From 028021d29ea069390e1f60c6aa5b3511d218454b Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Wed, 17 Feb 2016 22:39:06 -0800 Subject: [PATCH] soc: qcom: smd: Support opening additional channels With the qcom_smd_open_channel() API we allow SMD devices to open additional SMD channels, to allow implementation of multi-channel SMD devices - like Bluetooth. Channels are opened from the same edge as the calling SMD device is tied to. Signed-off-by: Bjorn Andersson Signed-off-by: Bjorn Andersson Signed-off-by: Andy Gross --- drivers/soc/qcom/smd.c | 76 ++++++++++++++++++++++++++++++++++++ include/linux/soc/qcom/smd.h | 4 ++ 2 files changed, 80 insertions(+) diff --git a/drivers/soc/qcom/smd.c b/drivers/soc/qcom/smd.c index c3fa0fd724f7..b6434c4be86a 100644 --- a/drivers/soc/qcom/smd.c +++ b/drivers/soc/qcom/smd.c @@ -129,6 +129,8 @@ struct qcom_smd_edge { unsigned smem_available; + wait_queue_head_t new_channel_event; + struct work_struct scan_work; struct work_struct state_work; }; @@ -1042,6 +1044,77 @@ void qcom_smd_driver_unregister(struct qcom_smd_driver *qsdrv) } EXPORT_SYMBOL(qcom_smd_driver_unregister); +static struct qcom_smd_channel * +qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name) +{ + struct qcom_smd_channel *channel; + struct qcom_smd_channel *ret = NULL; + unsigned long flags; + unsigned state; + + spin_lock_irqsave(&edge->channels_lock, flags); + list_for_each_entry(channel, &edge->channels, list) { + if (strcmp(channel->name, name)) + continue; + + state = GET_RX_CHANNEL_INFO(channel, state); + if (state != SMD_CHANNEL_OPENING && + state != SMD_CHANNEL_OPENED) + continue; + + ret = channel; + break; + } + spin_unlock_irqrestore(&edge->channels_lock, flags); + + return ret; +} + +/** + * qcom_smd_open_channel() - claim additional channels on the same edge + * @sdev: smd_device handle + * @name: channel name + * @cb: callback method to use for incoming data + * + * Returns a channel handle on success, or -EPROBE_DEFER if the channel isn't + * ready. + */ +struct qcom_smd_channel *qcom_smd_open_channel(struct qcom_smd_device *sdev, + const char *name, + qcom_smd_cb_t cb) +{ + struct qcom_smd_channel *channel; + struct qcom_smd_edge *edge = sdev->channel->edge; + int ret; + + /* Wait up to HZ for the channel to appear */ + ret = wait_event_interruptible_timeout(edge->new_channel_event, + (channel = qcom_smd_find_channel(edge, name)) != NULL, + HZ); + if (!ret) + return ERR_PTR(-ETIMEDOUT); + + if (channel->state != SMD_CHANNEL_CLOSED) { + dev_err(&sdev->dev, "channel %s is busy\n", channel->name); + return ERR_PTR(-EBUSY); + } + + channel->qsdev = sdev; + ret = qcom_smd_channel_open(channel, cb); + if (ret) { + channel->qsdev = NULL; + return ERR_PTR(ret); + } + + /* + * Append the list of channel to the channels associated with the sdev + */ + list_add_tail(&channel->dev_list, &sdev->channel->dev_list); + + return channel; +} +EXPORT_SYMBOL(qcom_smd_open_channel); + /* * Allocate the qcom_smd_channel object for a newly found smd channel, * retrieving and validating the smem items involved. @@ -1178,6 +1251,8 @@ static void qcom_channel_scan_worker(struct work_struct *work) dev_dbg(smd->dev, "new channel found: '%s'\n", channel->name); set_bit(i, edge->allocated[tbl]); + + wake_up_interruptible(&edge->new_channel_event); } } @@ -1341,6 +1416,7 @@ static int qcom_smd_probe(struct platform_device *pdev) for_each_available_child_of_node(pdev->dev.of_node, node) { edge = &smd->edges[i++]; edge->smd = smd; + init_waitqueue_head(&edge->new_channel_event); ret = qcom_smd_parse_edge(&pdev->dev, node, edge); if (ret) diff --git a/include/linux/soc/qcom/smd.h b/include/linux/soc/qcom/smd.h index 65a64fcdb1aa..bd51c8a9d807 100644 --- a/include/linux/soc/qcom/smd.h +++ b/include/linux/soc/qcom/smd.h @@ -56,4 +56,8 @@ void qcom_smd_driver_unregister(struct qcom_smd_driver *drv); int qcom_smd_send(struct qcom_smd_channel *channel, const void *data, int len); +struct qcom_smd_channel *qcom_smd_open_channel(struct qcom_smd_device *sdev, + const char *name, + qcom_smd_cb_t cb); + #endif -- 2.39.5