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 <[email protected]>
---
arch/arm64/configs/defconfig | 2 ++
drivers/rpmsg/rpmsg_core.c | 20 ++++++++++++++++++++
drivers/rpmsg/rpmsg_internal.h | 2 ++
include/linux/rpmsg.h | 15 +++++++++++++++
4 files changed, 39 insertions(+)
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 0b6af33..2df3778 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -26,6 +26,8 @@ CONFIG_CGROUP_CPUACCT=y
CONFIG_CGROUP_PERF=y
CONFIG_CGROUP_BPF=y
CONFIG_USER_NS=y
+CONFIG_RPMSG=y
+CONFIG_RPMSG_CHAR=y
CONFIG_SCHED_AUTOGROUP=y
CONFIG_BLK_DEV_INITRD=y
CONFIG_KALLSYMS_ALL=y
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
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 <[email protected]>
Signed-off-by: Deepak Kumar Singh <[email protected]>
Signed-off-by: Sarannya S <[email protected]>
---
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
Please send another revision with a proper cover letter that details
the changes made between the last version.
On Mon, 28 Nov 2022 at 06:28, Sarannya S <[email protected]> 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 <[email protected]>
> ---
> arch/arm64/configs/defconfig | 2 ++
> drivers/rpmsg/rpmsg_core.c | 20 ++++++++++++++++++++
> drivers/rpmsg/rpmsg_internal.h | 2 ++
> include/linux/rpmsg.h | 15 +++++++++++++++
> 4 files changed, 39 insertions(+)
>
> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
> index 0b6af33..2df3778 100644
> --- a/arch/arm64/configs/defconfig
> +++ b/arch/arm64/configs/defconfig
> @@ -26,6 +26,8 @@ CONFIG_CGROUP_CPUACCT=y
> CONFIG_CGROUP_PERF=y
> CONFIG_CGROUP_BPF=y
> CONFIG_USER_NS=y
> +CONFIG_RPMSG=y
> +CONFIG_RPMSG_CHAR=y
> CONFIG_SCHED_AUTOGROUP=y
> CONFIG_BLK_DEV_INITRD=y
> CONFIG_KALLSYMS_ALL=y
> 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
>