[PATCH 1/2] ARM: OMAP2+: prm44xx: Introduce context save/restore for am43 PRCM IO

[PATCH 1/2] ARM: OMAP2+: prm44xx: Introduce context save/restore for am43 PRCM IO

[Keerthy]

From: Dave Gerlach <d-gerlach@ti.com> 

There are two registers on am43x needed for IO daisy chain wake to work
properly, however currently after an RTC+DDR cycle they are lost. We
must take care to save and restore these before and after entering RTC
mode otherwise IO daisy chain wake will stop working from DeepSleep
after resuming.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
---
 arch/arm/mach-omap2/prm44xx.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
index acb9593..0a4aa90 100644
--- a/arch/arm/mach-omap2/prm44xx.c
+++ b/arch/arm/mach-omap2/prm44xx.c
@@ -57,6 +57,13 @@
 	.reconfigure_io_chain	= &omap44xx_prm_reconfigure_io_chain,
 };
 
+struct omap_prm_irq_context {
+	unsigned long irq_enable;
+	unsigned long pm_ctrl;
+};
+
+static struct omap_prm_irq_context omap_prm_context;
+
 /*
  * omap44xx_prm_reset_src_map - map from bits in the PRM_RSTST
  *   hardware register (which are specific to OMAP44xx SoCs) to reset
@@ -689,6 +696,28 @@ struct pwrdm_ops omap4_pwrdm_operations = {
 
 static int omap44xx_prm_late_init(void);
 
+void prm_save_context(void)
+{
+	omap_prm_context.irq_enable =
+			omap4_prm_read_inst_reg(AM43XX_PRM_OCP_SOCKET_INST,
+						omap4_prcm_irq_setup.mask);
+
+	omap_prm_context.pm_ctrl =
+			omap4_prm_read_inst_reg(AM43XX_PRM_DEVICE_INST,
+						omap4_prcm_irq_setup.pm_ctrl);
+}
+
+void prm_restore_context(void)
+{
+	omap4_prm_write_inst_reg(omap_prm_context.irq_enable,
+				 OMAP4430_PRM_OCP_SOCKET_INST,
+				 omap4_prcm_irq_setup.mask);
+
+	omap4_prm_write_inst_reg(omap_prm_context.pm_ctrl,
+				 AM43XX_PRM_DEVICE_INST,
+				 omap4_prcm_irq_setup.pm_ctrl);
+}
+
 /*
  * XXX document
  */
-- 
1.9.1

[PATCH 2/2] ARM: mach-omap2: prm44xx: Inroduce cpu_pm notifiers for context save/restore

[Keerthy]

Inroduce cpu_pm notifiers for context save/restore. This will be
needed for am43xx family in case of rtc only mode with ddr in
self-refresh.

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
 arch/arm/mach-omap2/prm44xx.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
index 0a4aa90..5478c71 100644
--- a/arch/arm/mach-omap2/prm44xx.c
+++ b/arch/arm/mach-omap2/prm44xx.c
@@ -12,6 +12,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/cpu_pm.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
@@ -30,6 +31,7 @@
 #include "prcm44xx.h"
 #include "prminst44xx.h"
 #include "powerdomain.h"
+#include "pm.h"
 
 /* Static data */
 
@@ -718,6 +720,22 @@ void prm_restore_context(void)
 				 omap4_prcm_irq_setup.pm_ctrl);
 }
 
+static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
+{
+	switch (cmd) {
+	case CPU_CLUSTER_PM_ENTER:
+		if (enable_off_mode)
+			prm_save_context();
+		break;
+	case CPU_CLUSTER_PM_EXIT:
+		if (enable_off_mode)
+			prm_restore_context();
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
 /*
  * XXX document
  */
@@ -738,6 +756,7 @@ void prm_restore_context(void)
 
 int __init omap44xx_prm_init(const struct omap_prcm_init_data *data)
 {
+	static struct notifier_block nb;
 	omap_prm_base_init();
 
 	prm_init_data = data;
@@ -759,6 +778,12 @@ int __init omap44xx_prm_init(const struct omap_prcm_init_data *data)
 		omap4_prcm_irq_setup.mask = AM43XX_PRM_IRQENABLE_MPU_OFFSET;
 	}
 
+	/* Only AM43XX can lose prm context during rtc-ddr suspend */
+	if (soc_is_am43xx()) {
+		nb.notifier_call = cpu_notifier;
+		cpu_pm_register_notifier(&nb);
+	}
+
 	return prm_register(&omap44xx_prm_ll_data);
 }
 
-- 
1.9.1

[PATCH 1/2] ARM: OMAP2+: prm44xx: Introduce context save/restore for am43 PRCM IO

[Tony Lindgren]

* Keerthy <j-keerthy@ti.com> [180518 08:42]:
> From: Dave Gerlach <d-gerlach@ti.com> 
> 
> There are two registers on am43x needed for IO daisy chain wake to work
> properly, however currently after an RTC+DDR cycle they are lost. We
> must take care to save and restore these before and after entering RTC
> mode otherwise IO daisy chain wake will stop working from DeepSleep
> after resuming.

OK applying these two also into omap-for-v4.18/soc.

Regards,

Tony