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From 63a0c32028148e91ea91cfbf95841c4ecd69d21b Mon Sep 17 00:00:00 2001
From: Claudiu Beznea <claudiu.beznea@microchip.com>
Date: Mon, 11 Oct 2021 14:27:06 +0300
Subject: [PATCH 235/247] 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: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20211011112719.3951784-3-claudiu.beznea@microchip.com
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
---
drivers/clk/at91/pmc.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c
@@ -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(unsig
}
#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;
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