On Wed, May 13, 2020 at 10:41:09AM +0530, Arun Kumar Neelakantam 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@xxxxxxxxxxxxxx>
> Signed-off-by: Arun Kumar Neelakantam <aneela@xxxxxxxxxxxxxx>
> ---
> drivers/rpmsg/qcom_glink_native.c | 126 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 126 insertions(+)
>
> diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
> index fc8ef66..68e039a 100644
> --- a/drivers/rpmsg/qcom_glink_native.c
> +++ b/drivers/rpmsg/qcom_glink_native.c
> @@ -1,5 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0
> /*
> + * Copyright (c) 2018, The Linux Foundation.
Again, not sure what this is for.
> * Copyright (c) 2016-2017, Linaro Ltd
> */
>
> @@ -17,6 +18,7 @@
> #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>
>
> @@ -150,6 +152,8 @@ enum {
> * @intent_req_lock: Synchronises multiple intent requests
> * @intent_req_result: Result of intent request
> * @intent_req_comp: Completion for intent_req signalling
> + * @lsigs: local side signals
> + * @rsigs: remote side signals
> */
> struct glink_channel {
> struct rpmsg_endpoint ept;
> @@ -181,6 +185,10 @@ struct glink_channel {
> struct mutex intent_req_lock;
> bool intent_req_result;
> struct completion intent_req_comp;
> +
> + unsigned int lsigs;
> + unsigned int rsigs;
> +
> };
>
> #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
> @@ -201,9 +209,15 @@ 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 BIT(31)
> +#define NATIVE_CTS_SIG BIT(30)
> +#define NATIVE_CD_SIG BIT(29)
> +#define NATIVE_RI_SIG BIT(28)
Please align theres with the BIT(1) of _INTENTLESS.
> +
> static void qcom_glink_rx_done_work(struct work_struct *work);
>
> static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
> @@ -975,6 +989,76 @@ static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
> return 0;
> }
>
> +/**
> + * qcom_glink_send_signals() - convert a signal cmd to wire format and transmit
s/signal cmd/signal cmd
> + * @glink: The transport to transmit on.
> + * @channel: The glink channel
> + * @sigs: The signals to encode.
> + *
> + * Return: 0 on success or standard Linux error code.
> + */
> +static int qcom_glink_send_signals(struct qcom_glink *glink,
> + struct glink_channel *channel,
> + u32 sigs)
> +{
> + struct glink_msg msg;
> +
> + /* convert signals from TIOCM to NATIVE */
> + sigs &= 0x0fff;
> + if (sigs & TIOCM_DTR)
> + sigs |= NATIVE_DTR_SIG;
> + if (sigs & TIOCM_RTS)
> + sigs |= NATIVE_CTS_SIG;
> + if (sigs & TIOCM_CD)
> + sigs |= NATIVE_CD_SIG;
> + if (sigs & TIOCM_RI)
> + sigs |= NATIVE_RI_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 signals)
> +{
> + struct glink_channel *channel;
> + unsigned long flags;
> + u32 old;
> +
> + 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;
> + }
> +
> + old = channel->rsigs;
> +
> + /* convert signals from NATIVE to TIOCM */
> + if (signals & NATIVE_DTR_SIG)
> + signals |= TIOCM_DSR;
In qcom_glink_send_signals(), TIOCM_DTR (and not TIOCM_DSR) converts to
NATIVE_DTR_SIG.
> + if (signals & NATIVE_CTS_SIG)
> + signals |= TIOCM_CTS;
Similarly, NATIVE_CTS_SIG converts to TIOCM_RTS. I would have expected to have
a match between what gets sent and what comes back up. If this is intentional
please at some comments to justify your choices.
> + if (signals & NATIVE_CD_SIG)
> + signals |= TIOCM_CD;
> + if (signals & NATIVE_RI_SIG)
> + signals |= TIOCM_RI;
> + signals &= 0x0fff;
> +
> + channel->rsigs = signals;
> +
> + if (channel->ept.sig_cb) {
> + channel->ept.sig_cb(channel->ept.rpdev, channel->ept.priv,
> + old, channel->rsigs);
What is the relevance of old and channel->rsigs? They are certainly not used in
patch 4.
> + }
> +
> + return 0;
> +}
> +
> static irqreturn_t qcom_glink_native_intr(int irq, void *data)
> {
> struct qcom_glink *glink = data;
> @@ -1036,6 +1120,10 @@ 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;
> @@ -1340,6 +1428,42 @@ static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
> return __qcom_glink_send(channel, data, len, false);
> }
>
> +static int qcom_glink_get_sigs(struct rpmsg_endpoint *ept)
> +{
> + struct glink_channel *channel = to_glink_channel(ept);
> +
> + return channel->rsigs;
> +}
> +
> +static int qcom_glink_set_sigs(struct rpmsg_endpoint *ept, u32 set, u32 clear)
> +{
> + struct glink_channel *channel = to_glink_channel(ept);
> + struct qcom_glink *glink = channel->glink;
> + u32 sigs = channel->lsigs;
> +
> + if (set & TIOCM_DTR)
> + sigs |= TIOCM_DTR;
> + if (set & TIOCM_RTS)
> + sigs |= TIOCM_RTS;
> + if (set & TIOCM_CD)
> + sigs |= TIOCM_CD;
> + if (set & TIOCM_RI)
> + sigs |= TIOCM_RI;
> +
> + if (clear & TIOCM_DTR)
> + sigs &= ~TIOCM_DTR;
> + if (clear & TIOCM_RTS)
> + sigs &= ~TIOCM_RTS;
> + if (clear & TIOCM_CD)
> + sigs &= ~TIOCM_CD;
> + if (clear & TIOCM_RI)
> + sigs &= ~TIOCM_RI;
> +
> + channel->lsigs = sigs;
> +
> + return qcom_glink_send_signals(glink, channel, sigs);
> +}
> +
> /*
> * Finds the device_node for the glink child interested in this channel.
> */
> @@ -1373,6 +1497,8 @@ static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
> .destroy_ept = qcom_glink_destroy_ept,
> .send = qcom_glink_send,
> .trysend = qcom_glink_trysend,
> + .get_signals = qcom_glink_get_sigs,
> + .set_signals = qcom_glink_set_sigs,
> };
>
> static void qcom_glink_rpdev_release(struct device *dev)
> --
> 2.7.4
