[PATCH V5 9/9] firmware: imx: scu-irq: support identifying SCU wakeup source from sysfs

Peng Fan (OSS)
2023-07-31T09:02:26Z

From: Ranjani Vaidyanathan <ranjani.vaidyanathan@nxp.com>

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>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
drivers/firmware/imx/imx-scu-irq.c | 66 +++++++++++++++++++++++++++---
1 file changed, 61 insertions(+), 5 deletions(-)

diff --git a/drivers/firmware/imx/imx-scu-irq.c b/drivers/firmware/imx/imx-scu-irq.c
index 8d902db1daf2..fcbaa393897c 100644
--- a/drivers/firmware/imx/imx-scu-irq.c
+++ b/drivers/firmware/imx/imx-scu-irq.c
@@ -11,6 +11,8 @@
#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
@@ -40,6 +42,20 @@ struct imx_sc_msg_irq_enable {
u8 enable;
} __packed;

+struct scu_wakeup {
+ u32 mask;
+ u32 wakeup_src;
+ bool valid;
+};
+
+/* Sysfs functions */
+static 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);
@@ -71,16 +87,24 @@ 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",
- i, ret);
+ pr_err("get irq group %d status failed, ret %d\n", i, ret);
return;
}

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);
}
@@ -135,6 +159,11 @@ 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);
@@ -144,6 +173,25 @@ 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)
+{
+ int i;
+
+ for (i = 0; i < IMX_SC_IRQ_NUM_GROUP; i++) {
+ if (!scu_irq_wakeup[i].wakeup_src)
+ continue;
+
+ if (scu_irq_wakeup[i].valid)
+ sprintf(buf, "Wakeup source group = %d, irq = 0x%x\n",
+ i, scu_irq_wakeup[i].wakeup_src);
+ else
+ sprintf(buf, "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;
@@ -173,8 +221,7 @@ int imx_scu_enable_general_irq_channel(struct device *dev)

INIT_WORK(&imx_sc_irq_work, imx_scu_irq_work_handler);

- if (!of_parse_phandle_with_args(dev->of_node, "mboxes",
- "#mbox-cells", 0, &spec))
+ if (!of_parse_phandle_with_args(dev->of_node, "mboxes", "#mbox-cells", 0, &spec))
i = of_alias_get_id(spec.np, "mu");

/* use mu1 as general mu irq channel if failed */
@@ -183,6 +230,15 @@ 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);
--
2.37.1