pinctrl: pinctrl-single: Add functions to save and restore pinctrl contex

index 7f02743..f2e16e3 100644
@@ -35,6 +35,7 @@
 #include "omap-secure.h"
 #include "soc.h"
 #include "hsmmc.h"
+#include "pm.h"
 
 static struct omap_hsmmc_platform_data __maybe_unused mmc_pdata[2];
 

@@ -489,12 +490,17 @@ static int ti_sysc_shutdown_module(struct device *dev,
 	.shutdown_module = ti_sysc_shutdown_module,
 };
 
+int context_may_be_lost(void)
+{
+	return enable_off_mode;
+}
 static struct pcs_pdata pcs_pdata;
 
 void omap_pcs_legacy_init(int irq, void (*rearm)(void))
 {
 	pcs_pdata.irq = irq;
 	pcs_pdata.rearm = rearm;
+	pcs_pdata.context_may_be_lost = context_may_be_lost;
 }
 
 /*

index 1cf36fd..f07c1f2 100644
@@ -10,4 +10,5 @@
 struct pcs_pdata {
 	int irq;
 	void (*rearm)(void);
+	int (*context_may_be_lost)(void);
 };

index a7c5eb3..3062ebb 100644
@@ -16,6 +16,7 @@
 #include <linux/err.h>
 #include <linux/list.h>
 #include <linux/interrupt.h>
+#include <linux/cpu_pm.h>
 
 #include <linux/irqchip/chained_irq.h>
 

@@ -144,6 +145,7 @@ struct pcs_soc_data {
  * struct pcs_device - pinctrl device instance
  * @res:	resources
  * @base:	virtual address of the controller
+ * @saved_vals: saved values for the controller
  * @size:	size of the ioremapped area
  * @dev:	device entry
  * @np:		device tree node

@@ -172,11 +174,13 @@ struct pcs_soc_data {
 struct pcs_device {
 	struct resource *res;
 	void __iomem *base;
+	void *saved_vals;
 	unsigned size;
 	struct device *dev;
 	struct device_node *np;
 	struct pinctrl_dev *pctl;
 	unsigned flags;
+#define PCS_CONTEXT_LOSS_OFF	(1 << 3)
 #define PCS_QUIRK_SHARED_IRQ	(1 << 2)
 #define PCS_FEAT_IRQ		(1 << 1)
 #define PCS_FEAT_PINCONF	(1 << 0)

@@ -195,6 +199,7 @@ struct pcs_device {
 	struct list_head gpiofuncs;
 	struct list_head irqs;
 	struct irq_chip chip;
+	struct notifier_block nb;
 	struct irq_domain *domain;
 	struct pinctrl_desc desc;
 	unsigned (*read)(void __iomem *reg);

@@ -1649,6 +1654,86 @@ static int pcs_quirk_missing_pinctrl_cells(struct pcs_device *pcs,
 	return error;
 }
 
+static int pcs_save_context(struct pcs_device *pcs)
+{
+	int i, mux_bytes;
+	u64 *regsl;
+	u32 *regsw;
+	u16 *regshw;
+
+	mux_bytes = pcs->width / BITS_PER_BYTE;
+
+	if (!pcs->saved_vals)
+		pcs->saved_vals = devm_kzalloc(pcs->dev, pcs->size, GFP_ATOMIC);
+
+	switch (pcs->width) {
+	case 64:
+		regsl = (u64 *)pcs->saved_vals;
+		for (i = 0; i < pcs->size / mux_bytes; i++)
+			regsl[i] = pcs->read(pcs->base + i * mux_bytes);
+		break;
+	case 32:
+		regsw = (u32 *)pcs->saved_vals;
+		for (i = 0; i < pcs->size / mux_bytes; i++)
+			regsw[i] = pcs->read(pcs->base + i * mux_bytes);
+		break;
+	case 16:
+		regshw = (u16 *)pcs->saved_vals;
+		for (i = 0; i < pcs->size / mux_bytes; i++)
+			regshw[i] = pcs->read(pcs->base + i * mux_bytes);
+		break;
+	}
+
+	return 0;
+}
+
+static void pcs_restore_context(struct pcs_device *pcs)
+{
+	int i, mux_bytes;
+	u64 *regsl;
+	u32 *regsw;
+	u16 *regshw;
+
+	mux_bytes = pcs->width / BITS_PER_BYTE;
+
+	switch (pcs->width) {
+	case 64:
+		regsl = (u64 *)pcs->saved_vals;
+		for (i = 0; i < pcs->size / mux_bytes; i++)
+			pcs->write(regsl[i], pcs->base + i * mux_bytes);
+		break;
+	case 32:
+		regsw = (u32 *)pcs->saved_vals;
+		for (i = 0; i < pcs->size / mux_bytes; i++)
+			pcs->write(regsw[i], pcs->base + i * mux_bytes);
+		break;
+	case 16:
+		regshw = (u16 *)pcs->saved_vals;
+		for (i = 0; i < pcs->size / mux_bytes; i++)
+			pcs->write(regshw[i], pcs->base + i * mux_bytes);
+		break;
+	}
+}
+
+static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
+{
+	struct pcs_device *pcs = container_of(nb, struct pcs_device, nb);
+	struct pcs_pdata *pdata = dev_get_platdata(pcs->dev);
+
+	switch (cmd) {
+	case CPU_CLUSTER_PM_ENTER:
+		if (pdata->context_may_be_lost())
+			pcs_save_context(pcs);
+		break;
+	case CPU_CLUSTER_PM_EXIT:
+		if (pdata->context_may_be_lost())
+			pcs_restore_context(pcs);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
 static int pcs_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;

@@ -1792,6 +1877,11 @@ static int pcs_probe(struct platform_device *pdev)
 
 	dev_info(pcs->dev, "%i pins, size %u\n", pcs->desc.npins, pcs->size);
 
+	if (soc->flags & PCS_CONTEXT_LOSS_OFF) {
+		pcs->nb.notifier_call = cpu_notifier;
+		cpu_pm_register_notifier(&pcs->nb);
+	}
+
 	return pinctrl_enable(pcs->pctl);
 
 free:

@@ -1807,6 +1897,9 @@ static int pcs_remove(struct platform_device *pdev)
 	if (!pcs)
 		return 0;
 
+	if (pcs->flags & PCS_CONTEXT_LOSS_OFF)
+		cpu_pm_unregister_notifier(&pcs->nb);
+
 	pcs_free_resources(pcs);
 
 	return 0;

@@ -1824,7 +1917,7 @@ static int pcs_remove(struct platform_device *pdev)
 };
 
 static const struct pcs_soc_data pinctrl_single_am437x = {
-	.flags = PCS_QUIRK_SHARED_IRQ,
+	.flags = PCS_QUIRK_SHARED_IRQ | PCS_CONTEXT_LOSS_OFF,
 	.irq_enable_mask = (1 << 29),   /* OMAP_WAKEUP_EN */
 	.irq_status_mask = (1 << 30),   /* OMAP_WAKEUP_EVENT */
 };