Add the notifier call chain to EUD driver. The notifier call chain
is added to check the role-switch status of EUD. When multiple
modules are switching roles on the same port, they need to call this
notifier to check the role-switch status of EUD. If EUD is disabled,
then the modules can go for the role-switch, otherwise it needs to
be blocked. The notifier chain can be used to link multiple modules
switching roles on the same port and create a ordering, priority and
conflict resolution among them. The wrapper functions are defined here
which can be used to register a notifier block to the chain, deregister
it and also call the chain.
Signed-off-by: Souradeep Chowdhury <quic_schowdhu@xxxxxxxxxxx>
---
drivers/usb/misc/qcom_eud.c | 52 +++++++++++++++++++++++++++++++++++--
1 file changed, 50 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/misc/qcom_eud.c b/drivers/usb/misc/qcom_eud.c
index 7f371ea1248c..e6c97a2cf2df 100644
--- a/drivers/usb/misc/qcom_eud.c
+++ b/drivers/usb/misc/qcom_eud.c
@@ -11,10 +11,13 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/usb/role.h>
+#include "qcom_eud_notifier.h"
#define EUD_REG_INT1_EN_MASK 0x0024
#define EUD_REG_INT_STATUS_1 0x0044
@@ -22,14 +25,16 @@
#define EUD_REG_VBUS_INT_CLR 0x0080
#define EUD_REG_CSR_EUD_EN 0x1014
#define EUD_REG_SW_ATTACH_DET 0x1018
-#define EUD_REG_EUD_EN2 0x0000
+#define EUD_REG_EUD_EN2 0x0000
#define EUD_ENABLE BIT(0)
-#define EUD_INT_PET_EUD BIT(0)
+#define EUD_INT_PET_EUD BIT(0)
#define EUD_INT_VBUS BIT(2)
#define EUD_INT_SAFE_MODE BIT(4)
#define EUD_INT_ALL (EUD_INT_VBUS | EUD_INT_SAFE_MODE)
+static RAW_NOTIFIER_HEAD(eud_nh);
+
struct eud_chip {
struct device *dev;
struct usb_role_switch *role_sw;
@@ -41,6 +46,42 @@ struct eud_chip {
bool usb_attached;
};
+int eud_register_notify(struct notifier_block *nb)
+{
+ return raw_notifier_chain_register(&eud_nh, nb);
+}
+EXPORT_SYMBOL_GPL(eud_register_notify);
+
+void eud_unregister_notify(struct notifier_block *nb)
+{
+ raw_notifier_chain_unregister(&eud_nh, nb);
+}
+EXPORT_SYMBOL_GPL(eud_unregister_notify);
+
+void eud_notifier_call_chain(unsigned long role_switch_state)
+{
+ raw_notifier_call_chain(&eud_nh, role_switch_state, NULL);
+}
+EXPORT_SYMBOL_GPL(eud_notifier_call_chain);
+
+static int eud_vbus_spoof_attach_detach(struct notifier_block *nb, unsigned long event,
+ void *data)
+{
+ struct device_node *eud = of_find_compatible_node(NULL, NULL, "qcom,eud");
+ struct device *eud_device = bus_find_device_by_of_node(&platform_bus_type, eud);
+ struct eud_chip *eud_data = dev_get_drvdata(eud_device);
+
+ if (eud_data->enabled && event != USB_ROLE_DEVICE)
+ return NOTIFY_BAD;
+ else
+ return NOTIFY_OK;
+}
+
+static struct notifier_block eud_notifier = {
+ .notifier_call = eud_vbus_spoof_attach_detach,
+ .priority = 1,
+};
+
static int enable_eud(struct eud_chip *priv)
{
writel(EUD_ENABLE, priv->base + EUD_REG_CSR_EUD_EN);
@@ -196,6 +237,10 @@ static int eud_probe(struct platform_device *pdev)
return dev_err_probe(chip->dev, ret,
"failed to add role switch release action\n");
+ ret = eud_register_notify(&eud_notifier);
+ if (ret)
+ return dev_err_probe(chip->dev, ret, "failed to register notifier\n");
+
chip->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(chip->base))
return PTR_ERR(chip->base);
@@ -226,6 +271,9 @@ static void eud_remove(struct platform_device *pdev)
device_init_wakeup(&pdev->dev, false);
disable_irq_wake(chip->irq);
+ eud_unregister_notify(&eud_notifier);
+
+ return 0;
}
static const struct of_device_id eud_dt_match[] = {
--
2.17.1
