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Commit 565fa91f authored by Robert Lee's avatar Robert Lee Committed by Sascha Hauer
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ARM: imx: clean and consolidate imx5 suspend and idle code 



The imx5 idle code that existed in mm-imx5.c is moved to pm-imx5.c.
The imx5_pm_init call is now exported and called during the
MACHINE_START late_init in supported imx5 platforms.

Remove various enabling/disabling of the gpc_dvfs clock and
enable it once during initialization.  This is a very low
power clock that must be enabled during low power operations.

There are only two "suspend_state_t" imx5 low power modes ever
used.  STOP_POWER_OFF for suspend to mem and
WAIT_UNCLOCKED_POWER_OFF for idle and suspend to standby.  The
latter mode only requires 500 nanoseconds of extra hardware
exit time beyond a basic WFI operation (WAIT_CLOCKED mode) so
no other idle mode is necessary.  Given this information, it
is more efficient to keep the registers in the often used
WAIT_UNCLOCKED_POWER_OFF state and only to and from the
STOP_POWER_OFF register state as needed when suspend to
mem is required.

Signed-off-by: default avatarRobert Lee <rob.lee@linaro.org>
Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
parent eee4f400

arch/arm/mach-imx/mm-imx5.c

+1 −20
Original line number Diff line number Diff line
@@ -16,7 +16,6 @@ 
#include <linux/clk.h>

#include <linux/pinctrl/machine.h>



#include <asm/system_misc.h>

#include <asm/mach/map.h>



#include <mach/hardware.h>
@@ -24,24 +23,6 @@ 
#include <mach/devices-common.h>

#include <mach/iomux-v3.h>



static struct clk *gpc_dvfs_clk;



static void imx5_idle(void)

{

	/* gpc clock is needed for SRPG */

	if (gpc_dvfs_clk == NULL) {

		gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");

		if (IS_ERR(gpc_dvfs_clk))

			return;

		clk_prepare(gpc_dvfs_clk);

	}

	clk_enable(gpc_dvfs_clk);

	mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);

	if (!tzic_enable_wake())

		cpu_do_idle();

	clk_disable(gpc_dvfs_clk);

}



/*

 * Define the MX50 memory map.

 */
@@ -105,7 +86,6 @@ void __init imx51_init_early(void) 
	mxc_set_cpu_type(MXC_CPU_MX51);

	mxc_iomux_v3_init(MX51_IO_ADDRESS(MX51_IOMUXC_BASE_ADDR));

	mxc_arch_reset_init(MX51_IO_ADDRESS(MX51_WDOG1_BASE_ADDR));

	arm_pm_idle = imx5_idle;

}



void __init imx53_init_early(void)
@@ -241,4 +221,5 @@ void __init imx53_soc_init(void) 
void __init imx51_init_late(void)

{

	mx51_neon_fixup();

	imx51_pm_init();

}

arch/arm/mach-imx/pm-imx5.c

+41 −26
Original line number Diff line number Diff line
@@ -13,18 +13,27 @@ 
#include <linux/io.h>

#include <linux/err.h>

#include <asm/cacheflush.h>

#include <asm/system_misc.h>

#include <asm/tlbflush.h>

#include <mach/common.h>

#include <mach/hardware.h>

#include "crm-regs-imx5.h"



static struct clk *gpc_dvfs_clk;

/*

 * 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.

 */

void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)

static void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)

{

	u32 plat_lpc, arm_srpgcr, ccm_clpcr;

	u32 empgc0, empgc1;
@@ -87,11 +96,6 @@ void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode) 
	}

}



static int mx5_suspend_prepare(void)

{

	return clk_prepare_enable(gpc_dvfs_clk);

}



static int mx5_suspend_enter(suspend_state_t state)

{

	switch (state) {
@@ -99,7 +103,7 @@ static int mx5_suspend_enter(suspend_state_t state) 
		mx5_cpu_lp_set(STOP_POWER_OFF);

		break;

	case PM_SUSPEND_STANDBY:

		mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);

		/* DEFAULT_IDLE_STATE already configured */

		break;

	default:

		return -EINVAL;
@@ -114,12 +118,10 @@ static int mx5_suspend_enter(suspend_state_t state) 
		__raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);

	}

	cpu_do_idle();

	return 0;

}



static void mx5_suspend_finish(void)

{

	clk_disable_unprepare(gpc_dvfs_clk);

	/* 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)
@@ -129,25 +131,38 @@ static int mx5_pm_valid(suspend_state_t state) 


static const struct platform_suspend_ops mx5_suspend_ops = {

	.valid = mx5_pm_valid,

	.prepare = mx5_suspend_prepare,

	.enter = mx5_suspend_enter,

	.finish = mx5_suspend_finish,

};



static int __init mx5_pm_init(void)

static void imx5_pm_idle(void)

{

	if (!cpu_is_mx51() && !cpu_is_mx53())

		return 0;

	if (likely(!tzic_enable_wake()))

		cpu_do_idle();

}



	if (gpc_dvfs_clk == NULL)

		gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");

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)) {

		if (cpu_is_mx51())

			suspend_set_ops(&mx5_suspend_ops);

	} else

		return -EPERM;

	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);



	return 0;

}

device_initcall(mx5_pm_init);
 


void __init imx51_pm_init(void)

{

	int ret = imx5_pm_common_init();

	if (!ret)

		suspend_set_ops(&mx5_suspend_ops);

}

arch/arm/plat-mxc/include/mach/common.h

+2 −1
Original line number Diff line number Diff line
@@ -95,7 +95,6 @@ enum mx3_cpu_pwr_mode { 
};



extern void mx3_cpu_lp_set(enum mx3_cpu_pwr_mode mode);

extern void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode);

extern void imx_print_silicon_rev(const char *cpu, int srev);



void avic_handle_irq(struct pt_regs *);
@@ -146,8 +145,10 @@ extern void imx6q_clock_map_io(void); 


#ifdef CONFIG_PM

extern void imx6q_pm_init(void);

extern void imx51_pm_init(void);

#else

static inline void imx6q_pm_init(void) {}

static inline void imx51_pm_init(void) {}

#endif



#ifdef CONFIG_NEON