_ops);
}