[PATCH V4 0/3] rpmsg signaling/flowcontrol patches

[PATCH V4 0/3] rpmsg signaling/flowcontrol patches

[Sarannya S]

[Change from V3]:
Fixed review comments in previous set.

Sarannya S (3):
  rpmsg: core: Add signal API support
  rpmsg: glink: Add support to handle signals command
  rpmsg: char: Add TIOCMGET/TIOCMSET ioctl support

 drivers/rpmsg/qcom_glink_native.c | 63 +++++++++++++++++++++++++++++++++++++++
 drivers/rpmsg/rpmsg_char.c        | 60 ++++++++++++++++++++++++++++++++-----
 drivers/rpmsg/rpmsg_core.c        | 20 +++++++++++++
 drivers/rpmsg/rpmsg_internal.h    |  2 ++
 include/linux/rpmsg.h             | 15 ++++++++++
 5 files changed, 152 insertions(+), 8 deletions(-)

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH V4 1/3] rpmsg: core: Add signal API support

[Sarannya S]

Some transports like Glink support the state notifications between
clients using flow control signals similar to serial protocol signals.
Local glink client drivers can send and receive flow control status
to glink clients running on remote processors.

Add APIs to support sending and receiving of flow control status by
rpmsg clients.

Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com>
Signed-off-by: Sarannya S <quic_sarannya@quicinc.com>
---
 drivers/rpmsg/rpmsg_core.c     | 20 ++++++++++++++++++++
 drivers/rpmsg/rpmsg_internal.h |  2 ++
 include/linux/rpmsg.h          | 15 +++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index d6dde00e..0c5bf67 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -331,6 +331,24 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
 EXPORT_SYMBOL(rpmsg_trysend_offchannel);
 
 /**
+ * rpmsg_set_flow_control() - sets/clears serial flow control signals
+ * @ept:	the rpmsg endpoint
+ * @enable:	enable or disable serial flow control
+ *
+ * Return: 0 on success and an appropriate error value on failure.
+ */
+int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable)
+{
+	if (WARN_ON(!ept))
+		return -EINVAL;
+	if (!ept->ops->set_flow_control)
+		return -ENXIO;
+
+	return ept->ops->set_flow_control(ept, enable);
+}
+EXPORT_SYMBOL(rpmsg_set_flow_control);
+
+/**
  * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
  * @ept: the rpmsg endpoint
  *
@@ -539,6 +557,8 @@ static int rpmsg_dev_probe(struct device *dev)
 
 		rpdev->ept = ept;
 		rpdev->src = ept->addr;
+
+		ept->flow_cb = rpdrv->flowcontrol;
 	}
 
 	err = rpdrv->probe(rpdev);
diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index 39b646d..4fea45a 100644
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h
@@ -55,6 +55,7 @@ struct rpmsg_device_ops {
  * @trysendto:		see @rpmsg_trysendto(), optional
  * @trysend_offchannel:	see @rpmsg_trysend_offchannel(), optional
  * @poll:		see @rpmsg_poll(), optional
+ * @set_flow_control:	see @rpmsg_set_flow_control(), optional
  * @get_mtu:		see @rpmsg_get_mtu(), optional
  *
  * Indirection table for the operations that a rpmsg backend should implement.
@@ -75,6 +76,7 @@ struct rpmsg_endpoint_ops {
 			     void *data, int len);
 	__poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
 			     poll_table *wait);
+	int (*set_flow_control)(struct rpmsg_endpoint *ept, bool enable);
 	ssize_t (*get_mtu)(struct rpmsg_endpoint *ept);
 };
 
diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index 523c98b..cc7a917 100644
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h
@@ -64,12 +64,14 @@ struct rpmsg_device {
 };
 
 typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32);
+typedef int (*rpmsg_flowcontrol_cb_t)(struct rpmsg_device *, void *, bool);
 
 /**
  * struct rpmsg_endpoint - binds a local rpmsg address to its user
  * @rpdev: rpmsg channel device
  * @refcount: when this drops to zero, the ept is deallocated
  * @cb: rx callback handler
+ * @flow_cb: remote flow control callback handler
  * @cb_lock: must be taken before accessing/changing @cb
  * @addr: local rpmsg address
  * @priv: private data for the driver's use
@@ -92,6 +94,7 @@ struct rpmsg_endpoint {
 	struct rpmsg_device *rpdev;
 	struct kref refcount;
 	rpmsg_rx_cb_t cb;
+	rpmsg_flowcontrol_cb_t flow_cb;
 	struct mutex cb_lock;
 	u32 addr;
 	void *priv;
@@ -106,6 +109,7 @@ struct rpmsg_endpoint {
  * @probe: invoked when a matching rpmsg channel (i.e. device) is found
  * @remove: invoked when the rpmsg channel is removed
  * @callback: invoked when an inbound message is received on the channel
+ * @flowcontrol: invoked when remote side flow control status is received
  */
 struct rpmsg_driver {
 	struct device_driver drv;
@@ -113,6 +117,7 @@ struct rpmsg_driver {
 	int (*probe)(struct rpmsg_device *dev);
 	void (*remove)(struct rpmsg_device *dev);
 	int (*callback)(struct rpmsg_device *, void *, int, void *, u32);
+	int (*flowcontrol)(struct rpmsg_device *, void *, bool);
 };
 
 static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val)
@@ -192,6 +197,8 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
 
 ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept);
 
+int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable);
+
 #else
 
 static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev,
@@ -316,6 +323,14 @@ static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
 	return -ENXIO;
 }
 
+static inline int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable)
+{
+	/* This shouldn't be possible */
+	WARN_ON(1);
+
+	return -ENXIO;
+}
+
 #endif /* IS_ENABLED(CONFIG_RPMSG) */
 
 /* use a macro to avoid include chaining to get THIS_MODULE */
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH V4 2/3] rpmsg: glink: Add support to handle signals command

[Sarannya S]

Remote peripherals send signal notifications over glink with commandID 15.

Add support to send and receive the signal command and based signals
enable or disable flow control with remote host.

Signed-off-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com>
Signed-off-by: Sarannya S <quic_sarannya@quicinc.com>
---
 drivers/rpmsg/qcom_glink_native.c | 63 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index 115c0a1..01d0a49 100644
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -17,6 +17,7 @@
 #include <linux/rpmsg.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
+#include <linux/termios.h>
 #include <linux/workqueue.h>
 #include <linux/mailbox_client.h>
 
@@ -203,9 +204,15 @@ static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 #define RPM_CMD_TX_DATA_CONT		12
 #define RPM_CMD_READ_NOTIF		13
 #define RPM_CMD_RX_DONE_W_REUSE		14
+#define RPM_CMD_SIGNALS			15
 
 #define GLINK_FEATURE_INTENTLESS	BIT(1)
 
+#define NATIVE_DTR_SIG			NATIVE_DSR_SIG
+#define NATIVE_DSR_SIG			BIT(31)
+#define NATIVE_RTS_SIG			NATIVE_CTS_SIG
+#define NATIVE_CTS_SIG			BIT(30)
+
 static void qcom_glink_rx_done_work(struct work_struct *work);
 
 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
@@ -1001,6 +1008,57 @@ static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 	return 0;
 }
 
+/**
+ * qcom_glink_set_flow_control() - convert a signal cmd to wire format and
+ * 				   transmit
+ * @ept:	Rpmsg endpoint for channel.
+ * @enable:	True/False - enable or disable flow control
+ *
+ * Return: 0 on success or standard Linux error code.
+ */
+static int qcom_glink_set_flow_control(struct rpmsg_endpoint *ept, bool enable)
+{
+	struct glink_channel *channel = to_glink_channel(ept);
+	struct qcom_glink *glink = channel->glink;
+	struct glink_msg msg;
+	u32 sigs = 0;
+
+	if (enable)
+		sigs |= NATIVE_DTR_SIG | NATIVE_RTS_SIG;
+
+	msg.cmd = cpu_to_le16(RPM_CMD_SIGNALS);
+	msg.param1 = cpu_to_le16(channel->lcid);
+	msg.param2 = cpu_to_le32(sigs);
+
+	return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
+}
+
+static int qcom_glink_handle_signals(struct qcom_glink *glink,
+				     unsigned int rcid, unsigned int sigs)
+{
+	struct glink_channel *channel;
+	unsigned long flags;
+	bool enable = false;
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	channel = idr_find(&glink->rcids, rcid);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+	if (!channel) {
+		dev_err(glink->dev, "signal for non-existing channel\n");
+		return -EINVAL;
+	}
+
+	if (!channel->ept.flow_cb)
+		return 0;
+
+	if (sigs & (NATIVE_DSR_SIG | NATIVE_CTS_SIG))
+		enable = true;
+
+	channel->ept.flow_cb(channel->ept.rpdev, channel->ept.priv, enable);
+
+	return 0;
+}
+
 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 {
 	struct qcom_glink *glink = data;
@@ -1065,6 +1123,10 @@ static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 			qcom_glink_handle_intent_req_ack(glink, param1, param2);
 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
 			break;
+		case RPM_CMD_SIGNALS:
+			qcom_glink_handle_signals(glink, param1, param2);
+			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
+			break;
 		default:
 			dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
 			ret = -EINVAL;
@@ -1440,6 +1502,7 @@ static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
 	.sendto = qcom_glink_sendto,
 	.trysend = qcom_glink_trysend,
 	.trysendto = qcom_glink_trysendto,
+	.set_flow_control = qcom_glink_set_flow_control,
 };
 
 static void qcom_glink_rpdev_release(struct device *dev)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH V4 3/3] rpmsg: char: Add TIOCMGET/TIOCMSET ioctl support

[Sarannya S]

Add TICOMGET and TIOCMSET ioctl support for rpmsg char device nodes
to get/set the low level transport signals.

Signed-off-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com>
Signed-off-by: Sarannya S <quic_sarannya@quicinc.com>
---
 drivers/rpmsg/rpmsg_char.c | 60 +++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 52 insertions(+), 8 deletions(-)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 3e0b8f3..34822de 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -23,6 +23,7 @@
 #include <linux/rpmsg.h>
 #include <linux/skbuff.h>
 #include <linux/slab.h>
+#include <linux/termios.h>
 #include <linux/uaccess.h>
 #include <uapi/linux/rpmsg.h>
 
@@ -68,6 +69,8 @@ struct rpmsg_eptdev {
 	struct sk_buff_head queue;
 	wait_queue_head_t readq;
 
+	u32 remote_signals;
+	bool signals_pending;
 };
 
 int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data)
@@ -109,7 +112,22 @@ static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len,
 	skb_queue_tail(&eptdev->queue, skb);
 	spin_unlock(&eptdev->queue_lock);
 
-	/* wake up any blocking processes, waiting for new data */
+	wake_up_interruptible(&eptdev->readq);
+
+	return 0;
+}
+
+static int rpmsg_ept_flow_cb(struct rpmsg_device *rpdev, void *priv, bool enable)
+{
+	struct rpmsg_eptdev *eptdev = priv;
+
+	if (enable)
+		eptdev->remote_signals = TIOCM_DSR | TIOCM_CTS;
+	else
+		eptdev->remote_signals = 0;
+
+	eptdev->signals_pending = true;
+
 	wake_up_interruptible(&eptdev->readq);
 
 	return 0;
@@ -146,6 +164,7 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
 		return -EINVAL;
 	}
 
+	ept->flow_cb = rpmsg_ept_flow_cb;
 	eptdev->ept = ept;
 	filp->private_data = eptdev;
 	mutex_unlock(&eptdev->ept_lock);
@@ -166,6 +185,7 @@ static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
 		eptdev->ept = NULL;
 	}
 	mutex_unlock(&eptdev->ept_lock);
+	eptdev->signals_pending = false;
 
 	/* Discard all SKBs */
 	skb_queue_purge(&eptdev->queue);
@@ -279,6 +299,9 @@ static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait)
 	if (!skb_queue_empty(&eptdev->queue))
 		mask |= EPOLLIN | EPOLLRDNORM;
 
+	if (eptdev->signals_pending)
+		mask |= EPOLLPRI;
+
 	mask |= rpmsg_poll(eptdev->ept, filp, wait);
 
 	return mask;
@@ -289,14 +312,35 @@ static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
 {
 	struct rpmsg_eptdev *eptdev = fp->private_data;
 
-	if (cmd != RPMSG_DESTROY_EPT_IOCTL)
-		return -EINVAL;
-
-	/* Don't allow to destroy a default endpoint. */
-	if (eptdev->default_ept)
-		return -EINVAL;
+	bool set;
+	u32 val;
+	int ret;
+	
+	switch (cmd) {
+	case TIOCMGET:
+		eptdev->signals_pending = false;
+		ret = put_user(eptdev->remote_signals, (int __user *)arg);
+		break;
+	case TIOCMSET:
+		ret = get_user(val, (int __user *)arg);
+		if (ret)
+			break;
+		set = (val & (TIOCM_DTR | TIOCM_RTS)) ? true : false;
+		ret = rpmsg_set_flow_control(eptdev->ept, set);
+		break;
+	case RPMSG_DESTROY_EPT_IOCTL:
+		/* Don't allow to destroy a default endpoint. */
+		if (eptdev->default_ept) {
+			ret = -EINVAL;
+			break;
+		}
+		ret = rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
+		break;
+	default:
+		ret = -EINVAL;
+	}
 
-	return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
+	return ret;
 }
 
 static const struct file_operations rpmsg_eptdev_fops = {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V4 1/3] rpmsg: core: Add signal API support

[Arnaud POULIQUEN]

Hi Sarannya,

On 11/28/22 19:02, Sarannya S wrote:
> Some transports like Glink support the state notifications between
> clients using flow control signals similar to serial protocol signals.
> Local glink client drivers can send and receive flow control status
> to glink clients running on remote processors.
> 
> Add APIs to support sending and receiving of flow control status by
> rpmsg clients.
> 
> Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com>
> Signed-off-by: Sarannya S <quic_sarannya@quicinc.com>
> ---
>  drivers/rpmsg/rpmsg_core.c     | 20 ++++++++++++++++++++
>  drivers/rpmsg/rpmsg_internal.h |  2 ++
>  include/linux/rpmsg.h          | 15 +++++++++++++++
>  3 files changed, 37 insertions(+)
> 
> diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
> index d6dde00e..0c5bf67 100644
> --- a/drivers/rpmsg/rpmsg_core.c
> +++ b/drivers/rpmsg/rpmsg_core.c
> @@ -331,6 +331,24 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
>  EXPORT_SYMBOL(rpmsg_trysend_offchannel);
>  
>  /**
> + * rpmsg_set_flow_control() - sets/clears serial flow control signals
> + * @ept:	the rpmsg endpoint
> + * @enable:	enable or disable serial flow control
> + *
> + * Return: 0 on success and an appropriate error value on failure.
> + */
> +int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable)

Seems that you did not take into account comment in your V3 asking you to
add the destination address of the endpoint as parameter

Regards,
Arnaud

> +{
> +	if (WARN_ON(!ept))
> +		return -EINVAL;
> +	if (!ept->ops->set_flow_control)
> +		return -ENXIO;
> +
> +	return ept->ops->set_flow_control(ept, enable);
> +}
> +EXPORT_SYMBOL(rpmsg_set_flow_control);
> +
> +/**
>   * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
>   * @ept: the rpmsg endpoint
>   *
> @@ -539,6 +557,8 @@ static int rpmsg_dev_probe(struct device *dev)
>  
>  		rpdev->ept = ept;
>  		rpdev->src = ept->addr;
> +
> +		ept->flow_cb = rpdrv->flowcontrol;
>  	}
>  
>  	err = rpdrv->probe(rpdev);
> diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
> index 39b646d..4fea45a 100644
> --- a/drivers/rpmsg/rpmsg_internal.h
> +++ b/drivers/rpmsg/rpmsg_internal.h
> @@ -55,6 +55,7 @@ struct rpmsg_device_ops {
>   * @trysendto:		see @rpmsg_trysendto(), optional
>   * @trysend_offchannel:	see @rpmsg_trysend_offchannel(), optional
>   * @poll:		see @rpmsg_poll(), optional
> + * @set_flow_control:	see @rpmsg_set_flow_control(), optional
>   * @get_mtu:		see @rpmsg_get_mtu(), optional
>   *
>   * Indirection table for the operations that a rpmsg backend should implement.
> @@ -75,6 +76,7 @@ struct rpmsg_endpoint_ops {
>  			     void *data, int len);
>  	__poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
>  			     poll_table *wait);
> +	int (*set_flow_control)(struct rpmsg_endpoint *ept, bool enable);
>  	ssize_t (*get_mtu)(struct rpmsg_endpoint *ept);
>  };
>  
> diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
> index 523c98b..cc7a917 100644
> --- a/include/linux/rpmsg.h
> +++ b/include/linux/rpmsg.h
> @@ -64,12 +64,14 @@ struct rpmsg_device {
>  };
>  
>  typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32);
> +typedef int (*rpmsg_flowcontrol_cb_t)(struct rpmsg_device *, void *, bool);
>  
>  /**
>   * struct rpmsg_endpoint - binds a local rpmsg address to its user
>   * @rpdev: rpmsg channel device
>   * @refcount: when this drops to zero, the ept is deallocated
>   * @cb: rx callback handler
> + * @flow_cb: remote flow control callback handler
>   * @cb_lock: must be taken before accessing/changing @cb
>   * @addr: local rpmsg address
>   * @priv: private data for the driver's use
> @@ -92,6 +94,7 @@ struct rpmsg_endpoint {
>  	struct rpmsg_device *rpdev;
>  	struct kref refcount;
>  	rpmsg_rx_cb_t cb;
> +	rpmsg_flowcontrol_cb_t flow_cb;
>  	struct mutex cb_lock;
>  	u32 addr;
>  	void *priv;
> @@ -106,6 +109,7 @@ struct rpmsg_endpoint {
>   * @probe: invoked when a matching rpmsg channel (i.e. device) is found
>   * @remove: invoked when the rpmsg channel is removed
>   * @callback: invoked when an inbound message is received on the channel
> + * @flowcontrol: invoked when remote side flow control status is received
>   */
>  struct rpmsg_driver {
>  	struct device_driver drv;
> @@ -113,6 +117,7 @@ struct rpmsg_driver {
>  	int (*probe)(struct rpmsg_device *dev);
>  	void (*remove)(struct rpmsg_device *dev);
>  	int (*callback)(struct rpmsg_device *, void *, int, void *, u32);
> +	int (*flowcontrol)(struct rpmsg_device *, void *, bool);
>  };
>  
>  static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val)
> @@ -192,6 +197,8 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
>  
>  ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept);
>  
> +int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable);
> +
>  #else
>  
>  static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev,
> @@ -316,6 +323,14 @@ static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
>  	return -ENXIO;
>  }
>  
> +static inline int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable)
> +{
> +	/* This shouldn't be possible */
> +	WARN_ON(1);
> +
> +	return -ENXIO;
> +}
> +
>  #endif /* IS_ENABLED(CONFIG_RPMSG) */
>  
>  /* use a macro to avoid include chaining to get THIS_MODULE */

Re: [PATCH V4 0/3] rpmsg signaling/flowcontrol patches

[Bjorn Andersson]

On Mon, Nov 28, 2022 at 11:32:52PM +0530, Sarannya S wrote:
> [Change from V3]:
> Fixed review comments in previous set.
> 

Please do list the actual changes that you did. This ensures that new
people can focus on the new areas, if preferred, and that returning
reviewers get confirmation that their feedback was addressed.

Thanks,
Bjorn

> Sarannya S (3):
>   rpmsg: core: Add signal API support
>   rpmsg: glink: Add support to handle signals command
>   rpmsg: char: Add TIOCMGET/TIOCMSET ioctl support
> 
>  drivers/rpmsg/qcom_glink_native.c | 63 +++++++++++++++++++++++++++++++++++++++
>  drivers/rpmsg/rpmsg_char.c        | 60 ++++++++++++++++++++++++++++++++-----
>  drivers/rpmsg/rpmsg_core.c        | 20 +++++++++++++
>  drivers/rpmsg/rpmsg_internal.h    |  2 ++
>  include/linux/rpmsg.h             | 15 ++++++++++
>  5 files changed, 152 insertions(+), 8 deletions(-)
> 
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 

Re: [PATCH V4 1/3] rpmsg: core: Add signal API support

[Mathieu Poirier]

On Tue, 29 Nov 2022 at 02:29, Arnaud POULIQUEN
<arnaud.pouliquen@foss.st.com> wrote:
>
> Hi Sarannya,
>
> On 11/28/22 19:02, Sarannya S wrote:
> > Some transports like Glink support the state notifications between
> > clients using flow control signals similar to serial protocol signals.
> > Local glink client drivers can send and receive flow control status
> > to glink clients running on remote processors.
> >
> > Add APIs to support sending and receiving of flow control status by
> > rpmsg clients.
> >
> > Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com>
> > Signed-off-by: Sarannya S <quic_sarannya@quicinc.com>
> > ---
> >  drivers/rpmsg/rpmsg_core.c     | 20 ++++++++++++++++++++
> >  drivers/rpmsg/rpmsg_internal.h |  2 ++
> >  include/linux/rpmsg.h          | 15 +++++++++++++++
> >  3 files changed, 37 insertions(+)
> >
> > diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
> > index d6dde00e..0c5bf67 100644
> > --- a/drivers/rpmsg/rpmsg_core.c
> > +++ b/drivers/rpmsg/rpmsg_core.c
> > @@ -331,6 +331,24 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
> >  EXPORT_SYMBOL(rpmsg_trysend_offchannel);
> >
> >  /**
> > + * rpmsg_set_flow_control() - sets/clears serial flow control signals
> > + * @ept:     the rpmsg endpoint
> > + * @enable:  enable or disable serial flow control
> > + *
> > + * Return: 0 on success and an appropriate error value on failure.
> > + */
> > +int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable)
>
> Seems that you did not take into account comment in your V3 asking you to
> add the destination address of the endpoint as parameter

I will not review this patchset until Arnaud's comment is addressed or
a reason for the omission is provided.

>
> Regards,
> Arnaud
>
> > +{
> > +     if (WARN_ON(!ept))
> > +             return -EINVAL;
> > +     if (!ept->ops->set_flow_control)
> > +             return -ENXIO;
> > +
> > +     return ept->ops->set_flow_control(ept, enable);
> > +}
> > +EXPORT_SYMBOL(rpmsg_set_flow_control);
> > +
> > +/**
> >   * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
> >   * @ept: the rpmsg endpoint
> >   *
> > @@ -539,6 +557,8 @@ static int rpmsg_dev_probe(struct device *dev)
> >
> >               rpdev->ept = ept;
> >               rpdev->src = ept->addr;
> > +
> > +             ept->flow_cb = rpdrv->flowcontrol;
> >       }
> >
> >       err = rpdrv->probe(rpdev);
> > diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
> > index 39b646d..4fea45a 100644
> > --- a/drivers/rpmsg/rpmsg_internal.h
> > +++ b/drivers/rpmsg/rpmsg_internal.h
> > @@ -55,6 +55,7 @@ struct rpmsg_device_ops {
> >   * @trysendto:               see @rpmsg_trysendto(), optional
> >   * @trysend_offchannel:      see @rpmsg_trysend_offchannel(), optional
> >   * @poll:            see @rpmsg_poll(), optional
> > + * @set_flow_control:        see @rpmsg_set_flow_control(), optional
> >   * @get_mtu:         see @rpmsg_get_mtu(), optional
> >   *
> >   * Indirection table for the operations that a rpmsg backend should implement.
> > @@ -75,6 +76,7 @@ struct rpmsg_endpoint_ops {
> >                            void *data, int len);
> >       __poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
> >                            poll_table *wait);
> > +     int (*set_flow_control)(struct rpmsg_endpoint *ept, bool enable);
> >       ssize_t (*get_mtu)(struct rpmsg_endpoint *ept);
> >  };
> >
> > diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
> > index 523c98b..cc7a917 100644
> > --- a/include/linux/rpmsg.h
> > +++ b/include/linux/rpmsg.h
> > @@ -64,12 +64,14 @@ struct rpmsg_device {
> >  };
> >
> >  typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32);
> > +typedef int (*rpmsg_flowcontrol_cb_t)(struct rpmsg_device *, void *, bool);
> >
> >  /**
> >   * struct rpmsg_endpoint - binds a local rpmsg address to its user
> >   * @rpdev: rpmsg channel device
> >   * @refcount: when this drops to zero, the ept is deallocated
> >   * @cb: rx callback handler
> > + * @flow_cb: remote flow control callback handler
> >   * @cb_lock: must be taken before accessing/changing @cb
> >   * @addr: local rpmsg address
> >   * @priv: private data for the driver's use
> > @@ -92,6 +94,7 @@ struct rpmsg_endpoint {
> >       struct rpmsg_device *rpdev;
> >       struct kref refcount;
> >       rpmsg_rx_cb_t cb;
> > +     rpmsg_flowcontrol_cb_t flow_cb;
> >       struct mutex cb_lock;
> >       u32 addr;
> >       void *priv;
> > @@ -106,6 +109,7 @@ struct rpmsg_endpoint {
> >   * @probe: invoked when a matching rpmsg channel (i.e. device) is found
> >   * @remove: invoked when the rpmsg channel is removed
> >   * @callback: invoked when an inbound message is received on the channel
> > + * @flowcontrol: invoked when remote side flow control status is received
> >   */
> >  struct rpmsg_driver {
> >       struct device_driver drv;
> > @@ -113,6 +117,7 @@ struct rpmsg_driver {
> >       int (*probe)(struct rpmsg_device *dev);
> >       void (*remove)(struct rpmsg_device *dev);
> >       int (*callback)(struct rpmsg_device *, void *, int, void *, u32);
> > +     int (*flowcontrol)(struct rpmsg_device *, void *, bool);
> >  };
> >
> >  static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val)
> > @@ -192,6 +197,8 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
> >
> >  ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept);
> >
> > +int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable);
> > +
> >  #else
> >
> >  static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev,
> > @@ -316,6 +323,14 @@ static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
> >       return -ENXIO;
> >  }
> >
> > +static inline int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable)
> > +{
> > +     /* This shouldn't be possible */
> > +     WARN_ON(1);
> > +
> > +     return -ENXIO;
> > +}
> > +
> >  #endif /* IS_ENABLED(CONFIG_RPMSG) */
> >
> >  /* use a macro to avoid include chaining to get THIS_MODULE */

Re: [PATCH V4 1/3] rpmsg: core: Add signal API support

[Sarannya S]

On 11/30/2022 11:53 PM, Mathieu Poirier wrote:
> On Tue, 29 Nov 2022 at 02:29, Arnaud POULIQUEN
> <arnaud.pouliquen@foss.st.com> wrote:
>>
>> Hi Sarannya,
>>
>> On 11/28/22 19:02, Sarannya S wrote:
>>> Some transports like Glink support the state notifications between
>>> clients using flow control signals similar to serial protocol signals.
>>> Local glink client drivers can send and receive flow control status
>>> to glink clients running on remote processors.
>>>
>>> Add APIs to support sending and receiving of flow control status by
>>> rpmsg clients.
>>>
>>> Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com>
>>> Signed-off-by: Sarannya S <quic_sarannya@quicinc.com>
>>> ---
>>>   drivers/rpmsg/rpmsg_core.c     | 20 ++++++++++++++++++++
>>>   drivers/rpmsg/rpmsg_internal.h |  2 ++
>>>   include/linux/rpmsg.h          | 15 +++++++++++++++
>>>   3 files changed, 37 insertions(+)
>>>
>>> diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
>>> index d6dde00e..0c5bf67 100644
>>> --- a/drivers/rpmsg/rpmsg_core.c
>>> +++ b/drivers/rpmsg/rpmsg_core.c
>>> @@ -331,6 +331,24 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
>>>   EXPORT_SYMBOL(rpmsg_trysend_offchannel);
>>>
>>>   /**
>>> + * rpmsg_set_flow_control() - sets/clears serial flow control signals
>>> + * @ept:     the rpmsg endpoint
>>> + * @enable:  enable or disable serial flow control
>>> + *
>>> + * Return: 0 on success and an appropriate error value on failure.
>>> + */
>>> +int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable)
>>
>> Seems that you did not take into account comment in your V3 asking you to
>> add the destination address of the endpoint as parameter
> 
> I will not review this patchset until Arnaud's comment is addressed or
> a reason for the omission is provided.
> 
Arnaud, Mathieu,
Sorry, I did not find this comment in V3 patch.
I will update the patch by adding destination address as parameter.

Regards,
Sarannya
>>
>> Regards,
>> Arnaud
>>
>>> +{
>>> +     if (WARN_ON(!ept))
>>> +             return -EINVAL;
>>> +     if (!ept->ops->set_flow_control)
>>> +             return -ENXIO;
>>> +
>>> +     return ept->ops->set_flow_control(ept, enable);
>>> +}
>>> +EXPORT_SYMBOL(rpmsg_set_flow_control);
>>> +
>>> +/**
>>>    * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
>>>    * @ept: the rpmsg endpoint
>>>    *
>>> @@ -539,6 +557,8 @@ static int rpmsg_dev_probe(struct device *dev)
>>>
>>>                rpdev->ept = ept;
>>>                rpdev->src = ept->addr;
>>> +
>>> +             ept->flow_cb = rpdrv->flowcontrol;
>>>        }
>>>
>>>        err = rpdrv->probe(rpdev);
>>> diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
>>> index 39b646d..4fea45a 100644
>>> --- a/drivers/rpmsg/rpmsg_internal.h
>>> +++ b/drivers/rpmsg/rpmsg_internal.h
>>> @@ -55,6 +55,7 @@ struct rpmsg_device_ops {
>>>    * @trysendto:               see @rpmsg_trysendto(), optional
>>>    * @trysend_offchannel:      see @rpmsg_trysend_offchannel(), optional
>>>    * @poll:            see @rpmsg_poll(), optional
>>> + * @set_flow_control:        see @rpmsg_set_flow_control(), optional
>>>    * @get_mtu:         see @rpmsg_get_mtu(), optional
>>>    *
>>>    * Indirection table for the operations that a rpmsg backend should implement.
>>> @@ -75,6 +76,7 @@ struct rpmsg_endpoint_ops {
>>>                             void *data, int len);
>>>        __poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
>>>                             poll_table *wait);
>>> +     int (*set_flow_control)(struct rpmsg_endpoint *ept, bool enable);
>>>        ssize_t (*get_mtu)(struct rpmsg_endpoint *ept);
>>>   };
>>>
>>> diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
>>> index 523c98b..cc7a917 100644
>>> --- a/include/linux/rpmsg.h
>>> +++ b/include/linux/rpmsg.h
>>> @@ -64,12 +64,14 @@ struct rpmsg_device {
>>>   };
>>>
>>>   typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32);
>>> +typedef int (*rpmsg_flowcontrol_cb_t)(struct rpmsg_device *, void *, bool);
>>>
>>>   /**
>>>    * struct rpmsg_endpoint - binds a local rpmsg address to its user
>>>    * @rpdev: rpmsg channel device
>>>    * @refcount: when this drops to zero, the ept is deallocated
>>>    * @cb: rx callback handler
>>> + * @flow_cb: remote flow control callback handler
>>>    * @cb_lock: must be taken before accessing/changing @cb
>>>    * @addr: local rpmsg address
>>>    * @priv: private data for the driver's use
>>> @@ -92,6 +94,7 @@ struct rpmsg_endpoint {
>>>        struct rpmsg_device *rpdev;
>>>        struct kref refcount;
>>>        rpmsg_rx_cb_t cb;
>>> +     rpmsg_flowcontrol_cb_t flow_cb;
>>>        struct mutex cb_lock;
>>>        u32 addr;
>>>        void *priv;
>>> @@ -106,6 +109,7 @@ struct rpmsg_endpoint {
>>>    * @probe: invoked when a matching rpmsg channel (i.e. device) is found
>>>    * @remove: invoked when the rpmsg channel is removed
>>>    * @callback: invoked when an inbound message is received on the channel
>>> + * @flowcontrol: invoked when remote side flow control status is received
>>>    */
>>>   struct rpmsg_driver {
>>>        struct device_driver drv;
>>> @@ -113,6 +117,7 @@ struct rpmsg_driver {
>>>        int (*probe)(struct rpmsg_device *dev);
>>>        void (*remove)(struct rpmsg_device *dev);
>>>        int (*callback)(struct rpmsg_device *, void *, int, void *, u32);
>>> +     int (*flowcontrol)(struct rpmsg_device *, void *, bool);
>>>   };
>>>
>>>   static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val)
>>> @@ -192,6 +197,8 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
>>>
>>>   ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept);
>>>
>>> +int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable);
>>> +
>>>   #else
>>>
>>>   static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev,
>>> @@ -316,6 +323,14 @@ static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
>>>        return -ENXIO;
>>>   }
>>>
>>> +static inline int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool enable)
>>> +{
>>> +     /* This shouldn't be possible */
>>> +     WARN_ON(1);
>>> +
>>> +     return -ENXIO;
>>> +}
>>> +
>>>   #endif /* IS_ENABLED(CONFIG_RPMSG) */
>>>
>>>   /* use a macro to avoid include chaining to get THIS_MODULE */

[PATCH V4 0/3] rpmsg signaling/flowcontrol patches

[Sarannya S]

Added destination address of the endpoint as parameter in rpmsg_set_flow_control.
Zero initialized sigs variable in qcom_glink_set_flow_control.
Renamed rpmsg_flow_cb to rpmsg_ept_flow_cb.


Sarannya S (3):
  rpmsg: core: Add signal API support
  rpmsg: glink: Add support to handle signals command
  rpmsg: char: Add TIOCMGET/TIOCMSET ioctl support

 drivers/rpmsg/qcom_glink_native.c | 64 +++++++++++++++++++++++++++++++++++++++
 drivers/rpmsg/rpmsg_char.c        | 60 +++++++++++++++++++++++++++++++-----
 drivers/rpmsg/rpmsg_core.c        | 21 +++++++++++++
 drivers/rpmsg/rpmsg_internal.h    |  2 ++
 include/linux/rpmsg.h             | 15 +++++++++
 5 files changed, 154 insertions(+), 8 deletions(-)

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