Commit 4d21be86 authored by Claudiu Beznea's avatar Claudiu Beznea Committed by Stephen Boyd
Browse files

clk: at91: pmc: execute suspend/resume only for backup mode 



Before going to backup mode architecture specific PM code sets the first
word in securam (file arch/arm/mach-at91/pm.c, function at91_pm_begin()).
Thus take this into account when suspending/resuming clocks. This will
avoid executing unnecessary instructions when suspending to non backup
modes.

Signed-off-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20211011112719.3951784-3-claudiu.beznea@microchip.com


Acked-by: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent 36971566

drivers/clk/at91/pmc.c

+39 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/clkdev.h>

#include <linux/clk/at91_pmc.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/mfd/syscon.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>
@@ -110,13 +111,35 @@ struct pmc_data *pmc_data_allocate(unsigned int ncore, unsigned int nsystem, 
}



#ifdef CONFIG_PM



/* Address in SECURAM that say if we suspend to backup mode. */

static void __iomem *at91_pmc_backup_suspend;



static int at91_pmc_suspend(void)

{

	unsigned int backup;



	if (!at91_pmc_backup_suspend)

		return 0;



	backup = readl_relaxed(at91_pmc_backup_suspend);

	if (!backup)

		return 0;



	return clk_save_context();

}



static void at91_pmc_resume(void)

{

	unsigned int backup;



	if (!at91_pmc_backup_suspend)

		return;



	backup = readl_relaxed(at91_pmc_backup_suspend);

	if (!backup)

		return;



	clk_restore_context();

}
@@ -144,6 +167,22 @@ static int __init pmc_register_ops(void) 
	}

	of_node_put(np);



	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam");

	if (!np)

		return -ENODEV;



	if (!of_device_is_available(np)) {

		of_node_put(np);

		return -ENODEV;

	}

	of_node_put(np);



	at91_pmc_backup_suspend = of_iomap(np, 0);

	if (!at91_pmc_backup_suspend) {

		pr_warn("%s(): unable to map securam\n", __func__);

		return -ENOMEM;

	}



	register_syscore_ops(&pmc_syscore_ops);



	return 0;