MLK-25649-1 firmware: imx: imx-scu-irq: Add support for identifying SCU wakeup source from sysfs

Record SCU wakeup interrupt in /sys/power/pm_wakeup_irq
The user can further identify the exact wakeup source by using the
following interface:
cat /sys/firmware/scu_wakeup_source/wakeup_src

The above will print the wake groups and the irqs that could have
contributed to waking up the kernel. For example if ON/OFF button was the
wakeup source:
cat /sys/firmware/scu_wakeup_source/wakeup_src
Wakeup source group = 3, irq = 0x1

The user can refer to the SCFW API documentation to identify all the
wake groups and irqs.

Signed-off-by: Ranjani Vaidyanathan <ranjani.vaidyanathan@nxp.com>
(cherry picked from commit d49daabfb43eddf94144560fc2eef58015311454)
(cherry picked from commit fed9f95ad512fd4b4cca7c8bfd08a78ddcaebeb9)

2 files changed, 81 insertions, 3 deletions

diff --git a/drivers/firmware/imx/imx-scu-irq.c b/drivers/firmware/imx/imx-scu-irq.c
index 369621c14105..b4272a75a315 100644
--- a/drivers/firmware/imx/imx-scu-irq.c
+++ b/drivers/firmware/imx/imx-scu-irq.c
@@ -10,10 +10,11 @@
 #include <linux/firmware/imx/sci.h>
 #include <linux/mailbox_client.h>
 #include <linux/suspend.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
 
 #define IMX_SC_IRQ_FUNC_ENABLE	1
 #define IMX_SC_IRQ_FUNC_STATUS	2
-#define IMX_SC_IRQ_NUM_GROUP	7
 
 static u32 mu_resource_id;
 
@@ -39,6 +40,20 @@ struct imx_sc_msg_irq_enable {
 	u8 enable;
 } __packed;
 
+struct scu_wakeup {
+	u32 mask;
+	u32 wakeup_src;
+	bool valid;
+};
+
+/* Sysfs functions */
+struct kobject *wakeup_obj;
+static ssize_t wakeup_source_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf);
+static struct kobj_attribute wakeup_source_attr = __ATTR(wakeup_src, 0660, wakeup_source_show, NULL);
+
+static struct scu_wakeup scu_irq_wakeup[IMX_SC_IRQ_NUM_GROUP];
+
+
 static struct imx_sc_ipc *imx_sc_irq_ipc_handle;
 static struct work_struct imx_sc_irq_work;
 static BLOCKING_NOTIFIER_HEAD(imx_scu_irq_notifier_chain);
@@ -70,6 +85,10 @@ static void imx_scu_irq_work_handler(struct work_struct *work)
 	u8 i;
 
 	for (i = 0; i < IMX_SC_IRQ_NUM_GROUP; i++) {
+		if (scu_irq_wakeup[i].mask) {
+			scu_irq_wakeup[i].valid = false;
+			scu_irq_wakeup[i].wakeup_src = 0;
+		}
 		ret = imx_scu_irq_get_status(i, &irq_status);
 		if (ret) {
 			pr_err("get irq group %d status failed, ret %d\n",
@@ -79,7 +98,12 @@ static void imx_scu_irq_work_handler(struct work_struct *work)
 
 		if (!irq_status)
 			continue;
-
+		if (scu_irq_wakeup[i].mask & irq_status) {
+			scu_irq_wakeup[i].valid = true;
+			scu_irq_wakeup[i].wakeup_src = irq_status & scu_irq_wakeup[i].mask;
+		} else {
+			scu_irq_wakeup[i].wakeup_src = irq_status;
+		}
 		pm_system_wakeup();
 		imx_scu_irq_notifier_call_chain(irq_status, &i);
 	}
@@ -134,6 +158,11 @@ int imx_scu_irq_group_enable(u8 group, u32 mask, u8 enable)
 		pr_err("enable irq failed, group %d, mask %d, ret %d\n",
 			group, mask, ret);
 
+	if (enable)
+		scu_irq_wakeup[group].mask |= mask;
+	else
+		scu_irq_wakeup[group].mask &= ~mask;
+
 	return ret;
 }
 EXPORT_SYMBOL(imx_scu_irq_group_enable);
@@ -143,6 +172,24 @@ static void imx_scu_irq_callback(struct mbox_client *c, void *msg)
 	schedule_work(&imx_sc_irq_work);
 }
 
+static ssize_t wakeup_source_show(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	u8 i = 0, size = 0;
+
+	for (i = 0; i < IMX_SC_IRQ_NUM_GROUP; i++) {
+		if (scu_irq_wakeup[i].wakeup_src != 0) {
+			if (scu_irq_wakeup[i].valid)
+				size += sprintf(buf + size, "Wakeup source group = %d, irq = 0x%x\n",
+							i, scu_irq_wakeup[i].wakeup_src);
+			else
+				size += sprintf(buf + size, "Spurious SCU wakeup, group = %d, irq = 0x%x\n",
+							i, scu_irq_wakeup[i].wakeup_src);
+		}
+	}
+	return strlen(buf);
+}
+
 int imx_scu_enable_general_irq_channel(struct device *dev)
 {
 	struct of_phandle_args spec;
@@ -182,6 +229,15 @@ int imx_scu_enable_general_irq_channel(struct device *dev)
 
 	mu_resource_id = IMX_SC_R_MU_0A + i;
 
+	/* Create directory under /sysfs/firmware */
+	wakeup_obj = kobject_create_and_add("scu_wakeup_source", firmware_kobj);
+
+	if (sysfs_create_file(wakeup_obj, &wakeup_source_attr.attr)) {
+		pr_err("Cannot create sysfs file......\n");
+		kobject_put(wakeup_obj);
+		sysfs_remove_file(firmware_kobj, &wakeup_source_attr.attr);
+	}
+
 	return ret;
 }
 EXPORT_SYMBOL(imx_scu_enable_general_irq_channel);
diff --git a/include/linux/firmware/imx/sci.h b/include/linux/firmware/imx/sci.h
index e749594436bb..70fe789aa842 100644
--- a/include/linux/firmware/imx/sci.h
+++ b/include/linux/firmware/imx/sci.h
@@ -17,12 +17,34 @@
 #include <linux/firmware/imx/svc/rm.h>
 #include <linux/firmware/imx/svc/seco.h>
 
-#define IMX_SC_IRQ_GROUP_WAKE       3U /* Wakeup interrupts */
+#define IMX_SC_IRQ_NUM_GROUP            9
+
+#define IMX_SC_IRQ_GROUP_TEMP           0   /* Temp interrupts */
+#define IMX_SC_IRQ_GROUP_WDOG           1   /* Watchdog interrupts */
+#define IMX_SC_IRQ_GROUP_RTC            2   /* RTC interrupts */
+#define IMX_SC_IRQ_GROUP_WAKE           3   /* Wakeup interrupts */
+#define IMX_SC_IRQ_GROUP_SYSCTR         4   /* System counter interrupts */
+#define IMX_SC_IRQ_GROUP_REBOOTED       5   /* Partition reboot complete */
+#define IMX_SC_IRQ_GROUP_REBOOT         6   /* Partition reboot starting */
+#define IMX_SC_IRQ_GROUP_OFFED          7   /* Partition off complete */
+#define IMX_SC_IRQ_GROUP_OFF            8   /* Partition off starting */
+
+#define IMX_SC_IRQ_RTC               BIT(0)    /* RTC interrupt */
+#define IMX_SC_IRQ_WDOG              BIT(0)    /* Watch Dog interrupt */
+#define IMX_SC_IRQ_SYSCTR            BIT(0)    /* System Counter interrupt */
+#define IMX_SC_IRQ_BUTTON            BIT(0)    /* Button interrupt */
+#define IMX_SC_IRQ_PAD               BIT(1)    /* Pad wakeup */
+#define IMX_SC_IRQ_USR1              BIT(2)    /* User defined 1 */
+#define IMX_SC_IRQ_USR2              BIT(3)    /* User defined 2 */
+#define IMX_SC_IRQ_BC_PAD            BIT(4)    /* Pad wakeup (broadcast to all partitions) */
+#define IMX_SC_IRQ_SW_WAKE           BIT(5)    /* Software requested wake */
 #define IMX_SC_IRQ_SECVIO            BIT(6)    /* Security violation */
+#define IMX_SC_IRQ_V2X_RESET         BIT(7)    /* V2X reset */
 
 int imx_scu_enable_general_irq_channel(struct device *dev);
 int imx_scu_irq_register_notifier(struct notifier_block *nb);
 int imx_scu_irq_unregister_notifier(struct notifier_block *nb);
 int imx_scu_irq_group_enable(u8 group, u32 mask, u8 enable);
 int imx_scu_irq_get_status(u8 group, u32 *irq_status);
+
 #endif /* _SC_SCI_H */