diff mbox series

[V1,2/3] rpmsg: glink: Add support to handle signals command

Message ID 1633015924-881-4-git-send-email-deesin@codeaurora.org (mailing list archive)
State Changes Requested
Headers show
Series rpmsg and glink signaling api support | expand

Commit Message

Deepak Kumar Singh Sept. 30, 2021, 3:32 p.m. UTC
Remote peripherals send signal notifications over glink with commandID 15.

Add support to send and receive the signal command and convert the signals
from NATIVE to TIOCM while receiving and vice versa while sending.

Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
---
 drivers/rpmsg/qcom_glink_native.c | 75 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

Comments

Stephen Boyd Sept. 30, 2021, 4:33 p.m. UTC | #1
Quoting Deepak Kumar Singh (2021-09-30 08:32:03)
> diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
> index 05533c7..384fcd2 100644
> --- a/drivers/rpmsg/qcom_glink_native.c
> +++ b/drivers/rpmsg/qcom_glink_native.c
> @@ -976,6 +984,68 @@ 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;

Drop assignment.

> +
> +       /**
> +        * convert signals from TIOCM to NATIVE
> +        * sigs = TIOCM_DTR|TIOCM_RTS
> +        */
> +       if (enable)
> +               sigs |= (NATIVE_DTR_SIG | NATIVE_CTS_SIG);

sigs = NATIVE_DTR_SIG | NATIVE_CTS_SIG;

> +       else
> +               sigs |= (~(NATIVE_DTR_SIG | NATIVE_CTS_SIG));

sigs = ~(NATIVE_DTR_SIG | NATIVE_CTS_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;
> +
> +       spin_lock_irqsave(&glink->idr_lock, flags);

irqsave can be skipped because this is only called from an irq handler.

> +       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;
> +       }
> +
> +       /* convert signals from NATIVE to TIOCM */
> +       if (sigs & NATIVE_DTR_SIG)
> +               sigs |= TIOCM_DSR;
> +       if (sigs & NATIVE_CTS_SIG)
> +               sigs |= TIOCM_CTS;
> +       if (sigs & NATIVE_CD_SIG)
> +               sigs |= TIOCM_CD;
> +       if (sigs & NATIVE_RI_SIG)
> +               sigs |= TIOCM_RI;
> +       sigs &= 0x0fff;

Is this to only keep TIOCM_* bits? Maybe make this an ORed together mask
of those bits so we know what 0xfff means.

> +
> +       if (channel->ept.sig_cb)
> +               channel->ept.sig_cb(channel->ept.rpdev, channel->ept.priv, sigs);
> +
> +       return 0;
> +}
> +
>  static irqreturn_t qcom_glink_native_intr(int irq, void *data)
>  {
>         struct qcom_glink *glink = data;
> @@ -1037,6 +1107,10 @@ 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);

Should the return value be handled and if there isn't a channel then
treat it as a spurious irq?

> +                       qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
> +                       break;
>                 default:
>                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
>                         ret = -EINVAL;
Matthias Kaehlcke Nov. 24, 2021, 7:17 p.m. UTC | #2
On Thu, Sep 30, 2021 at 09:02:03PM +0530, Deepak Kumar Singh wrote:
> Remote peripherals send signal notifications over glink with commandID 15.
> 
> Add support to send and receive the signal command and convert the signals
> from NATIVE to TIOCM while receiving and vice versa while sending.
> 
> Signed-off-by: Chris Lew <clew@codeaurora.org>
> Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
> ---
>  drivers/rpmsg/qcom_glink_native.c | 75 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 75 insertions(+)
> 
> diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
> index 05533c7..384fcd2 100644
> --- a/drivers/rpmsg/qcom_glink_native.c
> +++ b/drivers/rpmsg/qcom_glink_native.c
>
> ...
>
> +static int qcom_glink_handle_signals(struct qcom_glink *glink,
> +				     unsigned int rcid, unsigned int sigs)
> +{
> +	struct glink_channel *channel;
> +	unsigned long flags;
> +
> +	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;
> +	}
> +
> +	/* convert signals from NATIVE to TIOCM */
> +	if (sigs & NATIVE_DTR_SIG)
> +		sigs |= TIOCM_DSR;
> +	if (sigs & NATIVE_CTS_SIG)
> +		sigs |= TIOCM_CTS;
> +	if (sigs & NATIVE_CD_SIG)
> +		sigs |= TIOCM_CD;
> +	if (sigs & NATIVE_RI_SIG)
> +		sigs |= TIOCM_RI;
> +	sigs &= 0x0fff;

'sigs' is only used when the channel has a signal handler, hence you could
return before the above block if there is no signal handler and remove the
condition below.

> +
> +	if (channel->ept.sig_cb)
> +		channel->ept.sig_cb(channel->ept.rpdev, channel->ept.priv, sigs);
> +
> +	return 0;
> +}
diff mbox series

Patch

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index 05533c7..384fcd2 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>
 
@@ -201,9 +202,16 @@  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			BIT(31)
+#define NATIVE_CTS_SIG			BIT(30)
+#define NATIVE_CD_SIG			BIT(29)
+#define NATIVE_RI_SIG			BIT(28)
+
+
 static void qcom_glink_rx_done_work(struct work_struct *work);
 
 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
@@ -976,6 +984,68 @@  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;
+
+	/**
+	 * convert signals from TIOCM to NATIVE
+	 * sigs = TIOCM_DTR|TIOCM_RTS
+	 */
+	if (enable)
+		sigs |= (NATIVE_DTR_SIG | NATIVE_CTS_SIG);
+	else
+		sigs |= (~(NATIVE_DTR_SIG | NATIVE_CTS_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;
+
+	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;
+	}
+
+	/* convert signals from NATIVE to TIOCM */
+	if (sigs & NATIVE_DTR_SIG)
+		sigs |= TIOCM_DSR;
+	if (sigs & NATIVE_CTS_SIG)
+		sigs |= TIOCM_CTS;
+	if (sigs & NATIVE_CD_SIG)
+		sigs |= TIOCM_CD;
+	if (sigs & NATIVE_RI_SIG)
+		sigs |= TIOCM_RI;
+	sigs &= 0x0fff;
+
+	if (channel->ept.sig_cb)
+		channel->ept.sig_cb(channel->ept.rpdev, channel->ept.priv, sigs);
+
+	return 0;
+}
+
 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 {
 	struct qcom_glink *glink = data;
@@ -1037,6 +1107,10 @@  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;
@@ -1382,6 +1456,7 @@  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)