diff mbox series

[V1,2/3] usb: misc: Add notifier call chain to Embedded USB Debug(EUD) driver

Message ID 18212c7abbb8c833cc07f8500d4905b79c49ec59.1689148711.git.quic_schowdhu@quicinc.com (mailing list archive)
State New, archived
Headers show
Series Add notifier call chain to Embedded USB Debug(EUD) driver | expand

Commit Message

Souradeep Chowdhury July 12, 2023, 8:22 a.m. UTC
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@quicinc.com>
---
 drivers/usb/misc/qcom_eud.c | 52 +++++++++++++++++++++++++++++++++++--
 1 file changed, 50 insertions(+), 2 deletions(-)

Comments

Bhupesh Sharma July 12, 2023, 6:22 p.m. UTC | #1
Hi Souradeep,

On Wed, 12 Jul 2023 at 13:58, Souradeep Chowdhury
<quic_schowdhu@quicinc.com> wrote:
>
> 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@quicinc.com>
> ---
>  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)

These indentation issues are already addressed in my EUD patches.
Please rebase your patches on the same to reuse those.

> +#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);

Probably I missed it, but you have not provided any example users of
these APIs in the patchset or reference to another one which shows how
these APIs are used.

> +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,

Why do you need a 'priority = 1' here, it can be 0 or even lower?

Thanks,
Bhupesh

> +};
> +
>  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
>
Souradeep Chowdhury July 13, 2023, 8:30 a.m. UTC | #2
On 7/12/2023 11:52 PM, Bhupesh Sharma wrote:
> Hi Souradeep,
> 
> On Wed, 12 Jul 2023 at 13:58, Souradeep Chowdhury
> <quic_schowdhu@quicinc.com> wrote:
>>
>> 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@quicinc.com>
>> ---
>>   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)
> 
> These indentation issues are already addressed in my EUD patches.
> Please rebase your patches on the same to reuse those
Ack

> 
>> +#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);
> 
> Probably I missed it, but you have not provided any example users of
> these APIs in the patchset or reference to another one which shows how
> these APIs are used.

Ack, the usage for this will be posted in the next version.

> 
>> +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,
> 
> Why do you need a 'priority = 1' here, it can be 0 or even lower?

Priority is 0 by default for a notifier block, since eud notifier
needs to be the first to be called in the chain to check the
role-switch status, I have kept the priority as 1 here.

> 
> Thanks,
> Bhupesh
> 
>> +};
>> +
>>   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
>>
diff mbox series

Patch

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[] = {